Project report

On

PV Measurement System for performance monitoring

Submitted

By

Sohanpal Bansal

Under the guidance of

Dr. O.S. Sastry

DDG/Scientist ‗F‘

National Institute of Solar Energy

Gurgaon, Haryana

JULY 2015

CERTIFICATE

This is to certify that this project report titled ―PV Measurement System

forperformance monitoringis a bonafied work done bySohanpal Bansal at

National Institute of Solar Energy, Gurgaon under my supervision.

Dr. O.S Shastri DDG/Scientist ‘F’ National Institute of Solar Energy Gurgaon

Acknowledgment

I acknowledge my sincere thanks to Dr. O.S. Sastry, DDG/Scientist ‗F‘ (SPV Testing), NISE

for his valuable guidance and help bestowed for completion of the project. I would also like to

thank Prof. S.S Chandel, Centre for Energy and Environment, NIT Hamirpur for giving me the

opportunity and valuable suggestion to do this training.

Finally, Iam also thankful to Mr. Vikrant Sharma (SRS) Solar Energy Centre (MNRE), whose constant guidance and help resulted in the successful completion of the project.

I would also thank all the staff of NISE and other trainee without whom this project would have been a distant reality.

(Sohanpal Bansal) Date:

Place:

Abstract

As the world‘s demand increase and resources become scarce, the search for alternative energy

resources has become an important issue for our time. With advancements in technology, the

renewable energy sector has been recognized as important natural energy resources because it is

clean, abundant and pollution free. The use of solar energy by using solar photovoltaic is one of

the best solutions to meet the energy demand. Advantages of photovoltaic (PV) include:

completely renewable, absence of moving parts, flexibility to meet milli watts to giga watts, and

permanent fuel sources. The measurement of the performances of solar cell is done by measuring

I-V characteristics at STC condition. STC (Standard test condition) refers to incident radiation

1000 W/m2, temperature 25

0C and air mass 1.5.usually the performances of PV module is tested

at STC condition. But usually in the real outdoor condition the performances of solar cell

module behaves differently. At NISE, the radiation level is not 1000W/m2, and the temperature

and air mass are also being not exactly matched with the STC condition. So, the prediction of

energy output of a particular PV system under a given set of weather condition is always in

particular interest of people.

Now a day various PV technologies are there in the market but which technology is better for a

particular application and a particular weather condition is important to find out performance

monitoring to study comparative behavior is an important tool to predict which technology

among the various technologies is best.

Contents

List of figure List of Table

1. Introduction 2. Existing System Specification 3. System Operation 4. Proposed Modification 5. Modified System operation 6. Conclusion

Reference…………………………………………………………………

List of Figure

Figure1.1 PV Module of different technology installed at NISE Figure2.1 Multicrystalline PV Module Figure2.2 HIT PV Module Figure2.3

Amorphous PV Module Figure2.4

Front View of PV scanner Figure2.5 Internal circuit of PV scanner

Figure2.6 PV Analyzer (PVA01928, 01930)

Figure2.7 Internal circuit of PV Analyzer Figure2.7.Internal circuit of MPPT electric load Figure2.8 Charge Controller Figure2.9.Internal power control unit Figure2.10.Block diagram of Data Logger Figure3.1.Basic circuit diagram of the system (Multicrystalline) Figure3.2.Time chart of operation Figure3.3.Power Flow with operation

Figure3.4.Power flow diagram during IV

Trace Figure3.5.Power indication Figure3.6.Power flow diagram during MPPT Mode Figure3.7.Power flow indication Figure3.8.Power flow during DC charge

Figure3.9.Power Flow indication during DC Charge

Figure3.10.Power flow during AC charge

Figure3.11.Power flow indication during AC charge

Figure4.1.Proposed modification in system

Figure4.2. Complete modified system Figure4.4. Modified Connection Figure4.3. Previous Connection

Figure4.6. Initial battery backup

Figure4.7. Modified battery backup

Figure4.8.Chanel 1-4 disabled Figure4.9.Timing for daytime and night mode are changed Figure4.10.Tables not used are disabled

List of tables

TABLE2.2 TABLE2.1

Chapter-1: Introduction Performance monitoring system for different technology of PV Modules {Developed By: AIST System (National Institute of Advanced Industrial Science and technology, Japan)} Concept:-

1. This system analyzes three different technology a. Multi crystal silicon b. Heterojunction with Intrinsic thin-layer c. Amorphous Thin film

2. In each technology one module is kept open, one short and rest of the modules are

connected in series and parallel combinations to form an array. Open circuit module is

the worst condition i.e. in this situation degradation of module is more. Short circuit

module is the best condition i.e. degradation of module in this configuration is very

less. Load connected modules have performance in between open and short. 3. Short circuit and open circuit modules are taken as reference for performance analysis.

