PCC35_MN.pdf - Northern Regional Power Committee

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भारत सरकार

Government of India

विद्युत मंत्रालय

Ministry of Power

उत्तर क्षेत्रीय विद्युत सममतत

Northern Regional Power Committee

No. उक्षेवव /प्रचालन/107/01/2018/9106-9144 ददनािंक: 10.08.2018

फैक्स संदेश / FAX MESSAGE

ेवा में : िंिक्षण उप- समतत के दस्य ( ूची के अनु ाि) । To: Members of Protection Sub-Committee (As per List)

ववषय: िंिक्षण उप- समतत की 35 वीिं बैठक का कायगवतृ्त || Subject: Minutes of 35th Protection Sub-Committee Meeting.

िंिक्षण उप- समतत की 53 वीिं बैठक, 20.06.2018 को 10:30 बज े े उ.क्षे.वव. . चचवालय,

नई ददल्ली में आयोजजत की र्ई थी | उक्त बठैक का कायगवतृ उत्ति क्षेत्रीय ववद्युत ् समतत की वेब ाइट (http://www.nrpc.gov.in) पि उपलब्ध है |

The 35th meeting of Protection Sub-Committee was held on 20th June, 2018 at 10:30

Hrs at NRPC Secretariat, New Delhi. The minute of the meeting is available on NRPC

website (http://www.nrpc.gov.in).

-Sd-

(Upendra Kumar)

S.E. & Member Convener, PSC

http://www.nrpc.gov.in/




List of Members of PSC

S.No. Designation Organization Fax No.

1 Director (P&C) BBMB 0172-2652054

2 General Manager (SLDC) DTL 011-23236462

3 GM (O&M) Delhi Transco Limited 011-23236462

4 GM (T)

Common Services

IPGCL 23370247

5 Chief Engineer (TS) HVPNL 0172-2591244

6 SE (M&P) HVPNL 0172-2540014

7 SE (SO & SLDC) HVPNL 0172-2560622

8 SE (SLDC) PTCUL 0135-2763570/2451160

9 SE(T&C) PTCUL 0135-2451826

10 Chief Engineer (SLDC) UPPTCL 0522-2287880/2288736

11 SE(Tech) HPGCL 0172-5022436

12 SE(O&M-VI) HPGCL 0180-2566768

13 Chief Engineer (Transmission) HPSEB 01972-223435

14 SE (PR& ALDC) HPSEB 0177-2837143

15 Chief Engineer (C&S Wing) PDD 0191-2474233

16 Chief Engineer (SLDC) PSTCL 0175-2365340

17 Chief Engineer (P&M) PSTCL 0161-2741280/2451491

18 CE (M&P) RRVPNL 0141-2291891

19 SE (Electrical) RRVUNL 01509-245299

20 Chief Engineer (LD) RRVPNL 0141-2740920

21 SE (SO&LD) RRVPNL 0141-2740920

22 Superintending Engineer (T&C) UPPCL 0121-2666062

23 Chief Engineer, (L-2) UPRVUNL 0522-2287822/2287880

24 DGM (T&C) PTCUL 0135-2760331

25 Chief Engineer (O&M) NHPC 0129-2272413

26 GM (O&M) NR – I PGCIL 011-26601079

27 GM (O&M), NR-II PGCIL 01951-237186

28 Chief Manager (TS) N.R.L.D.C 011-26852747

29 GM(OS-NR) NTPC 0522-2305848

30 GM (OS) NTPC Ltd 0120-2410082/2410068

31 DGM (Maintenance) SJVNL 0177-2673283

32 DGM (O&M) THDC India Ltd 01376-236305

33 Director (GM division) CEA 011-26109750

34 General Manager APCLP 01251-266326

35 Director JPPVL 0120-4516201/4609464/4609496

36 Assistant Vice President BRPL 39996055/39999765

37 GM (Production) Jhajjar Power Ltd 01251-270155

38 GM(P&M) APL 7925557176

39 Sh. Umesh Gupta, AsVP BRPL 011-26419833

40 President (Power Systems) LPGCL +91-22- 22048681

41 Director (NPC) CEA

42 NPCIL

1.Maintenance Superintendent NAPS 05734-222167

2.Maintenance Superintendent RAPS 01475-242060

Minutes of 35th meeting of Protection Sub-Committee (PSC) held on 20.06.2018 at

10:30 hrs. at NRPC Secretariat, New Delhi

35th meeting of Protection Sub- Committee (PSC) of NRPC was held on

20.06.2018 at NRPC Secretariat, New Delhi. The list of participants is enclosed at

Annex-I.

MS, NRPC welcomed all the participants to the 35th meeting of Protection Sub-

Committee. He stated that

1. 35th Protection Sub-Committee scheduled earlier was postponed due to

inadvertent reason and couldn’t be scheduled later due to paucity of time. Now

onwards, Protection Sub-committee meetings shall be held on the monthly basis

clubbed with OCC meetings.

2. All the utilities are requested to send the representation from Protection

background to the meetings with relevant data of DR/EL of tripping so that

fruitful and conclusive discussion can be held in the meetings.

3. Actions taken against the remedial measures recommended for the tripping

discussed in the previous meetings should be submitted to NRPC/NRLDC before

the next meeting.

He further asked representative of APRL to proceed with presentation about the

issues regarding SPS in Kawai – Chhabara complex.

Representative of ARPL discussed the operation of Bus bar Protection at 765/400

kV Anta Substation on 02/05/2018 at 14:40:46 Hrs due to which both 400 kV Kawai-

Anta Lines were offloaded and further severe oscillations were observed over Kawai-

Chhabara line and generator at Kawai. He informed that Kawai-Chhabara line were also

offloaded due to tripping of lines from Chhabara S/S but the zero power SPS did not

operate as the GT power was oscillating up to 740 MW. He told that existing schemes

and settings do not offer reliable detection of conditions experienced during oscillations.

He requested that SPS in this complex needs to be reviewed and operation of SPS should

be co-ordinated with the oscillations in the system.

MS, NRPC told that issue should be discussed in the separate meeting where the

current SPS scheme would be reviewed.

A.1. Confirmation of minutes of 33rd meeting of protection sub-committee

Minutes of 34th meeting of Protection Sub-Committee held on 04.08.2017 at

NRPC Secretariat, New Delhi were issued vide letter No. उक्षेवव /प्रचालन/107/01/2017/

13829-867 dated 19.12.2017. No comments were received.

Sub-Committee confirmed the Minutes of 34th PSC meeting.

A.2. Implementation of Recommendations of Task Force

As a follow up of one of the recommendations of Enquiry Committee headed by

Chairperson, CEA on grid disturbances that took place on 30th and 31st July 2012,

Ministry of Power had constituted a ‘Task Force on Power System Analysis under

Contingencies’ in December 2012. The Task Force had submitted its report in August

2013. In a meeting taken by Secretary (Power), GoI on 11.03.2014, it was decided that

the report be given wide circulation and its recommendations be implemented in a time

bound manner. Some of the issues arising out of recommendations of the Task Force

were as under:

A.2.1. Database of protection settings

Based on the recommendations of the Task Force, it was decided that data

regarding settings of relays shall be compiled by the CTU and STUs in their respective

network and furnished to RLDC and SLDC respectively with a copy to RPC for

maintaining the database. The database was to be kept updated and verified during the

audit.

A format for submission of database was finalized in 30th PSC meeting.

The issue was deliberated in 34th TCC/38th NRPC meeting held on 24th/25th

October, 2016 wherein it was decided that protection setting data would be provided by

all the utilities within 02 months for 400 kV and 220 kV S/S.

33rd PSC meeting on 22nd February, 2017 – During 33rd PSC meeting, it was

noted that only few utilities had submitted the data. PSC advised all the utilities to submit

the data in prescribed format by March,2017. It was also opined that if data were not

submitted by utilities then engagement of third party in line with ERPC and SRPC may

be considered.

The issue was discussed in the 35th TCC/39th NRPC meeting held on 1st/2nd May,

2017 in which TCC expressed their concern over the non-submission of protection

database by the utilities. In the meeting, it was also informed that a project of Protection

Database Management System is being implemented by ERPC and SRPC by engaging

3rd party with funding through PSDF. TCC recommended and NRPC thereafter approved

the proposal for engaging a third party for Protection database and authorised NRPC

sectt. to take further action.

34th PSC meeting on 4th August, 2017—During the meeting, M/s PRDC gave

presentation about the various provisions included in the project being implemented by

them in ER. Citing the concerns of utilities, it was proposed to form a core committee to

define the comprehensive Scope of the project comprising members from NRPC

secretariat, NRLDC, and all the utilities of NR.

Approval of Chairperson, NRPC has been obtained authorizing Member Secretary,

NRPC to carry out following activities:

i. Formation of group for finalization of detail scope of work of

the Project.

ii. Submission of proposal for financing the Project through

Power System Development fund (PSDF).

iii. Opening of a separate account in the name of ‘NRPC Protection

Database Fund’ for receiving the grant from PSDF for the

Project.

iv. Carry out e-tendering process including tender publication,

opening, evaluation etc. for selecting contractor for

implementing the scheme based on scope of work of the

Project finalized by the group.

Nominations for the committee for finalization of detailed scope of work of the project

were sought from the utilities and based on the nomination received a committee has

been formed. The first meeting of the committee was held on 1st February 2018 at NRPC

Secretariat, New Delhi. Based on the inputs received from the members, Bidding

Document shall be modified and circulated for the approval of the committee in its next

meeting.

NRPC Secretariat has submitted the DPR of the project for PSDF funding.

Tender shall be floated after the finalization of the Bidding Document by the

committee.

38th TCC and 41st NRPC meeting on 27th and 28th February, 2018- Based on the

discussions held in 34th PSC meeting, a core committee has been formed to define the

comprehensive Scope of the project comprising members from the utilities of NR.

First meeting of the group for defining the scope of the project was held on

01.02.2018 and based on the inputs received from the members, Draft Bidding Document

has been prepared by the NRPC Secretariat.

In the 35th PSC meeting, it was told that the Draft Bidding document

incorporating all the inputs given by members in the meeting was further circulated for

suggestions/comments, if any. The Bid document including all the relevant

suggestions/comments of the members has been finalized.

NRPC Secretariat has also submitted the DPR of the project for PSDF funding

based on the draft bidding document. The proposal of NRPC was scrutinized by the

Techno-Economic Sub Group and further examined by Appraisal Committee.

Appraisal Committee has recommended the proposal for the grant from PSDF

funding and also qualified proposal for 100% funding through PSDF. The e-tendering

Creation and maintenance of web based Protection Database Management and PC

based Protection setting calculation tool for Northern Region Power System Network

will be initiated on the receipt of MoM of Monitoring Committee.

A.2.2. Zone-III settings

PSC of NRPC had decided that the setting of Zone-III would be carried out by the

concerned utility at their end. The utility at other end would provide all the required

parameter. The utilities can share the Zone-III setting so arrived at, with each other and

with PSC for better coordination. The issues, if any, would be deliberated in the PSC.

32nd PSC meeting on 30th November, 2016 – It was noted that no issue had been

reported. However, some members pointed out that there was a need to formulate a

procedure to intimate the concerned utilities regarding change in configuration in the

system with the other utilities. PSC reiterated that the setting of Zone-III should be shared

with each other and with PSC for better coordination.

33rd PSC meeting on 22nd February, 2017 – NTPC stated that if Zone-III settings

are done as per the recommendation, there may be over-reach or under-reach issue. And

suggested for carrying out protection co-ordination study before its implementation.

UP representative suggested engaging 3rd party for getting the coordination study

done.

PSC was of the view that there is a need to carry out the protection coordination

studies for proper Zone-III setting and it was suggested that a third party may be hired to

carry out the study.

34th PSC meeting on 4th August, 2017—PSC informed that these studies will be

part of the project for maintaining database of protection setting database.

In the 35th PSC meeting, members were informed these studies are included in

the scope of Protection Database Management project.

A.2.3. Periodicity of Third Party Protection Audit

The enquiry committee constituted by Govt of India to enquire into grid

disturbances on 30th and 31st July, 2012 has recommended a thorough third party

protection audit need to be carried out in time bound manner as there is need to review

the protection schemes.

In 18th PSC meeting on 03rd Sept, 2012, it was agreed that the exercise of

protection audit should be carried out periodically and frequency of the same could be 2-

3 years.

The following points are proposed to review the protection schemes periodically :

• Periodicity of Third Party Audit from CPRI .

• Periodicity of Third Party Audit from members of STUs nominated by NRPC

Secretariat for Third Party Protection Audit of different STUs .

• The scope of Third Party Protection audit of STUs .

• Any other Agency other than CPRI authorized to carry out Third Party

Protection Audit.

SE(O) emphasized on the need of Protection audit and requested members to

suggest suitable periodicity for the same. Representative of NRLDC requested that

periodicity should be decided uniformly at NPC level and each RPC should give them a

suggestion. Members deliberated and recommended that the exercise of third party

protection audit should be carried out periodically and frequency of the same should be

5 years.

Representative of BBMB queried about the agency and scope of the Third Party

Protection audit. It was deliberated that any other agency than CPRI or team of

Protection Engineers finalized by the Protection Sub-Committee should also be

allowed for Protection Audit.

MS, NRPC also stated that Third Party Protection audit can be done any

reputed agency working in the field of Power System protection other than CPRI. He

emphasized the importance of continuing the practice of carrying Protection Audit.

Members were requested to send the updated nominations of the protection

engineers which would be carrying out the Third Party Protection audit. The previous

list was finalized in 24th PSC meeting is attached as Annexure – II.

A.3. Preparation of Reliability standards for Protection system for Indian power

systems

CERC in its Order dated 05.08.2015 wrt Petition No. 009/SM/2015 in the matter

of following up actions on the recommendations of CAC Sub-Committee on Congestion

in Transmission, directed National Reliability Council for Electricity (NRCE) to prepare

Standards for Protection System. NRCE in its 6th meeting held on 17th March 2016 had

formed a Subgroup for Preparation of the Reliability Standards for Protection system and

Communication system for Indian Power System.

Five meetings were held by the Subgroup. A draft of Reliability Standards for Protection

System for Indian Power System has been prepared which is also available at

http://www.nrpc.gov.in/Reports/other/Reliability%20Standards.pdf.

NRPC in their letter dated 05.10.2017 and 08.01.2018 has requested all utilities to

submit the comments/inputs. BBMB, NHPC and RRVPNL have submitted their

comments. (Attached as Annexure – I of 35th PSC agenda) Other utilities are requested

to submit the comments/inputs, if any at the earliest.

In the 35th PSC, Members were requested to submit their comments at the

earliest for its further submission to NPC, CEA.

A.4 Violation of Protection standard in case of Inter-Regional lines of voltage 220kV

and above

The section 3.e of Grid Standards Regulation of CEA, 2010 states that

“Provide standard protection systems having the reliability, speed, selectivity and

sensitivity to isolate the faulty equipment and protect all components from any type of

faults, within the specified fault clearance time and shall provide protection co-

ordination as specified by the Regional Power Committee

Explanation : For purpose of this regulation “fault clearance time” means the maximum

fault clearance time as specified below :

Sr.

No.

Nominal System Voltage (kV rms) Maximum Time (in msec)

1. 765 and 400 100

2. 220 and 132 160

Provided that in the event of non clearance of the fault by a circuit breaker

within the limit specified in Table, the breaker fail protection shall initiate tripping of all

other breakers in the concerned bus section to clear the fault in the next 200 msec. “

Such delayed clearance of faults of Inter-regional lines may prove fatal to the security of

the grid. The list of tripping of Inter Regional Lines of voltage 220kV and above is

attached as Annexure –II of 35th PSC agenda in which fault had not cleared within

specified time as mentioned in section 3.e of Grid Standards Regulations of CEA, 2010.

Since, these events are matter of concern to Grid security suitable action needs to be

taken.

As per the IEGC clause 5.2.r and clause 15.3 of CEA grid standard , DR/EL of all the

tripping of 220kV and above level shall be sent within 24 hours of NRLDC. In reference,

tripping of 220 kV and above level are attached as Annexure – III of 35th PSC agenda.

Representative of NRLDC stated that violation of Protection Standard should

be avoided and DR/EL should be sent to NRPC/NRLDC within 24 hours. He told that

tripping analysis for inter regional lines is very important for safe and reliable

operation of Grid. He further informed that it was also followed up regularly in the

OCC meetings.

Members were requested to submit the DR/EL of all the tripping of 220kV and

above level within 24 hours to NRLDC and avoid delayed clearance of faults of Inter-

regional lines.

A.5 Actions taken on the outcome of the meeting of Protection Analysis Sub Group

(PSAG)

It was deliberated in the 31st PSC meeting to create a Protection Analysis Sub-

Group (PSAG) for conducting a detailed discussion of grid events of greater importance

requiring immediate attention on regular basis as the discussion of a large number of grid

events are not possible in the regular PSC meeting.

Subsequently, in the 32nd PSC meeting the members of group were decided. The

Protection Analysis Sub Group has met thrice between the 34th and 35th PSC meeting to

discuss the multiple tripping. The following tripping were discussed in these meeting.

Sr

No

Incident Discussed PSAG meeting

held on

Utility concerned

1. Tripping of RWPL units 4, 5, 6, 7

and 8 on 15.11.2017 after opening

of a 400 kV Rajwest-Barmer line

05.12.2018 RWPL

2. Multiple tripping multiple tripping

due to 3 phase fault at 400kV

Panki(UP) on 2nd Nov 2017 and

multiple tripping at 400kV

Unnao(UP) on 30th Nov 2017

09.01.2018 UPPTCL, NTPC,

POWERGRID

3. Multiple tripping at 400kV Bawana

dated 14.10.2017, 06.01.2018 and

28.01.2018

08.02.2018 DTL

Representative of NRLDC emphasized that remedial actions as recommended

by PSAG and PSC should be compiled in tabular form with the time frame by utility

and submitted to NRPC/NRLDC. He also stated that PSAG group is to be expanded

with more than one nominations from the utilities which might be sent for the physical

audit in case of important multiple element tripping.

MS, NRPC stated that expanding the group shall also help in manpower

development as it is a learning exercise for Protection Engineers. Members were

requested to send the additional nominations for the PSAG group. (Enclosed as

Annexure - III)

A.6 Approval for Special Protection Scheme of unit tripping when ICT overloads

(Agenda by RWPL)

The 7th PSAG meeting was held to discuss tripping of Rajwest units 4,5,6,7 and 8

on 15.11.2017 after opening of a 400 kV Rajwest - Barmer line. Rajwest had applied for

a OCC approved planned shutdown of this line on 15.11.2017. The code for opening of

this line was obtained from both NRLDC and Rajasthan SLDC. However, as soon as the

line breaker was opened at 400 kV GSS, Barmer end, the RWPL units 4,5,6,7 tripped on

operation of System Protection Scheme (SPS) implemented by power plant which

triggers on ICT being overloaded to 110 %. In the meeting, Sub-group noticed that

implemented SPS scheme at Rajwest was not in knowledge of either NRLDC or NRPC

and tripping of units were mainly due to the operation of SPS scheme on ICT overload.

Hence, the sub-group advised Rajwest to modify the SPS scheme accordingly and

approve at RPC forum. As per the decision in Sub-group, Rajwest has proposed the

revised SPS scheme which is attached as Annexure- IV of 35th PSC agenda.

There was no representation from RWPL in the 35th PSC meeting. It was also

informed that line stringing of circuit 2 of 400kV Rajwest – Barmer line has been done

but could not be charge due to unavailability of bay at Rajwest.

A.7 RAPS-A outage due to Grid disturbance on 05/04/2018 at 15.02hrs (Agenda by

NPCIL )

RAPS-A which was generating 186MW, tripped on loss of evacuation corridors at

15:02:28:306 hrs on 05/04/2018. The trigger was tripping of 220kV RAPS-Udaipur

(Debari) line in zone-1 at RAPS end. It was followed by tripping of Kota-1 and Kota-3

lines to RAPS at Kota end in zone-1 protection. This led to loss of evacuation corridors

and subsequent unit outage. Copy of the event report (sent to NRLDC) is enclosed as

Annexure – V of 35th PSC agenda. It appears to be a case of Kota end relays over

reaching for a fault in zone-2 (zone-1 of RAPS-Udaipur line). The relay settings of Kota-

RAPS lines at Kota end need review.

The agenda point is deliberated in NRLDC trippings discussion at V.

A.8 Grid disturbance at NAPS on 15.02.2018 due to Bus fault at 220kV Atrauli S/S

(Agenda by NPCIL )

On 15.02.2018, NAPS both units were operating smoothly at full power, Grid

parameters were also maintaining normal. All 220kV lines were in service. (Annexure-

VI of 35th PSC agenda) At 19:17:10 Hrs, voltage dip from 220 kV up to 120 kV was

observed at NAPS, however NAPS both units survived. 220kV Atrauli S/S is connected

only with NAPS, Narora and Harduganj TPS, both are generating stations and hence an

important element of grid network. At around 19.15hrs, normalization of one ICT was in

progress at Atrauli S/S. During the process, its 220kV side circuit breaker developed fault

causing flashover/ damage of the CB resulting into bus fault. Atrauli S/S does not have

220kV Bus differential protection scheme hence fault propagated into remote end 220kV

S/S Narora and Harduganj.

Representative of NPCIL told that damage of the CB resulted into bus fault at

220kV side of Atruali S/s. He further told that Atrauli S/S does not have 220kV Bus

differential protection scheme hence fault propagated into remote end 220kV S/S

Narora and Harduganj, however distance relay of line protection operated and 220kV

Atrauli-Narora, Atrauli - Harduaganj lines tripped in zone -4 at Atrauli end. The fault

duration was 250 msec. It was informed that it is mandatory for all 220kV and above

S/s to have bus differential protection as per the CEA regulations. He further told that

lines were charged after the incidence without informing either Narora or Harduaganj

end.

Representative of UPPTCL informed that bus differential protection at Atrauli

s/s is to be commissioned by the end of July. He also informed that zone-4 setting has

been changed to 160 msec.

Representative of NPCIL also told that there is no bus differential scheme at

220kV Sambhal s/s and 220 kV Simbhaoli s/s. Representative of UPPTCL assured to

look into matter and expedite the installation of bus differential scheme.

A.9.Final report of the group to suggest measures for bringing improvement in the

field of Power System Protection among the utilities in Northern Region

A group was constituted by Member Secretary, NRPC vide letter No.

NRPC/OPR/107/06/ 2015/ dated: 26.08.2015 to suggest measures for bringing

improvement in the field of Power System Protection among the utilities in Northern

Region. The report was submitted in 34th TCC/38th NRPC meeting held on 24th /25th

October, 2016 wherein the report was accepted for implementation. It was also agreed in

the NRPC meeting that individual utilities would immediately start working to develop

training module for Basic Training on Protection System for Sub-Station Engineers

(Level -1) and start training programs within 6 months. The issue was also discussed in

32nd PSC meeting wherein utilities were requested to organize Level-1 training and

would submit the details.

BBMB, POWERGRID NR-I and PITCUL are conducting the training on

Protection System (Level - I) at regular intervals.

First training programme of Level-2 was conducted successfully from 21st-25th

November, 2016 for 25 nos. of participants through POWERGRID. 35th TCC/39th NRPC

meeting held on 1st/2nd May, 2017 - Advised to conduct more such programmes including

Level-3 for Protection System Engineers.

Protection training for level -3 was conducted successfully from 19th-23rd March,

2018 at Udaipur for 25 nos. of participants through POWERGRID.

Members were informed that 1 batch of level - 2 and level – 3 training was

completed and another batch for training is to be taken up shortly. Utilities were

requested to share the details regarding content, no. of days of level-I training

arranged by them.

Representative of RRVPNL and DTL told that training is being arranged by

them and details will be shared. Other utilities were also requested to share the details

at the earliest.

A.10. Format for Detailed Analysis report

Members of the Protection sub-committee had raised the issue of devising a

common format/template for submission of detailed analysis report of the tripping event.

Accordingly a format had been prepared and same is enclosed as Annex-VII of 35th PSC

agenda. In the discussions held in 33rd PSC meeting, it was decided to align the format as

per the SOPR. A committee to align the format as per SOPR is constituted and advised to

submit the report by 04.08.2017.

In the 34th PSC meeting, it was decided to deliberate on format once the

constituted committee submits its report.

All the members were requested to give the suggestions/comments about the

format for Detailed Analysis Report enclosed as Annex-VII of 35th PSC agenda.

A.11. Follow up action on outstanding issues from previous meetings:

A.11.1. Non-functional carrier-inter-trip feature

23rd PSC meeting on 5th September, 2013- BBMB had intimated that carrier-inter-trip

feature (Carrier aided protection of transmission line) of following lines was disabled due to

faulty PLCC channels (at PSTCL and HVPNL ends). Status updated in 35th PSC meeting is as

given below:

Sl.

No.

Transmission Line

(220 kV)

Other

end

Status as updated in 35th

PSC

1. Barnala-Lehra

Mohabbat D/C

PSTCL • PLCC panels had

installed and end to

end testing has been

done. Working

presently.

A.11.2. Non- availability/defective PLCC link of STU Lines terminated at

POWERGRID (NR-2) substations

22nd PSC meeting on 22nd July, 2013- POWERGIRD had submitted a list of its NR-2

sub-station in 22nd PSC meeting where PLCC was non-functional at other side.

35th PSC meeting on 20th June, 2018- Status of PLCC work in these sub-stations, as

updated in the meeting is as under:

Sl. No.

Name of

Substation

Name of

Transmission Line

Availability

of PLCC

Updated

Status in 34th

PSC

Present status

PLCC issues with J&K PDD

1 Wagoora

220 KV Zainakot-I

Not

Available

Exp

ecte

d t

o

be

com

ple

ted

by 1

5.0

9.2

017

Laying of

OPGW done.

2 220 KV Zainakot-II

Not

Available

3

Kishenpur

220 kV Barn-I

Not

Available

4 220 kV Barn-II

Not

Available

5 220 kV Mirbazar -

6 220 kV Ramban

PLCC issues with PSTCL

1

Amritsar

220 kV Verpal –I

Not installed

Would be

installed by

31.10.2017

PLCC Panels are

installed on both

end & wiring

has been

completed on

PSTCL end&

wiring on

PGCILend will

be done with co-

ordination of

PLCC team of

PSTCL by

PGCIL. End to

end testing will

be completed by

30.09.2018

2 220 kV Verpal –II Installed but

not working

End to end

testing done

&Working

presently.

A.11.3. PLCC and Auto Re-closure issues related to UPPTCL

28th PSC meeting on 19th December, 2014 - POWERGRID had informed that there were

various lines of UPPTCL wherein PLCC panels and auto re-closure schemes were not in

working condition due to which frequent tripping of lines on transient faults were taking place.

35th PSC meeting on 20th June, 2018- Status updated by UPPTCL and POWERGRID

in the meeting was as under:

Sl.

No.

Name of

Transmission Line Details of PLCC

Status as updated

in 34th PSC

Present status

Allahabad S/S

1. 220kV Allahabad-

Rewa Road-I

PLCC link was

through but failed

PLCC

commissioned but

2. 220kV Allahabad-

Rewa Road-II

frequently due to

non availability of

wave trap at Rewa

Road end.

not functional as

end to end testing

was pending.

Kanpur S/S

1. 220kV Kanpur-

Mainpuri

PLCC panels not

available

-

Gorakhpur S/S

1. 220kV Gorakhpur-

Barhua

PLCC were not

functional

PLCC has been

commissioned but

available relays do

not have carrier

feature which were

to be replaced in 1

month.

2. 220kV Gorakhpur-

Basti

PLCC panels were

not available

PLCC allotment

was expected in

August 2017

UPPTCL/POWERGRID were requested to update the status.

A.11.4. Islanding scheme for Rajasthan and Punjab

A.11.4.1. Islanding scheme for Rajasthan

30th PSC meeting on 21st September, 2015 - RVPNL had stated that existing islanding

scheme meant for RAPP-A and RAPP-B would change entirely if Mahi HPS is excluded from

the scheme. Also, result of dynamic simulation studies had not yet been received from CPRI.

RVPNL was requested to implement the scheme provisionally & necessary actions for

procurement of relays etc. was to be initiated with completion target of one year. RRVPNL had

agreed for the same.

31st PSC meeting on 7th June, 2016 - RVPNL stated that the procurement process for

this islanding scheme was underway and the scheme, without considering Mahi, was expected to

be functional by December, 2016.

32nd PSC meeting on 30th November, 2016 - RVPNL informed that the scheme

excluding Mahi HPS would be implemented by June 2017.

33rd PSC meeting on 22nd February, 2017 - Status could not be confirmed as no

representative of RVPNL attended the meeting.

34th PSC meeting on 4th August, 2017 - RVPNL intimated that relay purchase in

process and the scheme is to be implemented by 31.01.2018.

Representative RRVPNL intimated that scheme has been approved but the

purchase process was reverted back. He further told that re-tendering for relays is in

process.

A.11.4.2. Islanding scheme for Punjab

A meeting was held on 27th November, 2014 at NRPC Secretariat to review the

islanding schemes for Punjab. In this meeting, it was decided that PSTCL would implement the

scheme envisaged for Lehra Mohhabat TPS and Bhatinda TPS at first instance. Thereafter, based

on the experience of such scheme, the islanding scheme meant for Ropar TPS would be

implemented. PSTCL had informed that stability study for the scheme was being carried out by

CPRI and report of the same would be available by 31.12.2014. Thereafter, procurement would

start.

29th PSC meeting on 9th February, 2015 - PSTCL had informed that CPRI has submitted

the dynamic study for islanding scheme for Bhantida TPS and PSTCL was under process of

implementing the scheme. Procurement process was underway and the scheme would get

implemented by 30.11.2015. PSTCL was requested to share the approved scheme with NRPC

Sectt. and NRLDC. PSTCL had agreed for the same.

31st PSC meeting on 7th June, 2016 - PSTCL had informed that relays for islanding

scheme of Bhatinda TPS had already been procured and installation of these relays was under

process. He further stated that the scheme would be made functional by 30.09.2016.

32nd PSC meeting on 30th November, 2016 - PSTCL informed that Bhatinda, which is a

part of the islanding scheme, would be in operation for a limited period during summer. In view

of this, the scheme needs revision. Once the revised scheme is finalised it would be

implemented. PSC advised PSTCL to finalise the scheme at the earliest and to share it with all

the concerned including NRPC Sectt.

33rd PSC meeting on 22nd February, 2017 - PSTCL was requested to expedite the

process and submit the information at the earliest.

34th PSC meeting on 4th August, 2017 – PSTCL was given approval to implement

islanding scheme for only GHTP control area citing the plans of PSPCL to shut the GNDTP

Bathinda plant by the year end. They were further requested to complete the same by 30.09.2017

and to submit the details of actual implemented schemes to NRLDC Secretariat and NRPC.

Representative of PSTCL stated that consent of PSPCL was received a one week

before for the execution of Islanding scheme on only GHTP control area. It will be executed

by 30.09.2018.

A.11.5 Progress of rectification of deficiencies observed/improvements suggested in

Basic Protection Audit.

The status of rectification of deficiencies observed in Basic Protection Audit carried out

by POWERGRID & CPRI is to be submitted on monthly basis.

The updated status in regard to expected completion time of rectification of protection

related deficiencies as informed by utilities is enclosed as Annexure-IV.

Utilities were requested to update the latest status.

A.11.6. Third Party Protection Audit by the Protection Experts for intra-state

system/ balance system not covered in Basic Protection Audit.

The status of TPPA as updated in the 34th PSC meeting is enclosed as Annex-VIII. In the

34th PSC meeting, PSC again stressed over non-rectification of deficiencies by most of the

utilities. Utilities which have not submitted the action plan were requested to submit the same at

the earliest. All the utilities were again requested to submit the action plan and to ensure

expediting the process for rectification of discrepancies found in the audit. Annexure-V

Utilities were requested to update the latest status.

A.11.7. Status of Bus Bar protection

As per the report of Basic Protection Audit carried out by CPRI and POWERGRID

in 2012, non-availability/non-functionality of Bus Bar Protection at many of the S/S was

one of the major observations.

19th PSC meeting on 21st November, 2012 - Action plan for rectification of deficiencies

enumerated in the report was updated by the utilities during the meeting. This status has

subsequently been revised based on information submitted by the utilities from time to time.

20th PSC meeting on 5th April, 2013 – As per the decision taken in 83rd OCC held on

17th January, 2013, it was agreed that each transmission and generation utility would nominate

two protection experts and thereafter protection audit at intra-State sub-stations and generating

stations can be carried out by a team drawn from these experts. List of nominations was prepared

and updated subsequently.

21st PSC meeting on 25th June, 2013 – Bus Bar Protection Status as available with

NRPC secretariat was discussed in the form of tabled agenda item and utilities were requested to

update the same with 15 days.

22nd PSC meeting on 22nd July, 2013 – Information was not submitted by any of the

utilities. Members were requested to update the status of Bus Bar Protection.

23rd PSC meeting on 9th September, 2013 – Only DTL, BBMB PSTCL, POWERGRID,

NHPC and HPSEB Ltd. submitted the status. All other utilities were requested to update the

status of Bus Bar Protection.

24th PSC meeting on 17th December, 2013 – Only DTL, BBMB PSTCL, POWERGRID,

NHPC and HPSEB Ltd. had submitted the status. All other utilities were requested to update the

status of Bus Bar Protection.

25th PSC meeting on 12th February, 2014 – Immediate Alternative of Bus Bar

Protection Scheme - RVPNL stated that in the Sub stations, where Bus Bar Protection Scheme

was currently not available, time setting of bus coupler connected in between main Buses may be

reduced to 100 ms (operating time) and reverse reach of feeders may be reduced to 2 km and

with time of operation as 160 ms. With above settings, in case of actual Bus fault, bus coupler

operation will isolate the faulty buses from other main buses and feeders will also trip. This

operation will reduce the fault duration and the healthy buses will remain intact.

PSC was of the view that scheme can be used purely as a temporary substitute till Bus

Bar Protection is not installed. But at the same time, members expressed that endeavor should be

made to operationalize Bus Bar Protection at the earliest.

28th PSC meeting on 19th December, 2014 – Utilities were requested to expedite the

implementation of Bus Bar Protection and submit the information.

31st PSC meeting on 7th June, 2016 – PSC expressed concern of non-functioning of Bus

Bar Protection at many sub-stations in the region. It was decided that efforts would be made to

expedite implementation of Bus Bar protection and submit the information to NRPC Sectt with

progressive commissioning of Bus Bar protection.

Attention of members was also drawn towards deliberations in the 25th meeting of PSC

held in Feb, 2014, wherein it was decided that as an interim arrangement an alternative to Bus

Bar protection can be implemented. In this arrangement time setting of Bus coupler connected in

between main Buses may be reduced to 100 ms (operating time) and reverse reach of feeders

may be reduced to 2 km and with time of operation as 160 ms. With above settings, in case of

actual Bus fault, Bus coupler operation will isolate the faulty Buses from other main Buses and

feeders will also trip. This operation will reduce the fault duration and the healthy Buses will

remain intact.

32nd PSC meeting on 30th November, 2016 – UPPTCL stated that as agreed in 25th PSC

meeting held in Feb, 2014, an interim arrangement alternative to Bus Bar protection has been

implemented in some of their sub-stations. It was also informed that as normal operation has

been reported, therefore, UP was planning to implement the same in other sub-stations. Delhi

and Rajasthan also informed the similar action. It was felt that other states e.g. Haryana and

Punjab may also implement the same as an interim measure till the bus -bar protection is

installed. However, it was again emphasized that this would be a temporary arrangement only

and must not be considered as an alternative to bus -bar protection.

33rd PSC meeting on 22nd February, 2017 – PSC advised all the concerned utilities to

make interim arrangement as decided in 32nd PSC meeting, till the Bus bar protection is not

installed.

34th PSC meeting on 4th August, 2017- PSC advised to remove the alternate arrangement

wherever Bus bar protection has been installed. UP has installed alternative schemes in almost

all of the substations where Bus bar protection is installed. Rajasthan will start procurement after

finalizing contract for implementation of Bus bar protection.

Representative of UPPTCL informed that alternated arrangements was removed in all

the substations wherever a bus bar protection was installed.

Representative of Rajasthan informed that out of 74 locations where bus bar protection

was to be installed 56 locations have been completed. He informed that installation at other

locations is in process.

A.11.8. CERC order on Petition No. 9/SM/2014 and 10/SM/2014

SE, NRPC stated that CERC in its order dated 14.06.2016 in Petition no. 9/SM/2014 for

investigation of tower collapse and load crash in Northern Region on 30.5.2014 and Petition no.

10/SM/2014 for investigation of Line Outage due to Tower Collapse in Northern Region during

April 2015 to June 2015 directed RPC Secretariat to examine the cases of delayed clearance of

faults on transmission system during last two years and to submit an analysis report within six

month from the date of issue of the order. The status of the delayed clearance of the fault from

01.04.2014 to 01.06.2015 was enclosed as Annex-VI of the agenda of 32nd PSC meeting. In the

agenda following action was proposed:

Utilities which had not submitted the detailed report along with the remedial

measures taken/being taken were requested to submit the same.

Utilities whosoever had submitted the report along with the measures to avoid the

recurrences of these types of tripping were requested to submit the status of action

suggested in report.

In the 32nd PSC meeting, members were requested to submit the reason for

delayed clearance of faults and action taken to avoid recurrence, by 15th Dec, 2016 to

NRPC Sectt.

Again in the 33rd PSC expressed concern over non-submission of data. Utilities were

requested to furnish the information by 07.03.2017, so that the report may be submitted to

CERC.

Subsequently, vide letter dated 10.07.2017, members of PSC were asked to

submit the action taken on the recommendation of the discussions held in last 04 PSC

meetings (30th, 31st, 32nd, 33rd ) by 25.07.2017).

The issue was again flagged in 34th PSC meeting in which all the members

agreed to submit the details as required. The status of details received is as given below:

Description Information submitted by

Details regarding Event List as mentioned at

Annex-VI to 34th PSC Minutes (Reasons /Action

taken for Delayed Clearance of faults)

UPPTCL and NJHPS

Action taken status on the recommendation of

the discussions held in last 04 PSC meetings

(30th, 31st, 32nd, 33rd )

BBMB, NHPC, POWERGRID

(NR-2) and NAPS

Utilities were again requested to furnish the information as mentioned above at

the earliest as the details need to be submitted to CERC. Representative of

POWERGRID intimated that information will be shared within one week. However, if

no further information is received, CERC will be intimated accordingly.

A.11.9. Submission of information in compliance to Hon’ble CERC Standards of

Performance of inter-state transmission licensees Regulations, 2012:

In 32nd PSC meeting it was intimated that the Hon’ble CERC SOPR-2012

regulation mandates inter-State Transmission Licensees to furnish the protection

system reliability indices on monthly basis as attached at Annexure-I of the

additional agenda of 32nd PSC. It had been observed that presently no such

information was being received from the ISTS licensees.

It was requested that ISTS licensees submit such information on monthly

basis to NRLDC.

Utilities were requested to share the DR/EL of the single element tripping

and details of the tripping in desired format attached as Annexure-2 of the

additional agenda of 32nd PSC.

PGCIL has submitted the details. Other utilities were again requested to send the data

from September 2016 onwards at the earliest.

A.11.10 Creation of Protection Analysis Sub-Group (PSAG):

SE, NRPC informed that in 31st PSC meeting it was deliberated that owing to the large

number of grid events in the region and the intervening period between two successive PSC

meetings, a detailed discussion of such large events during the limited time frame of the meeting

becomes difficult. Further, it has been observed that several events in the grid require immediate

analysis and rectification of defects.

He added that considering the above, it was proposed that a Protection Analysis Sub-

Group (PSAG) would be formed to discuss and analyze major grid events, which require

immediate attention. The subgroup would suggest specific corrective actions required by

respective entity. The entities would submit the status of compliance of these recommendations

in a stipulated time frame.

SE, NRPC further informed that PSC had decided to constitute a Protection Analysis

Sub-Group with members from NRPC Secretariat, NRLDC and POWERGRID as permanent

members. Further, all other utilities of Northern Region would provide one nomination each. The

nominee from the utilities would be called when the tripping related to that utility is to be

discussed. The group shall conduct its business on monthly basis and submit its report to PSC. In

32nd PSC meeting, members of the group were decided.

Updated list of members of PSAG attached as Annexure-III. Members were requested

to submit the additional nominations for PSAG at the earliest.

A.11.11 General Recommendations/Best Practices in PSC meeting

In the 32nd PSC meeting it was deliberated that there is a need to keep the compilation of

the general recommendations of the Protection Sub- Committee for reference. The compiled list

of recommendations of PSC was circulated with the agenda of 33rd PSC meeting. (Enclosed as

Annexure – XII of 35th PSC agenda)

Members were requested to adhere to these general recommendations and follow

the best practices as suggested by PSC. Members were also requested to forward best practices in

their utility or any other utility which can be adopted to include in this compilation.

It was informed that list of general recommendations was formed considering best

practices as suggested by PSC but it has been observed that these practices were not being

implemented. All the utilities were requested update the status regarding actions taken to

adhere these general recommendations.

A.12 The group to formulate Detailed Talent Recognition Mechanism for the

Protection Engineers (Additional Agenda)

As per the recommendations of the group constituted in Aug 2015 to suggest

measure for improvement in protection system of Northern Region, it was decided in 38th

NRPC meeting that the effort of the protection engineers needs to be acknowledged and

rewarded by the management. Consequently, a group comprising of members from

utilities was constituted to formulate Detailed Talent recognition mechanism for the

Protection Engineers. A meeting of the group was held on 23.10.2017 at NRPC

Secretariat, New Delhi. The draft minutes of the meeting were circulated amongst the

members for the comments, if any, but no comments were received. The Minutes of the

meeting are attached as Annexure XIII of 35th PSC agenda.

MS, NRPC informed that mechanism is formulated to encourage the Protection

engineers. He further emphasized on the need for recognizing the efforts put in by the

Protection Engineers citing that they have to often work in odd hours and under short

response time for ensuring safe and stable operation of the grid. Members agreed for

the proposed monetary reward. It was also informed that mechanism shall be further

deliberated at NRPC meeting for approval.

A.13 Tripping Events:

The complete summary of the events along with the information reported, action taken by

entities is attached at Annexure-VII.

The recommendations of PSC are as follows:

A. Multiple Element tripping at 400/220kV Bikaner at 11:40hrs of 12th Sep 2017

1. A detailed report covering the following points along with remaining DR, station

EL shall be submitted: (Action: Rajasthan; Time: by 15.07.2018):

a. Reason for delayed tripping of bus bar protection and results for diagnosis

of the same to be shared.

b. As per SCADA SoE, tripping of 400kV Bikaner-Bhadla ckts from Bhadla

end at different timings to be ascertained and shared.

c. As per PMU, fault is in R-phase, whereas as per DR details fault is in B-

phase. The DRs to be checked for mapping w.r.t. polarity.

d. Exact sequence of events in view of cause of event; protection

operation/non-operation; opening, closing of breaker, isolator; relevant

alarms and any other relevant detail to be shared.

B. Multiple element tripping at 400/220kV Lucknow (UP) at 17:27hrs of 22nd Sep 2017

and 17:23hrs of 25th Dec 2017


EL shall be submitted: (Action: UP; Time: by 15.07.2018)

a. For 22nd Sep 2017:

i. Reason for non-opening of 220kV Unnao ckt from Lucknow end

on LBB protection operation of bus coupler to be shared.

ii. LBB protection operation for bus coupler needs to be reviewed as

tripping didn’t occur in the breaker connected to that bus. Fault fed

for 1.5second and ICTs finally tripped on back up over current

earth fault protection.

iii. LBB protection operation of 400/220kV ICT-2 after ~1.5sec of

fault to be explained.

iv. Three simultaneous LBB operations need to be reviewed

thoroughly.

v. Time synchronization error for 220kV LBB/ Bus Bar Protection

numerical relays to be checked.

vi. Exact sequence of events in view of cause of event; protection

operation/non-operation; opening, closing of breaker, isolator;

relevant alarms and any other relevant detail to be shared.

b. For 25th Dec 2017:

i. Reason for delayed clearance of fault needs to be ascertained. In

case of operation of bus bar protection fault would be cleared

within 100ms.

ii. Reason for opening of 220kV Lucknow (UP)-Gomti Nagar ckt to

be ascertained.

iii. Tripping of other 400kV elements at Lucknow (UP) in interval of

msec to be explained.

iv. Multiple closing/opening of 400kV Singrauli/Unnao ckts to be

explained.

v. Exact sequence of events in view of cause of event; protection



C. Multiple element tripping at 400/220kV Muzaffarnagar, Vishnuprayag at 12:02hrs of

09th Oct 2017 and 16:24hrs of 20th Dec 2017

1. For 09th Oct 2017 event:

a. Reason for tripping of 400kV Muzaffarnagar-Ataur in Z-2 from Ataur to

be explained. (Action: UP, Time: by 15.07.2018)

b. Time synchronization w.r.t. SCADA digital status data at Muzaffarnagar

(UP) needs to be checked and corrected. (Action: UP, Time: by

15.07.2018)

2. For 20th Dec 2017 event:

a. At a substation having two bus bars, both buses should be coupled to

enhance reliability. (Action: All NR constituents, Time: by 15.07.2018)

b. DR (COMTRADE files) of bus bar protection relay at Vishnuprayag to be

shared. (Action: UP, Time: by 15.07.2018)

c. Time synchronization w.r.t. SCADA digital status data at Muzaffarnagar

(UP) needs to be checked and corrected. (Action: UP, Time: by

15.07.2018)

D. Multiple element tripping at 400/220kV Talwandi Sabo TPS at 02:57hrs of 07th Nov

2017 and 07:13hrs of 12th Nov 20172017

1. For 7th Nov 2017 event:

a. As per SCADA data, it seems only two out of three units tripped at

T.Sabo. Reason and time (in ms) of tripping of units at T.Sabo to be

shared. (Action: PSPCL, Time: by 15.07.2018)

b. POWERGRID stated that 400kV T.Sabo-Moga didn’t trip from Moga

end. Further, as per SCADA data also, MW flow is observed on the line.

Hence, status and reason of tripping (if any) of 400kV T. Sabo-Moga from

T.Sabo end to be confirmed. (Action: PSPCL, Time: by 15.07.2018)

c. Exact sequence of events in view of cause of event; protection


alarms and any other relevant detail to be shared. (Action: Punjab, Time:

by 15.07.2018)

d. Better line maintenance to avoid frequent tripping in 400 kV ring needs to

be expedited. (Action: Punjab, Time: by 15.07.2018)

2. For 12th Nov 2017 event:

a. As per PMU and SCADA data, auto-reclosing time difference observed in

400kV T. Sabo-Moga (PG). It seems auto-reclosing from Moga (PG) was

delayed (~1300ms) which needs to be checked. (Action: POWERGRID,

Time: by 15.07.2018)

b. PSTCL reported that 400kV T.Sabo-Dhuri-1 remained charged from

Dhuri end but tripped from T.Sabo end. Reason for tripping of aforesaid

ckt from T.Sabo to be ascertained and shared. (Action: PSPCL, Time: by

15.07.2018)



alarms and any other relevant detail. . (Action: Punjab, Time: by

15.07.2018)

d. Better line maintenance to avoid frequent tripping in 400 kV ring needs to

be expedited. (Action: Punjab, Time: by 15.07.2018)

E. Complete outage of 400kV Kurukshetra and blocking of HVDC Champa-Kurukshetra

Bipole at 03:25hrs of 10th Nov 2017

1. Kurukshetra station hosts important high capacity WR-NR link in NR (Champa

(WR)-Kurukshetra(NR)). Hence, the substation is very important. Multiple lines

tripping from Kurukshetra may lead to system contingency. Hence, the over

voltage settings of all the lines to be checked and modified in view of grading

among different lines, pick up to drop off ratio of relay etc. so as to avoid cascade

tripping. (Action: POWERGRID, Time: by 15.07.2018)

F. Multiple element tripping at 220kV Panipat BBMB at 11:29hrs of 19th Nov 2017 and

00:35hrs of 01st Jan 2018

1. Haryana shall confirm about load loss figure (Action: Haryana, Time: by

15.07.2018)

2. Non-auto reclosing of 220kV Chajjpur circuit to be checked and rectified.

(Action: BBMB, Time: by 15.07.2018)

3. Time synchronization of DR (Chajjpur-2) needs to be checked and rectified, as it

is not matching with the bus bar trip (DR) and PMU based fault timings. (Action:

BBMB, Time: by 15.07.2018)

4. As advised in 34th PSC meeting, at a substation (Action: BBMB, Time: by

15.07.2018):

a. Better monitoring tool shall be used for isolator auxiliary contact input to

bus bar protection.

b. Bus tied operation alarm shall be brought in front panel so that the shift

operator could easily monitor the same.

c. Line/Bus isolator auxiliary contacts status input to bus bar protection/ stub

protection operation needs to be checked after every isolator operation.

5. Compliance report for point number four to be submitted by all NR constituent

(Action: All NR constituents, Time: by 15.07.2018):

G. Multiple element tripping at 400/220kV Sarnath (UP) Station at 01:22hrs of 29th Nov

2017


EL shall be submitted: (Action: UP; Time: by 15.07.2018)

a. As reported by UP, bus bar protection operated at Sarnath. However, as

per PMU data, no fault observed. Exact reason for operation of bus bar

protection to be ascertained and shared.

b. Reason for power flow of 400kV Sarnath-Varanasi ckt-2 becoming zero

5min prior to actual event.




H. Multiple Element tripping at 400/220kV Dadri (NTPC) Station at 17:30hrs of 09th

Dec 2017

1. All the NR constituents shall follow the better maintenance practices and more

frequent thermo-scanning in the switch yard. (Action: All NR constituents; Time:

periodically)

2. All the NR constituents should be vigilant during bus shutdown of important

station and it needs to be discussed in detail during planning of shutdown.

(Action: All NR constituents; Time: periodically)

3. Detailed report along with DR/EL for tripping of 400kV Dadri-Harsh Vihar ckt-1

& 2 to be submitted. (Action: Delhi; Time: by 15.07.2018)

4. Reason of tripping of filter bank-5 at HVDC Agra (end) for Agra-BNC to be

ascertained and shared. (Action: POWERGRID; Time: by 15.07.2018)

5. Detailed report of filter bank switching along with event log at HVDC Dadri end

of HVDC Rihand-Dadri to be shared. (Action: POWERGRID; Time: by

15.07.2018)

6. Non-tripping of 220kV Modipuram, Gobindgarh and Laltokalan station on SPS to

be checked and corrected. (Action: POWERGRID, UP, Punjab; Time: by

15.07.2018)

7. Haryana and Rajasthan shall improve the MW load shedding on the dedicated

feeders in SPS operation. (Action: Haryana, Rajasthan; Time: by 15.07.2018)

8. Reason of MVAR fluctuations of unit-6 of Dadri Thermal to be checked and

observations in this regard to be shared. (Action: NTPC; Time: by 15.07.2018)

I. Multiple element tripping at 400/220kV Rewa Road (UP) on 23, 29 & 30th Dec 2017

1. In view of the lack of information and clarity about all three events and no

representative from Rewa Road (UP) attended the meeting, the event would be

included again for discussion in the next PSC meeting.

2. A detailed report covering the following points along with DR, station EL shall be

submitted: (Action: UP; Time: Within 15days)

a. Event on 23rd Dec 2017:

i. Exact sequence of events in view of cause of event; protection


relevant alarms and any other relevant detail.

ii. Non-reporting of digital status SCADA data of Banda and Rewa

Road.

iii. Preliminary report, DR/EL and detail report is still awaited from

UP

b. Event on 29th Dec 2017:

i. For 400kV Rewa Road-Panki:

• Delayed tripping from Panki end.

• Non auto-reclosing from Panki end.

ii. Exact sequence of events in view of cause of event; protection



iii. Reason of delayed clearance of fault.

iv. Non-reporting of digital status SCADA data of Banda and Rewa

Road.

v. Preliminary report, DR/EL and detail report is still awaited from

UP

vi. Exact sequence of events in view of cause of event; protection


relevant alarms and any other relevant detail to be shared

c. Event on 30th Dec 2017:

i. For 400kV Rewa Road-Panki:

• Delayed tripping from Panki end.

• Non auto-reclosing from Panki end.

• Tripping from Rewa Road end after 6sec of fault.

ii. Reason of delayed clearance of fault.

iii. Reason for LBB protection operation from Rewa Road end after

5sec of fault.

iv. Non-reporting of digital status SCADA data of Banda.

v. Exact sequence of events in view of cause of event; protection



vi. Preliminary report, DR/EL and detail report is still awaited from

UP

J. Multiple Element tripping at 400/220kV Bhiwadi(PG) at 10:33hrs of 22nd Jan 2018

1. At Bhiwadi (PG), time of opening of CB as captured from SCADA SoE is not

consistent with PMU based fault timings. Time synchronization in view of above

needs to be checked at Bhiwadi (PG). (Action: POWERGRID; Time: by

15.07.2018)

2. As per SCADA SoE, tripping of feeders at different timings in case of bus fault

(not being simultaneous) needs to be checked. (Action: POWERGRID; Time: by

15.07.2018)

3. Back up auxiliary supply for HVDC Pole-1 & 2 needs to be ensured. (Action:

POWERGRID)

4. Setting of distance protection of 220kV Bhiwadi (PG)-Bhiwadi (RJ) ckt-1 to be

reviewed. (Action: POWERGRID; Time: by 15.07.2018)

5. Detail analysis report also to be submitted by Rajasthan. (Action: Rajasthan;

Time: by 15.07.2018)

K. Multiple Element tripping in Delhi control area and islanded operation of Pragati GT

at 12:28hrs of 21st Feb 2018

1. As reported by DTL, the overloading of 220 kV Naraina-Ridge Valley could be

taken care of by SPS (in operation) at Naraina which shed load on I>700A.

Details of SPS to be shared. (Action: Delhi; Time: by 15.07.2018)

2. Separate SPS booklet shall be prepared for SPS implemented in one’s control

area. The same shall be shared. (Action: All NR constituents; Time: by

30.08.2018)

L. Multiple Element tripping at 400 kV Agra (UP) at 18:09hrs of 04th Mar 2018


EL shall be submitted: (Action: UP, POWERGRID; Time: Within 15days)

a. Exact sequence of events in view of cause of event; protection



b. Reason of operation of bus bar protection for both 400 kV buses at Agra

(UP).

c. Lightening Mast design in 400 kV Agra (UP) also needs to be looked into

as both bus fault occurred due to lightening in the switchyard.

d. As per SCADA SoE:

i. Reason for tripping of 400kV Agra-Unnao ckt from Unnao end in

~140ms of fault to be looked into and shared.

ii. Reason for opening of 400kV Agra(UP)-Agra(PG) ckt from

Agra(PG) end (tie CB during fault and main CB after ~1sec of

fault) to be looked into and shared.

e. As per UP report, ICT-3 didn’t trip. However, fault cleared in ~320ms.

How the fault get cleared if ICT-3 didn’t trip.

f. As per UP report, bus bar protection of bus-2 operated and LBB of

Fatehabad-1 ckt (connected to bus-2) also operated after operation of Z-4

relay (250ms time setting).

M. Tripping of multiple lines and generation in Baspa-Karcham-Jhakri-Rampur

complex at 17:15hrs of 29th Mar 2018

1. As per DR, at 17:21hrs, 400kV Jhakri-Panchkula (end)-1, line tripped on DEF

protection. Non-timely triggering of distance protection for a fault in line and

tripping of line on DEF protection in 900ms even after triggering of Z-2

protection to be checked and rectified. (Action: POWERGRID, Time: by

15.07.2018)

2. Setting of DEF protection at Panchkula (PG) to be reviewed and shared. (Action:

POWERGRID, Time: by 15.07.2018)

3. As per DR, at 17:18hrs, all three phases of 400kV Jhakri (end)-Rampur-2 tripped

without auto-reclosing. Reason for the same to be checked and shared. (Action:

SJVNL, Time: by 15.07.2018)

4. As per DR of 400kV Jhakri (end)-Punchkula-2, it seems time synchronization

error of around 100ms is present. The same needs to be checked and rectified.

(Action: SJVNL, Time: by 15.07.2018)

5. As per DR received from Rampur, it seems time synchronization error is present.

The same needs to be checked and rectified. (Action: SJVNL, Time: by

15.07.2018)

6. DR configuration at Rampur HEP needs to be looked into in view of following

points (Action: SJVNL, Time: by 15.07.2018):

a. Name of the element

b. DR of which end

c. Main-I or Main-II protection

d. Mapping of minimum standard signal as approved in PSC meeting

7. Tripping details of Karcham/ Baspa end as its in Himachal control area, needs to

be checked and shared. (Action: HP, Time: by 15.07.2018)

8. Jhakri/Rampur/Karcham/Baspa Hydro complex is an important generation

complex having more than 3000MW capacity. Simultaneous outage of such large

no. of lines of complex lead to very critical grid conditions. In view of this,

patrolling of lines in the complex could be carried out to ascertain the reason for

large no. of fault incidents. Necessary action wherever found necessary to be

taken. (Action: POWERGRID, SJVNL, Time: periodically)

N. Multiple Element tripping at 400/220kV Sarnath (UP) at 22:07hrs of 30th Mar 2018

1. It seems 400 kV Anpara-Sarnath line tripped from Anpara end in Z-1 however

fault was at the bus of Sarnath (UP). Distance protection setting at Anpara (end)

of 400kV Anpara-Sarnath line needs to checked and corrected. (Action: UP,

Time: by 15.07.2018)

2. As seen from PMU, reason for Y-N fault followed by R-N fault followed by 3-

phase fault to be ascertained and informed. (Action: UP, Time: by 15.07.2018)

3. Reason of three phase tripping of 400 kV Sarnath-Azamgarh line during Y-phase

to earth fault in the line to be checked and corrected. (Action: UP, Time: by

15.07.2018)

4. In case of bus fault, delayed clearance of fault (~450ms) to be checked. (Action:

UP, Time: by 15.07.2018)

5. As reported by UP, station event logger would be commissioned by Sep’18.

Expeditious commissioning of same is requested. (Action: UP)

6. 34th PSC Recommendation:

• Better monitoring tool shall be used for isolator auxiliary contact input

to bus bar protection.

• Bus tied operation alarm shall be brought in front panel so that the

shift operator could easily monitor the same.

• Line/Bus isolator auxiliary contacts status input to bus bar protection/

stub protection operation needs to be checked after every isolator

operation.

7. It was discussed and approved in PSC meeting that Auxiliary contact status of

isolator would be regularly checked in every shift and alarm should be available

to the operator of the station with DMT (Double Main Transfer Breaker Bus Bar)

scheme however it seems, it is yet to be implemented at 400kV Sarnath (UP).

8. NR constituents may kindly share the compliance report of aforesaid

recommendation for 220kV and above station (All NR constituents)

O. Multiple element tripping at 220 kV Sakatpura and KTPS (Kota TPS) at 01:42hrs of

01st Apr 2018

1. Expeditious commissioning of bus bar protection at 220kV Sakatpura. Tentative

date of commissioning to be informed. (Action: Rajasthan, Time: by 30.07.2018)

2. As per IEGC sec 4.6.3, CEA technical standards for connectivity of electrical

plants and electrical lines sec. 43.4.D and CEA Technical standards for

connectivity to the grid Regulation, 2007 Schedule part 1.7, Station event log to

be installed at Sakatpura. Status of procurement of same needs to be confirmed.

(Action: Rajasthan, Time: by 30.07.2018)

3. For a fault in Bus coupler of Bus B & C, elements connected to Bus-B & C would

have tripped leaving buses A & D healthy through operation of bus sectionaliser.

As per SCADA SoE, bus sectionaliser opened but still the elements connected to

other buses tripped. This needs to be investigated further. (Action: Rajasthan,

Time: by 15.07.2018)

4. At Sakatpura, directionality of back up E/F protection w.r.t tripping of 220kV

Sakatpura-KTPS-1 to be checked and rectified. (Action: Rajasthan, Time: by

15.07.2018)

5. Non-operation of interim alternate bus bar arrangement (Z-4, 160ms) to be

checked and rectified. (Action: Rajasthan, Time: by 15.07.2018)

6. Reason for tripping of 220kV KTPS-Beawer, 220kV KTPS-Bundi and 220kV

KTPS-Heerapura in Z-1 from KTPS end needs to be ascertained and corrected.


7. Reason for tripping of 220kV KTPS-Kota (PG) D/C on power swing to be

ascertained and corrected. (Action: Rajasthan, Time: by 15.07.2018)

8. Time synchronization error at following stations needs to be resolved :

a. Sakatpura

b. Kota TPS

c. Vatika

d. Dahra

9. 220kV RAPS-Sakatpura-1, tripped from RAPS end only for on distance

protection picked up by main-1 relay (Micom P442 relay) only. Setting of

distance protection for Micom P442 relay to be shared and reviewed at RAPS.

(Action: NPCIL, Time: by 15.07.2018)

P. Multiple element tripping at 400/220kV Bareilly (UP) at 22:39hrs of 05th Apr 2018

and 10:51hrs of 08th Apr 2018

1. Audit of Bareilly(UP) substation to be carried out especially considering the

following points:

• Reason for stuck status of trip contacts of 86B and reason for the same not

updating in control panel to be ascertained and shared.

• N.I.T. switch positioning at Intermediate instead of Transfer lead to tripping

of complete 400kV elements at the substation.

• As advised in 34th PSC meeting for all NR constituents, at a substation:

o Bus tied operation alarm shall be brought in front panel so that the

shift operator could easily monitor the same.

o Line/Bus isolator auxiliary contacts status input to bus bar protection/

stub protection operation needs to be checked after every isolator

operation

• Detailed report and remedial measures report to be submitted.

The audit report along with remedial measures to avoid above tripping in future

shall be shared. (Action: UP, Time: by 20.07.2018)

Q. Multiple element tripping at 400/220kV Jodhpur (Raj) Station at 21:41hrs of 05th Apr

2018

1. Reason for tripping of CB (bus-B) of 400kV Akal to be ascertained and shared.


2. As per information and details received from POWERGRID during meeting, At

Jodhpur, General Trip signal is mapped for LBB protection for all three phases

even in case of single phase pole operation. This resulted in operation of LBB

during fault auto-reclosing of 400kV Jodhpur-Kankroli. It is to be confirmed that

whether LBB operated due to above or actual stuck breaker situation. The above

setting of LBB also needs to be rectified. (Action: Rajasthan, Time: by

15.07.2018)

3. As per Rajasthan report, DT sent in to remote end for Merta-2, Akal ckts and not

sent for Merta-1 ckt. Also, as per DR of 400kV Jodhpur (end)-Kankroli ckt, DT

sent to Kankroli end as well. At Jodhpur, there is one and a half breaker scheme.

Reason and logic for DT sent for ckts at Jodhpur station to be shared. (Action:

Rajasthan, Time: by 15.07.2018)

4. As per DR details of 400kV Jodhpur(end)-Kankroli, LBB operated in around

130ms in place of recommended setting of 200ms. Also, Setting of LBB

protection at Jodhpur to be checked and rectified. (Action: Rajasthan, Time: by

15.07.2018)

5. As per Rajasthan report, Akal and Merta-1 were charged from one CB only.

Reason for non-availability of other Tie/main CB to be shared. (Action:

Rajasthan, Time: by 15.07.2018)

6. Time synchronization of DR of 400kV Jodhpur (end)-Kankroli needs to checked

and rectified. (Action: Rajasthan, Time: by 15.07.2018)

R. Multiple element tripping at 400/220kV Rewa Road (UP) on 08, 16 & 19th Apr 2018

1. In view of the lack of information and clarity about both the events, the event

would be included again for discussion in the next PSC meeting.

2. A detailed report covering the following points along with DR, station EL shall be

submitted: (Action: UP, POWERGRID; Time: Within 15days)

a. Event on 08th Apr 2018:

i. Exact location of fault to be reported.





iv. Reason of tripping of multiple elements at 01:49hrs without any

fault in the system

v. Non-reporting of digital status SCADA data of Meja TPS and

Rewa Road.

vi. Preliminary report, DR/EL and detail report is still awaited from

UP.

b. Event on 16th Apr 2018:

i. Exact location of fault to be reported.





iv. Reason of tripping of 400 kV Obra-Panki line.

v. Reason of complete outage of 400 kV Rewa Road (UP).

vi. Reason of tripping of multiple elements at 13:49:24hrs on over

voltage protection needs to be looked into.

vii. Voltage staggering w.r.t. time and voltage. Over voltage setting

of all the outgoing line from Rewa Road, Meja TPS and its

remote end needs to be shared.

viii. Non-reporting of digital status SCADA data of Meja TPS and

Rewa Road.

ix. DR/EL from Rewa Road (UP) and detailed report of the incident

is still awaited from UP.

c. Event on 19th Apr 2018:

i. Staggering of over voltage protection setting w.r.t. time and

voltage.




iii. Reason of simultaneous tripping of all three lines.

iv. Reason of rise in the voltage.

v. Over Voltage setting to be shared for all outgoing lines from

Rewa Road and Meja TPS.

vi. Non-reporting of digital status SCADA data of Meja TPS and

Rewa Road.

vii. Preliminary report, DR/EL and detail report is still awaited from

UP.

3. Availability of DR and its extraction software shall be available at the site.

4. Reporting of DR/EL shall be improved. DR/EL of any tripping to be submitted

within 24hrs.