4. Meteorological data are also recorded for analysis. Here wind speed ,solar radiation and

solar spectrum are recorded

5. After a year of data logging, study of data is done and based on study the comparative behavior of the different technology is presented.

Figure1.1. PV modules of different technology installed at NISE

Chapter-2: Existing system specification 2(a): Hardware description

1. PV Modules

In this system three different technology based PV Modules are installed. They

are Multicrystalline, Amorphous and Heterojunction with Intrinsic thin layer.

Therespecification is as follows.

Figure2.1. Multicrystalline PV module

Figure2.2. HIT PV Module

Figure2.3. Amorphous PV Module

TABLE2.1 Type Multicrystalline HIT Amorphous

Model ND-160AV HIP-210BKH5 Z-EA075

Product SHARP SANYO KANEKA

Module

specification

Voc 25.60 73.6 91.8

Isc 8.42 3.79 1.4

Vm 21.28 59.7 67

Im 7.52 3.52 1.12

Pm 160 210 75

Array 10 series 1 parallel 4 series 2 parallel 4 series 4 parallel

Specification

Voc 256 294.4 367.2

Isc 8.42 7.58 5.6

Vm 212.8 238.8 268

Im 7.52 7.04 4.48

Pm 1600 1680 1200

2. Measurement System

The measurement system consists of Scanner, PV Analyzer, MPPT Electric load,

Expansion load, charge controller, Battery Bank and data logger (CR1000). The specifications of this component are shown below.

TABLE2.2 1.PV Scanner Model:PVC01802 Contact:DC400(V),60(A)

Product: Kernel System DC power relay G9EA-1 (OMRON)

Chanel: In(6),out(2)

2.PV Analyzer Model:PVA1928(1930) Range:400(V),30(A),10(kW) Product: Kernel System Method: Electric load Data item:

IV Curve(1024 points)

Voc , Isc, Pmax , Vpm , Ipm , Fill Factor Irradiance, temperature(2)

3.MPPT Electric load Model:ECL02401 Range: 60(V) ,16(A) ,2(kW) Product: Kernel System Control: MPPT charge output

5.Charge controller Model:

Product:

6.Battery Unit Model:SF38B20RD Capacity:35(Ah)X12 Product: SF SONIC

7.Data Logger Model: Backup:2GB CR1000(CAMPBELL)

Product: climatec

8.Charge controller Model: SS-20L-24V 24V dc solar in Product: Sun saver 20A

PV Scanner-

1. The PV scanner is the multiplexing unit which connects the PV module output to PV

analyzer and MPPT electric load.

2. It consists of a decoder and relay assembly. The decoder gives signal to relay for switching.

3. The relay is a single pole single through type switch. There are total of 18 relays used

in which 9 are for +ve and 9 are for –ve terminal. 4. The scanner has 6 input channels which are used in 8 configurations for measurement. 5. The Decoder is controlled by data logger control signal.

6. Of the six input channel of the scanner 5 are used for individual module and 6th

channel

is for array. The scanner also control dc and ac signal required for the operation of the system.

7. The scanner has 10 indicators in which 8 are for the channel configuration and two

are for AC and DC power. 8. Until the scanner is switched on no system operation will takes place?

Figure2.4. Front View of PV scanner

Figure2.5. Internal circuit of PV scanner

PV Analyzer

PV scanner connects the PV module to PV analyzer for IV-characterization. PV

analyzer traces the IV-curve of the PV Modules and array. Time taken by PV analyzer

to trace IV is approximately 10sec and total time taken by analyzer to trace all the IVs is

1min (6*10sec). There are two model of PV analyzer used as shown below.

Figure2.6.PV Analyzer (PVA01928 and PVA01930)

Figure2.7.Internal circuit of PV Analyzer

MPPT Electric load and expansion load

This operates the array at maximum power point. It tracks the maximum power point of

the array and provides that amount of load to operate it at MPPT. It has an expansion load

which is used to meet the extra load of the system. Surplus power from the expansion

load is used to charge the DC battery and power electronic circuitry.

Figure2.7. Internal circuit of MPPT electric load

Charge controller

Charge controller is used to decide the charging of the battery. It selects the source for

battery charging either from Grid or Solar. It switches the solar power in the daytime

from 4am to 8pm

and switches grid power from 8 pm to 4 am. Solar power (DC) coming from expansion load is stepped down using DC to DC converter to 28V and fed to charge controller.