5. Availability of digital status of Rewa Road and Meja TPS needs to be improved.

S. Loss of connectivity at 765kV Aligarh(PG) GIS at 00:39hrs of 20th Apr 2018

1. OEM report, study, findings of the incident including the reason for such high

over voltage (operation of over voltage stage-2) to be shared. (Action:

POWERGRID; Time: Within 3days of receipt of report)

2. Setting of over voltage of lines emanating from 765kV Aligarh (PG) to be shared.

(Action: POWERGRID; Time: Within 7 days)

3. DR/EL, detailed report of the incident to be shared along with remedial measures

taken/being taken to avoid such incidents in future. (Action: POWERGRID;

Time: Within 7 days)

T. Multiple Element tripping at 220 kV Pong HEP at 21:04hrs of 30th Apr 2018

1. Date by which new CTs at Pong HEP would be available to be reported. (Action:

BBMB; Time: Within 7days)

2. Date by which new numerical bus bar protection at Pong HEP would be available

(to replace conventional bus bar scheme) to be reported. (Action: BBMB; Time:

Within 7days)

3. Bus bar operation signal in DR configuration of as many 220kV feeders possible

to be mapped. (Action: BBMB; Time: Within 7 days)

4. Spare CT, CVT available in with the utility should also be checked once in a year.

(General Recommendation to all NR constituents)

U. Multiple element tripping in NR during thunderstorm from 18:20hrs onward of 11th

Apr 2018:

1. The following were the discussion on the electrical clearance of transmission lines

during high wind condition:

a. In normal weather condition, the clearance seems to be OK. However,

during high wind in stormy weather, the eucalyptus tree, in particular,

bends. This could result in less clearance and subsequent permanent fault

condition.

b. The polymer insulators are light weighted. During high wind condition,

the conductor could swing resulting in inadequate clearance and

subsequent fault condition. Counter weights are sometimes added at few

locations to avoid the above.

c. Pilot wire string also used for tension towers to keep the adequate

clearance even in high wind scenario.

In view of above, it has been recommended to carry out the patrolling of 400kV

and above transmission lines for any clearance issue or rectification thereof at

least once in a year preferably before the onset of stormy weather. A line-wise

report including the rectification work, wherever done is to be submitted to

NRPC/NRLDC. (Action: All NR transmission utilities; Time: once in a year or

less)

2. As per DR details, following needs to be clarified:

a. 765kV Agra(PG)-Aligarh(PG) : No auto-reclosing observed at

Agra(PG) end.

b. 400kV Agra(PG)-Fatehabad(UP): Auto-reclosing in 2sec from

Fatehabad(UP) end.

c. 400kV Agra(PG)-Agra(UP) : Imbalance in current (B-phase) observed at

Agra(PG) end.

(Action: POWERGRID, UPPTCL; Time: within 7 days)

3. Point may be included: reason for tripping of elements during stormy weather

should not be like “tripped during bade weather/storm”. Proper reason to be

provided.

V. Complete outage of 200kV RAPS A at 15:02hrs of 05th Apr 2018 (AGENDA BY

NPCIL):

1. 220kV RAPS A-Sakatpura D/C tripped from Sakatpura end only for on distance

protection picked up by main-1 relay (Micom P442 relay) only. Setting of

distance protection for Micom P442 relay to be shared and reviewed at Sakatpura.

(Action: RRVPNL; Time: Within 7 days)

2. Implementation of single phase auto-reclosing facility in feeders at 220kV RAPS

A to be discussed with OEM and discussion to be shared with reason for

implementation or non-implementation of auto-reclosing. (Action: RAPS-A,

NPCIL; Time: Within 7 days)

3. Reason for non-survival of unit on house load to be shared and modifications

done to avoid such incident which may lead to poisoning out of units also to be

shared. (Action: RAPS-A, NPCIL; Time: Within 7 days)

4. Time synchronization error as seen in RAPS-A Disturbance Records (DR) to be

rectified. (Action: RAPS-A, NPCIL; Time: Within 7 days)

5. RRVPNL shall submit the DR/EL, detailed report of the incident answering the

concerned points and shall also mention the corrective actions already taken/being

taken (with time line) to avoid such events (Action: RRVPNL; Time: Within

7days)

W. Tripping other than to be discussed in 35th PSC meeting:

For better reliability of power system each and every multiple element tripping

should be analyzed properly and remedial measures to be taken by utilities. Total

139 multiple element tripping event reported by NRLDC to RPC and constituents.

Preliminary reports of all these trippings are available at NRLDC website and

already send to concerned utilities within 24hrs of the incident.

Among 139 events, around 30 events would be discussed in 35th PSC meeting.

For rest events, utilities may kindly submit the details (DR/EL and detailed report

along with remedial measures) to NRLDC and NRPC at mail ID:

[email protected], [email protected], [email protected] and sep-

[email protected].

List of the all the multiple elements tripping event is available at NRPC website.

Member may kindly submit the detailed report of all the tripping along with

remedial measures report incorporating the pending action with time frame for

completion.

mailto:[email protected]




Annexure - I

List of participants for 35th Protection Sub- Committee

Sl.

No. Name Designation

Organisatio

n

Tel. No./

Mobile No. E-mail

1 Sh. Sunil Kumar SE T&C UPPTCL 9458096744

[email protected]

m

2 Sh.Arvind Kumar EE T&C UPPTCL 9458096639 [email protected]

3 Sh. Lakhi Chand EE T&C UPPTCL 9412738898 [email protected]

4 Sh. Kishori Lal SE T&C UPPTCL 9458096601 [email protected]

5 Sh. Navin Ranjan SE T&C UPPTCL 9412749817 [email protected]

6

Sh. Mohd. Waris

Khan SE T&C UPPTCL 9415311083 [email protected]

7 Sh. S R Rai DGM (EMD)

APCPL/IGS

TPP 9416600553 [email protected]

8 Sh. S K Das Mgr. (E) NHPC, Co. 9717786721 [email protected]

9 Sh. B.L. Yadav AGM NTPC 9650993044 [email protected]

10

Sh. Sandeep

Gupta SME(E) NPCIL 9413356564

[email protected].

in

11

Sh. Sanjay

Kumar SETE(E&I) NPCIL 9412768003

[email protected].

in

12 Sh. P. Dhariwal SE (EM) RRVUNL 9414049718 [email protected]

13

Sh. Ratnesh

Kumar EE T&C NRPC 9811101805 [email protected]

15 Sh. Ankit Gupta विं असियिंता उ क्ष ेिा पे्र के 9560270520 [email protected]

16 Sh. Nitin yadav Dy. Mgr. NRLDC 9560050257 [email protected]

17 Sh. A K Gupta AEE RVPN 9414061096 [email protected]

18

Sh. R. C.

Mahawar XEN RVPN 9413384026

[email protected]

o.in

19 Sh. Mohd. Zia AGM (OS) NTPCL 9415005883 [email protected]

20 Sh. Rajat Sharma AEE HPSEBL 9418080445 [email protected]

21

Sh. K S

Chambrial Addl. SE HPSEBL 9418457416

kschambrial1960@gmai

l.com

22

Sh. P.B.

Venkatesh

AGM

(Comml) NTPC 9650990226 [email protected]

23

Sh. Deepak

Bhavdwj XEN HVPN 9315315640

[email protected]

n

24

Sh. Md. Raghib

Hasan Sr. Manager NTPC 9650990611 [email protected]

25 Er. PK Verma SE HVPN 9315353650 [email protected]

26

Sh. Sukhginder

Singh Visk AEE PSTCL 9646162144

srxen-

[email protected]

27 Sh. R K Chandan

तनदेशक पी एविं ी BBMB 9417202059 [email protected]

28

Sh. Rajender

Singh Redhu िं तनदेशक BBMB 9466121202

[email protected]

m

29 Sh. Salau Deen AE(E) HVPNL 9354307677

[email protected]

rg.in






































30 Sh. Hitesh Kumar DGM (T) DTL 9999533662

hiteshkumar.dtl@gmail.

com

31 Sh. BL Gujar Manager Prot. DTL 9999533985 [email protected]

32 Sh. Paritosh Joshi Mgr(T) Prot. DTL 9999533933

paritoshjoshi2013@gma

il.com

33 Sh. Vikas Saxena President (PS) LPGCL 9971200857 [email protected]

34

Sh. Praveen

Kumar Manager Prot.

POWERGR

ID NR-II 9419245474

mr.praveenkumar@pow

ergridindia.com

35 Sh H. K. Chawla DGM

NRLDC

POSOCO 9650074803

[email protected]

m

36

Sh. Mahendra

Singh Hada

Chief

Manager

POWERGR

ID NR-I 9650555997

mshada@powergridindi

a.com

37 Sh. Nitin Verma Manager

POWERGR

ID NR-II 8005499952

nverma@powergridindia

.com

38 Sh. Anil Kumar XEN

PTPS/

HPGCL 9355084435 [email protected]

39

Sh. S.S.S.

Laxman Rao Manager THDCIL 9557735777

[email protected]

m

40

Sh. Amandeep

Singh ASE BBMB 9478200223 [email protected]

41

Sh. Abhishek

Gautam Sr. Engineer NLDC 9419260635 [email protected]

42

Sh. Aman

Gautam Engineer NLDC 9650277732 [email protected]

43 Sh. Rahul Shukla Dy. Mgr.

NLDC-

POSOCO 9650555388 [email protected]

44

Sh. Shashank

Tyagi Dy. Mgr. NRLDC 9599441243

[email protected]

m

45 Sh. Amit Gupta Dy. Mgr. NRLDC 8800690954 [email protected]

46 Sh. KNM Rao

Chief

Manager NRPC 9717296928

[email protected]

m



























Annexure-IV

S.No Constituent/ Utility

Nomination

Name Designation Address Ph. (O) /Mob. No. 1.

SJVNL

1.Sh. Prakash Chand

Manager (E)

NJHPS, Jhakri,Distt-Shimla, HP 01782-275140

2.Sh. Pintu Das Dy.Manager (E)

NJHPS, Jhakri,Distt-Shimla, HP 01782-275140

2.

DTL

1.Sh.Samba Siva Rao

GM (T) 220 kV Grid S/stn Bldg., Park Street, Delhi-1

011-23369008

2.Sh.Gaurav Gangawar

AM (T) Prot. 220 kV Grid S/stn Bldg., Park Street, Delhi-1

011-23369008

3.

POWERGRID

1.Sh. Y.S. Rana Sr. Engr.

POWERGRID, Moga

09501102085

2.Sh. Subhas Kumar

Sr. Engr.

POWERGRID, Hisar

09729872353

3. Sh. Ajay Gola Sr. Engr. NR-I HQ, New Delhi 09899555175

4. NTPC 1.Sh. B.L.Yadav AGM (OS) 09650993044 5.

PSTCL

1.Sh. Sandeep Verma

Sr. XEN, Protection

PSTCL, Patiala 09646118375

2.Sh. Shiv Kumar Asst. EXN, Protection

PSTCL, Jalandhar 09646118315

6. HVPNL 1.Sh. Y.S. Gulia Executive Engineer

HVPNL, M&P, Panipat 09354194830

7 RRVPNL 1. Sh.Jyotirma Jaiminy

AEN-III (C&M) 400 kV GSS, Heerapura 09413382408

2. Sh. Vijay Pal Yadav

AEN (Prot.)

RRVPNL, Alwar 09414061407

8 UPPTCL 1.Sh. D.K Acharya

Advisor to Director (Op) UPPTCL

Shakti Bhawan Extn (11th Floor) 14, Ashok Marg, Lucknow-226001

Ph.(O) –Director (Op) office 0522-2287833 Fax- 0522-2286476

2.Sh. Kavindra Singh

Advisor to CE (TW), Meerut UPPTCL

9 HPSEBL 1. Sh. Sat Pal Jamwal

Exe.Engg.

Protection & Testing Division, HPSEB Ltd. Kangra (HP)

09418122067 Telefax- 01892-264519

2. Sh. Dharam Singh Rana

Asst. Engg. Protection & Testing Division, HPSEB Ltd. Kangra (HP)

09418017213 Telefax- 01892-264519

10 PTCUL 1.Anupum Singh Exe.Engg.

T&C

2. Asim Beg Asst. Engg.

T&C

11 NPCIL 1. Sh. N. K. Pushpakar

Maintenance Superintendent NAPS, or his nominee

Plant Site, Narora, Bulandshahar Distt. UP-202397

(5734) (O) 222167 (R) 222228 M-09412768002 e-mail- [email protected]

2. Sh. Virender Yadav

RAPS-A Rawatbhata Rajasthan Site, P.O. Anushakti, via: Kota, Rajasthan-323303

M- 09413358024

3. Sh. Sanjay Jhamtani

RAPS-B Rawatbhata Rajasthan Site, P.O. Anushakti, via: Kota, Rajasthan-323303

M- 09413356912

4. Sh. Randhir Misra

RAPS-C Rawatbhata Rajasthan Site, P.O. Anushakti, via: Kota, Rajasthan-323303

M- 09413358237

Annexure - II

----------------------

12 RRVPNL 1. Sh. Jyotimay Jaiminy

AEn-III (O&M) 400 kV GSS Heerapura, Jaipur 09413382408

2. Vijay Pal Yadav AEn(Prot.) RRVPNL, Alwar 09414061407

13 Rosa Power Supply Co. Ltd.

1. Sh. N. Kishore Kumar

DGM Rosa Power Supply Co.Ltd., Hardoi Road, Service Building, Rosa Shahajahanpur-242406

05842-306675/09389495241

2.Sh. Gaurav Gupta Sr. Manager Rosa Power Supply Co.Ltd., Hardoi Road, Service Building, Rosa Shahajahanpur-242407

05842306789/09369076402

14 NHPC

Sh. Amitabh Jha Sr. Manager (E)

Uri Power Station, Baramullah, J&K

Sh. P. K. Das Manager (E) Baira Siul Power Station, Chamba, HP

15 UJVN Limited

1. Sh. Manoj Rawat A.E. Dakpathar, Distt: Dehradun 09456590406

2. Sh. Anoop Deepak

A.E. Galogi, Distt: Dehradun 09456590173

18-ए, शहीद जीत स िंह मार्ग, कटवारिया िाय, नई ददल्ली- 110016 फोन:011-26967842 फेक् : 011-26865206 ई-मेल: [email protected] वेब ाईट: www.nrpc.gov.in

18-A, Shaheed Jeet Singh Marg, Katwaria Sarai, New Delhi-110016 Phone: 011-26967842 Fax: 011-26865206 e- mail: [email protected] Website: www.nrpc.gov.in

Annex-III

List of members of Protection Analysis Sub-Group (PSAG)

Sl.

No.

Organisation Nominated

Officer

Contact Details

1. NRPC

Secretariat

Sh. B S Meena +91-8750251805

2. NRLDC Sh. Nitin

Yadav

+91-9560050257

[email protected]

3. PGCIL, NR-1 Sh. M S Hada +91-9650555997

[email protected]

4. PGCIL, NR-2 Sh Praveen

Kumar

+91-9501102054

[email protected]

5. BBMB Sh. Sunil

Shivaj

+91-9728107866

[email protected]

6. DTL Sh. B L Gujar +91-9999533985

7. UPPTCL

8. NTPC, NR Sh. Md. Zia +91-9415005883

9. NTPC, NCR Sh. B L Yadav +91-9650993044

10. NPCIL Sh. Sanjay

Jamtani

+91-9413356912

11. HVPNL Sh. R N Mishra +91-9312712754

[email protected],

[email protected]

12. RVPNL Sh. R C

Mahavar

+91-9413384026

[email protected]

13. PSTCL Sh. Rajbir

Walia

+91-9646118223

14. PTCUL Sh. Anupam

Singh

+91-7088117919

15. HPSEB Sh. Rajender

Kumar Singh

+91-9418225566

16. NHPC Sh. S K Das +91-9717786721

17. SJVNL Sh. Pintu Das

Sh. Prakash

Chand

+91-9418475284

+91- 9418492085










18. Adani Power Sh. Sanjay

Bhatt

+91-9099005221

[email protected]

19. PSPCL

20. HPGCL Sh. Raman

Sobti, (PTPS,

Panipat)

Sh. Jitender

Kumar,

(DCRTPP,

Yamunanagar)

Sh. Vineet

Mishra,

(RGTPP,

Khedar)

9355084410

[email protected]

21. UPRVUNL Mr. Shekh

Salim

9415900086

[email protected]

22. IPGCL Mr. Arif

Rahman

Mr. Satyendra

Prakash

+91- 9717694928

+91- 9717694813

23. UJVNL

24. PGCIL, NR-3 Sh D

Kushwaha

+91-9425409591

[email protected]




Annex-IV

Status of pending rectification of defects observed during BPA

Sl.

No.

Utility No. of sub-

stations

covered

under

BPA

Expected

Completion

Remarks

1 UPPTCL 21 - Representative of UPPTCL informed

that in 220 kV stations, auto recloser

deficiency due to PLCC issue is

remaining rest all have been rectified.

Order has been placed for PLCC and

deficiency will be rectified once the

equipments are supplied.

2 UPRVUNL 4 - Obra ’A’ – including rectification of time

synchronization & BBP, PLCC (to be

installed by UPPTCL). To be completed

by November, 2016.

Harduaganj – to be completed by March,

2017

Status could not be updated as there

was no representation from UPRVUNL

in the last 03 (33rd PSC, 34th PSC and

35th PSC) meetings.

3 HPSEB Ltd. 1 October 2017 • Out of 12 deficiencies observed, 8

already rectified.

• 1 no. deficiency to be rectified by

March 2017 and

• 3 others by October 2017.

4 UJVNL 1 December, 2016 Breaker for 220 kV Khodri-I &II needs to

be replaced. Expected date as intimated by

SLDC Uttarakhand in 127th OCC meeting

was 31.12.2016.


was no representation from UJVNL in

the meetings.

5 PDD, J&K 3 Status of

progress is not

submitted.

Target

completion not

known.

As informed during 33rd NRPC meeting

that deficiencies where procurement was

not involved had been rectified and other

works where procurement is involved are

yet to be taken up. PDD J&K informed

that they have submitted the proposal for

PSDF funding and deficiencies will be

rectified when fund will be disbursed

from PSDF.

As informed by PSTCL defects at 220kV

Sarna-Udhampur line, pertains to PDD,

J&K.


was no representation from PDD J&K

in the meetings.

Annex-V

Protection audit of intra-state system/balance system not covered in Basic

Protection Audit

Utility Third

party

protecti

on audit

carried

out by

No. of sub-

stations

covered/

expected to

be covered

Status of

Audit

Status of

Report

Status of

submission of

action Plan for

rectification of

deficiencies

RRVPNL,

RRVUNL

CPRI RRVPNL-39

RRVUNL-5

Completed Submitted RRVPNL- Lead

Acid Batteries have

been procured and

installed.

RRVUNL- Action

Plan submitted.

BBMB -do- 20 Completed Submitted The action to

attend the

deficiencies

observed in the

audit is underway.

PSTCL,

PSPCL

-do- PSTCL-22

PSPCL-3

Completed Not submitted Representative of

PSTCL informed

that Report on

CPRI Audit

already submitted

and emailed.

UPRVUNL -do- 2 Completed Submitted Parichha TPS and

Panki TPS: All the

deficiencies are

likely to be rectified

by March, 2018

UPPTCL -do- 41 Completed Shall be

submitted after

receipt and

examination of

Report, same.

Action plan to be

submitted by

11.08.2017.

Utility Third

party

protecti

on audit

carried

out by

No. of sub-

stations

covered/

expected to

be covered

Status of

Audit

Status of

Report

Status of

submission of

action Plan for

rectification of

deficiencies

Rosa Power -do- 1 Completed Submitted Action Plan

submitted and the

deficiencies

observed rectified.

UJVNL -do- 2

(Chilla,

Chhibra)

Completed Submitted Action Plan not

submitted. No

representative was

present.

PDD J&K -do- 3

(Janipur,

Amargarh,

Hiranagar)

Completed Submitted Action Plan for

Heeranagar and

Amargarh not

submitted. No

representative was

present.

JSW -do- 1 Completed Submitted Rectification of

observation

complied

HPSEB

Ltd.,

-do- 6

(Uprela

Nangal, Giri

220 kV,

Jassore 220

kV, Baddi,

220 kV

Kangoo, 220

kV Kotla)

Completed Submitted Action Plan for 220

kV Kotla not yet

submitted.

Rectification of

observation partly

complied.

Rectification will be

completed by

October 2017

UT

Chandigarh

-do- 1

(Kishengarh)

Completed Submitted Not submitted. No

representative was

present.

Budhil

Power

-do- 1 Completed Submitted Not submitted. No

representative was

present.

Utility Third

party

protecti

on audit

carried

out by

No. of sub-

stations

covered/

expected to

be covered

Status of

Audit

Status of

Report

Status of

submission of

action Plan for

rectification of

deficiencies

HVPNL -do- 4 (Sector 72,

Gurgaon ;

Tepla;

Bastara; A-5,

Faridabad)

Completed Submitted To be rectified by

December 2017

DTL -do- 4

(Rohini;

Mehrauli;

Mundka;

Shalimar

Bagh)

Completed Submitted Action has already

been taken. Report

will be submitted.

PTCUL -do- 4

(Pantnagar,

Haridwar,

Kashipur,

Roorkee)

Completed Submitted Not submitted for

Haridwar,

Roorkee

Relays have been

delivered at the

site.

To be completed by

31st October, 2017

Annex-VI

Status of Bus bar Protection for Northern Region Constituents

State/

Constituent

TRANSC

O/GENC

O

Total no.

of S/S/

Sw.

yards

(220 kV

and

above)

No. of S/S/

Sw. yards

where Bus

bar

protection is

functioning

Remarks Action Plan

Delhi DTL 37 34 For 220 kV S/S

namely,

Gopalpur and

Kanjhawala is

being

planned.(Lodi

Road is GSS)

PO awarded to M/s

GE T&D India Ltd.

for the work of

Supply and ETC of

26nos. Bus Bar

Schemes in 400 and

220kV DTL

substations on

06.04.18.

Completion period

is 9 months.

Haryana HVPNL 56 39 17 nos. defective 1 done; next 14 by

June ,17 and other 2

in 2017-18, as

control cable was

not available.

HPGCL 03 03

Rajasthan RVPNL 133 46

(7 defective)

74 nos. Bus bar

Protection scheme

under

commissioning.

RVUNL 05 05

Himachal

Pradesh

HPSEB 08 04 At one s/s it was

working, 2 sub‐

station it was

defective.

04 nos.

commissioned and

for remaining 04

s/s to be done by

Oct 2017.

Punjab PSTCL 98(5 no

400 kV

s/s)

46(5 no. 400

kV s/s)

Work in progress

for BBPS

protection, 46/98

(220kV) 05/05

(400kV)

completed. Till then

reverse zone

protection time set

to 160 ms. For

remaining

substations, work

has been

undertaken by TS

organization and

will be completed

by 31.12.19. by TS

organization.

Procurement

process for BBPS

delayed due to re-

tendering twice by

Finance wing of

PSTCL. Re-

tendered again last

month and target

date is 31-12-19 &

PSDF funding

available. PLCC

work will also be

completed by 31-3-

19 as procurement

process is

underway.

PSPCL 03 03

J&K PDD 06 - The status for the

same could not be

ascertained as

representative

from PDD, J&K

was not present in

the meeting.

Uttarakhand PTCUL 10 09 Order placed for

01 defective.

Would be

completed by May

2017.

UJVNL - -

BBMB BBMB 23 20 Not required at

Dhulkote and

Jagadhari.

also for Sangrur,

Kurukshetra and

Delhi as no. of

feeders is less

than five. PSC

decided that it

needs to be

installed.

Sangrur-

commissioned

19.01.2016.

For Kurukshetra

and Delhi, LOI

has been issued on

27.06.18 &

material is likely

to be received by

March, 2019.

For Barnala it is to

be provided by

PSTCL as agreed in

PSC. PSTCL were

to commission it by

31.12.2016.

Uttar Pradesh UPPTCL 99 10 04 no. are

pending

For the remaining

stationed

procurement action

has been initiated.

UVUNL 05 -

POWERGRID PGCIL 55 55

Central

Generating

Stations

NTPC 11 11

NHPC 09 09

NPCIL 02 02

THDC 02 02

SJVNL 02 02

Northern Regional Load Despatch Centre

MoM for 35th PSC meeting

20/06/2018

1. Tripping events

A. Multiple Element tripping at 400/220kV Bikaner at 11:40hrs of 12th Sep 2017

Event category: GD-1

Generation loss: 221MW (As per Rajasthan report)

Loss of load: 214MW (As per Rajasthan report)

Data Summary received/available at NRLDC:

Description Reference Fault Info Remarks

Fault Clearance Time

PMU data 500ms

Phase of the fault PMU data R-phase

Description Utilities Status Remarks

Availability of Digital Data (SCADA Data)

Rajasthan Available

DR/EL Rajasthan Received After 24hrs

Preliminary Report Rajasthan Received After 24hrs

Detailed Report Rajasthan Not Received

Remedial action report pending

Description Clauses Utility Remarks

Violation of Clauses

1. IEGC 5.2.r & 5.9.6.c (VI) 2. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 4. CEA Grid Standard 3.1.e 5. CEA Transmission Planning Criteria

Rajasthan

1. DR/EL, Preliminary report didn’t provide within 24hrs 2. Detailed Report didn’t provide 3. Adequately Sectionalized and graded protective relaying system 4. Delayed Clearance of Fault

Based on above information description of the events is:

1. Single Line Diagram of Bikaner (Raj) station:

2. 400/220kV Bikaner station is connected with 400kV Bhadla D/C, 400kV

Sikar D/C, 400kV Merta S/C, 400kV Deedwana S/C, 400kV Suratgarh

TPS S/C. It also have 400/220kV 315MVA ICT-1&2, 50MVAr & 125MVAr

reactor. One and half breaker scheme at 400kV Bikaner.

3. 400kV Bikaner-Sikar D/C was not in service. (CoD after this incident)

4. The configuration of various 400kV feeders / equipments at the time of the

fault is given below:

• Dia 1:- 400kV Merta with 50MVA line reactor (Bus1) and 315MVA,

400/220kV Transformer (Bus2) & all three CBs i.e. Bus1, Tie &

Bus2 were closed.

• Dia2:- 400kV STPS line (Bus1) and 50MVAR Bus reactor (Bus 2) &

all three CBs i.e. Bus1, Tie & Bus2 were closed.

• Dia3:- No line or equipment. (Future)


• Dia5:- 400kV SCTPS2 (Future) (Bus1) and 400kV Deedwana (Bus2)

& all three CBs i.e. Bus1, Tie & Bus2 were closed.


• Dia7:- 400kV Bhadla 1 (Bus1) and 125MVAR Bus Reactor (Work in

progress) (Bus2) & only Bus1 CB was closed.

• Dia8:- 400kV Bhadla 2 (Bus1) and Future (Bus2) & only Bus1 CB

was closed.

5. Name of the tripped elements are as below:

• 400kV Bikaner-Merta

• 400kV Bikaner-Suratgarh

• 400kV Bikaner-Bhadla D/C

• 400kv Bikaner-Deedwana

• 400/220kV 315MVA ICT-1 & 2

6. A bus fault developed on 400kV Bus 1 of 400/220 kV Bikaner station at

11:40:11 hours due to the breaking of Blue - phase IPV tube between

Main Circuit Breaker & Current Transformer from CT end and falling on

the ground which resulted in bus fault for 400kV bus-1 of Bikaner.

7. Due to above all CBs connected to bus-1 tripped.

8. However, due to delay in operation of bus bar protection, few lines also

tripped in zone-2 resulted in tripping of all lines emanating from Bikaner.

9. Sequence of Event as per Rajasthan report:

• As per DR of CUA of Bus Bar protection the fault was started at

11:40:11.089 hrs and suddenly the peak value current reached at

11:40:11:098 hrs. These fault current values taken from DR are as

➢ IC(diff.) = 10029A

➢ IN(diff.) = 8017A

➢ IC(bias) = 15249A

➢ IN(bias) = 15929A

But the Bus bar protection operated at 11:40:11.488 hrs and reset at

11:40:11.688 hrs i.e. picked up duration is 200msec. So, it took

approximately 400msec for the Bus Bar protection to operate after the

fault actually occurred in the system.

• As per DR of PUA of Bhadla 1, the fault started at 11:40:11.090 hrs but

the output relays of PUA were only picked up at 11:40:11.487 hrs &

reset at 11:40:11.687 (same time frame as of CUA). So, the line

tripped on Bus Bar protection with the Bus 1 CB poles opened at

11:40:11.521 hrs. DT command was sent to the other end but the

other end of the line (with 50MVAR line reactor) also observed

tripping of reactor with REF (64R) relay.

• As per DR of PUA of Bhadla 2 the output relays of PUA picked up at

11:40:11.489 hrs & reset at 11:40:11.688 hrs (almost same time frame

as of CUA). So, the line tripped on Bus bar protection with the

Bus1 CB poles opened at 11:40:11.522 hrs. DT command was

sent to the other end but the other end of the line (with 50MVAR

line reactor) also observed tripping of reactor with REF (64R)

relay and DT received reset at this end was observed at

11:40:12.211 hrs (as per event record).

• As per relay fault record of PUA of 400kV SCTPS2 the relay observed

the system disturbance at 11:40:11.087 hrs and the relay picked up at

11:40:11.487 hrs and reset at 11:40:11.687 hrs (same time frame as of

CUA) the Bus1 CB of DIA 5 also opened at Bus Bar operation at

11:40:11.522 hrs and the Tie & Bus2 CB remained closed but the

400kV Deedwana feeder running on Bus2 side observed tripping

on the remote end of Distance Protection Zone2 (As the Bus Bar

protection took approx. 400msec to operate after the fault has

occurred).The time frame shown in the DR has been corrected to

calculate the actual time of operation.

• As per relay fault record of PUA of 400kV STPS the relay observed the

system disturbance at 11:40:11.087 hrs and the relay picked up at

11:40:11.487 hrs and reset at 11:40:11.687 hrs (same time frame as of

CUA) the Bus1 CB of STPS line opened at Bus Bar operation at

11:40:11.522 hrs and the Tie & Bus2 CB remained closed but the

remote end of the STPS line observed tripping of Distance

Protection Zone2 (As the Bus Bar protection took approx. 400msec to

operate after the fault has occurred).

• As per DR record of 50MVAR line reactor REF(64R) relay of 400kV

Merta line, REF relay observed the system disturbance at

11:40:11.087 hrs as the I sensitive current started increasing from this

moment and the relay picked up at 11:40:11.119 hrs and reset at

11:40:11.188 hrs. As the tripping was observed on REF relay so

both the Bus 1 & Tie CB were opened at 11:40:11.188 hrs. As the

400kV Merta line was already in the opened condition at the time

when Bus Bar protection operated so no Bus bar tripping

observed on this line.

10. Conclusion as per Rajasthan report:

• The Bus Bar protection operated at 400msec delay after sensing the

disturbance.

• Four out of five CBs connected on Bus1 were tripped on operation of

Bus Bar protection.

• 400kV Merta line did not trip on Bus Bar protection as the same was

already tripped due to the operation of line reactor REF relay.

• 400kV Suratgarh TPS and 400kV Deedwana lines opened at remote

end on distance protection zone2 due to the time of 400msec taken by

the Bus Bar protection to operate.

11. PMU plots:

12. As per PMU data:

• R-N fault occurred at 11:40:11.080hrs and cleared in 440msec.

13. Extract of Rajasthan report:

announciation Relay indicatoin announciation Relay indicatoin

1SE (T&C),

BIKANER

400 kV GSS,

BIKANER

400kV BKN-BHADLA

LINE112.09.17. 11:40

08:03/

14.09.17.

BUS BAR

PROTECTION

OPTD.

Bus Bar PUA optd,

Fault in Zone1, Trip

ABC, Start Element -

No; Fault alarms- No,

Relay Trip

time=203.0ms, DT

RECD. RX1 & RX2, DT

Send 85X1 & 85X2

DT RECD; DT

SEND; REF64R

OPTD

DT RECDRX1,RX2;

DT SEND 85S1 &

85S2; REACTOR

PROT. 64R(REF)

OPTD

C phase:-IPV TUBE BETWEEN MAIN CT &

MAIN CB BROKEN FROM CT END AND FALL

DOWN ON GROUND.

2SE (T&C),

BIKANER

400 kV GSS,

BIKANER

400kV BKN-BHADLA

LINE212.09.17. 11:40 13:05

BUS BAR

PROTECTION

OPTD.

Bus Bar PUA optd,




Relay Trip

time=203.0ms, DT

RECD. RX1 & RX2, DT

Send 85X1 & 85X2

DT RECD; DT

SEND; REF64R

OPTD

DT RECDRX1,RX2;

DT SEND 85S1 &

85S2; REACTOR

PROT. 64R(REF)

OPTD

3SE (T&C),

BIKANER

400 kV GSS,

BIKANER

400kV BKN- SCTPS2

(FUTURE LINE ONLY

CB CHARGED TO

COMPLETE THE DIA

WITH DEEDWANA

LINE)

12.09.17. 11:40 13:07

BUS BAR

PROTECTION

OPTD.

Bus Bar PUA optd,




Relay Trip

time=203.0ms.

NA NA

4SE (T&C),

BIKANER

400 kV GSS,

BIKANER

400kV BKN-STPS

LINE12.09.17. 11:40 13:36

BUS BAR

PROTECTION

OPTD.

Bus Bar PUA optd,




Relay Trip

time=203.0ms,

DP ZONE2

OPTD

Zone-2 , Y-phase,

Dist.prot.optd.,

Dist.142.7 Kms

5SE (T&C),

BIKANER

400 kV GSS,

BIKANER

400kV BKN-MERTA

LINE12.09.17. 11:40 13:01

REACTOR

REF 64R

OPTD, DT

SEND 85S1 &

85S2

Reactor REF(64R); Trip

Phase N; REF-Trip

Relay Trip Time-0.0s;

IN sensitive=42.93A;

DT SEND 85S1 & 85S2

_ _CB NOT TRIPPED AT MERTA END AS DT NOT

RECEIVED AT MERTA END..

6SE (T&C),

BIKANER

400 kV GSS,

BIKANER

BUS BAR

PROTECTION 87M112.09.17. 11:40 _

BUS BAR

PROTECTION

OPTD.

Start Phase C; 87BB

Trip; Fault Alarms-No;

Fault duration-3mS;

IA(CZ diff.)=85.64A;

IB(CZ diff.)=63.51A;

IC(CZ diff.)=3.902kA;

IN(CZ diff.)=3.258kA;

IA(CZ Bais)= 2.023A;

IB(CZ Bais)=2.933kA;

IC(CZ Bais)=7.512kA;

IN(CZ Bais)=8.840kA;

Fault in Zone1; Trip

Zone1;

NA NA

Time In Hrs. Relay Indications

ONE END OTHER ENDS.No

.

Name of

CircleName Of GSS

Name Of

Equipment/Line

Date Of

Tripping Tripping closingREMARKS

14. As per DR details:

• From bus bar CU-DR (at Bikaner) that BBP tripping occurred at

11:40:11.490hrs.

• From lines DR (at Bikaner end), it seems B-N fault occurred at

11:40:11.090hrs and lines finally tripped at 11:40:11.520hrs

15. SCADA Analog data and SoE:

Time Voltage Element Equipment Status Remarks

11:40:11.161 400kV BIKANER400 -14MER_T1 CB Open Main & tie breaker of 400kV Bikaner (end)-Merta line opened11:40:11.166 400kV BIKANER400 -13MERTA1 CB Open

11:40:11.399 400kV SURAT_THER -22BKNER CB Close Main & tie breaker of 400kV Suratgarh (end)-Bikaner closed11:40:11.400 400kV SURAT_THER -23TIE CB Close

11:40:11.439 400kV BHDLA_R -04BKNR2 CB Open Main & tie breaker of 400kV Bhadla (end)-Bikaner ckt-2 opened11:40:11.442 400kV BHDLA_R -05BKNR2 CB Open

11:40:11.521 400kV BIKANER400 -16BHADL2 CB Open Main breaker of 400kV Bhadla -Bikaner (end)-ckt-1&2 opened11:40:11.521 400kV BIKANER400 -17BHADL1 CB Open

11:40:11.522 400kV BIKANER400 -10SURTP CB OpenMain breaker of Suratgarh RS, Suratgarh-1&2 at Bikaner end

opened11:40:11.522 400kV BIKANER400 -04SURTP2 CB Open

11:40:11.522 400kV BIKANER400 -07SURTP1 CB Open

11:40:11.528 400kV BIKANER400 -20SIKAR2 CB Open Main Breaker of Sikar ckt-1&2 at Bikaner end11:40:11.529 400kV BIKANER400 -23SIKAR1 CB Open

11:40:11.571 400kV BHDLA_R -01BKNR1 CB Open Main & tie breaker of 400kV Bhadla (end)-Bikaner ckt-1 opened11:40:11.571 400kV BHDLA_R -02BKNR1 CB Open

16. As per SCADA details:

• 400kV Bikaner-Merta tripped from Merta end on REF protection.

• 400kV Bikaner-Suratgarh tripped from Suratgarh end in zone-2.

• 400kV Bikaner-Bhadla ckt-2 tripped from Bhadla end at

11:40:11.440hrs wheras ckt-1 tripped later on at 11:40:11.570hrs.

17. Rajasthan representative informed the following in the meeting:

• Main-I bus bar protection was defective and same has been restored. Main-II bus bar protection which was delayed operated at the time of incident, put out of service at 400 kV Bikaner (Raj).

• 400 kV Bikaner-Merta ckt tripped from Merta end due to tripping of Line Reactor on REF protection. After detailed investigation, reverse polarity in setting observed and same has been corrected. 400kV Bikaner-Bhadla ckt-1 & 2 also tripped due to tripping of line reactor on REF protection due to reverse polarity in REF (Restricted earth fault) setting.

• Bus Bar Protection didn’t send direct trip command however in case of tripping of line reactor DT (direct trip) received at 400 kV Bikaner end from remote end.

• Bus Bar Protection issue would be discussed with OeM and revert back.

18. Actions taken by Rajasthan as informed in the meeting:

• Reverse Polarity of REF protection at remote end line reactor of outgoing lines from Bikaner has been corrected.

• 400 kV Bus Bar Protection-II of Bikaner (Raj) has put out of service till visit of OeM engineer at Bikaner (Raj).

B. Multiple element tripping at 400/220kV Lucknow (UP) at 17:27hrs of 22nd

Sep 2017 and 17:23hrs of 25th Dec 2017


Generation loss:

Nil (22.09.2017, As per UP Report)


Loss of load:

220MW (22.09.2017, As per UP Report)

Nil MW (25.12.2017, As per UP Report)




PMU data 1720ms 22.09.2017

880ms and 80ms

25.12.2017

Phase of the fault PMU data

R-phase 19.11.2017

Y-N followed by R-N

01.01.2018



UP Not Available

22.09.2017

25.12.2017

DR/ EL UP

Received (After 24hrs)

22.09.2017


25.12.2017

Preliminary Report UP Received 22.09.2017

Received 25.12.2017

Detailed Report UP Received 22.09.2017

Received 25.12.2017



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3, 3.1.e 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 4. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines

UP

1. DR/EL within 24hrs 2. Correct operation of Protection System 3. Adequately Sectionalized and graded protective relaying system


1. Connectivity Diagram:

a. 400/220kV Lucknow(UP) has following connections:

• 400kV Lucknow-Singrauli S/C

• 400kV Lucknow-Lucknow (PG) S/C

• 400kV Lucknow-Bareilly (PG) S/C

• 400kV Lucknow-Unnao S/C

• 400/220kV 315MVA ICT-1,2 & 3

• 220kV Lucknow-Gomti nagar

• 220kV Lucknow-Rai bareilly ckt

• 220kV Lucknow-Unnao ckt-1 & 2

• 220kV Lucknow-Hardoi Road

• 220/132kV two 200MVA and one 160MVA ICT

2. Event Description for 22nd Sep 2017 event:

a. SLD with tripped elements:

b. B phase to earth fault occurred on 220kV Sarojini nagar –

Raebareilly PG line. Line distance protection operated but circuit

breaker of line did not open which caused LBB to operate which

further tripped all elements connected to 220kV bus-I of Lucknow

(UP). As per event log and DR of bus bar protection relay, retrip

issued to Raebareilly breaker after 101ms and CBF operated after

200ms.

c. Though trip was issued to 220kV bus coupler but its circuit breaker

also did not open due to which all elements connected to 220kV

bus-2 also tripped. 220kV Unnao-2 line tripped from Unnao end

and 315MVA 400/220kV ICT-2 on backup protection which fed fault

for about 600ms as seen from DR of 220kV bus bar relay. Tripping

of all elements caused blackout situation at 220kV substation

Sarojini nagar.

d. With the tripping of 315MVA 400/220kV ICT -2 on backup earth

fault protection, LBB on 400kV side of ICT operated erratically

which caused tripping of following elements connected on main

400kV bus A.

• 400kV Sarojini nagar – Unnao line

• 400kV Sarojini nagar - Lucknow PG line

• 400kV Bus coupler

e. Tripped Element and respective restoration time:

f. PMU data of frequency, df/dt and phase voltages:

g. SCADA SoE data:

Time (in hrs) Station Voltage Element Device Status

17:27:32,306 LUCK2_UP 220kV E_02(T2) CB Open

17:27:32,313 LUCK2_UP 220kV E_82(UNNAO-1) CB Open

17:27:32,314 LUCK2_UP 220kV E_83(HRDOI) CB Open

17:27:32,323 LUCK1_UP 400kV F_07(T1) CB Open



17:27:32,338 LUCK2_UP 220kV E_87(GOMTI) CB Open

17:27:32,341 LUCK2_UP 132kV D_02(T2) CB Open



17:27:33,572 UNNAO_UP 220kV E_05(LUCK2-2) CB Open

17:27:33,667 LUCK1_UP 400kV F_05(UNNAO) CB Open

17:27:33,686 LUCK1_UP 400kV 01MBC CB Open

h. Probable SoE:

i. As per PMU data:

• R phase to earth fault occurred at 17:27:32.000hrs and cleared

in 1720msec.

j. As per SCADA data:

• It seems 220kV LBB protection operated.

• It seems LBB of 400kV CB of 400/220kV ICT-2 operated after

~1.5sec of fault

k. Remedial Action taken:

• At 220kV substation Sarojini nagar, problem in trip circuit of B-

phase to trip coil of breaker was found which was rectified. In

220kV Bus coupler breaker, problem was detected in control

circuit of breaker which was set right.

• At 400kV substation Sarojini nagar, LBB relay of SEL was

checked and problem was detected in software logic of LBB

(Threshold current detection bit dropout time was set at 0.25

seconds instead of zero which resulted operation of LBB even

after timely tripping of transformer). The same was set right

after consultation with SEL engineer

l. Lesson learnt reported by UP: There are numerous settings in

numerical relays which are not very much clear to service

engineers being deputed at site from relay manufacturers. Service

engineers must be properly trained at manufacturer’s end

particularly for bus bar protection relays and transformer protection

relays

m. Preliminary report, DR/EL and Report has received from UPPTCL.

3. Event Description for 25th Dec 2017 event:

a. In antecedent condition, 400kV Bus-2 of Lucknow (UP) was under

shutdown for replacement of Bus-2 Pantograph isolator of 400kV

Sarojini Nagar- Lucknow (PG) line. This line was charged through

transfer bus. Other 400kV elements charged through 400kV Bus-1

at Lucknow (UP).

b. SLD and tripped elements status:

c. In antecedent condition, 400kV Bus-2 of Lucknow (UP) (Sarojini

Nagar) was under shutdown since 18th Dec 2017, for replacement

of Bus-2 Pantograph isolator of 400kV Sarojini Nagar- Lucknow

(PG) line. 400kV Lucknow (UP)-Lucknow (PG) line was charged

through transfer bus. Other 400kV elements and ICTs were

charged through 400kV Bus-1 at Lucknow (UP). Bay was tied

through local earthling.

d. Bus-1 isolator of Lucknow (UP)-Lucknow (PG) ckt got operated due

to mixing of DC supply in control wiring of bus-1 & II.

e. The above resulted in bus fault at 400kV bus-1 of Lucknow (UP)

and tripping of all 400kV Feeders/ICTs at Lucknow (UP).

f. Following element connected to 400kV bus-1 0f Lucknow (UP)

tripped:

• 400kV Sarojini Nagar-Unnao

• 400kV Sarojini Nagar-Lucknow PG

• 400kV Sarojini Nagar-Bareilly (PG)

• 400kV Sarojini Nagar-Singrauli

• 400/220kV 315MVA ICT-1 & 2 at Sarojini Nagar

g. PMU plots of frequency, df/dt and phase voltage:

h. SCADA SoE data:


17:23:26,565 LUCK1_UP 400kV 02TBC CB Open

17:23:26,606 UNNAO_UP 400kV F_01(LUCK1) CB Open

17:23:26,805 GOMTI_UP 220kV E_04(LUCK2) CB Open

17:23:27,022 LUCK1_UP 400kV F_06(BRELY) CB Open

17:23:27,075 BAREILLY 400kV 6LUCK1 CB Open

17:23:27,081 BAREILLY 400kV 5CBG1LU1 CB Open





17:23:27,634 SINGRAULI 400kV 01LUCK1 CB Close

17:23:27,670 UNNAO_UP 400kV F_01(LUCK1) CB Close

17:23:30,568 LUCK1_UP 400kV F_05(UNNAO) CB Open

17:23:31,057 SINGRAULI 400kV 01LUCK1 CB Open

i. Probable SoE:

j. Extract of DR of 400kV Lucknow (PG) end-Lucknow (UP) ckt:

k. As per PMU data:

• Y-N fault occurred at 17:23:26.480hrs and cleared in 880msec.

• R-N fault occurred again at 17:23:30.520hrs and cleared in

80msec

l. As per UP details:

m. Restoration time:

n. Remedial measures taken: Mixing of DC supply in old wiring of

pantograph isolator was detected and set right on 27.12.2017.

SLDC has taken this incident with great concern and sought

appropriate action in this regard from higher authorities of UP

Power Transmission Corporation Ltd, so that reoccurrence of such

incident be avoided in future, all over U.P. state.

o. Preliminary Report, DR/EL and detailed report has received from

UPPTCL.

Points for Discussion:

1. Event on 22nd Sep 2017:

a. Reason for non-opening of 220kV Unnao ckt from Lucknow end on

LBB protection operation of bus coupler to be shared.

b. LBB protection operation for bus coupler needs to be reviewed as

tripping didn’t occur in the breaker connected to that bus. Fault fed

for 1.5second and ICTs finally tripped on back up over current earth

fault protection.

c. LBB protection operation of 400/220kV ICT-2 after ~1.5sec of fault

to be explained.

d. Three simultaneous LBB operations need to be reviewed

thoroughly.

e. Exact sequence of events in view of cause of event; protection



f. Time synchronization error for 220kV LBB/ Bus Bar Protection

numerical relays to be checked

2. Event on 25th Dec 2017:

a. Reason for delayed clearance of fault needs to be ascertained. In

case of operation of bus bar protection fault would be cleared within

100ms.

b. Reason for opening of 220kV Lucknow (UP)-Gomti nagar ckt to be

ascertained.

c. Tripping of other 400kV elements at Lucknow (UP) in interval of

msec to be explained.

d. Multiple closing/opening of 400kV Singrauli/Unnao ckts to be

explained.




No representative of South West (Lucknow (UP)) zone of UPPTCL was present

in the meeting.

MS, NRPC raised concern for absence of member of many NR utilities during the

meeting and suggested all the utilities to make sure its representation in the

meeting for fruitful discussion.

C. Multiple element tripping at 400/220kV Muzaffarnagar, Vishnuprayag at

12:02hrs of 09th Oct 2017 and 16:24hrs of 20th Dec 2017


Generation loss:


200MW (20.12.2017, As per UP report)

Loss of load:


Nil MW (20.12.2017, As per UP Report)




PMU data 440ms 09.10.2017

100ms 20.12.2017

Phase of the fault PMU data B-phase 09.10.2017

Y-phase 20.12.2017



UP Partial Available 09.10.2017

20.12.2017

DR/ EL UP

Partially Received (After 24hrs)

09.10.2017

Only Flag details (Within 24hrs)

20.12.2017

Preliminary Report UP


09.10.2017

Received 20.12.2017

Detailed Report UP Not Received 09.10.2017

Not Received 20.12.2017



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 3. 43.4.A & 43.4.D of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) CEA (Technical standard for connectivity to the Grid, Amendment Regulation 2013), part-II, B2

UP

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Correct operation of Protection System 4. Delayed Clearance of fault 5. Adequately Sectionalized and graded protective relaying system



2. Event Description for 07th Nov 2017 event:

a. 400kV Muzaffarnagar (UP) has following connections with the grid:

• 400kV Muzaffarnagar-Meerut S/C

• 400kV Muzaffarnagar-Vishnu Prayag S/C

• 400kV Muzaffarnagar-Alaknanda (Srinagar) S/C

• 400kV Muzaffarnagar-Roorkee S/C

• 400kV Muzaffarnagar-Ataur S/C

• 400/220kV 315MVA ICT-1,2 & 3

b. In antecedent condition, emergency shutdown of 400kV Bus-A of

Muzaffarnagar (UP) was allowed to attend the hotspot at 400k line

connected with 400kV Bus-A.

c. While transferring 400kV Muzaffarnagar-Roorkee line from Main

Bus to Transfer bus, earth switch of line isolator (Blue-phase) was

wrongly operated, leads to tripping elements connected at

Muzaffarnagar station on bus bar protection.

d. It leads to evacuation constraints for Vishnuprayag, Alaknanda

generation. Generation also tripped and finally after offloading of

connected 400kV lines, these lines tripped on over voltage.

e. Tripped Element and respective restoration time:

f. SCADA SoE data:


12:02:11,337 MUZA1_UP 400 95MBC CB Open

12:02:11,365 MUZA1_UP 400 F_91(RORKE) CB disturbe

12:02:11,382 MUZA1_UP 400 F_92(T3) CB Open

12:02:11,382 MUZA1_UP 400 F_97(MEERT-1) CB Open

12:02:11,382 MUZA1_UP 400 F_96(VISNU-2) CB Open

12:02:11,386 MUZA1_UP 400 F_94(VISNU-1) CB Open

12:02:11,426 MUZA1_UP 400 F_99(T2) CB Open

12:02:11,685 MUZA1_UP 400 F_93(MUR1N) CB Open

12:02:11,921 ATAUR_U 400 03MUZA1 CB Open

12:02:11,940 ROORKEE 400 2T1MU1 CB Open

12:02:11,941 ROORKEE 400 1MUZA1 CB Open

g. As per PMU data:

• B-N fault occurred at 12:02:11.520hrs and cleared in 400ms.

Fault occurred again in reclosing time and tripped again timely.

h. As per SCADA data:

• It seems Muzaffarnagar (UP) digital status signals are not time

synchronised.

i. As per UP report:

400KV

BUS BARSEL 487B

CP-BUS BAR Optd RP-B Ph,Z2,87 BTR, 96 ATUR,96 MEERUT(PG),96

VP,96 RKE, 96 SRN, 96 ICT1, 96 ICT2, 96 ICT3, 96

TBC, 96 BC

09.10.17

14:11

315MVA

ICT1

P643

P14D

P14NTripped on BUS BAR Protn.

09.10.17

14:12

240MVA

ICT2

P643

P14D

P14NTripped on BUS BAR Protn.

09.10.17

14:10

315MVA

ICT3Siprotech 7UT61 Tripped on BUS BAR Protn.

Vishnu

Pryag

SEL421

Micom P 444Tripped on BUS BAR Protn.

400 KV Muzaffar

NagarREL 316 REL521

CP-DT receive,RP-186R2,286R2,28Y2, 286B2,

186Y2, 186B2 400 KV

Muzaffar

Nagar

AlaknandaSEL421

Micom P444Tripped on BUS BAR Protn.

Alaknanda400 KV Muzaffar

Nagar

micom P437

micom P442CP-DT receive ,RP-85Z1,85Z2,86A,86B,86AX,86BX

400 KV

Muzaffar

Nagar

AtaurMicom P444

REL670Tripped on BUS BAR Protn.

400 KV Ataur400 KV Muzaffar

Nagar

micom P444

REL670 CP-M1 M2 prot trip,RP-B,N,Z2,86A,86B

400 KV

Muzaffar

Nagar

MEERUT(PG)SEL421

SiprotecTripped on BUS BAR Protn.

MEERUT(PG)400 KV Muzaffar

Nagar

Siproptec

7SA611CP-DT receive,RP-86A,86B

400 KV

Muzaffar

Nagar

RoorkeeMicom P442

REL 670Tripped on BUS BAR Protn.

Roorkee400 KV Muzaffar

Nagar

Siprotech

REL 670RP-B,N,Z2,RTT-354ms

09/10/17

12:10220 KV Nara

Busbar

Protection

Operated

CSC 150

Main Bus -I Busbar Protection Operated. Differential

Start Up. 194 ms BZ1 Diff. Op: Ph A

Trip Bay 2 (Meerut PG line), 96-2

Trip Bay 3 (Jansath line), 96-3

Trip Bay 4 (Roorkee line), 96-4

Trip Bay 5 (Muzaffarnagar line), 96-5

Trip Bay 6 (160 MVA T/F-I), 96-6

Trip Bay 7 (160 MVA-II) 96-7 (TBC)

96-1

…

As 400 KV Bus Bar protection operated

at 400 KV S/S Muzaffernagar, heavy

load started flowing through 400 KV

Nara-Meerut (PG) line resulted in to CT

R Phase jumper form line side came

out and touch with other side of CT

making 220 KV Bus Bar fault and

ultimately tripping of all 220 KV lines

and transformers there.

09/10/17

12:10

09/10/17

15:45Nara

(T) 81

Meerut (PG)… Tripped on Busbar Protection … …

09/10/17

12:10

09/10/17

16:20Nara

(T) 82

Jansath… Tripped on Busbar Protection … …

09/10/17

12:10

09/10/17

15:50Nara

(T) 83

Roorkee… Tripped on Busbar Protection … …

09/10/17

12:10

09/10/17

14:17Nara

(T) 84

Muzaffernagar… Tripped on Busbar Protection … …

09/10/17

12:10

09/10/17

14:19Nara

(T) 886

160 MVA T/F-I… Tripped on Busbar Protection … …

09/10/17

12:10

09/10/17

14:19Nara

(T) 887

160 MVA T/F-II… Tripped on Busbar Protection … …

09.10.17

13:01

09.10.17

13:32

2

F/L,

D/R,

S/R,

Analysis with discrepancy in flags if any

109.10.17

12:02:11

Emergency Shut down was taken for

attending Red hot point on B ph of

400KV Bus -I pantograph isolator of

400KV Muzaffarnagar - Roorkee line.

All 400 KV Lines & ICTs were shifted

from main Bus-I to main Bus-II and

Roorkee line was transfred to 400 KV

transfer Bus coupler (CB90). R and B

phase of line isolators of 400 KV

Roorkee line opened but instead of

opening of B phase isolator, Earth link

of B phase operated due to manual

error by shift staff, causing 400 KV Bus

II fault and resulted in to operation of

400 KV Bus Bar protection, there by

tripping of all ICTs and 400 KV lines. All

400KV lines also tripped at remote

end.

09.10.17

13:35

09.10.17

13:44

400KV

Muzaffar

Nagar

400 KV

Vishnu Pryag

09.10.17

13:34

SI

NO

.

Tripping

Date/Time

Closing

Date/Time

Name of

Substation

C.B.No. with

Direction (Code)

Type of Relay

SchemeFlags & Indications Observed

j. Preliminary report, Flag details, DR/EL and Report has received

from UPPTCL. Remedial action taken report yet to be received.


a. 400kV Vishnuprayag has following connections with the grid:

• 400kV Vishnu Prayag-Alaknanda

• 400kV Vishnu Prayag-Muzaffarnagar

• 400V 100MW Unit-1,2,3 & 4

b. SLD of Vishnu Prayag HEP:

c. In antecedent Condition:

• Unit #1 at Vishnuprayag already under S/D since

09:49hrs/18.12.17.

• 400kV Bus-1 at Vishnuprayag was under S/D

(Vishnuprayag/UP may confirm the reason and time)

d. Following element connected to bus-2 tripped:

• 400kV Vishnuprayag-Alaknanda

• 400kV Vishnuprayag-Muzaffarnagar

• 400kV Unit #2, #4 at Vishnuprayag

e. At HEP Vishnu Prayag, Due to system mal function, 400 kV bus-

bar-2 Protection operated at 1624Hrs on 20.12.17. Circuits

connected on 400 kV bus of Vishnuprayag HEP tripped.

f. 400 kV Bus-bar-1 was taken into service after isolating 400 kV Bus-

bar-2 at 1630hrs on 20.12.17.

g. 400 kV VP (Vishnu Prayag)-MZN (Muzaffarnagar) line was charged

from MZN end at 1652 Hrs & CB at VP end was closed at 1653hrs

and Unit-3 was synchronized at 1705hrs on 20.12.17.

h. 400 kV VP-Srinagar line was charged from Srinagar end at 1903

Hrs & CB at VP end was closed at 1904hrs on 20.12.17. On

detailed inspection/checking no abnormality/discrepancy was found

i. PMU plots of frequency, df/dt and phase voltage:

j. SCADA SoE data:


16:23:38,776 MUZA1_UP 400kV F_94(VISNU-1) CB Open

16:23:39,297 ALKND_UP 400kV 09VSNPG2 CB disturbe

16:23:40,756 ALKND_UP 400kV 09VSNPG2 CB Open

k. As per PMU data:

• Y-N fault occurred at 16:23:38.880hrs and cleared within time in

80ms.

l. As per SCADA SoE data:

• It seems Muzaffarnagar (UP) digital status signals are not time

synchronized.

m. As per UP details:

1 2 3 4 5 6 7 8 9

20.12.17

16:24

20.12.17

16:30

Busbar Panel

(400KV HEP)

CP: 400 kV Bus 1/2 Bus bar Prot optd.

RP: 400 kV Bus bar-2 tripped.

96 L1, 96L2, 96 U1, 96 U2, 96 U4

20.12.17

16:24

20.12.17

16:53

400 kV VP-

MZN line

T-152L-1

/T-94

SEL-421

MICOM

REL-316

/REL-521

VP end:

CP: Nil

RP: Main-1: 400 kV Bus bar prot Optd.

Direct trip Send

MZN end:

CP: Direct trip CH-1/2 recd.

Gr. A/B trip relay optd.,

RP: 79B, 79LOX(A/R Lock out),

85LOX1(Direct trip channel -Ist, 85LOX2

(Direct trip channel -2nd,86A, 86B

20.12.17

16:24

20.12.17

19:04

400 kV VP-

SNGR line

VP end:

CP: Nil

RP: Main-1: 400 kV Bus bar prot Optd.

Direct trip Send

Srinagar end:

Not available

20.12.17

16:24

Unit-2

(400KV

HEP)

ESD

20.12.17

16:24

Unit-4

(400KV

HEP)

ESD

1

20.12.17

17:05

(Unit-3)

At HEP Vishnupryag, Due to system mal

function, 400 kV bus-bar-2 Protection

operated at 1624 Hrs on 20.12.17. Circuits

connected on 400 kV bus-bar -2 tripped

i.e.400 kV VP-MZN Line, 400 kV VP-

Srinagar line, running units 2 & 4 . Unit-1

was already under shut down since 0949

Hrs on 18.12.17.

400 kV Bus-bar-1 was taken into service

after isolating 400 kV Bus-bar-2 at 1630 hrs

on 20.12.17.

400 kV VP-MZN line was charged from

MZN end at 1652 Hrs & CB at VP end was

closed at 1653 Hrs and Unit-3 was

synchronised at 1705 Hrs on 20.12.17.

400 kV VP-Srinagar line was charged from

Srinagar end at 1903 Hrs & CB at VP end

was closed at 1904 Hrs on 20.12.17. On

detailed inspection/checking no

abnormality/discrepacy was found.

SL.

N0.

Tripping

Date

Closing

Date /

Time

Name of

Substation

C.B.No.

with

Direction

(Code)

Type of

Relay

Scheme

Flags & Indications ObservedF/L,

(KM)Analysis

n. EL from Vishnu Prayag HEP:

o. DR/EL and detailed report still awaited from UPPTCL.

UP representative informed the following in the meeting:

1. Event on 9th Oct 2017:

a. As informed, Emergency Shutdown was taken for attending Red hot point on B phase of 400 kV Bus -I Pantograph isolator of 400 kV Muzaffarnagar - Roorkee line. All 400 kV Lines & ICTs were shifted from main Bus-I to main Bus-II and Roorkee line was transferred to 400 kV transfer Bus coupler (CB90). R and B phase of line isolators of 400 kV Roorkee line opened but instead of opening of B phase isolator, earth link of B phase operated due to manual error by shift staff, causing 400 kV Bus II fault and resulted in to operation of 400kV Bus Bar protection, there by tripping of all ICTs and 400 kV lines. All 400 kV lines also tripped at remote end.

b. Bus-1 was already vacated for planned shutdown and earth switch of Bus-II side of 400 kV Muzaffarnagar - Roorkee line was closed by mistake. It resulted into bus fault for 400 kV Bus-2 of Muzaffarnagar (UP).

c. 400 kV Muzaffarnagar-Ataur line end to end testing has been done.

Counter is increasing


a. Bus Bar Protection at Vishnuprayag is REB-500 & DR extraction

cable is not available.

b. 400 kV Vishnuprayag bus -1 was under shutdown as two units

were running in antecedent condition. Both the buses at 400 kV

Vishnuprayag has segregated and each two units running on one

bus.

c. Details still awaited from Vishnuprayag also.

Actions taken by UP as informed in the meeting:

1. Event on 9th Oct 2017:

• A.E. (Operation) & A.E. (Maintenance) has been instructed that operation of any 400 kV element should be in their presence to avoid any manual error by shift staff.

• Proper training has been given to field staff for skill operation.

• It has been requested to S.E., SCADA & S.E., Microwave & Telecom vide letter no. 375/ETCC/MT dt. 25.06.18 to get time synchronized the digital status signal of 400 KV Muzaffarnagar.

• There is alarm on carrier cabinet of 400 kV Muzaffarnagar-Roorkee line. PGCIL may kindly check.

• 400 kV Muzaffarnagar-Ataur line end to end testing has been done. Counter is increasing.


• No action taken.

NRLDC raised concern about unreliable operation at 400 kV Vishnuprayag HEP

by segregating the both 400 kV buses.

D. Multiple element tripping at 400/220kV Talwandi Sabo TPS at 02:57hrs of

07th Nov 2017 and 07:13hrs of 12th Nov 2017


Generation loss:

600MW (07.11.2017, As per Punjab Report)

1100MW (12.11.2017, As per Punjab Report)

Loss of load:

Nil (07.11.2017, As per Punjab Report)

Nil (12.11.2017, As per Punjab Report)



Fault Clearance Time PMU data PMU data not available 07.11.2017

100ms 12.11.2017

Phase of the fault PMU data PMU data not available 07.11.2017

R-phase 12.11.2017



Punjab Available 07.11.2017

12.11.2017

DR/ EL Punjab Not Received 07.11.2017

Received (After 24hrs) 12.11.2017

Preliminary Report Punjab Not Received 07.11.2017

Received (After 24hrs) 12.11.2017

Detailed Report Punjab Not Received 07.11.2017

Partial Received 12.11.2017



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 3. CEA Grid Standard 15(3), 3.1.e 4. 43.4.A & 43.4.D of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) CEA (Technical standard for connectivity to the Grid, Amendment Regulation 2013), part-II, B2

Punjab

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Correct operation of Protection System 4. Adequately Sectionalized and graded protective relaying system


1. 400kV Talwandi Sabo TPS has following connections with the grid:

a. 400kV Talwandi Sabo-Muktsar D/C

b. 400kV Talwandi Sabo-Dhuri D/C

c. 400kV Talwandi Sabo-Moga

d. 400kV Talwandi Sabo-Nakodar

e. 400V 660MW Unit-1,2 & 3



a. Following lines was already out on fault since 06-Nov-17:

i. 400kV T.Sabo-Muktsar D/C

ii. 400kV Makhu-Muktsar D/C

iii. 400kV Makhu-Amritsar-1

b. Event based on available information:

c. Multiple lines/units tripped in Punjab during foggy weather.

d. At 02:57hrs, 400kV Talwandi Sabo-Nakodar ckt tripped, at the

same time unit-2 & 3 of Talwandi Sabo TPS also tripped.

e. At 02:57hrs, unit #2, #3 also tripped whereas unit #1 remained

synchronized.

f. Tripped Element:

i. 400kV Makhu-Amritsar-2 at 01:50hrs

ii. 400kV T.Sabo-Dhuri D/C at 01:54hrs

iii. 400kV T.Sabo-Nakodar at 02:57hrs

iv. Unit #2, #3 of T.Sabo at 02:57hrs

g. SCADA SoE data:

Time (in hrs) Station Voltage Element Device Status Remarks

01:50:28,156 AMRITSAR 400kV 17MA2TIE CB disturbe Makhu-2 tie

01:50:29,373 AMRITSAR 400kV 17MA2TIE CB Close Makhu-2 tie

01:50:29,406 AMRITSAR 400kV 1JALAN CB Open Jalandhar-1 main

01:50:29,416 AMRITSAR 400kV 7JALAN2 CB Open Jalandhar-2 main

01:50:29,440 AMRITSAR 400kV 17MA2TIE CB Open Makhu-2 tie

01:50:30 ,*** AMRITSAR 400kV 13MLRKT1 CB Open Malerkotla main

01:53:47,760 TALWANDI THER 400kV F_5 (K'DAM-2 BUS R CB disturbe Dhuri-1, U#2 Tie

01:53:47,763 TALWANDI THER 400kV F_4 (K'DAM-2 BUS-1) CB disturbe Dhuri-1 main

01:53:48,832 TALWANDI THER 400kV F_4 (K'DAM-2 BUS-1) CB Close Dhuri-1 main

01:53:48,835 TALWANDI THER 400kV F_5 (K'DAM-2 BUS R CB Close Dhuri-1, U#2 Tie

01:53:48,885 TALWANDI THER 400kV F_4 (K'DAM-2 BUS-1) CB Open Dhuri-1 main

01:53:48,900 TALWANDI THER 400kV F_5 (K'DAM-2 BUS R CB Open Dhuri-1, U#2 Tie

01:53:49,353 TALWANDI THER 400kV F_2 (K'DAM-1 JALAN CB disturbe Dhuri-2, U#1 Tie

01:53:49,354 TALWANDI THER 400kV F_3 (JALAN BUS-2) CB disturbe U#1 main

01:53:50,427 TALWANDI THER 400kV F_2 (K'DAM-1 JALAN CB Close Dhuri-2, U#1 Tie

01:53:50,431 TALWANDI THER 400kV F_3 (JALAN BUS-2) CB Close U#1 main

01:53:50,495 TALWANDI THER 400kV F_2 (K'DAM-1 JALAN CB Open Dhuri-2, U#1 Tie


01:53:50,496 TALWANDI THER 400kV F_3 (JALAN BUS-2) CB Open U#1 main

01:53:51,371 DHURI 400KV 400kV F_5 (K'DAM-2 BUS R CB Open

02:56:15,069 TALWANDI THER 400kV F_10 (MLERK-1 BUS-1) CB Close Moga main

02:57:14,440 TALWANDI THER 400kV F_6 (BUS REACTOR BUS CB Open U#2 main

02:57:49,120 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB disturbe Nakodar, ST#1 Tie

02:57:49,143 TALWANDI THER 400kV F_7 (PATIA BUS-1) CB Open Nakodar main

02:57:49,171 TALWANDI THER 400kV F_10 (MLERK-1 BUS-1) CB Open Moga main

02:57:49,273 NAKODAR 400KV 400kV 1TLDTP CB disturbe T.Sabo main

02:57:50,196 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB Close Nakodar, ST#1 Tie

02:57:50,256 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB Open Nakodar, ST#1 Tie

02:57:50,343 NAKODAR 400KV 400kV 1TLDTP CB Close T.Sabo main

02:57:50,390 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB disturbe T.Sabo, ICT#1 Tie

02:57:50,414 NAKODAR 400KV 400kV 1TLDTP CB Open T.Sabo main

02:57:52,360 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB Open T.Sabo, ICT#1 Tie

02:58:01,645 TALWANDI THER 400kV F_9 (XFMR-1 BUS-2) CB Open ST#1 main

02:58:01,647 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB Open Nakodar, ST#1 Tie

h. As per PMU data:

• PMU data was unavailable at NRLDC.

i. As per SCADA data:

• It seems 400kV Amritsar-Makhu-2, 400kV T. Sabo-Dhuri D/C

and 400kV T. Sabo-Nakodar tripped after unsuccessful auto-

reclosing.

• As per SCADA data it seems, 400kV Talwandi Sabo unit-1

didn’t trip and unit-3 tripped after some time of unit-2.

j. Preliminary report, Flag details, DR/EL and detailed report has

received from Punjab.

k. As per Detailed report:


a. 400kV T. Sabo-Mukatsar D/C line was already out on fault.

b. Event based on available information:

c. At 06:45hrs, 400kV T. Sabo-Nakodar tripped on R-N fault.

d. At 07:13hrs, 400kV T. Sabo-Moga tripped on Y-N fault. At the same

time, 400kV Dhuri-T. Sabo-2 tripped because of wrong mapping of

A/R signal (from pickup instead of Z-1) and subsequent SOTF

command.

e. PMU plots of frequency, df/dt and phase voltage:

f. At 06:45hrs, 400kV Talwandi Sabo-Nakodar ckt tripped.

g. Tripped Element at 07:13hrs:

i. 400kV T.Sabo-Dhuri-2

ii. 400kV T. Sabo-Moga

iii. Unit #1, #2, #3 at T. Sabo

h. SCADA SoE data:


06:45:45,009 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB disturbe Nakodar Tie

06:45:45,032 TALWANDI THER 400kV F_7 (PATIA BUS-1) CB Open Nakodar main

06:45:45,047 TALWANDI THER 400kV F_10 (MLERK-1 BUS-1) CB Open

06:45:45,153 NAKODAR 400KV 400kV 1TLDTP CB disturbe T,Sabo main

06:45:45,160 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB disturbe T.sabo, ICT-1 tie

06:45:46,085 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB Close Nakodar Tie

06:45:46,145 TALWANDI THER 400kV F_8 (PATIA-1 XFMR-1 CB Open Nakodar Tie

06:45:46,440 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB Close T.sabo, ICT-1 tie

06:45:46,484 NAKODAR 400KV 400kV 1TLDTP CB Open T,Sabo main

06:45:46,500 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB disturbe T.sabo, ICT-1 tie


06:45:48,460 NAKODAR 400KV 400kV F_2 (K'DAM-1 JALAN CB Open T.sabo, ICT-1 tie

06:46:29,000 TALWANDI THER 400kV F_10 (MLERK-1 BUS-1) CB Close Moga main



07:13:31,846 TALWANDI THER 400kV F_11 (MLERK-1 XFMR- CB disturbe Moga tie

07:13:32,915 TALWANDI THER 400kV F_11 (MLERK-1 XFMR- CB Close Moga tie

07:13:33,006 TALWANDI THER 400kV F_11 (MLERK-1 XFMR- CB Open Moga tie


07:13:38,137 TALWANDI THER 400kV F_3 (JALAN BUS-2) CB Open U#1 main

07:13:38,137 TALWANDI THER 400kV F_4 (K'DAM-2 BUS-1) CB Open Dhuri-1 main

07:13:38,137 TALWANDI THER 400kV F_10 (MLERK-1 BUS-1) CB Open Moga main

07:13:38,137 TALWANDI THER 400kV F_11 (MLERK-1 XFMR- CB Open Moga tie


07:14:06,702 TALWANDI THER 400kV F_6 (BUS REACTOR BUS CB Open U#2 main

07:14:06,704 TALWANDI THER 400kV F_5 (K'DAM-2 BUS R CB Open Dhuri-1 U#2 tie

07:14:20,187 TALWANDI THER 400kV F_9 (XFMR-1 BUS-2) CB Open ST#1 main

07:14:29,168 TALWANDI THER 400kV F_1(K'DAM-1 BUS-1) CB Open Dhuri-2 main

07:14:29,169 TALWANDI THER 400kV F_2 (K'DAM-1 JALAN CB Open Dhuri-2 U#1 tie

i. As per PMU data:

• R-N fault occurred at 06:45:44.960hrs and cleared timely. Fault

occurred again in reclosing time and tripped again timely.

• Y-N fault occurred at 07:13:31.760hrs and cleared timely. Fault

occurred again in reclosing time and tripped again timely

j. As per SCADA SoE data:

• CB status captured for T. Sabo, Dhuri and Nakodar.

k. As per Punjab details:

l. Probable SoE:

Time(in hrs)

Reference time

Event Corroboration

06:45:44,980 0ms R-N fault in 400kV T.Sabo-Nakodar PMU, DR

06:45:45,030 50ms400kV T.Sabo-Nakodar tripped from T.Sabo

SOE

06:45:45,120 140ms400kV T.Sabo-Nakodar tripped from Nakodar

PMU, DR

06:45:46,085 1105ms 400kV T.Sabo-Nakodar A/R from T.Sabo PMU, SOE

06:45:46,145 1165ms400kV T.Sabo-Nakodar opened in reclaim time from T.Sabo

PMU, SOE

06:45:46,380 1400ms400kV T.Sabo-Nakodar A/R from Nakodar

PMU, DR, SOE

06:45:46,470 1490ms400kV T.Sabo-Nakodar opened in reclaim time from Nakodar

PMU, DR, SOE

Time(in hrs)

Reference time

Event Corroboration

07:13:31,800 0msY-N fault in 400kV T.Sabo-Moga; 400kV Dhuri-T.Sabo also sensed fault in Z-3

PMU

07:13:31,845 45ms400kV T.Sabo-Moga tripped from T.Sabo

PMU, SOE

07:13:31,860 60msFault cleared; IT seems 400kV T.Sabo-Moga tripped from Moga

PMU

07:13:32,915 1115ms 400kV T.Sabo-Moga A/R from T.Sabo PMU, SOE

07:13:33,005 1205ms400kV T.Sabo-Moga opened in reclaim time from T.Sabo; 400kV Dhuri-T.Saboalso tripped on SOTF from Dhuri

PMU, DR, SOE

07:13:33,040 1240ms 400kV T.Sabo-Moga A/R from Moga PMU

07:13:33,120 1320ms400kV T.Sabo-Moga opened in reclaim time from Moga

PMU

m. Preliminary Report, DR/EL and detailed report received from

Punjab.

Punjab representative informed the following in the meeting:

1. Event on 7th Nov 2017:

a. 400 kV Makhu-Amritsar ckt-2 tripped on B-phase to earth fault, line A/R (auto reclosed) operated from Amritsar end but didn’t operate at Makhu end resulted into 3-phase tripping. Auto reclosure issue was resolved.

b. As per SCADA data, it seems unit-1 of Talwandi Sabo TPS and 400 kV T.Sabo-Moga line was in service. Punjab representative informed that status of 400kV T. Sabo-Moga and unit-1 of T. Sabo.

c. Information from Talwandi Sabo TPS yet to be received. d. Reason of tripping of Unit-2 & 3 would also be collected from T.

Sabo TPS and detailed report based on input would be again submitted.

2. Event on 12th Nov 2017:

a. Reason of tripping of 400 kV T.Sabo-Dhuri ckt-1 (which seemed to

be the only evacuating line remained for T. Sabo generation)

tripped at 07:13hrs from T. Sabo end would be checked and revert

back.

b. SOTF function issue of 400kV T.Sabo-Dhuri ckt-2 at Dhuri end has

been resolved.

c. Z-2 and Z-3 start was not mapped at Nakodar end of 400kV T.

Sabo-Nakodar ckt, same has been mapped. In this line fault,

initially Z-2 signal may have sensed and it converted into Z-1 fault

after increasing the fault current. It may be reason of tripping of

Nakodar end after 100ms of start of fault.

d. POWERGRID & Punjab confirmed that A/R functionality in 400kV

T. Sabo-Moga(PG) in view of ~1300ms dead time would be

checked.

NRPC raised concern about large number of tripping in 400 kV ring of Punjab

and it resulted into generation outage. Better maintenance practice needs to be

adhered and pre winter cleaning also to be done to avoid unreliable operation.

E. Complete outage of 400kV Kurukshetra and blocking of HVDC Champa-

Kurukshetra Bipole at 03:25hrs of 10th Nov 2017

Event category: GI-2

Generation loss: Nil

Loss of load: Nil



Fault Clearance Time PMU data NA No fault

Phase of the fault PMU data NA No fault



POWERGRID Available

DR/EL POWERGRID Received Within 24hrs

Preliminary Report POWERGRID Received Within 24hrs

Detailed Report POWERGRID Not Received



1. IEGC 5.2 (r), 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d

POWERGRID 1. Detailed Report didn’t provide


1. Single Line Diagram and connectivity diagram of Kurukshetra station:

2. 400/220kV Kurukshetra station is connected with 400kV Malerkotla D/C,

400kV Abdullapur D/C, 400kV Sonipat D/C, 400kV Jalandhar S/C, 400kV

Nakodar S/C and connection with HVDC converter transformer. It also

have 400/220kV 500MVA ICT-1&2. One and half breaker scheme at

400kV Kurukshetra station.

3. Antecedent condition:

S. No Description of Line Condition O.V Settings

1 400kV Kurukshetra-Abdullapur ckt2 Open

2 400kV Kurukshetra-Sonipat ckt 1 open

3 400kV Kurukshetra-Nakodar open

4 400kV Kurukshetra-Jalandhar open

5 400kV Kurukshetra-Malerkotla ckt 2 open

6 400kV Kurukshetra-Abdullapur ckt1 In service 440kV, 5sec

7 400kV Kurukshetra-Sonipat ckt 2 In service 448kV, 4sec

8 400kV Kurukshetra-Malerkotla ckt 1 In service 440kV , 5sec


• 400kV Kurukshetra-Abdullapur ckt-1

• 400kV Kurukshetra-Sonipat ckt-2

• 400kV Kurukshetra-Malerkotla ckt-1

• HVDC Champa-Kurukshetra Pole-1 & 2

5. At 03:25:51hrs ,400kV Kurukshetra-Abdullapaur Ckt 1 tripped on Over

voltage, further Voltage shoot up to ~448kV and 400kV Kurukshetra-

Sonipat ckt 2 and 400kV Kurukshetra-Malerkotla ckt 1 also tripped on over

voltage protection.

6. After tripping of all 400kV HVAC line finally pole blocked on loss of

evacuation path

7. PMU plots of phase voltages:

8. As per PMU data:

• Max voltage observed in Blue phase (around 435kV).

9. SCADA data and SoE:

Time Station NameVoltage Level

(in kV)Element

NameElement

typeStatus Remarks

03:25:53,107 KURHV_P 400kV 18ABDUL1 CB Open Main CB of 400kV Kurukshetra (end)-Abdullapur ckt1

03:25:55,191 SONIPAT 400kV 1KURHV2 CB Open Main CB of 400kV Sonipat (end)-Kurukshetra ckt 2

03:25:55,192 SONIPAT 400kV 2T3AB2 CB OpenTie CB (at present main CB for future bay) of Kurukshetra ckt-2 at Sonipat

03:25:56,175 MALERKOTLA 400kV 18KURHV1 CB Open Main CB of 400kV Malerkotla (end)-Kurukshetra ckt 1

03:25:56,178 MALERKOTLA 400kV 17AMR2TI CB OpenTie CB of 400kV Amritsar ckt-2 and Kurukshetra ckt-1 at Malerkotla

03:25:58,083 KURHV_P 400kV 1ICT1 CB Open Main CB of 400/220kV 500MVA ICT-1 at Kurukshetra

03:25:58,083 KURHV_P 400kV 2MLRICT CB OpenTie CB of 400kV Malerkotla ckt-1 and ICT-1 at Kurukshetra

03:25:58,083 KURHV_P 400kV 23SONPT2 CB Open Main CB of 400kV Kurukshetra (end)-Sonipat ckt2

03:25:58,083 KURHV_P 400kV BKC3_1 CB Open CB of Filter bank-3 and branch first03:25:58,083 KURHV_P 400kV BKC1_2 CB Open CB of Filter bank-1 and branch second

03:25:58,083 KURHV_P 400kV 3MALER1 CB Open Main CB of 400kV Kurukshetra (end)-Malerkotla ckt1

03:26:00,345 KURHV_P 400kV 14KURHV2 CB OpenMain CB of 400kV HVAC and converter transformer for Pole-2

03:26:00,345 KURHV_P 400kV 15KUR2TI CB OpenTie CB of 400kV HVAC and converter transformer for Pole-2

03:26:00,345 KURHV_P 400kV 20HV1TIE CB OpenTie CB of 400kV HVAC and converter transformer for Pole-1

03:26:00,345 KURHV_P 400kV 19KURHV1 CB OpenMain CB of 400kV HVAC and converter transformer for Pole-1

03:26:00,345 KURHV_P 400kV BKC1_1 CB Open CB of Filter bank-1 and branch first

10. DR details:


• After tripping of 400kV Kurukshetra- Abdullapur ckt 1, the power was

shared between Malerkotla and Sonipat lines, From the DR, it is

evident that even 600A flow in 400kV Kurukshetra-Malerkotla ckt , the

line voltage was around 460kV

12. Power imported through Bi-pole was evacuated through Abdullapur-1,

Sonepat-2 and Malerkotl-1 at Kurukshtera. Voltage on the Abdullapur ckt

– 1 rose to 439 kV and line tripped on Over voltage stage -1 at

03:25:51.064 hrs.

13. Tripping of Abdullapur-1 line led to further rise in voltage up to 449 kV

resulting in tripping of Sonepat-2. Cascading effect in voltage increase

resulted in tripping of third line i.e. Malerkotla-2


• 400kV Kurukshetra-Abdullapur ckt-1 was (exporting) around

200MVAR before tripping

15. Preliminary Report, DR/EL has been received from POWERGRID.

However, detailed report and remedial measures report is still awaited

from POWERGRID.

16. POWERGRID representative informed the following in the meeting:

• Tripping of 400 kV Kurukshetra Abdullapur ckt – 1 before voltage

reached. Reply: It can be seen that line tripped at 439 kV.

• The reason/ necessity of Surplus Filter banks (around 450 MVAr). Reply:

Bipole was running with 500MW at the time of Blocking, the minimum

filter requirement for Bipole was three filters and reactive power

absorption of converter is approx. 50-60 % of active power. The net

exchange of reactive power to grid at the time of incident is as per below

table:

Item Reactive Power Supplied by filter at 400KV AC voltage

Reactive Power supplied by filter at 438KV AC Voltage

No. of Filter required

2A+1B (125 MVAR each) 2A+1B (125 MVAR each)

MVAR Supplied by Filter

375 MVAR 435 MVAR

MVAR Exchange 125 MVAR 185 MVAR

• If the system voltage would have been within the limits, excessive

reactive power would have not been injected in the grid and the tripping

could have been avoided. Non operation of Transient over voltage (TOV),

which trips the unwanted filter bank. Reply: As per TOVC scheme if the

Bi-pole is running with minimum filters, it will not give tripping command

as tripping of any filter at this time will cause blocking of bipole.

(2A+1B= 3 filters) are minimum filters required to run the Bi-pole. Further,

Transient over voltage (TOVC) was working satisfactorily.

• Mode of operation (RPC) with Reactive Power mode was in manual or

Auto mode. Reply: RPC was in automatic mode. APEX log is as below:

As per the attachment it can be seen that the RPC is in automatic mode since 22/10/2017.

• Reason of such High Voltage even after tripping of one circuit (400 kV

Kurukshetra-Abdullapur ckt-1). Reply: During the mentioned event,

Kurukshetra sub-station was initially connected with 03 no AC lines and

all other lines were kept out of service due to system high voltage as per

NRLDC instructions. On 10.11.2017, 400 KV Kurukshetra-Abdullapur-1

tripped on operation of over voltage stage –I protection which further

aggravated the situation and decreased the short circuit MVA of

Kurukshetra resulting in shooting of voltage due to weak grid and tripping

of KKR-Malerkotla-1 and KKR-Sonepat-2 on o/v stage-1 operation. To

avoid such conditions, it is advisable to keep at least 4 lines connected at

Kurukshetra station.

• Exact Sequence of events. Reply: Station EL is enclosed for reference.

• Restoration Time:

i. 400 kV Kurukshetra Abdullapur-1 charged at 03:57 hrs

ii. 400 kV Kurukshetra Sonepat-2 charged at 03:54 hrs.

iii. 400 kV Kurukshetra Malerkotla-1 charged at 04:17 hrs.

iv. 800 kV HVDC Champa Kurukshetra Bipole charged at 04:58

hrs

v. 800 kV HVDC Champa Kurukshetra Bipole charged at 05:32

hrs

17. MS, NRPC raised concern about frequent tripping of HVDC Champa-

Kurukshetra and requested POWERGRID to take the remedial measures

accordingly.

F. Multiple element tripping at 220kV Panipat BBMB at 11:29hrs of 19th Nov

2017 and 00:35hrs of 01st Jan 2018


Generation loss:

Nil (19.11.2017, As per BBMB report)

Nil (01.01.2018, As per BBMB Report)

Loss of load:

Nil (19.11.2017, As per BBMB report, Haryana may confirm)

438MW (01.01.2018, As per BBMB report, Haryana may confirm)




PMU data 440ms 19.11.2017

100ms 01.01.2018


R-phase followed by Y-phase

19.11.2017

R-phase 01.01.2018



BBMB Not Available 19.11.2017

01.01.2018

DR/ EL BBMB


19.11.2017


01.01.2018

Preliminary Report BBMB


19.11.2017


01.01.2018

Detailed Report BBMB Received 19.11.2017

Received 01.01.2018



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3, 3.1.e 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 4. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines

BBMB

1. DR/EL, Preliminary report within 24hrs 2. Correct operation of Protection System 3. Adequately Sectionalized and graded protective relaying system


1. 220kV Panipat BBMB has following connection:

a. 220kV Panipat Thermal ckt-1, 2 & 3

b. 220kV Dhulkote ckt-1 & 2

c. 220kV Narela ckt-1, 2 & 3

d. 220kV Chhajpur ckt-1 & 2

e. 220kV Charkhi Dadri

f. 220kV Kurukshetra ckt

g. 400/220kV 450MVA ICT-1 & 2

h. 220/132kV 100MVA ICT-1 & 2

i. 220/33kV 60MVA ICT-1 & 2



a. In antecedent condition, 220kV Panipat(BBMB)-Thermal-2 was

under S/D

b. Antecedent connectivity:

c. Red phase CVT of 220KV Thermal-III busted and caught fire. The

Main-1 & Main-2 DP schemes of this circuit detected 1- phase fault

in Z-1 at a distance 155m and opened the red phase limb for the

purpose of 1-phase auto-reclosing but during the ‘Dead Pole Time’

, after 459ms of initiation of the fault, the single phase fault turned

in to phase-phase fault thus the auto-reclose lock out feature

activated and the DP scheme issued three phase tripping and

opened the breaker completely.

d. During the bursting of the CVT, a cloud of fire strikes between the

Red & Yellow phases (at the Gantry) of the Sub-Bus conductors

coming from common point of the Bus-1 & Bus-2 isolators of

Thermal-3 feeder. This led to the Bus-Bar Fault and as a

consequence of this, the 220KV Bus-Bar Protection operated in Z-1

(Bus-1) and Z-3 (Bus-2 RHS) operated. At this instance, MiCOM

P122 – (H/Set Ie>> ) of Bus Coupler-1 (between Bus-1 & LHS Bus-

2) also operated. All the circuits connected to 220KV Bus-1 & Bus-2

RHS tripped through BBP 96 Trip relays. 220kV Bus-2 (LHS)

remained charged through 220KV Thermal-4 & 220KV Chhajpur-2.

e. Following elements connected to 220kV bus-1, bus-2(RHS) tripped:

• 220kV Panipat-Thermal ckt-1, 3

• 220kV Panipat-Narela ckt-1, 2, 3

• 220kV Panipat-Charkhi Dadri

• 220kV Panipat-Dhulkote ckt-1,2

• 220kV Panipat-Chajpur ckt-1

• 220kV Panipat-Kurukshetra

• 400/220kV 450MVA ICT-1, 2

• 220/33kV, 100MVA ICT-1, 60MVA ICT-1&2

f. As per BBMB report:

• At 11:29:43 hrs of dt. 19/11/17, Red phase CVT of 220KV

Thermal-III busted and caught fire. The Main-1 & Main-2 DP

schemes of this circuit detected 1- phase fault in Z-1 at a

distance 155.0 mtrs. and opened the red phase limb for the

purpose of 1-phase auto-reclosing but during the ‘Dead Pole

Time’ , after 459ms of initiation of the fault, the single phase

fault turned in to phase-phase fault thus the auto-reclose lock

out feature activated and the DP scheme issued three phase

tripping and opened the breaker completely.

• During the bursting of the CVT, a cloud of fire strikes between

the Red & Yellow phases (at the Gantry) of the Sub-Bus

conductors coming from common point of the Bus-1 & Bus-2

isolators of Thermal-3 feeder. This led to the Bus-Bar Fault

and as a consequence of this, the 220 kV Bus-Bar Protection

operated in Z-1 (Bus-1) and Z-3 (Bus-2 RHS) operated. At

this instance, MiCOM P122 – (H/Set Ie>>) of Bus Coupler-1

(between Bus-1 & LHS Bus-2) also operated. All the circuits

connected to 220 kV Bus-1 & Bus-2 RHS tripped through

BBP 96 Trip relays. 220 kV Bus-2 (LHS) remained charged

through 220 kV Thermal-4 & 220 kV Chhajpur-2.

• Note: Bus Coupler MiCOM P122: Fault Current: IA: 8.050 kA,

IB: 8.085 kA, IC: 126A; Threshold Ie>>=9.357 kA; e>> setting

= 4.0 Ien & DTD: 200ms, CT Ratio: 1200/1A.

• Lesson Learnt: After thorough examination of the related

DRs & events, it was observed that Bus Bar Protection

operated on actual fault at 11:29:45hrs but somehow time

stamping in the Central Unit / PUs of the numerical Bus-Bar

Protection showed operation of Bus Bar Protection at

11:29:19 hrs. . Time synchronization of Central Unit / PUs is

now healthy.

g. PMU data of frequency, df/dt and phase voltage:

h. As per PMU data:

• R-N fault occurred at 11:29:43.160hrs and cleared in 200msec.

• Y-N fault occurred at 11:29:43.640hrs and cleared in 120msec.

• R-Y fault occurred at 11:29:45.120hrs and cleared in 320msec.

i. As per SCADA data:

• No tripping related SCADA SoE data reported at NRLDC.

j. BBMB SoE:

k. As per DR details:

l. Probable SoE:

Time(in hrs)

Reference time (ms)

Event Corroboration

11:29:43,090 0 R-N fault occurred DR

11:29:43,160 70R-ph of Thermal-3 ckt opened from Panipat(BBMB) end; R-N fault occurred as per PMU

PMU, DR

11:29:43,360 270 Fault got cleared PMU

11:29:43,560 470Y-N fault also occurred in Thermal-3 ckt (R-ph already open)

DR

11:29:43,635 5453-ph trip occurred for Thermal-3 ckt from Panipat(BBMB) end; Y-N fault occurred as per PMU

PMU, BBMB SoE, DR

11:29:43,760 670 Fault got cleared PMU

11:29:45,120 2030 R-Y fault occurred PMU

11:29:45,255 2165 Ch. Dadri ckt tripped from Panipat BBMB end BBMB SoE

11:29:45,370 2280 Thermal-1 ckt tripped from Panipat(BBMB) end BBMB SoE

11:29:45,395 2305Rest of the elements connected to bus-1, bus-2(RHS) tripped

BBMB SoE

11:29:45,440 2350 Fault cleared PMU

m. Restoration time: Sr.

No.

Tripped Grid Element Date / Time of Restoration

1 220kV Panipat- Dhulkote - II 19:11:17 / 12:25 hrs.

2 220kV Bus Coupler - II 19:11:17 / 12:31 hrs.

3 220/33kV, 60MVA T/F T-2 19:11:17 / 12:34 hrs.

4 220/33kV, 60MVA T/F T-1 19:11:17 / 12:36 hrs.

5 400/220kV, 450MVA, ICT Bank-1, 220KV side 19:11:17 / 12:44 hrs.

6 400/220kV, 450MVA, ICT Bank-2, 220KV side 19:11:17 / 12:44 hrs.

7 220KV Panipat - Kurukshetra 19:11:17 / 12:44 hrs.

8 220KV Panipat – Ch. Dadri 19:11:17 / 12:45 hrs.

9 220/132KV, 100MVA T/F T-1 19:11:17 / 12:46 hrs.

10 220/132KV, 100MVA T/F T-2 19:11:17 / 12:46 hrs.

11 220kV Bus Coupler - I 19:11:17 / 12:49 hrs.

12 220kV Bus Sectionalizer 19.11.17 / 12:49 Hrs

13 220kV Panipat- Dhulkote - I 19:11:17 / 12:50 hrs.

14 220kV Panipat-Thermal-4 19.11.17 / 12:50 Hrs

15 220kV Panipat-Thermal-1 19.11.17 / 12:51 Hrs

16 220KV Panipat- Narela-1 19.11.17 / 12:54 Hrs

17 220KV Panipat- Narela-II 19.11.17 / 12:54 Hrs

18 220KV Panipat- Narela-III 19.11.17 / 12:54 Hrs

19 220KV Panipat- Chhajpur-1 19.11.17 / 12:56 Hrs

20 220KV Panipat- Chhajpur-II 19.11.17 / 12:56 Hrs

n. Preliminary report, DR/EL and detailed report has been received

from BBMB.

4. Event Description for 01st Jan 2018 event:

a. Antecedent Connectivity of Panipat BBMB:

b. On 01:01:18 at 00:30hrs 220kV Panipat-Chhajpur -2 (Both end)

tripped in Zone-1. 220kV Panipat-Chhajpur -2 was connected on

Bus-2 LHS.

c. At the instance of tripping of 220kV Chhajpur-2, 220KV Bus-2

(LHS) also tripped.

d. In addition to the BBP trip Zone-2, all the 220kV circuits connected

on Bus-1 & Bus-2 (RHS) also tripped through 96 trip relays on

extending of DC supply to BBP Trip Bus of Zone-1 & Zone-3 (Bus-2

RHS) through wrong positioning of BBP DC Trip links of 100MVA

ICT-1 and 220kV Charkhi Dadri feeder respectively.

e. 220KV Panipat-Chhajpur-2: CSC: Ph A, Trip Ph ABC, Z-1, Dist:

3.156km (Other end A/R)

f. Bus Bar Protection – Central Unit (MiCOM P741):

• Fault Ph B, Trip 87BB, Fault in Zone-2, Trip Zone 2; Fault

Duration : 3ms

• IA CZ Diff : 7.487kA; IB CZ Diff: 2.764kA; IC CZ Diff: 9.943 A;

IN CZ Diff : 10.35kA

• IA CZ Bias: 33.46kA; IB CZ Bias: 6.957kA; IC CZ Bias :

3.572kA; IN CZ Bias : 31.99kA

g. PMU plots of frequency, df/dt and phase voltage:

h. As per PMU data:

• R-N fault occurred at 00:30:47.880hrs and cleared timely in

80msec.

i. As per SCADA SoE data:

• No tripping related SCADA SoE data reported at NRLDC.

j. As per DR details:

k. Remedial Measures already taken by BBMB:

• The LHS Bus including bay of Chhajpur-2 was checked

thoroughly and no physical damage was observed. BBP

operation may be due to some tracking over the disc insulators.

• Awareness to operational staff was made regarding proper

positioning of Bus Zone DC link after operation of Bus Isolator.

Register has been maintained to monitor daily regarding Bus

Zone DC links position.

• Punctured Insulator Detector (PID) test was carried out for

Chhajpur-2 bay (Sub Bus Tension Disc Insulators strings) on

06.01.18. Red Phase tension insulator disc string found

punctured and yellow phase found weak. All 6 Nos. tension

insulator disc strings replaced with polymer on 03.02.18. It is

also added that 6 Nos. Sub Bus suspension discs Disc

Insulators strings replaced with polymer type on 18.05.2017.

• Punctured Insulator Detector (PID) test was carried out for Bus-

2 LHS (Suspension Disc Insulators) was carried out on

20.01.18. Three suspension insulator disc string found weak

and replaced with polymer on 24.01.18.

l. Restoration Time: CIRCUIT RESTORATION TIME (01-01-18)

220KV Dhulkote-1 01:05hrs.

400/220KV, 450MVA ICT Bank-1 01:10hrs.

400/220KV, 450MVA ICT Bank-2 01:12hrs.

220/132KV, 100MVA T-2 01:12hrs.

220/132KV, 100MVA T-1 01:25hrs.

220KV Bus Coupler-1 01:33hrs.

220KV Bus Coupler-2 01:34hrs.

220KV Ch. Dadri 01:38hrs.

220KV Kurukshetra 01:38hrs.

220KV Chhajpur-1 01:38hrs.

220KV Narela-1 01:40hrs.

220KV Narela-2 01:52hrs.

220KV Thermal-1 01:32hrs



m. Preliminary Report, DR/EL and detailed report has received from

BBMB.

BBMB representative informed the following in the meeting:

1. Point wise reply of event on 19th Nov 2017:

a. Tripping of Charkhi Dadri ckt: MiCOM P442 relay was installed on

06.06.17 in place of defective REL670. During installation of this

relay, tripping was wrongly configured on Ph-Ph fault in PSL (as

given below). On start of Ph-Ph fault, this tripping took place.

PSL has been corrected

b. Reason of tripping of 220 kV Bus-1: During the bursting of the CVT,

of Thermal-3 (connected on bus-1), a cloud of fire strikes between

the Red & Yellow phases (at the Gantarry) of the Sub-Bus

conductors coming from common point of the Bus-1 & Bus-2

isolators of Thermal-3 feeder. This led to the Bus-1 fault and as a

consequence of this, the 220KV Bus-Bar Protection operated in Z-1

(Bus-1) operated. This tripping was in order.

Reason of tripping of Bus-2 (RHS): There was no fault on Bus-2

(RHS). Tripping of RHS was not in order. 220kV Dhulkot -2 was

connected on Bus-2 (RHS) through isolator No. 272. Its Bus-1

isolator 273 was in open position. On analysis the events of PU of

Dhulkot-2, it has been observed that logic input “isolator 273 open”

became off at 11:23:18:257Hrs due to malfunctioning of isolator

auxiliary contact. At 11:23:18:262 Hrs unknown status alarm

appeared and that resulted into Bus-1 isolator status “Closed ON”

at 11:23:18:265 Hrs. Matter of chance, Bus-1 fault happened at

11:29:19:479 Hrs, thus leads to operation of Bus-2 (RHS) being

Bus-1 isolator status “Closed ON” of Dhulkot-2 which was

connected really on Bus-2 (RHS).

c. Time synchronization of Panipat Thermal - 3 set right.

d. Reporting of SCADA digital status SoE data at NRLDC shall be

insured in future.

e. Load loss details was not informed by Haryana at the time of

meeting.

2. Point wise reply of event on 01st Jan 2018:

a. Non auto reclosing of 220kV Chajjpur circuit to be looked into:

Auto-reclosing function of Chahhajpur-2 will be checked thoroughly

on schedule shutdown

b. Time synchronization of DR (Chajjpur-2) needs to be checked, as it

is not matching with the bus bar trip (DR) and PMU based fault

timings: No IRIG-B port for synchronization is available in CSC101

relays of Chhajpur Ckt. 1 & 2. However, it has been planned to put

the relays on LAN in near future

c. Bus scheme to be explained in detail with emphasis on how all

feeders tripped simultaneously and manual setting of isolator

selection for bus bar protection: During dense fogg there was a

transient Red phase to Earth fault with heavy noise on 220kV Bus-2

LHS (Zone-2), resulted into operation of Bus-2 (LHS) Bus-Bar

Protection. This tripping was in order. However, circuits connected

on 220KV Bus-2 (RHS) & 220KV Bus-1 also tripped through 96 trip

relays on extending of DC supply to BBP Trip Bus of Zone-1 &

Zone-3 (Bus-2 RHS) through wrong positioning of BBP DC Trip

links of 100MVA T-1 (connected on Bus-2 (LHS) but its Bus-1 & 2

DC link were in position) and Charkhi Dadri (connected on Bus-2

(LHS) but its Bus-1 & 2 DC link were in position). Manual

positioning of DC link arrangement has been shown as under:

Awareness to operational staff was made regarding proper

positioning of Bus Zone DC link after operation of Bus Isolator.

Register has been maintained to monitor daily regarding Bus Zone

DC links position.

d. Non reporting of SCADA digital status SoE data at NRLDC needs

to be addressed: Reporting of SCADA digital status SoE data at

NRLDC shall be insured in future

e. Haryana may confirm about load loss: Load loss details was not

informed by Haryana at the time of meeting

RLDC raised concern about frequent tripping of complete station outage due to

bus tied operation at the station. In this case bus tied operation occurred due to

manual intervention for the auxiliary contact input. Human error needs to be

minimised.

MS, NRPC also suggested all the NR utilities to kindly follow the decision

occurred in RPC meeting. General recommendation shall be followed by each

utility of NR.

G. Multiple element tripping at 400/220kV Sarnath (UP) Station at 01:22hrs of

29th Nov 2017

Event category: GI-2 or GD-1


Loss of load: Nil (UP may confirm about load loss)




PMU data No fault

Phase of the fault PMU data No fault



UP Partial Available

DR/EL UP Not Received

Preliminary Report UP Not Received

Detailed Report UP Not Received



1. IEGC 5.2.r & 5.9.6.c (VI) 2. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2)

UP

1. DR/EL, Preliminary report didn’t provide within 24hrs 2. Detailed Report didn’t provide 3. Adequately Sectionalized and graded protective relaying system


1. Single Line Diagram and affected area:

2. 400/220/132kV Sarnath (UP) is connected at 400kV with 400kV Varanasi

(PG) D/C, Anpara D/C and Azamgarh (UP). It has two 315MVA and one

500MVA 400/220kV ICTs and also has one 125MVAr bus reactor.

3. Sarnath (UP) has double main and transfer scheme.

4. As reported, bus bar protection operated at Sarnath (UP) due to CB failure

of 400kV Anpara-Sarnath ckt-2. It resulted into tripping of multiple

elements.

5. Tripped elements:

• 400 kV Anpara(UP)-Sarnath(UP) ckt-2

• 400 kV Sarnath(UP)-Varanasi(PG) D/C

• 400/220 kV, 315 MVA ICT 1&3 at Sarnath

6. PMU plots:

7. SCADA SoE and probable sequence of event is as given below:


01:22:23,984 ANPAR_UP 400kV F_18(VRNSI-2) CB Open

01:22:24,041 ANPAR_UP 400kV F_18(VRNSI-2) CB Close

01:22:26,635 VRNSI_UP 400kV F_03(SASAR) CB Open

01:17:26,636 VRNS1_PG 400kV 11SRNTT1 CB Open

01:17:26,636 VRNS1_PG 400kV 10SRNT2 CB Open

01:22:26,961 ANPAR_UP 400kV F_18(VRNSI-2) CB Open

Time(in hrs)

Reference time

Event Corroboration

01:22:23,985 0ms400kV Anpara-Sarnath-2 opened from Anpara end

SCADA SoE

01:22:24,040 55ms400kV Anpara-Sarnath-2 closed from Anpara end

SCADA SoE

01:22:24,120 135ms Variation in voltage observed PMU

01:22:26,635 2650ms400kV Varanasi-Sarnath-2 opened from both ends

SCADA SoE

01:22:24,680 2695ms Variation in voltage observed PMU

01:22:26,960 2975ms400kV Anpara-Sarnath-2 opened from Anpara end

SCADA SoE

8. As per PMU data and SCADA SoE:

• No fault observed.

• Variation in voltage observed at 01:22:24.120hrs and 01:22:26.680hrs


• Multiple operation of opening/closing of 400kV Anpara-Sarnath-2

opened from Anpara end observed.

• Tripping of 400kV Varanasi-Sarnath-2 captured

• From the SCADA plot, at 1:17hrs power flow of 400kV Sarnath-

Varnasi-2 became zero

10. Preliminary Report, DR/EL and detailed report is still awaited from

UPPTCL.

UPPTCL representative informed the following in the meeting:

1. 400 kV Sarnath (UP) station come under isolux and details is still awaited

from isolux. Following point was also forwarded to Isolux for the reply:

a. Reason for power flow of 400kV Sarnath-Varanasi ckt-2 becoming

zero 5min prior to actual event.

b. No fault observed. Reason for tripping of elements.

c. As reported CB failure but voltage dip didn’t capture in PMU data

d. Exact sequence of events in view of cause of event; protection




UPPTCL.

NRPC suggested UPPTCL to kindly take the details from M/s Isolux. M/s Isolux is

not the member of NRPC and sub-station come under state control area of

UPPTCL so UP state transmission utility shall take care about the tripping and

reporting.

H. Multiple Element tripping at 400/220kV Dadri (NTPC) Station at 17:30hrs of

09th Dec 2017


Generation loss: 1488MW (As per NTPC report)

Loss of load: 100MW (Delhi may confirm)


Description Fault Info Remarks

Fault Clearance Time 100ms As per PMU data

Phase of the fault Maximum dip in Y&B-phase

As per Preliminary Report and PMU data

Description Utilities

Present Status

Remarks


Received

DR/ EL NTPC Received After 24hrs

POWERGRID Not received

Preliminary Report NTPC Received Within 24hrs

POWERGRID Received After 24hrs

Detailed Report NTPC Not Received Final report still pending



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d

POWERGRID

1. Detailed Report yet to be received 2. DR/EL received after 24hrs


1. Single Line Diagram of Dadri (NTPC):

2. 400/220kV Dadri station is connected with 400kV Mandola D/C, 400kV

Harsh Vihar D/C, 400kV Panipat (BBMB) D/C, 400kV Muradnagar New

S/C, 400kV Kaithal S/C, 400kV Maharani Bagh S/C and 400kV G. Noida

S/C at 400kV voltage level. 400/220kV Dadri Thermal station have total

four units of 210MW connected at 220kV and two units of 490MW

connected at 400kV level. 220kV Dadri Gas station have total 829MW

(4x130.19+2x154.51) capacity including 4 GT (Gas Turbine) and 2 ST

(Steam Turbine). 220kV Gas is connected with Dadri Thermal and also

fed the Railway supply directly.

3. 400kV Dadri (NTPC) has one and half breaker scheme and 220kV Dadri

(NTPC) has DMT (double main transfer breaker) scheme.

4. 400 kV Dadri (NTPC) bus-2 was under shutdown from 08:58hrs of 9th Dec

2017 to attend hotspots.

5. At 17:18 hrs, 400 kV Dadri (NTPC) bus-2 was charged through Harsh

Vihar Circuit 1. Bus-2 was on floating condition and no other lines / units

were connected to 400 kV bus 2.

6. All the 400kV elements charged through 400kV Dadri (NTPC) bus-1. At

17:29hrs, Y-phase jack bus jumper of unit-6 snapped and fell on B-phase

of main bus-I resulting in tripping of 400 kV Dadri (NTPC) bus-1. All

running units (Unit-3, 4, 5 and 6) of Dadri Thermal tripped.

7. At Dadri Gas, one GT+ST module was running. Gas unit run in the island

with Railway load but couldn’t survive and finally tripped after 10 minute.


• 400kV Dadri(TH)-Harsh Vihar(DTL) -1&2

• 400kV Dadri(TH)-Panipat(BBMB) 2

• 400kV Dadri(TH)-Maharanibagh(PG)

• 400kV Dadri HVDC 400kV AC BUS A&B

• Dadri 500 MVA ICT 1,2,3, 4 &5

• Dadri Thermal Unit -3, 4, 5 & 6

• 500kV HVDC Rihand-Dadri

9. PMU plots:


• Maximum dip in all three phase.

• Fault occurred at 17:29:36,160hrs and cleared in 100ms.

• Frequency rise of ~0.095Hz.

• Dadri PMU voltage showing voltage: It may be due to AC filter bank

tripping after some time of HVDC Rihand-Dadri Bipole tripping.

11. During the incident HVDC Rihand-Dadri bipole carrying power order of

500MW also tripped. It resulted into SPS operation for HVDC Rihand-

Dadri and shed load in group C & D. Till now, details received only from

Samaypur BBMB and load shedding reported ~86MW on 220kV

Samaypur-Palwal D/C.

12. SCADA SoE and probable sequence of event is as given below:

Time Station Name

Voltage

Level

(in kV)

Element NameEquipment

typeStatus Remarks

17:13:04,829 DADRI (TH) 400kV 29FUTHRS CB Close

Tie CB of 400kV Harsh Vihar ckt-

1, Connected to 400kV Bus-1,

Incomplete dia, future

extension

17:18:31,718 DADRI (TH) 400kV 29FUTHRS CB disturbe

17:29:25,646 DADRI (TH) 400kV 18G6 CB disturbe Main CB of 400kV Unit-6

17:29:25,683 DADRI (TH) 400kV 17G5G6 CB Open Tie CB of 400kV Unit-6

17:29:25,684 DADRI (TH) 400kV 12PANPT1 CB Open Main CB of 400kV Panipat ckt-1

17:29:25,698 DADRI (TH) 400kV 6TIE CB Open

17:29:25,700 DADRI (TH) 400kV 15MANDU1 CB OpenMain CB of 400kV Mandola ckt-

1

17:29:25,754 DADRI (TH) 400kV 21GNODA1 CB Open Main CB of 400kV G. Noida ckt

17:29:25,892 DADRI (TH) 400kV 29FUTHRS CB Close

Tie CB of 400kV Harsh Vihar ckt-

1, Connected to 400kV Bus-1,

Incomplete dia, future

extension

17:29:28,222 LODHI ROAD 33kV B_16(HABTT-1) CB Invalid Disp

17:29:31,423 DADRI (TH) 400kV 24HARSH2 CB OpenMain CB of 400kV Harsh Vihar

ckt-2

17:29:31,441 DADRI (TH) 400kV 23MB1HR2 CB OpenTie CB of 400kV Harsh Vihar

and Maharani Bagh ckt

17:29:36,188 PANIPAT 400kV F_4(D_THM-1 BUS-1) CB Open Main CB of 400kV Dadri ckt-1

17:29:36,234 PANIPAT 400kV F_8(D_THM-2 BUS-1) CB Open Main CB of 400kV Dadri ckt-2

17:29:37,163 LODHI ROAD 33kV B_20(LJNGR-2) CB Invalid Disp

17:29:37,322 LODHI ROAD 33kV B_19(LJNGR-1) CB Invalid App

17:29:39,443 ALWAR 132kV D_14_B2(MLKHR-1) CB Open Tripped on SPS operation

17:29:39,574 SAMAYUR 220kV E_21(PLWAL-2) CB Invalid App Tripped on SPS operation

17:29:39,574 SAMAYUR 220kV E_20(PLWAL-1) CB Open Tripped on SPS operation

17:29:39,601 RIHND_HVDC 400kV 4CPBKC2 CB Open

17:29:39,602 RIHND_HVDC 400kV 10CPBKC3 CB Open

17:29:39,603 RIHND_HVDC 400kV 1CPBKC1 CB OpenMain CB of Filter Bank-1 at

Rihand HVDC

17:29:39,603 RIHND_HVDC 400kV 3DA2CP1 CB OpenTie CB of Dadri Pole-2 and

Filter Bank-1

17:29:39,605 RIHND_HVDC 400kV 9CPBKC3 CB OpenMain CB of Filter Bank at

Rihand HVDC

17:29:39,605 RIHND_HVDC 400kV 5DA1CP2 CB OpenTie CB of Dadri Pole-1 and

Filter Bank-2

17:29:39,733 ALWAR 132kV D_02_B1(BNSUR) CB Open Tripped on SPS operation

17:29:39,867 DADRI (TH) 220kV 09G3 CB Open Main CB of 210MW unit-3

17:29:40,487 HARSH VIHAR 220kV E_04(FDR02) CB Open

17:29:42,025 MAHARANI BAGH400kV 02D_THM1 CB OpenMain CB of Dadri ckt at

Maharani Bagh end

13. As per Discussion in 142nd OCC meeting:

• NTPC representative informed that Dadri (NTPC) station have one

and half breaker scheme and D type scheme and therefore, hot spot

of jack bus of main bus could not identified during thermo scanning of

the jack bus. Before few days of incident, bus bar protection operated

at 400kV Bus-1 at Dadri (NTPC) station and during this single bus

operation of 400kV Bus-2 at 400kV Dadri (NTPC), the hotspot could

be observed at jack bus of 400kV Bus-2 of Dadri (NTPC). Therefore,

this shutdown was taken for 400kV Bus-2.

• He further informed that as a remedial jack buses at Dadri (NTPC)

which are of twin moose conductor, are being planned with quad

moose conductors.

• NRLDC suggested NTPC to take bus shutdown of Dadri (NTPC)

during low generation or unit shutdown at Dadri plant.

• NRLDC representative also informed that after 12 second of the

incident one filter bank of HVDC Agra-BNC also tripped however no

power order change was observed in SCADA. The tripping of filter was

captured in SCADA as well as in Agra PMU voltage with small

decrease in voltage. PMU plot of Agra bus voltage is as below.

• No abnormality was observed at HVDC Champa-Kurukshetra (end).

• NRLDC representative informed that 220 KV side bus voltage became

zero after 2 minutes of tripping of 400 KV Buses of Dadri (NTPC), this

tripping needs analysis. The 220 kV Bus voltages observed wide

variations in the plot before tripping. SCADA data plots are as below:

• NRLDC representative also informed that, GT of unit-6 show small

fluctuations in MVAR values and rise in MW values, the dropper of

same unit GT has been reported snapped. SCADA data is as below:

• NRLDC also raised following points for HVDC Rihand-Dadri SPS

operation:

i. Non tripping of 220kV Modipuram

ii. Lower relief on 220kV Samaypur-Palwal ckt-1 & 2 (61%)

iii. Non tripping at Gobindgarh and Laltokalan station of Punjab

iv. Lower load relief from Rajasthan (73% of desired load relief)

v. Lower overall load relief (desired load relief of 520MW)

• NTPC representative further informed the following point about

multiple element tripping of Dadri:

i. 400kV Dadri-Harsh Vihar ckt-1 tripped on over voltage

protection from Dadri end and DT send to Harsh Vihar end.

It resulted into zero bus voltage for 400kV Bus-2 of Dadri

(NTPC).

ii. 400kV Dadri-Maharani Bagh ckt also tripped from Dadri end

on over voltage protection. It further resulted into tripping of

400kV Dadri-Harsh Vihar ckt-2 as this line charged through

tie breaker with 400kV Dadri-Maharani Bagh ckt.

iii. If 400kV Dadri-Harsh Vihar ckt-1 had not tripped on over

voltage than 400kV Bus-2 of Dadri (NTPC) may have

survived. Reason of such high voltage is yet to be

ascertained.

iv. Fault clearance time was ~100ms as other PMU was

showing recovery of voltage. At Dadri, PMU is installed at

AC side of HVDC Rihand-Dadri so voltage phenomena may

be due to AC side filter bank discharging of HVDC Rihand-

Dadri.

v. In last, unit-4 of Dadri (Thermal) survived on house load but

finally tripped on low vacuum.

vi. After tripping of all thermal units, Dadri Gas generation was

islanded with traction load of Railway. Railway load was ~25-

30MW, generation was more. It finally resulted into tripping

of Gas units on over frequency protection therefore 220kV

bus voltage persisted for 2minutes. Only one Gas unit

survived on house load at Dadri-Gas.

vii. As Railway supply was alternatively available from Auraiya

side, supply was not affected. Railway supply from Dadri

Gas was also extended within half an hour.

• NRLDC representative suggested NTPC to discuss with Railway to

provide the balance load with the use of Scott connection or any other

arrangement so that Dadri gas unit could island with railway load or

even provide power to railways after black starting

• Action Point decided in 142nd OCC meeting:

i. All the NR constituents shall follow the better maintenance

practices and more frequent thermo scanning in the switch

yard.

ii. All the NR constituents shall vigilant during bus shutdown of

important station and it needs to be discussed in detail

during planning of shutdown.

iii. DTL shall submit the detailed report along with DR/EL for

tripping of 400kV Dadri-Harsh Vihar ckt-1 & 2.

iv. POWERGRID shall check the reason of tripping of filter

bank-5 at HVDC Agra (end) –for Agra-BNC and submit

reports.

v. POWERGRID shall also submit the detailed report of filter

bank switching along with event log at HVDC Dadri end of

HVDC Rihand-Dadri.

vi. POWERGRID shall check and correct the non-tripping of

220kV Modipuram, Gobindgarh and Laltokalan station.

vii. Haryana and Rajasthan shall improve the MW load shedding

on the dedicated feeders in SPS operation.

viii. NTPC shall check the reason of MVAr fluctuations of unit-6

of Dadri Thermal and shall include observations in this

regard in the detailed report.

ix. NTPC shall discuss with Railways to provide the balance

load so that immediate revival of supply could be possible

14. Preliminary Report, DR/EL has been received from NTPC. However,

detailed report and remedial measures report is still awaited from NTPC.

NTPC representative agreed to submit the action taken report within 7days.

I. Multiple element tripping at 400/220kV Rewa Road at 14:26hrs of 23rd Dec

2017, 06:40hrs of 29thDec 2017 & 00:05hrs of 30thDec 2017


Generation loss:

Nil (23.12.2017, UP may confirm)



Loss of load:







PMU data

100ms 23.12.2017

560ms 29.12.2017

560ms 30.12.2017


R-phase 23.12.2017

R-phase 29.12.2017

R-phase 30.12.2017



UP Partial Available

23.12.2017

29.12.2017

30.12.2017

DR/ EL UP Not Received

23.12.2017

29.12.2017

30.12.2017


23.12.2017

29.12.2017

30.12.2017


23.12.2017

29.12.2017

30.12.2017



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 3. CEA Grid Standard 15(3), 3.1.e 4. 3. 43.4.A & 43.4.D of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) CEA (Technical standard for connectivity to the Grid, Amendment Regulation 2013), part-II, B2

UP



1. 400kV Rewa Road has following connections with the grid:

a. 400kV Rewa Road-Banda D/C

b. 400kV Rewa Road-Panki

c. 400kV Rewa Road-Obra

d. 400kB Rewa Road-Meja ckt

e. 400V Rewa Road-Bara ckt

f. 400/220kV 315MVA ICT-1 &2


3. 400kV Rewa Road(UP)-Bara(UP) ckt-2 under S/D since 09-Dec-17 for

LILO at Meja(UP).

4. Event Description for 23rd Dec2017 event:

a. R-N fault occurred.

b. 400kV Rewa Road-Banda D/C, 400/220kV 315MVA ICT-1 tripped

at Banda(UP).

c. PMU plots of frequency, df/dt and phase voltage:

d. Tripped Element:

i. 400kV Rewa Road(UP)-Banda(UP) D/C

ii. 315MVA, 400/220kV ICT-1 at Banda(UP)

e. SCADA SoE data:


14:25:04,412 BNDA1_U 220 209MBC CB Invalid

14:26:08,843 BNDA1_U 220 209MBC CB Invalid

f. As per PMU data:

• R-phase to earth fault occurred at 14:26:38.960hrs and cleared

timely.

• Fault clearance time: within 100ms

• It seems auto-reclosing occurred at 14:26:40.120hrs (after

1160ms).

g. Preliminary report, Flag details, DR/EL and detailed report is yet to

be received from UPPTCL.

h. No digital data available in NR SoE.


a. R-N fault occurred in 400kV Rewa Road-Panki.

b. 400kV Rewa Road-Banda ckt-2, 315MVA ICT-1 at Banda also

tripped along with above.


d. Tripped Element:

i. 400kV Rewa Road(UP)-Banda(UP) ckt-2

ii. 400kV Rewa Road(UP)-Panki(UP)

iii. 315MVA, 400/220kV ICT-1 at Banda(UP)

e. SCADA SoE data:


06:40:06,161 ALHA1_U 400 13PANKI CB disturbe

06:40:06,620 PANK1_UP 400 F_06(OBRAB) CB Open

06:40:07,283 ALHA1_U 400 13PANKI CB Close

f. As per PMU data:

• R phase to earth fault occurred at 06:40:06.080hrs

• Fault clearance time: 560ms.

g. As per SCADA SoE data:

• it seems 400kV Rewa Road-Panki auto-reclosed from Rewa

Road end.

h. Probable SoE:

Time(in hrs)

Reference time

Event Corroboration

06:40:06,080 0ms R-N fault in 400kV Rewa Road-Panki PMU

06:40:06,160 80ms400kV Rewa Road-Panki tripped from RewaRoad end; Partial rise in voltage observed

PMU, SCADA SoE

06:40:06,620 540ms400kV Rewa Road-Panki tripped from Pankiend; Fault cleared

PMU, SCADA SoE

06:40:07,280 1200ms400kV Rewa Road-Panki A/R from Rewa Road end

SCADA SoE

i. Preliminary report, Flag details, DR/EL and detailed report is yet to


j. Partial Digital status observed in NR SCADA SoE.


a. R-N fault occurred in 400kV Rewa Road-Panki.

b. LBB protection operated at Rewa road resulted in tripping of all

outgoing lines from Rewa Road.


d. Tripped elements: (All outgoing feeders from Rewa Road (UP)

i. 400kV Rewa Road(UP)-Banda(UP) D/C

ii. 400kV Rewa Road(UP)-Meja(UP)

iii. 400kV Rewa Road(UP)-Panki(UP)

iv. 400kV Rewa Road(UP)-Obra(UP)

v. 315MVA ICT-1 at Banda(UP)

e. SCADA SoE data:


00:04:49,857 ALHA1_U 400 13PANKI CB disturbe

00:04:50,321 PANK1_UP 400 F_06(OBRAB) CB Open

00:04:50,980 ALHA1_U 400 13PANKI CB Close

00:04:54,929 ALHA1_U 400 07MEJA1 CB Open

00:04:54,931 ALHA1_U 400 05BANDA2 CB Open

00:04:54,931 ALHA1_U 400 04BANDA1 CB Open

00:04:54,931 ALHA1_U 400 14OBRAB CB Open

00:04:54,948 BARA_UP 400 5T6OBRA CB Open

00:04:54,952 BARA_UP 400 06ALHA11 CB Open

00:04:56,80 ALHA1_U 400 13PANKI CB Open

f. As per PMU data:

• R-phase to earth fault observed in PMU.

• Fault occurred at 00:04:49.760hrs

• Fault Clearance time: 560ms.

g. As per SCADA SoE data:

• It seems 400kV Rewa Road-Panki auto-reclosed from Rewa

Road end.

• LBB operated at Rewa Road after ~5sec of fault

h. Probable sequence of events:



7. Exact Sequence of event could not finalize due to non-availability of time

synchronized DR/EL from the station.


1. Event on 23rd Dec 2017:

a. Exact sequence of events in view of cause of event; protection



b. Non-reporting of digital status SCADA data of Banda and Rewa

Road.

c. Preliminary report, DR/EL and detail report is still awaited from UP


a. For 400kV Rewa Road-Panki:

i. Delayed tripping from Panki end.

ii. Non auto-reclosing from Panki end.

b. Exact sequence of events in view of cause of event; protection



c. Reason of delayed clearance of fault.

d. Non-reporting of digital status SCADA data of Banda and Rewa

Road.

e. Preliminary report, DR/EL and detail report is still awaited from UP.


a. For 400kV Rewa Road-Panki:

i. Delayed tripping from Panki end.

ii. Non auto-reclosing from Panki end.

iii. Tripping from Rewa Road end after 6sec of fault.

b. Reason of delayed clearance of fault.

c. Reason for LBB protection operation from Rewa Road end after

5sec of fault.

d. Non-reporting of digital status SCADA data of Banda.




f. Preliminary report, DR/EL and detail report is still awaited from UP.

No representative of Rewa Road (UP) of UPPTCL was present in the meeting.

Details was not discussed at the time of meeting.

J. Multiple Element tripping at 400/220kV Bhiwadi Station at 10:33hrs of 22nd

Jan 2018



Loss of load: 260 (As per Rajasthan report)




Phase of the fault Maximum dip in R&Y-phase



Present Status

Remarks


Partially Received

Time Synch error

DR/ EL POWERGRID Received After 24hrs

Rajasthan Not received

Preliminary Report POWERGRID Received After 24hrs

Rajasthan Not received

Detailed Report POWERGRID Received



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d 4. 43.4.A of CEA Technical Standard for Construction

POWERGRID, Rajasthan

1. DR/EL received after 24hrs 2. Adequately Sectionalized and graded protective relaying system

of Electrical Plants and Electric Lines; 5. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3)


1. Single Line Diagram and connectivity diagram of Bhiwadi (PG):

220kV

400kV

2. 220kV Bhiwadi (PG) station is connected with 220kV Bhiwadi D/C, 220kV

Rewari D/C, 220kV Bawal S/C, 220kV Mau S/C, 220kV Neemrana S/C,

220kV Kushkhera S/C.

3. 220kV Bhiwadi(PG)-Bhiwadi(RJ) Ckt-I tripped at 10:29:36 Hrs in Zone-2

from Bhiwadi(PG) end on R-N fault.

4. At 10:33:05 Hrs fault re-appeared in 220kV Bhiwadi(PG)-Bhiwadi(RJ) Ckt-

II. It is verbally inform by RRVPNL that Jumper of Bhiwadi-2 line was

snapped and created the three phase Bus fault at their end. However,

during fault detected in 220kV Bhiwadi(PG)-Bhiwadi(RJ) Ckt-II, Bus Bar

Protection for 220 kV bus-2 operated and following feeders connected to

220 kV Bhiwadi (PG) bus-2 along with Bus Coupler tripped immediately

along with HVDC Balia-Bhiwadi Pole-2

5. Name of the tripped element:

• 220KV ICT-1

• 220KV ICT-2

• 220KV Bhiwadi-2

• 220KV Kushkhera

• 220KV Rewari-2(Charged at NO Load)

• 220KV Bawal

6. Distance protection of 220kV Bhiwadi(PG)-Bhiwadi(RJ) ckt-1 operated

correctly however zone2 timing kept to 100ms in view of frequent fault in

line, unreliable tele-protection and non-availability of Bus Bar at remote

end.

7. Phase-phase Fault (R-Y) was experienced which converted to 3-phase

fault in 220kV Bhiwadi(PG)-Bhiwadi(RJ) Ckt-I. After approx 70msec of

fault, Bus Bar Protection for 220 kV bus-2 operated which lead to tripping

of all 220kV elements connected to 220 kV bus-2 of Bhiwadi (PG).

8. HVDC Balia-Bhiwadi Pole-2 also tripped upon tripping of Bus-2. HVDC

Balia-Bhiwadi Bipole was running with 250MW power flow from Balia to

Bhiwadi and Earth Electrode line was in service

9. Auxiliary supply of HVDC Bi-pole was tripped on “under-voltage” due to

tripping of ICT-1 and ICT-2. UPS of pole-2 did not take backup before DG

could start, thus the Pole-2 tripped on “AC Supply Fault”. In present case,

batteries could not take load for the interrupted power which was installed

in Feb,17. However same batteries has taken load 3 times since

commissioning in Feb,17. Battery load test is under progress for

identification of Faulty battery element.

10. PMU plots:

ΔF~0.04

10:33:06.640hrs

10:33:06.760hrs

10:33:20.120hrs


• R-N fault occurred at 10:29:36.320hrs and cleared in 200ms.

• 3-phase fault occurred at 10:33:06.640hrs and cleared in 120ms



10:29:37,058 BHIWADI 220kV 06BHIWR1 CB Open

10:33:05,768 BHIWADI 220kV 10BAWAL CB Open

10:33:06,521 BHIWADI 400kV 3T1 CB Open


10:33:06,522 BHIWADI 400kV 2T1AG1 CB Open

10:33:06,522 BHIWADI 400kV 5T2BA1 CB Open

10:33:06,523 BHIWADI 220kV 09RWARI2 CB Open



10:33:07,101 BHIWADI 220kV 07BHIWR2 CB Open

10:33:07,397 BHIWADI 220kV 04MBC CB Open

13. As per SCADA SoE:

• As per SCADA SoE, feeders at Bhiwadi tripped at different timings

14. Restoration time:

• 220KV Bus-2 Restored at 11:18 Hrs

• 220KV Kushkhera line Restored at 11:25 Hrs

• 220KV Bawal line Restored at 13:03 Hrs

• 220KV Bhiwadi-1 line Restored at 14:40 Hrs

• 220KV Bhiwadi-2 line Restored at 14:21 Hrs

• 315MVA ICT-1 Restored at 10:54 Hrs

• 315MVA ICT-2 Restored at 10:55 Hrs

• Pole-2 HVDC Restored at 11:05 Hrs

15. Remedial measures (As per POWERGRID report):

• The suspected Faulty B-Phase card of Bus Bar Protection-2

measuring module of 220 kV Bus Bar-2 protection replaced with

spare.

• ICT-1 and ICT-2 is connected to separate 220kV Buses so that

auxiliary supply to HVDC will not be interrupted in case of single

220kV Bus outage.

16. Preliminary Report, DR/EL and detailed report has been received from

POWERGRID but still awaited from Rajasthan.

Rajasthan represented during the meeting:

1. R-ph jumper of 220kV Bhiwadi(PG)-Bhiwadi(Raj) ckt 2 snapped at

Bhiwadi(Raj) end, which caused the operation of Bus-Bar protection at

220kV Bus-2 of Bhiwadi(PG) leads to tripping of multiple elements at

400/220kV Bhiwadi station along with HVDC 500kV Balia-Bhiwadi.

2. 220kV Bhiwadi-Bhiwadi PG line-1 tripped on actual fault both end.

• Z-1 from RVPN end Load before trip=403 Amp.

• Z-2 from PG end Load before trip=401 Amp.

3. 220 kV Bhiwadi-Bhiwadi PG line-2 tripped on actual fault (due to heavy

load 800 amp. current, Jumper snapped at RVPN end, at 1st tower) from

PG end(Radial feeder).

4. Reason of tripping: - Both 220kV lines carrying 400 amps. Current before

tripping. 220kV Bhiwadi line-1 tripped and 800 amp current running on

line-2 cause snapped the jumper at RVPN end and line tripped from PG

end only because no source available at 220kV Bhiwadi RVPN end. Bus

bar operation at Bhiwadi PG end seems mal operation

POWERGRID informed during the meeting:

1. Reason of operation of bus bar protection at 220kV Bhiwadi (PG) during

through fault needs to be relooked: The suspected Faulty B-Phase card of

Bus Bar Protection-2 measuring module of 220 kV Bus Bar-2 protection

replaced with spare

2. At Bhiwadi(PG), time of opening of CB as captured from SCADA SoE is

not consistent with PMU based fault timings: Time synchronization in view

of above would be checked at Bhiwadi(PG)

3. As per SCADA SoE, tripping of feeders at different timings in case of bus

fault (not being simultaneous) needs to be checked: It would be checked

and reverted

4. In view of both the ICTs, feeding auxiliary to HVDC, getting tripped which

lead to tripping of HVDC pole, the following general recommendation is

proposed: ICT-1 and ICT-2 is connected to separate 220kV Buses so that

auxiliary supply to HVDC will not be interrupted in case of single 220kV

Bus outage

5. Back up auxiliary supply for HVDC Pole-1 & 2 needs to be looked into:

Earlier battery fault was suspected but batteries were performing well

during full load test of the battery. UPS would also be checked in view of

performance measures.

Northern Regional Load Despatch Centre

MoM for 35th PSC meeting

20/06/2018

1. Tripping events

K. Multiple Element tripping in Delhi control area and islanded

operation of Pragati GT at 12:28hrs of 21st Feb 2018


Generation loss: 100MW (As per Delhi Report)

Loss of load: 200MW (As per Delhi Report)




Phase of the fault R-Y phase to phase fault

As per PMU data and Delhi Report

Description Utilities Present Status Remarks


Available

DR/ EL

DTL Received After 24hrs

NTPC Not received

BBMB Received After 24hrs

Preliminary Report

DTL Received After 24hrs

NTPC Not received

BBMB Received After 24hrs

Detailed Report DTL Not Received

NTPC Not Received



1. CEA grid Standard 15.3 2. CEA (Technical

standards for connectivity to the Grid) Regulation,

2007-6. 4.d 3. 43.4.A of CEA Technical Standard for Construction

DTL, NTPC, BBMB

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Delayed clearance of fault

of Electrical Plants and Electric Lines



2. 220kV Badarpur TPS is connected with 220kV Bamnauli D/C, Ballabgarh

(BBMB) D/C, Okhla S/C, Sarita Vihar D/C and MIA Alwar S/C. Badarpur

TPS has 3*95 +2*210MW generation capacity.


• All 400/220kV ICTs at M.Bagh(PG) under planned S/D

• Bus splitting at 220kV Maharani Bagh with open bus coupler.

• 220kV M.Bagh-AIIMS D/C and 220kV M.Bagh-Lodhi Road D/C running

on separate bus at M.Bagh fed from Bamnauli

• 220kV Noida-Gazipur D/C in open condition

• No generation at BTPS

• Prior to the incident which occurred at 12:28 hrs., 220kV Bus coupler

at Pragati was in OFF position.

• The Pragati Generation, GT#1, GT#2 and STG was on 220kV Bus-I at

Pragati which was connected with Grid through Pragati-Sarita Vihar-

BTPS-Ballabhgarh, BTPS-Alwar and BTPS-Mehrauli-DIAL-Bamnauli

4. There was R-Y phase to phase fault occurred in 220 kV BTPS-Mehrauli

ckt-II.

5. This ckt tripped at BTPS end, while it couldn’t trip at Mehrauli end.

6. This led to tripping of 220 kV BTPS-Mehrauli ckt-I at BTPS end, tripping of

220 kV BTPS-Ballabhgarh ckt-I & II at Ballabhgarh end and tripping of

220kV bus coupler at 220 kV Mehrauli end.

7. 220 kV Sarita Vihar-Maharani Bagh and 220 kV Sarita Vihar-Pragati also

tripped at Sarita Vihar end.

8. At 12:32 hrs, failure of supply from Alwar occurred at BTPS end (over

current protection) resulting complete blackout at BTPS and Okhla.

9. After tripping of 220kV Sarita Vihar-Pragati, 220kV Sarita Vihar-M. Bagh

and 220kV M.Bagh-Masjid Moth-II, the GT#1, GT#2 and STG of Pragati

were disconnected from the grid and islanded with Parkstreet, Maharani

Bagh, Gazipur, Sarita Vihar.

10. Load shedding based on UFR scheme also occurred in the island.

11. 6-7 attempts were made to synchronize island with grid at M.Bagh, Pragati

but could not be successful.

12. Finally generation of Pragati was shut (momentary blackout of island) and

afterwards supply restored at around 13:45hrs.


• 220 kV Badarpur TPS-Ballabhgarh ckt-1 & 2

• 220 kV Badarpur TPS-Mehrauli ckt-1 & 2

• 220 kV Badarpur TPS-MIA Alwar

• 220kV Sarita Vihar-Maharani Bagh

• 220kV Sarita Vihar-Pragati

• Complete 220kV BTPS station went blackout.

• Masjid Moth, Electric Lane stations also went under blackout.

14. As per Delhi Report:

UFR operation details:

15. Sequence of Event as per Delhi report:

• At 12:28:54:20, 220kV BTPS-Mehrauli Ckt-II tripped at BTPS end. No

tripping occurred at Mehrauli end.

• At 12:28:55:818, 220kV BTPS-Okhla Ckt-II tripped at BTPS end.

• At 12:28:55:871, 220kV BTPS-Mehrauli Ckt-I tripped at BTPS end.

• At 12:28:56:147, 220kV Sarita Vihar-Pragati tripped at Sarita Vihar

end.

• At 12:28:56:229, 220kV Sarita Vihar-M. Bagh tripped at Sarita Vihar

end.


17. PMU plots:

18. As per SCADA data:

19. As per PMU & SCADA data:

• Fault cleared in around 1 sec.

• From SCADA SoE, it seems 220kV BTPS-Mehrauli ckt-2 tripped from

BTPS end around 400ms prior to observance of fault.

• Pragati island ran for more than an hour.

20. SCADA SoE:

21. Preliminary Report, DR/EL has been received from DTL, BBMB but still

awaited from NTPC. Detailed Report and remedial measures report is still

awaited from DTL.

Delhi representative informed during the meeting:

Point of Discussion Reason Action Taken

1 Reason for complete outage of Badarpur TPS.

2 Delayed Clearance of fault a

Non opening of circuit breaker at Mehrauli end for Mehrauli-BTPS ckt-2

Tripping circuit made healthy and problem rectified.

b.

Delayed fault clearance at BTPS end which results in tripping of Ballabgarh and Alwar circuits at BTPS end.

BTPS needs to clarify.

3 Exact Sequence of event to be establised. a.

Fault in BTPS-Mehrauli Ckt-2. No tripping at Mehauli end.

Tripping circuit was faulty and the problem was rectified.

b.

Multiple trippings of Mehrauli ckt-1, Okhla Circuit and Ballabgarh circuits at BTPS end.


c. Tripping of Pragati and M.bagh Circuit from Sarita Vihar end.

Phase-Phase tripping for A/R lockout was got enabled with Start element which was rectified to trip element.

4 Reason of Z-1 tripping of 220kV Sarita Vihar to Pragati and M.bagh needs to be checked as fault was in 220kV BTPS-Mehrauli Ckt-2

Phase-Phase tripping wrongly assigned for any ph-ph start

Phase-Phase tripping for A/R lockout was got enabled with Start element which was rectified to trip element.

5 Tripping of Ballabgarh (BBMB)-BTPS needs to be looked into.


6 Details of UFR, df/dt based load shedding to be confirmed.

UFR operated as per the feeders assigned on Park-Street, Gazipur, Sarita Vihar, Masjid Moth according to DTL islanding scheme.

7

The following arrangement as informed by DTL official to be discussed: a.) Splitting at 220kV M.Bagh to be avoided. b.) This would result in supply availability from Bamnauli through Bamnauli-Naraina-Ridge Valley-AIIMS-M. Bagh route. c.) The overloading of 220kV Naraina-Ridge Valley could be taken care of by SPS (in operation) at Naraina which shed load on I>700A.

SPS is already installed at Naraina to avoid overloading of Naraina-Ridge valley cable.

8 Synchronization issue and further mock drill exercise requirement.

Synchronisation issue was discussed in the Delhi OCC meeting and it was observed that the Bus Coupler at Pragati couldn't be closed due to large difference in 220kV Bus-I and Bus-II at Pragati.

It was decided in the Delhi OCC that (i)The voltage and frequency of both 220kV Buses be provided by DTL to PPCL. Similarly, the voltage and frequency of the GTs be provided by PPCL to DTL. The supply of necessary meters, wires, etc. including its laying be done by PPCL. (ii)PPCL to control the voltage, frequency parameters in order to synchronize both the 220kV bus at the earliest after the instruction of SLDC. (iii)During islanding and after the instructions of SLDC, the DTL and PPCL control room staff will communicate with each other in order to synchronize both the 220kV bus at the earliest. Also Mock drill exercise conducted on GT unit-3 in presence of NRPC and NRLDC officials on 13.04.18.

9 Planned versus actual UFR and df/dt operation

UFR operated as per the feeders assigned on Park-Street, Gazipur, Sarita Vihar, Masjid Moth according to DTL islanding scheme.

L. Multiple Element tripping at 400 kV Agra (UP) at 18:09hrs of 04th Mar 2018


Generation loss: Nil (As per UP report)

Loss of load: 100MW (As per UP report)

Energy Unserved: 0.1MU (As per UP report)




320ms &

440ms As per PMU data

Phase of the fault

Maximum dip in Y-phase

followed by B-phase.

As per PMU data


Present Status

Remarks

Availability of Digital Data

(SCADA Data) Available

DR/ EL Uttar Pradesh

Received (Partial)

After 24hrs


Preliminary Report

Uttar Pradesh Received Within 24hrs


Detailed Report Uttar Pradesh Not Received



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3

3. CEA (Technical standards for connectivity to the Grid)

Regulation, 2007-6. 4.d

4. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric

Lines; 5. CEA (Technical standards for

connectivity to the Grid) Regulation, 2007: Schedule Part

1. ( 6.1, 6.2, 6.3) 6. CEA (Technical standard for

connectivity to the Grid, Amendment Regulation 2013),

part-II, B2

POWERGRID, Uttar Pradesh

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Adequately Sectionalized and graded protective relaying system 4. Delayed clearance of fault


1. Connectivity Diagram and SLD of 400/220 kV Agra (UP):

2. 400 kV Agra (UP) is connected with rest of the grid via Fatehabad D/C,

Agra (PG) S/C, Unnao (UP) S/C. It also has transformation capacity of

2*500+1*315MVA.

3. Following were the feeders configuration at 400kV buses at Agra(UP):

• 400 kV Bus-1: 400/220 kV ICT-1, 3, Unnao, Fatehabad-2

• 400 kV Bus-2: 400/220 kV ICT-2, Fatehabad-1, Agra(PG)

4. Lightning struck on 400 kV Agra bus-1 (Y-ph) and Agra bus-2 (B-ph) at

18:09:37hrs and 18:09:41hrs respectively.

5. For 400 kV bus-1, all connected elements tripped except the following:

• ICT-1 Group B Over flux operated but HV side CB didn’t trip resulting

in LBB operation.

• ICT-3 didn’t trip. Manually opened at 18:15hrs.

6. For 400 kV bus-2, all connected elements tripped except the following:

• Fatehabad-1 ckt tripped on Z-4 (time setting 250ms) but CB opening

delayed resulting in LBB operation. Setting of Z-4 for above ckt revised

to 500ms.


• 400 kV Agra(UP)-Fatehabad 765 (UP) ckt-1 & 2

• 400 kV Agra(PG)-Agra(UP) ckt-1

• 400 kV Agra (UP)-Unnao (UP)

• 400/220 kV 500MVA ICT-1 & 2

8. As per UPPTCL Report:

10. PMU plots:

11. As per PMU & SCADA data:

• At 18:09:37.560hrs, Y-N fault occurred which cleared in 320ms.

• At 18:09:41.120hrs, B-N fault occurred which cleared in 440ms.

• From SCADA SoE, not all line tripping registered. Among the events

captured, tripping seems to be in order except tripping of 400kV

Agra(UP)-Agra(PG) ckt from Agra(PG).

12. SCADA SoE:

13. Preliminary Report, DR/EL has been received from UPPTCL but still

awaited from POWERGRID. Detailed Report and remedial measures

report is still awaited from UPPTCL.

UPPTCL representative informed following points during the meeting:

UPPTCL informed that bus bar protection operated for both 400 kV buses at

Agra (UP) due to simultaneous lightening in the switchyard.

Action Points (Point wise reply):

1. Time synchronization error is suspected in DR/EL of Agra(UP). Same

needs to be checked and rectified: Clock Synchronised on 05.06.2018

2. Feeder name, station name is not properly mentioned in DR of Agra(UP).

Same needs to be checked and rectified: After LILO of lines the changes

in names of feeders are not done. The same will be done shortly.


• Reason for tripping of 400kV Agra-Unnao ckt from Unnao end in

~140ms of fault to be looked into and shared.

• Reason for opening of 400kV Agra(UP)-Agra(PG) ckt from Agra(PG)

end (tie CB during fault and main CB after ~1sec of fault) to be looked

into and shared.

Information of Unnao end and Agra (PG) end was not available and same

would be collected and informed.

4. As per UP report and details:

• Reason for tripping of ICT-1 on over flux when there seems no

condition for over fluxing needs to be shared:

ICT-1 was not tripped on over flux as mentioned in analysis. This was

wrongly mentioned. 400/220 kV ICT-1 also tripped on LBB protection

as per flag details.

Points for Discussion (point wise reply):

1. As per UP report, ICT-3 didn’t trip. However, fault cleared in ~320ms.

How the fault get cleared if ICT-3 didn’t trip: ICT-2 didn’t trip on LBB/ Bus

Bar Protection due to DC problem. The problem has been shorted out and

taken in services.

2. As per UP report, bus bar protection of bus-2 operated and LBB of

Fatehabad-1 ckt (connected to bus-2) also operated after operation of Z-4

relay (250ms time setting): Fatehabad-I circuit has Z-4 setting of 250ms at

the time of event. The setting have been done 500ms.

3. Detailed report and remedial measures report to be submitted: To be

submitted within 10days

NRPC also asked for design of lightening mast as simultaneous lightening in

400kV switchyard is rarest of the rare event and asked UPPTCL to share the

photos and further details.

M. Tripping of multiple lines and generation in Baspa-Karcham-Jhakri-Rampur

complex at 17:15hrs of 29th Mar 2018


Generation loss: 600 MW

Loss of load: Nil

Energy Unserved: Nil




Phase of the fault

Maximum dip in R-phase at the time of delayed clearance of fault

As per PMU data (Multiple fault in the system)

Description Utilities Present Status Remarks


Available

DR/ EL

SJVNL Received Within 24hrs

JSW/ Himachal Pradesh Not received

POWERGRID Received Within 24hrs

Preliminary Report

SJVNL Received Within 24hrs


POWERGRID Received Within 24hrs

Detailed Report

SJVNL Not Received


POWERGRID Not Received



1. CEA grid Standard 15.3 2. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6.4.d 3. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines

POWERGRID, NJPC, JSW

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Delayed clearance of fault


1. Connectivity Diagram of Jhakri, Karcham, Baspa and Nathpa Jhakri

complex:

2. Thunderstorm and bad weather reported in the Baspa-Karcham-Jhakri-

Rampur complex.

3. Multiple faults occurred resulted in tripping of multiple lines in the complex

as well as generation due to evacuation constraint

4. Following elements tripped:

• 400kV Jhakri-Rampur D/C

• 400kV Jhakri-Panchkula D/C

• 400kV Jhakri-Karcham D/C

• 400kV Karcham-Baspa D/C

• 400kV Karcham-Kala Amb D/C

• Running units at Baspa, Karcham, Jhakri, Rampur HEP

5. SCADA SoE data:

6. PMU plots of frequency and phase voltage:

7. As per PMU data:

• Multiple faults occurred.

• At 17:21:21.640hrs, R-N fault occurred which cleared in ~900ms.

8. DR details:

9. Preliminary report, Flag details, DR/EL has been received from

POWERGRID/ SJVNL but still awaited from JSW/ Himachal Pradesh.

Detailed report is yet to be received from SJVNL/ POWERGRID.

Action Points:

1. As per DR, at 17:18hrs, all three phases of 400kV Jhakri (end)-Rampur-2

tripped without auto-reclosing. Reason for the same to be checked and

shared.

2. As per DR, at 17:21hrs, 400kV Jhakri-Panchkula (end)-1, line tripped on

TEF protection. Non-triggering of distance protection for a fault in line to

be looked into. Setting of TEF protection to be shared.

3. As per DR of 400kV Jhakri (end)-Punchkula-2, it seems time

synchronization error of around 100ms is present. The same needs to be

checked and rectified.

4. As per DR received from Rampur, it seems time synchronization error is

present. The same needs to be checked and rectified.

5. DR configuration at Rampur HEP needs to be looked into in view of

following points:

• Name of the element

• DR of which end

• Main-I or Main-II protection

• Mapping of minimum standard signal as approved in PSC meeting

POWERGRID representative informed during the meeting:

1. Delayed clearance of fault in 400 kV Jhakri-Panchkula ckt-1 was due to

operation of DEF (directional earth fault) protection from Panchkula end.

Distance zone protection delayed pick up after 600ms in Z-2 from

Panchkula end.

2. DEF protection setting of 400 kV Jhakri-Panchkula ckt-1 would be once

again reviewed and shared.

3. In normal weather condition, the clearance seems to be OK. However,



condition.

4. The polymer insulators are light weighted. During high wind condition, the

conductor could swing resulting in inadequate clearance and subsequent

fault condition. Counter weights are sometimes added at few locations to

avoid the above.

No representative from SJVNL/ JSW attended the meeting.

NRPC also requested HP to take data from JSW plants and share the details as

plants situated in Himachal control area.

N. Multiple Element tripping at 400/220kV Sarnath (UP) at 22:07hrs of 30th Mar

2018



Loss of load: 170MW

Energy Loss: 0.14 MU



1. Single Line Diagram of Sarnath (UP) station:

2. 400/220/132kV Sarnath (UP) is connected with 400kV Varanasi (PG) D/C,

Anpara D/C and Azamgarh (UP). It has two 315MVA and one 500MVA

400/220kV ICTs and also has one 125MVAr bus reactor.

3. Y-phase CT of 400kV Sarnath-Azamgarh ckt bursted. It resulted into

operation of bus bar protection for 400kV Bus-1 at Sarnath (UP).

4. As isolator auxiliary contact input to the bus bar protection for 400kV

Sarnath-Anpara ckt-1 (L-3) was shown connected for both the bus. It

resulted into bus tied operation and operation of both the bus bar

protection at 400 kV Sarnath (UP)

5. All the 400 kV connected lines and ICT’s at 400 kV Sarnath (UP) tripped.


• 400 kV Sarnath(UP)-Varanasi(PG) ckt-1

• 400 kV Sarnath(UP)-Varanasi(PG) ckt-2

• 400 kV Anpara-Sarnath ckt-1

• 400 kV Anpara-Sarnath ckt-2

• 400 kV Azamgarh-Sarnath ckt

• 400/220 kV 315MVA ICT-1 & 3

• 400/220 kV 500MVA ICT-2

7. PMU plots:

8. As per PMU data:

• At 22:07:48.080hrs, Maximum voltage dip in Y-phase followed by R-

phase. Fault clearance time: 440ms

• At 22:07:49.360hrs, Voltage dip in all three phase. Fault clearance

time: 80ms

9. Extract of UPPTCL report:

10. As per DR/ EL details:

• All three phase of 400 kV Sarnath-Azamgarh line tripped on single

phase to earth fault (Y-phase to earth fault).

• Y-phase conducted after opening of the breaker (It seems breaker

didn’t open properly)

• After 300ms of initial fault, R-phase to earth fault also observed.

• After 1100ms of initial, again fault current observed in all three phase

of the line

11. SCADA Analog data and SoE:


• Time synch error.

• 400kV Anpara-Sarnath line tripped from Anpara end within 100ms of

fault occurrence and auto reclosed after ~1200ms. Line finally tripped

due to persistent nature of fault in the system.

• After ~2second of opening of line, 400kV Anpara (end)-Sarnath line

again closed and opened after ~700ms.

• ICTs tripping of Sarnath (UP) captured but with time synch error.

13. Preliminary Report, DR/EL (partial) has been received from UPPTCL.

However, detailed report and remedial measures report is still awaited

from UPPTCL.

UPPTCL representative informed during the meeting:

Point wise reply of Action Point & point for discussion, mentioned in the

Agenda:

1. Station Event Log of Sarnath (end) is not time synch. Station event logger

should be time synch for proper analysis of multiple element tripping: New

event logger is under progress and may be implemented by Sep-2018

2. DR recording time is 500ms only, It needs to be changed with 2500ms

(500ms pre triggering and 2000ms post triggering): In Alstom relay, it has

been changed but in Siprotec relay, no provision available to change the

post fault time from 500ms to 2000ms.

3. SCADA SoE time synchronization and complete availability of digital

status needs to be looked into: Time Synchronisation would be checked

separately.

4. It seems 400 kV Anpara-Sarnath line tripped from Anpara end in Z-1

however fault was at the bus of Sarnath (UP). Distance protection setting

at Anpara (end) of 400kV Anpara-Sarnath line needs to checked and

corrected: It seems Anpara end over reached during the fault in the

system. Zone protection setting would be reviewed and shared.

5. Exact location of fault. Was it bus fault? : Yes, it is bus fault as Y-phase

CT busted during the incident and bus bar protection also operated.

6. Reason of complete station outage: Bus tied operation at 400 kV Sarnath

(UP). Bus tied signal provided in the control room

7. Reason of three phase tripping of 400 kV Sarnath-Azamgarh line during

Y-phase to earth fault in the line: A/R function would be test and revert

back

8. Detailed report and remedial measures report of the incident to be shared.

9. In case of bus fault why delayed operation after ~450ms: To be

ascertained.

O. Multiple element tripping at 220 kV Sakatpura and KTPS (Kota TPS) at

01:42hrs of 01st Apr 2018


Generation loss: 700 MW (As per Rajasthan Report)

Loss of load: 500 MW (As per Rajasthan Report)




Phase of the fault Maximum dip in Y-phase



Present Status

Remarks


Available

DR/ EL Rajasthan Received After 24hrs POWERGRID Not received

Preliminary Report Rajasthan Received After 24hrs POWERGRID Not received




1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d 4. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; 5. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) 6. CEA (Technical standard for connectivity to the Grid, Amendment Regulation 2013), part-II, B2

POWERGRID, Rajasthan

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Adequately Sectionalized and graded protective relaying system 4. Delayed clearance of fault


1. 220kV Sakatpura (Kota) has following connection:

a. 220 kV Kota TPS-1, 2, 3 & 4

b. 220 kV Dahra ckt

c. 220 kV Anta ckt

d. 220 kV RAPP-A ckt-1 & 2

e. 220 kV RAPP-B ckt

f. 220 kV Bhilwara ckt

g. 220 kV Badod ckt

h. 220 kV Mandalgarh ckt

i. 220/132kV 100MVA ICT-1, 2, 3 & 4

2. Single Line Diagram:

SLD of Sakatpura (220kV Kota)

SLD of 220 kV Kota TPS

3. In antecedent condition Unit #1 & #2 out at KTPS and bus bar protection

of Sakatpura was also not in service.

4. At Sakatpura, Y-Phase CT of 220kV Bus Coupler B-C damaged due to

internal fault/Insulation failure. It was also observed that jumpers

connecting bus C to CB, CT and CB and Bus B isolator and CT also got

damaged badly.

5. All 220kV feeders connected to Sakatpura GSS tripped on fault either

from Sakatpura end or far end mostly on distance protection.

6. Since, 220kV Sakatpura-KTPS line is very small (<1km), differential

protection is in place as primary unit protection

7. Following elements tripped during the incident:

• Unit #3, #4, #5, #6, #7 at KTPS

• 220kV KTPS-Kota(PG) D/C

• 220kV KTPS-Heerpaura

• 220kV KTPS-Bundi

• 220kV KTPS-Beawar

• 220kV KTPS-Sakatpura-1, 3

• 220kV KTPS-Vatika

• 220kV KTPS-Morak

• 220kV Sakatpura-Bhanupura

• 220kV Sakatpura-RAPS-1, 2, 3

• 220kV Sakatpura-Dahra

• 220kV Sakatpura-Anta

• 220kV Sakatpura-Mandalgarh

• 220/132kV ICT-3 at Sakatpura

8. As per Rajasthan report:

• On 1.03.2018 Y-Phase CT of 220 KV Bus Coupler B-C damaged

due to internal fault/Insulation failure. It was also observed that

jumpers connecting bus C to CB, CT and CB and Bus B isolator

and CT also got damaged badly.

• During investigation it came into notice that multiple sounds were

heard and heavy flashover and flame was observed by GSS staff.

• DR recorded in RAPP-2 feeders distance relay shows that system

voltage fluctuated heavily many times during fault duration so fault

characteristics recorded by relay kept changing continuously.

• TMS setting of all the bus coupler and bus sectionalizer at 220 GSS

Sakatpura is 0.05 as Bus bar relay is defective. Bus coupler and

bus sectionalizer opened on E/F during the fault.

• All 220 KV feeders connected to Sakatpura GSS tripped on fault

either from Sakatpura end or far end on distance protection except

KTPS 1, 2, 3 and 4 feeders.

• KTPS 1 and 3 feeders were connected on faulty bus C and KTPS 2

and 4 were connected on bus A (Line diagram enclosed).

• Bus coupler B-C and A-D, sectionalizer A-B tripped at Sakatpura

end but all KTPS feeders remain coupled at KTPS end.

• As line length of Sakatpura-KTPS feeders is merely 0.9 Km no

distance protection but only line differential protection is installed on

these feeders along with backup protection. As Fault was out of the

zone for line differential relays, fault was cleared only when KTPS 1

and 3 opened on backup relays

9. As per Kota TPS details”

10. PMU data of frequency and phase voltage:


• At 01:42:53.960hrs, Maximum voltage dip in all three phase.

Fault clearance time: ~1200ms

12. SCADA SoE:

13. Event Description for 01st Jan 2018 event:

a. Preliminary Report, DR/EL and detailed report has received from

BBMB.

Rajasthan informed the following point during the meeting:

1. Status of availability of bus bar protection at 220kV Kota (Sakatpura)

having four number of bus bars to be shared: 220 kV Bus Bar Protection

of ABB make was not in service. Total 71 bus bar protection has procured

but have limitation of number of feeder so 21 new bus bar protection is

also under tendering stage. Once bus bar protection would be ordered, old

bus bar protection at 220 kV Sakatpura shall be replaced.

2. As approved in 25th PSC meeting, temporary arrangement for bus bar

protection, could be put in place till actual bus bar protection is available.

Status of the same to be apprised: TMS setting of all the bus coupler and

bus sectionaliser at 220 kV GSS Sakatpura is 0.05 as Bus bar relay is

defective. Bus coupler and bus sectionaliser opened on E/F during the

fault. In Rajasthan this scheme has been already implemented in total 129

station of 220kV and above voltage level.

3. Exact location of fault: Y-Phase CT of 220 kV Bus Coupler B-C damaged

due to internal fault/Insulation failure. It was also observed that jumpers

connecting bus C to CB, CT and CB and Bus B isolator and CT also got

damaged badly

4. Exact Sequence of Event needs to be finalised: Yet to be ascertained,

however healthiness of station event logger would be ascertained.

5. Most of the elements are reportedly tripping in Z-1, Z-2. However, fault

clearance time is ~1200ms (as per PMU data). Reason of delayed

clearance of fault to be looked into: Non tripping of 220 kV Sakatpura-Kota

TPS ckt may be resulted into delayed clearance of fault.

6. For a fault in Bus coupler of Bus B & C, elements connected to Bus-B & C

would have tripped leaving buses A & D healthy through operation of bus

sectionaliser. As per SCADA SoE, bus sectionliser opened but still the

elements connected to other buses tripped: This needs to be investigated

further and details would be shared

7. From DR, 220kV Sakatpura-RAPS-2 tripped from RAPS end in 240ms

(reportedly in Z-2 from RAPS-2 end). The setting of distance zone settings

at RAPS as well as other stations involved in the tripping be checked and

shared: Sensitive Z-1 Protection setting at RAPS end checked and

corrected.

8. Time synchronization error at following stations needs to be resolved :

a. Sakatpura

b. Kota TPS

c. Vatika

d. Dahra

Time Synchronization error would be resolved shortly.

NPCIL representative informed that P-442 Micom relay of 220 kV RAPP (end)-

Sakatpura ckt-1 tripped from RAPP end in Z-1 instead of Z-2. Distance zone

setting value has been changed accordingly.

P. Multiple element tripping at 400/220kV Bareilly (UP) at 22:39hrs of 05th Apr

2018 and 10:51hrs of 08th Apr 2018


Generation loss:



Loss of load (in MW):



Energy Loss (in MU):

0.05MU (05.04.2018, UP may confirm)

MU (08.04.2018, UP may confirm)



Fault Clearance Time No fault 05.04.2018

No fault 08.04.2018

Phase of the fault NA 05.04.2018

NA 08.04.2018


Present Status

Remarks


Received

DR/ EL

POWERGRID Not Received 05.04.2018

Uttar Pradesh Not Received 05.04.2018


Uttar Pradesh Not received 08.04.2018

Preliminary Report


Uttar Pradesh Received (within 24hrs)

05.04.2018


Uttar Pradesh Received (within 24hrs)

08.04.2018

Detailed Report

Uttar Pradesh Received (Not as per format)

05.04.2018

Uttar Pradesh Received (Not as per format)

08.04.2018



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA grid Standard 15.3 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007-6. 4.d 4. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; 5. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3)


1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Adequately Sectionalized and graded protective relaying system



a. 400 kV Bareilly (UP) has following connections:

• 400kV Bareilly (UP)-Bareilly (PG) D/C

• 400kV Bareilly (UP)-Unnao (UP) D/C

• 400/220 kV three 315MVA ICT

2. Event Description for 05th Apr 2018 event:

a. SLD with tripped elements:

b. In antecedent condition, 400kV Bareilly(UP)-Unnao(UP) D/C was

under planned S/D for relay testing at Unnao end and breaker

maintenance at Bareilly end.

c. During testing, trip contacts of 86B of Unnao-1 line stuck at

Bareilly(UP). However, there was no flag in this respect at Control

Panel.

d. 400kV Unnao-1 was being charged through TBC (Bus reactor was

earlier charged through TBC through bus-A).

e. Auxiliary contact of Bus-A isolator of TBC became unhealthy.

f. While charging the Unnao-1 ckt at Bareilly through bus-B, bus tied

operation resulted.

g. Since, the NIT switch was switch at Intermediate state, stuck 86B

gave tripping to LBB and due to bus tied operation all feeders

connected to Bus-A, B tripped.

h. Tripped Element and respective restoration time (As per UP

Report):

i. PMU data of frequency, df/dt and phase voltages:

j. SCADA SoE data:

k. As per PMU & SCADA data:

• No fault observed through PMU. As per SoE, all reported

elements tripped after ~200ms of closing of TBC

l. As per UP report:

m. Remedial Action taken:

• The 86B relay and auxiliary contacts problem has been

resolved.

• Thorough testing of 400 kV Bareilly S/S is required.

n. Preliminary report, station EL has been received from UPPTCL. DR

details and detailed report is still awaited from UPPTCL.


a. In antecedent condition, 400kV Bareilly (UP)-Unnao ckt-2 was

charged through transfer bus coupler. Reported power flow in

antecedent condition is tabulated below

b. SLD and tripped elements status:

c. Breaker of 400kV Bareilly(UP)-Unnao(UP)-2 was under S/D for

maintenance. Line was charged through TBC. Drive maintenance

work of 29A bus isolator of this line was also planned and going on.

d. The 29A isolator opened at 10:10hrs for maintenance work. During

this operation, due to improper shifting of auxiliary contacts

chattering observed in CT supervision relay and bus bar protection

got blocked.

e. Attempt made for proper shifting of auxiliary contacts but flashover

occurred in the relay led to burning and melting of this relay.

f. This led to extension of DC (+) to all trip relays of BBP panel via trip

bus

g. Following element connected to 400kV bus-1 0f Bareilly (UP)

tripped:

• 400kV Bareilly (UP)-Unnao ckt-1

• 400kV Bareilly (UP)-Unnao ckt-2

• 400kV Bareilly (UP)-Bareilly (PG) ckt-1

• 400kV Bareilly (UP)-Bareilly (PG) ckt-2

• 400/220kV 315MVA ICT-1, 2 & 3 at Bareilly (UP)

h. PMU plots of phase voltage:

i. SCADA SoE data:

j. As per PMU & SCADA data:

• No fault observed through PMU at the time of tripping of

elements.

• As per SoE, all reported elements except Unnao ckts tripped

around 10:51:09.100hrs

k. As per UP details:

l. Restoration time:

m. Preliminary Report, station EL has been received from UPPTCL but

detailed report is still awaited.

Action Points:

a. Reason for stuck status of trip contacts of 86B and reason for the

same not updating in control panel to be ascertained and shared.

UPPTCL representative submitted the following information:

a. N.I.T. switch positioning at Intermediate instead of Transfer lead to

tripping of complete 400kV elements at the substation: NIT switch

was not positioned to transfer and also it was not assured that 86B

has been reset properly resulted into bus bar protection operation.

Operation staff has been instructed accordingly to avoid recurrence

in future.

b. As advised in 34th PSC meeting, Bus tied operation alarm shall be

brought in front panel so that the shift operator could easily monitor

the same: Bus tied alarm has been provided on bus coupler panel.

c. Detailed report and remedial measures report to be submitted:

Tripping was due to operational error. Detailed report has been

submitted.

NRPC raised concern for frequent multiple element tripping at Bareilly (UP).

Protection Audit of 400 kV Bareilly(UP) to be carried out and report to be

submitted.

Q. Multiple element tripping at 400/220kV Jodhpur (Raj) Station at 21:41hrs of

05th Apr 2018



Loss of load: Nil

Energy Loss: Nil




PMU data 120ms

Phase of the fault

PMU data R-phase to earth fault



Rajasthan Partial Available

DR/EL Rajasthan Received After 24hrs

Preliminary Rajasthan Received After 24hrs

Report




1. IEGC 5.2.r & 5.9.6.c (VI) 2. 43.4.A of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) 3. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2)

Rajasthan

1. DR/EL, Preliminary report didn’t provide within 24hrs 2. Detailed Report didn’t provide 3. Adequately Sectionalized and graded protective relaying system 4. Operation of Bus bar protection resulting in large number of tripping in one and half breaker scheme


1. Single Line Diagram of Jodhpur (Raj):

2. 400 kV Jodhpur station has one and half breaker scheme. It is connected

with Merta D/C, Rajwest D/C, Akal S/C and Kankroli S/C, it also have two

315MVA ICTs.

3. 400kV Jodhpur-Kankroli line tripped on actual fault, line reclosed by Tie

C.B but main C.B not tripped.

4. LBB of 400kV Kankroli line operate due to stuck of main C.B and all C.B

connected to Bus-A tripped.

5. Tripped elements:

• 400kV Jodhpur-Kankroli

• 400kV Jodhpur-Merta D/C

• 400kV Jodhpur-Akal

6. PMU plots:

7. SCADA SoE:


• R-N fault observed at 21:41:38.040hrs

• Fault clearance time is 120ms.

• It seems from PMU voltage signature that line auto-reclosed after

1sec.

• At Jodhpur, tie CB of Merta-2 and main CB of Merta-1 opened ~40ms

of fault occurrence (as per PMU).

• At Kankroli, main CB of Jodhpur ckt opened in ~200ms of fault

occurrence (as per PMU)

9. As per Rajasthan Report:

• 400 kV Jodhpur-Kankroli line tripped on actual fault from both ends,

line reclosed by Tie C.B. but main C.B. not tripped.

• LBB of 400kV Kankroli line operate due to stuck of main C.B and all

C.B connected to Bus-A tripped. Details of breakers which are tripped

are as under:-

i. 400 kV Merta– I main CB.

ii. 400 kV Merta– II main & Tie CB.

iii. 400 kV Akal main CB.

iv. 400 kV Rajwest – I Tie CB.

v. 400 kV Rajwest – II Tie CB.

• Action Point: 400kV Merta-II Tie breaker also tripped with main

breaker on LBB operation which is incorrect tripping. Shutdown

proposed for testing/checking of tripping of tie breaker tripping.

11. Preliminary Report, DR/EL (partially) received from Rajasthan but detailed

report is still awaited from Rajasthan.

Action Points:

1. As per Rajasthan report, DT sent in to remote end for Merta-2, Akal ckts

and not sent for Merta-1 ckt. Also, as per DR of 400kV Jodhpur(end)-

Kankroli ckt, DT sent to Kankroli end as well. At Jodhpur, there is one and

a half breaker scheme. Reason and logic for DT sent for ckts at Jodhpur

station to be shared.

2. In one report from Rajasthan, no tripping from Kankroli end mentioned

whereas in other report, tripping from Kankroli end mentioned. As per

SoE, CB of 400kV Jodhpur-Kankroli tripped from Kankroli end. The

tripping of 400kV Jodhpur-Kankroli from Kankroli end and the protection

on which it tripped needs to be ascertained and shared.

3. Which CB of 400kV Jodhpur-Kankroli ckt at Jodhpur end stuck and at

which point (Whether at the first instance of fault or at the time of auto-

reclosing)? This needs to be ascertained and shared:

4. It seems from PMU data, line auto-reclosed after 1sec of fault. However,

from DR of 400kV Jodhpur(end)-Kankroli, no flag/channel indicated after

~1sec of fault. Whether 400kV Jodhpur-Kankroli auto-reclosed or not is to

be verified.

5. Time synchronization of DR of 400kV Jodhpur(end)-Kankroli needs to

checked and rectified.

6. As per Rajasthan report, Akal and Merta-1 were charged from one CB

only. Reason for non-availability of other Tie/main CB to be shared.

7. As 400 kV Akal-Jodhpur line charged through tie CB only at Jodhpur end.

Main CB was already under outage. During operation of bus bar protection

for 400 kV Bus-A at Jodhpur end, tripping of tie CB of 400kV Akal-Jodhpur

(end) needs to checked and corrected.

8. Reason of tripping of both main and tie CB of 400 kV Jodhpur (end)-Merta

ckt-II needs to be checked and rectified.

9. Bus Bar Protection setting at 400 kV Jodhpur needs to be reviewed and

shared.

POWERGRID representative informed that 400 kV Jodhpur-Kankroli line tripped

from Kankroli end on DT received from Jodhpur end. DR details is as blow:

Rajasthan submitted the following information:

1. At 21.42 hrs, 400 kV Jodhpur-Kankroli(PG) line tripped from Jodhpur end

on distance protection,Z-1 and R-phase. Tie CB R-phase opened but main

CB R-phase not opened and LBB of main CB operate.

2. Due to LBB protection operation all C.B connected to Bus-A tripped on

LBB/Busbar protection operation.

3. Details of feeders tripped are as under:-

a. Bus A

• 1.252A (Not tripped)

• 2.252T (dist operation)

• 3.452A

• 4.452T (Already off)

• 5.552A & 552T

• 6.852B

• 7.852A(Already off)

• 8.952T

• 9.1052T

b. BUS B

• Remain Healthy

4. Tie C.B not available in 400kV Akal line dia therefore 852A & 852 tripping

are common or looped.

5. 552T circuit breaker tripped because bus wire of LBB tripping was

connected from Main LBB relay.

6. DT not send to 400kV Kankroli(PG) GSS due to PLCC panel problem.

7. LBB tripping wire of main LBB relay to 552T C.B has been removed.

8. DT signal problem checked and resolved this problem

Rajasthan representative submitted the following action taken:

1. Tripping of Merta ckt-1 & 2, tie CB removed from LBB relay.

2. LBB relay setting and logic checked and revised as per norms. (130ms

time delay has also revised to 200ms)

3. Tripping wire of 400 kV Akal line, with bus bar operation has been

removed from 852B from LBB/ Bus Bar protection.

R. Multiple element tripping at 400/220kV Rewa Road at 01:11hrs & 01:49hrs of

8th Apr 2018, 13:49hrs of 16th Apr 2018 & 12:58hrs of 19th Apr 2018


Generation loss:

Nil (08.04.2018)

Nil (16.04.2018)

Nil (19.04.2018)

Loss of load:

Nil (08.04.2018)

Nil (16.04.2018)

Nil (19.04.2018)

Energy Unserved: Nil (UP may confirm)



Fault Clearance Time PMU data

160ms 08.04.2018

400ms 16.04.2018

No fault 19.04.2018


R-phase 08.04.2018

B-phase 16.04.2018

NA 19.04.2018



UP Not available

08.04.2018

16.04.2018

19.04.2018

DR/ EL UP Partial Received (In the event of 16th Apr from Meja TPS only)

08.04.2018

16.04.2018

19.04.2018


08.04.2018

16.04.2018

19.04.2018


08.04.2018

16.04.2018

19.04.2018



1. IEGC 5.2.r & 5.9.6.c (VI) 2. CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2) 3. 43.4.A & 43.4.D of CEA Technical Standard for Construction of Electrical Plants and Electric Lines; CEA (Technical standards for connectivity to the Grid) Regulation, 2007: Schedule Part 1. ( 6.1, 6.2, 6.3) CEA (Technical standard for connectivity to the Grid, Amendment Regulation 2013), part-II, B2

UP



1. 400kV Rewa Road has following connections with the grid:

a. 400kV Rewa Road-Banda D/C

b. 400kV Rewa Road-Panki

c. 400kV Rewa Road-Obra

d. 400kB Rewa Road-Meja ckt-1 & 2

e. 400/220kV 315MVA ICT-1 &2

f. 400/220 kV Rewa Road (UP) has DMT (Double Main Transfer

Breaker) scheme

2. Connectivity Diagram & SLD of Rewa Road (UP):


a. At 01:11hrs, Y-N fault occurred.

b. At 01:49hrs, no fault in the system

c. At 01:11hrs, Y-phase to earth fault occurred in the system. 400kV

Rewa Road-Meja ckt-1 &2 and 400kV Rewa Road-Banda ckt-2

tripped.

d. At 01:49hrs, 400kV Rewa Road-Banda ckt-1, Rewa Road-Panki ckt

and Rewa Road-Obra ckt also tripped

e. PMU plots of frequency and phase voltage:

f. Tripped Element:

i. 400 kV Rewa Road-Banda ckt-1 & 2

ii. 400kV Rewa Road-Meja ckt-1 & 2

iii. 400 kV Rewa Road-Panki ckt

iv. 400 kV Rewa Road-Obra B ckt

v. 400/220 kV 315MVA ICT-1 & 2

g. SCADA SoE data: No SoE reported in NR SCADA data

h. As per PMU data:

• Y-phase to earth fault occurred at 01:11:45.200hrs and cleared

timely.

• Fault clearance time: within 160ms

• No fault captured at 01:49hrs

• No change in frequency observed.



j. No digital data available in NR SoE.


a. Blue phase to earth fault occurred in 400kV Rewa Road-Obra line.

b. At the same time multiple element tripping occurred at 400/220 kV

Rewa Road (UP).

c. After 5 second all the lines connected to 400 kV Meja TPS also

tripped on over voltage stage-1 protection.

d. PMU plots of frequency and phase voltage:

e. Tripped Element:

i. 400 kV Rewa Road-Obra B ckt

ii. 400 kV Allahabad (PG)-Meja ckt-1

iii. 400kV Bara-Meja ckt-1 & 2

iv. 400kV Rewa Road-Meja ckt-1 & 2

f. SCADA SoE data: No SoE reported in NR SCADA data

g. As per PMU data:

• Blue-phase to earth fault observed at 13:49:18.520hrs

• Fault Clearance time: 400ms at the time of B-phase fault in

400kV Rewa Road-Obra line.

• No change in frequency

• No fault captured at 13:49:24.000hrs (Lines tripped on over

voltage protection operation)

h. SoE as per DR details of Meja TPS:

i. DR/EL has been received from Meja TPS for multiple element

tripping but still awaited from Rewa Road (UP).

j. Detailed report is yet to be received from UPPTCL.

k. No digital data available in NR SoE


a. In antecedent condition, 400kV Meja TPS-Bara D/C was under

open condition. 400kV Rewa Road-Meja ckt-1 was also open on

high voltage

b. No fault observed through PMU data.

c. At 12:58hrs, multiple element tripping occurred at 400 kV Rewa

Road due to high voltage.

d. PMU plots of frequency and phase voltage:

e. Tripped elements: (All outgoing feeders from Rewa Road (UP)

i. 400 kV Rewa Road-Obra B ckt

ii. 400kV Rewa Road-Panki ckt

iii. 400kV Rewa Road-Meja ckt-2

f. SCADA SoE data: No SoE reported in NR SCADA data

g. As per PMU data:

• Tripping occurred at 12:58:53.960hrs

• No fault in the system

h. Preliminary report, Flag details, DR/EL and detailed report is yet to


i. No digital data available in NR SoE.


1. Event on 08th Apr 2018:

a. Exact location of fault to be reported.





d. Reason of tripping of multiple elements at 01:49hrs without any

fault in the system

e. Non-reporting of digital status SCADA data of Meja TPS and Rewa

Road.

f. Preliminary report, DR/EL and detail report is still awaited from UP.


a. Exact location of fault to be reported.





d. Reason of tripping of 400 kV Obra-Panki line.

e. Reason of complete outage of 400 kV Rewa Road (UP).

f. Reason of tripping of multiple elements at 13:49:24hrs on over

voltage protection needs to be looked into.

g. Voltage staggering w.r.t. time and voltage. Over voltage setting of

all the outgoing line from Rewa Road, Meja TPS and its remote end

needs to be shared.

h. Non-reporting of digital status SCADA data of Meja TPS and Rewa

Road.

i. DR/EL from Rewa Road (UP) and detailed report of the incident is

still awaited from UP.


a. Staggering of over voltage protection setting w.r.t. time and voltage.




c. Reason of simultaneous tripping of all three lines.

d. Reason of rise in the voltage.

e. Over Voltage setting to be shared for all outgoing lines from Rewa

Road and Meja TPS.

f. Non-reporting of digital status SCADA data of Meja TPS and Rewa

Road.

g. Preliminary report, DR/EL and detail report is still awaited from UP.

Action Points

• Availability of DR and its extraction software needs to be looked into.

• Reporting of DR/EL needs to be improved.

• Availability of digital status of Rewa Road and Meja TPS needs to be

improved.

No representative of Rewa Road (UP) of UPPTCL was present in the meeting.

Details was not discussed at the time of meeting.

S. Complete outage of 765 kV Aligarh (PG) at 00:39hrs of 20th Apr 2018



Loss of load: Nil





Phase of the fault Maximum dip in R-phase



Present Status

Remarks


Received

DR/ EL POWERGRID Not Received

Uttar Pradesh Not received

Preliminary Report POWERGRID Not Received Uttar Pradesh Not received

Detailed Report POWERGRID Not Received





1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Adequately Sectionalized and graded protective relaying system 4. Operation of Bus bar protection resulting in large number of tripping in one and half breaker scheme


1. Single Line Diagram of Aligarh (PG):

2. 765 kV Aligarh (PG) connected with rest of the grid through Orai D/C,

Kanpur S/C, G. Noida S/C, Jhatikara S/C and Agra S/C. It has two

3*110MVAr Bus Reactor. Bus configuration at 765 kV Aligarh (PG) is one

an half breaker scheme.

3. R-N fault observed.

4. Bus bar protection operated at 765kV Aligarh(PG) resulted in loss of

connectivity at Aligarh(PG).

5. Both 765 kV buses of Aligarh (PG) became dead.


POWERGRID and UP

7. 220kV Bhiwadi (PG) station is connected with 220kV Bhiwadi D/C, 220kV


• 765kV Aligarh-G.Noida

• 765kV Aligarh-Orai D/C

• 765kV Aligarh-Kanpur

• 765kV Aligarh-Agra

• 765kV Aligarh-Jhatikara

• 765kV 3*110MVAr Bus Reactor-1 at Aligarh(PG)

9. PMU plots:


• R-N fault occurred at 00:39:50.720hrs and cleared in 80ms.

• Fault again occurred at 00:39:51.600hrs and cleared in 80ms

11. SCADA SoE:


• As per SCADA SoE, all breakers at Aligarh(PG) tripped except tie CB

of Bus Reactor-2 and Jhatikara.

a. It seems 765kV Jhatikara ckt remained charged through Bus

Reactor-2


POWERGRID and UP.

POWERGRID representative informed during the meeting:

1. Exact location of fault to be reported: 765 kV Aligarh (PG) station is GIS

(Hyosung make) station. First fault was in 765kV Bus-1 at Aligarh (PG)

due to flashover occurred in bus spacers insulators. Damage Module

replaced after the incident. 765 kV Bus Bar Protection operated for 765 kV

Aligarh Bus-1.

2. Exact sequence of events in view of cause of event; protection


alarms and any other relevant detail to be shared:

• Within 100ms of first incident of fault 765 kV Aligarh-Agra (PG) and

Aligarh-G Noida line tripped from 765 kV Aligarh end on over

voltage stage-2.

• Over voltage stage-2 protection may be operated due to high

frequency transient generation in GIS. This issue has already share

with OeM Hyosung and details is still awaited from OeM.

• After around 1 second of first incident of fault, bus fault also

occurred on 765 kV Aligarh (end)-Kanpur line. Bus Bar Protection

also operated for 765 kV Aligarh Bus-2 due to actual bus fault.

• At the time of operation of bus bar protection for 765 kV Aligarh

(PG) bus-2, tie CB of Aligarh-Kanpur ckt also tripped due to wrong

mapping of LBB/ Bus Bar trip to tie CB of the line and line also

tripped. LBB/ Bus Bar Protection wiring issue has been resolved.

• In GIS, very high frequency transient oscillation (VHFO)

phenomena observed many times.

• No surge arrestor in the GIS bus at Aligarh (PG).

3. Simultaneous operation of bus bar protection for both the buses needs to

be looked into: Two separate fault on separate bus at Aligarh (PG) with in

a time interval of 1000ms.

4. Reason for tripping of tie breakers in case of bus fault to be ascertained

and shared: Wrong mapping and same has been corrected

NRPC requested POWERGRID to take the issue of such high voltage rise and

VFT phenomena with OeM and share the outcome report.

T. Multiple Element tripping at 220 kV Pong HEP at 21:04hrs of 30th Apr 2018


Generation loss: 150 MW

Loss of load: Nil



Description Fault Info Remarks Fault Clearance Time 120ms As per PMU data

Phase of the fault Maximum dip in Y-phase



Present Status

Remarks


DR/ EL BBMB Received After 24hrs NHPC Received After 24hrs Punjab Not Received

Preliminary Report

BBMB Received (Partial)

After 24hrs

NHPC Not Applicable

Punjab Not Received Detailed Report BBMB Not Received




BBMB, Punjab

1. DR/EL, Preliminary report within 24hrs 2. Detailed Report 3. Adequately Sectionalized and graded protective relaying system


1. Single Line Diagram of Pong HEP:

2. 220kV Pong HEP have six units of 66MW and connected with remaining

grid via 220kV Dasuya D/C, Jalandhar (PG) D/C, Jasor S/C and Bairasuil

S/C. It also has one 220/66kV 40MVA ICT.

3. “Single bus with sectionaliser and transfer bus” scheme at 220 kV Pong.

4. Antecedent Condition:

• Unit-2, 4 & 6 was under shutdown for governor change work.

• Unit-1, 3 & 5 connected to 220kV Bus-1

• 220kV Jalandhar ckt-1, Dasuya ckt-III, Bairasiul ckt were connected

through 220kV Bus-1 of Pong HEP.

• 220kV Jalandhar ckt-2, Dasuya ckt-IV and Jasor ckt charged through

220kV Bus-2.

5. Blue phase CT of 220kV Unit-3 of Pong HEP bursted and it resulted into

bus bar protection operation for 220kV Bus-1 at Pong HEP. It resulted into

tripping of all the connected elements from Pong HEP.

6. 220kV Jasor-Pong ckt (connected on 220kV Bus-2 of Pong HEP) also

tripped from Jasor end.

7. 66MW unit-1,3 & 5 connected through 220kV Bus-1 of Pong HEP tripped.

8. As unit-2, 4 & 6 was already under planned outage, tripping of 220kV Bus-

1 resulted into nil generation at Pong HEP and remaining 220kV lines from

Pong HEP also off loaded.


• 220kV Unit-1, 3 & 5 of 66MW

• 220kV Bus-2 of Pong HEP

• 220kV Pong-Jalandhar ckt-1

• 220kV Pong-Bairasiul ckt

• 220kV Pong-Dasuya ckt-III

• 220kV Pong-Jasor ckt (From Jasor end)

10. PMU plots:


• B-phase to earth fault occurred at 21:04:17:120hrs

• Frequency dip of ~0.15Hz, Probable generation loss: ~150MW

• Fault Clearance time: 120ms.


14. NHPC also informed that 220 kV Pong-Bairasiul line tripped from Pong

end only not from Bairasiul end.

15. Similar type of incident also occurred on 2nd May and 22nd May 2018, all

the aforesaid element tripped due to failure of Blue phase CT of unit-3 at

Pong HEP.

16. Pending Information:

• DR of 220kV Pong-Jasor (Jasor end).

• DR of 220kV Bus Bar Protection at Pong (BBMB) HEP.

• Station EL details for 220kV Pong HEP.

17. DR has been received from BBMB for 220kV Pong-Bairasiul ckt, Pong-

Jalandhar ckt-1 and Unit-3 of Pong HEP but DR for bus bar protection and

station event log is still awaited.

18. Detailed report is still awaited from BBMB.

19. Action Points:

• Time Synch error of DR of 220kV unit-3 of Pong HEP needs to be

checked and corrected.

• Mapping of bus bar operation signal in DR configuration of 220kV

feeders to be ensured

Point wise reply of BBMB (Action Points):

1. Reason of delayed clearance of fault to be shared as fault clearance time

is 150ms: Delayed clearance (150ms) shall be checked

2. In case of operation of bus bar protection delayed clearance of fault needs

to be looked into: It shall be thoroughly checked

3. Mapping of bus bar operation signal in DR configuration of 220kV feeders

shall be made with any one of feeder numerical relay: It shall be done

within 15days

4. Time Synch error of DR of 220kV unit-3: Time Synch has been corrected.

5. DR of 220kV Bus Bar Protection at Pong (BBMB) HEP: Replacement of

existing conventional type BBP with Numerical BBP has been proposed

under PSDF. Procurement will be processed shortly

Point wise reply of BBMB (Points for Discussion):

1. Multiple times failure of B-phase CT of unit-3 of Pong HEP. (30th Apr, 02nd

May and 22nd May): The tripping was occurred due to failure of CTs which

were old and were in circuit since commissioning of Power Station. New

CTs were not available. Old & used CTs (lying unutilized in store) were

installed in replacement, but these CTs also proved to be out lived and

failed. The case of procurement of 49 Nos. new CTs was in process but

as special case speedy procurement of 6 Nos new CTs is processed and

will be soon replaced as and when are available with new ones

2. The issue of single and transfer bus arrangement at Pong station may

also be reviewed for improving the overall system reliability so that the

feeders/buses could be shifted to either of the two buses available at the

station.

3. Details to be submitted by BBMB:

4. Corrective actions already taken/being taken (with time line) to avoid such

events: The numerical protection of Bus Bars is proposed. 49 Nos. CTs of

various current ratios’ are under procurement for Pong Power House

Switchyard. However 6 Nos. current transformers are proposed to be

procured on priority

5. DR of 220kV Pong-Jasor (Jasor end):- Matter have been taken with the

Jasor Sub-Station as 220 KV Pong- Jasor line as it is being fed from Bus 2

which was in live condition and protection of said line with in the preview

of other end (HPSEB).

NRPC raised concern about replacement of old CT with high tan delta and

suggested all the utility not to use the CT, VT with deteriorated parameter.

.

U. Multiple Element tripping in NR during thunderstorm from 18:20hrs onward

of 11th Apr 2018



Loss of load: Nil

Description of the events is:



• 800kV Agra-BNC bipole was already under shutdown

• Following lines from Agra(PG) were under outage:

➢ 765kV Agra-Gwalior-2 (Emergency S/D)

➢ 765kV Agra-Fatehpur-2 (open on high voltage)

➢ 400kV Agra-Auraiya-2 (Planned S/D)

➢ 400kV Agra-Sikar-1 (open on high voltage)

➢ 400kV Agra-Jaipur South-1 (open on high voltage)

➢ 400kV Agra-Bhiwadi-2 (open on high voltage)

3. The Indian Meteorological Department (IMD) had issued warnings for

thunderstorm/squall in Northern Region. These warnings were apprised by

NRLDC to NR constituents through e-mails dated 09th & 11th Apr, 2018

(Annexure-1).

4. In the evening hours of 11-Apr-18, thunderstorm swept around in South-

Eastern Uttar Pradesh area with high wind speed reported.

5. The significant outages during this period having impact on grid security

are as follows:

➢ 765 kV and 400 kV lines emanating from Agra (PG) station tripped.

➢ All the 400 kV lines emanating from 765/400 kV Fatehabad (UP)

tripped except 400 kV Fatehabad-Agra(UP) ckt-1.

➢ 800kV HVDC Champa-Kurukshetra bipole, important inter-regional

link, also tripped multiple times during the event.


S.No. Element UtilityOutage

Date

Outage

Time

Revival

Date

Revival

TimeRemarks/Reason (as reported) PMU inference

1 765 kV Agra(PG)-Jhatikara(PG) POWERGRID 11-Apr-18 18:29

B-N fault. FD: Agra-64km, Jhatikara-182km. FC: Agra-8.2KA, Jhatikara-

4KA.5 Nos Towers damaged at Location No. 173, 174, 175, 176 and

177 (4 nos. A Type one No. A+3, one tower damaged completely,

one from waist level and three above waist level)

B-N Fault, A/R unsuccessful.

2 400 kV Agra(PG)-Sikar(PG) 2 POWERGRID 11-Apr-18 18:29

Tripped during thunderstorm in Agra area. Earth wire snapped and

entangled with circuit 2 conductors in 5 spans from location no. 229

to 233

B-N Fault, unsuccessful

autoreclosing observed.

3765 kV Lalitpur TPS 330 MVAR Bus

Reactor 1LPGCL 11-Apr-18 18:41 11-Apr-18 21:32 B-Phase differential protection operated

Y-N Fault. No auto-reclosing

observed.

4 765 kV Agra(PG)-Aligarh 765(PG) POWERGRID 11-Apr-18 19:15B phase insulator string broken and conductor fallen on ground a

Location No. 53Multiple faults observed.

5 400 kV Agra(PG)-Agra(UP) POWERGRID/UP 11-Apr-18 19:19

Four towrs damaged location no. 37, 36D, 36C and 36B - one tower

damaged completely, one from waist level and remaining two have

cross arms and earthwire peak damage.

6 400 kV Agra(PG)-Fatehabad 765 (UP) POWERGRID/UP 11-Apr-18 19:19 11-Apr-18 20:40

Four towrs damaged location no. 37, 36D, 36C and 36B - one tower

damaged completely, one from waist level and remaining two have

cross arms and earthwire peak damage.

7400 kV Agra(UP)-Fatehabad 765 (UP)

2POWERGRID/UP 11-Apr-18 19:22 Details awaited

Y-N Fault. No auto-reclosing

observed.

8 400 kV Manesar-Neemrana 1 POWERGRID 11-Apr-18 19:28 11-Apr-18 20:27 Hand tripped due to fire at Backyard at Manesar.

9400 kV Manesar(PG)-Neemrana(PG)

2POWERGRID 11-Apr-18 19:28 11-Apr-18 20:29 Hand tripped due to fire at Backyard at Manesar.

10400 kV Fatehabad 765(UP)-Mathura

400(UP) 1UP 11-Apr-18 19:33 11-Apr-18 20:37 Details awaited

B-N fault. It seems line

tripped in reclaim time.

11800 kV HVDC Champa(WR) -

Kurukshetra(NR) line -1POWERGRID 11-Apr-18 19:36 11-Apr-18 19:52 Auxillary supply failure at Kurukshetra No fault observed.

12400 kV Agra South (UP)-Fatehabad

765 (UP) 1UP 11-Apr-18 19:39 11-Apr-18 21:05 Details awaited

13400 kV Agra South (UP)-Fatehabad

765 (UP) 2UP 11-Apr-18 19:39 11-Apr-18 21:06 Details awaited

14400 kV Fatehabad 765(UP)-Mathura

400(UP) 2UP 11-Apr-18 19:58 11-Apr-18 20:39 Details awaited

B-N Fault. No auto-reclosing

observed.


Kurukshetra(NR) line -2POWERGRID 11-Apr-18 20:06 11-Apr-18 20:50 Details awaited No fault observed.

16 220 kV Auraiya(NTPC)-Malanpur(PG)NTPC/POWERGRI

D11-Apr-18 20:08 11-Apr-18 23:36 Details awaited

R-N Fault. No auto-reclosing

observed.


Kurukshetra(NR) line -1POWERGRID 11-Apr-18 20:10 11-Apr-18 20:24 Details awaited No fault observed.

18765 kV Jabalpur 765(PG)-Orai

765(PG) 2POWERGRID 11-Apr-18 21:34 11-Apr-18 22:31

B-N fault. However, neither fault current nor fault location flagged

in relay.

B-N Fault. No auto-reclosing

observed.

At 19:18:08hrs, B-N fault. It

seems line tripped in reclaim

time. At 19:19:35hrs, R-N fault

observed followed by Y-N

fault within a sec.

Multiple faults observed.

Charging

code were

issued but

many

attempts

failed as

lines

couldn’t

hold

7. As per PMU data, Multiple faults observed at the time of tripping of lines

8. The critical time during the event was:

➢ During 19:15-20:15hrs, there were only two ckts viz. 765kV Agra(PG)-

Gwalior-1 and 765kV Agra(PG)-Fatehpur-1 present at 765kV level at

Agra(PG).

➢ During 19:58-20:37hrs, tripping of all other lines from Fatehabad (UP)

rendered 400kV Fatehabad (UP)-Agra (UP)-1 as the major evacuating

path for Lalitpur generation. As a result, 400kV Fatehabad (UP)-Agra

(UP) became loaded to ~1000MW (near thermal loading of line).

➢ Apart from 400 kV Fatehabad line at 400kV Agra (UP), only one other

400kV Unnao line was in service at Agra (UP). Therefore, tripping of

either of any of the above ckts would have caused outage of entire

Lalitpur TPS.

➢ Tripping of 800 kV Champa-Kurukshetra multiple times resulted in less

reliability for Inter regional exchange (Annexure-3).

9. Constituent Details:

As per POWERGRID report:

As per Rajasthan Report:

As per UP Report:

As per POWERGRID report:

Action Points:

1. As per DR details, following needs to be clarified:

➢ 765kV Agra(PG)-Aligarh(PG) : No auto-reclosing observed at

Agra(PG) end.

➢ 400kV Agra(PG)-Fatehabad(UP): Auto-reclosing in 2sec from

Fatehabad(UP) end.

➢ 400kV Agra(PG)-Agra(UP) : Imbalance in current (B-phase)

observed at Agra(PG) end.

2. Tripping of 800kV HVDC Champa-Kurukshetra multiple times needs to be

investigated and measures to be taken to avoid such outages.


1. Tripping of multiple number of lines around the same area makes the

system critical. The measures are to be adopted to avoid such cascading

tripping.

During the discussion, NRLDC raised concern about large number of tripping of

HVAC line during storm. Further, it resulted into unreliable and unsecure grid

operation.

The following were the discussion on the electrical clearance of transmission

lines during high wind condition:

• In normal weather condition, the clearance seems to be OK. However,



condition.

• The polymer insulators are light weighted. During high wind condition, the

conductor could swing resulting in inadequate clearance and subsequent

fault condition. Counter weights are sometimes added at few locations to

avoid the above.

• Pilot wire string also used for tension towers to keep the adequate

clearance even in high wind scenario.

V. Complete outage of 200kV RAPS A at 15:02hrs of 05th Apr 2018 (AGENDA

BY NPCIL)

NPCIL has submitted a report (attached at Annexure-1) on tripping occurred at

RAPS A power station at 15:02hrs of 05th Apr 2018. The following is the brief of the

event based on the report submitted by NPCIL and details available at NRLDC:


Generation loss: 186MWe (As per NPCIL report)

Loss of load: Nil


Event Description:

1. Single Line Diagram of RAPS A:

2. B-N fault occurred in 220kV RAPS A-Debari ckt resulted in tripping of

above line.

3. 220kV RAPS A-Sakatpura D/C also tripped along with above.

4. On loss of evacuation, running unit #2 at RAPS A came to house load

(22MWe).

5. However, after around 2 min, turbine tripped on class-B protection.


• 220kV RAPS A-Debari

• 220kV RAPS A-Kota(Sakatpura) D/C

• Running unit #2 at RAPS A

7. PMU plots:

8. As per PMU data:

9. B-N fault observed at 15:02:13.120hrs and cleared in 120ms.

10. B-N fault observed at 15:03:45.640hrs and cleared in 120ms. It seems line

auto-reclosed after 1sec.

11. SCADA SoE:


• As per SCADA SoE, only closing of 220kV RAPS A-Kota ckts

captured.

13. As per NPCIL report:

14. As per DR details at RAPS A:

15. Rajasthan representative informed the following in the meeting:

• Distance protection in 220 kV Kota (Sakatpura) - RAPP is Micom P-

442 and setting at Sakatpura end is 80%, same has been shared to

RAPP also. Zone protection setting at Sakatpura end would be once

again reviewed and reverted.

• Auto reclosure function is not in service at Sakatpura end and RAPP

end.

16. NPCIL representative informed the following in the meeting:

• Auto reclosure function was disabled after discussion with OeM at the

time of commissioning of line and units. However for auto reclosure to

put in service, RAPP representative would agree to discuss with OeM.

• Units was not survived on house load and finally tripped. Remedial

action is being taken for survival of unit on house load.

W. Tripping other than to be discussed in 35th PSC meeting:

For better reliability of power system each and every multiple element tripping

should be analyzed properly and remedial measures to be taken by utilities. Total

88 multiple element tripping event reported by NRLDC to RPC and constituents.

Preliminary reports of all these trippings are available at NRLDC website and

already send to concerned utilities within 24hrs of the incident.

Among 139 events, around 30 events would be discussed in 35th PSC meeting.

For rest events, utilities may kindly submit the details (DR/EL and detailed report

along with remedial measures) to NRLDC and NRPC at mail ID:

[email protected], [email protected], [email protected] and sep-

[email protected].

List of the all the multiple elements tripping event is available at NRPC website.

Member may kindly submit the details.





PCC35_MN.pdf - Northern Regional Power Committee

Documents

Transcript of PCC35_MN.pdf - Northern Regional Power Committee