Figure2.8. Charge Controller Internal Power Control circuit

1. ACDC convert (AC200 [V] DC28 [V]). 2. DCDC Convert (DC400-200[V] DC28 [V] ). 3. Charge Control(SS-10L-24V(Morningstar)) 4. Monitoring Voltage and current(Output to Datalogger)

Figure2.9. Internal power control unit

Data logger

Acquiring data with a Campbell Scientific datalogger is a fairly defined procedure Involving the use of electronic sensor technology, the CR1000 datalogger, a Telecommunication link and datalogger support software.

A CR1000 is only one part of a data-acquisition system. To acquire good data,

Suitable sensors and a reliable data-retrieval method are required. A failure in any part of the system can lead to "bad" data or no data. A typical data-acquisition System is conceptualized in figure Data-Acquisition System ComponentsFollowing is a list of typical system components:

Sensors -Electronic sensors convert the state of a phenomenon to

anElectrical signal.

Datalogger—The CR1000 measures electrical signals or reads serialCharacters. It converts the measurement or reading to engineering units, Performs calculations, and reduces data to statistical values. Data are stored in memory to await transfer to a PC by way of an external storage device or a Telecommunication link.

Data Retrieval and Telecommunications —Data are copied (not

moved)From the CR1000, usually to a PC, by one or more methods using datalogger Support software. Most of these telecommunication options are bi-directional And so allow programs and settings to be sent to the CR1000.

Datalogger Support Software—Software retrieves data and

sendsprograms and settings. The software manages the telecommunication link and has options for data display.

Programmable Logic Control-Some data-acquisition systems requirethe

control of external devices to facilitate a measurement or to control a device based on measurements. The CR1000 is adept at programmable logic Control. Unfortunately, there is little discussion of these capabilities in this Manual. Consult CRBasic Editor Help or a Campbell Scientific Application Engineer for more information.

Measurement and Control Peripherals—Some system

requirementsexceed the standard input or output compliment of the CR1000. Most of these requirements can be met by addition of input and output expansion modules.

Figure2.10. Block diagram of Data Logger

Software Description

LoggerNet

LoggerNet is Campbell Scientific‘s full featured datalogger support software. It is

referred to as ―full- featured‖ because it provides a way to accomplish almost all the

tasks you will need to complete when using a datalogger. You can write datalogger

programs, transfer those programs to the datalogger, collect the data, and analyze the data

either in real-time or after the file has been saved to a PC.

Chapter-3: Operation of the System 3.1. Basic system outline

Figure3.1. Basic circuit diagram of the system(multicrystalline)

This system operates in two modes

Night Mode-Night mode is from 00:00-04:00 and 20:00-24:00. Day Time mode-This start from 04:00-20:00.

Figure3.2.Time chart of operation

Now daytime mode is further divided into following mode-

PV Measurement Mode-It consists of 1. IV Curve Data(Each PV) 2. Temperature Data 3. MPPT Operation result Data

MPPT Operation Mode The two mode repeat after every 10 min in the daytime mode Power flow for whole of the operation is shown below.

During Night Mode no operation takes place and AC power flow to charge the battery from grid

During Day time battery power, PV power and AC are used in combination to power the

system. During PV Measurement only battery power and AC power are used and during

MPPT operation all the three are used.

Figure3.3. Power Flow with operation

3.2.1. Power flow diagram during IV Trace

Figure3.4. Power flow diagram during IV Trace Figure3.5. Power indication

3.2.2. Power Flow diagram during MPPT Operation

Figure3.6. Power flow diagram during MPPT Mode

Figure3.7. Power flow indication

3.2.3. Power flow Diagram during MPPT Operation mode with DC charge

Figure3.8.Power flow during DC charge

Figure3.9. Power Flow indication during DC Charge

3.2.4.Power Flow Diagram during MPPT operation with AC Charge

Figure3.10.Power flow during AC charge

Figure3.11.Power flow indication during AC charge

Chapter-4: Proposed Modification

Initially there were three different measurement systems for the three technologies and the measurement involves measurement of-

I-V Curve of individual module I-V curve of the array MPPT operation of array

The above three measurement were done for all the technology by three different systems. Now the proposed changes require –

Single measurement system to measure IV curve of the three technologies and control MPPT operation.

Figure4.1.Proposed modification in system

To fulfill the above requirement changes in the software as well as hardware are required.

4.1.Complete modified system

For Multicrystalline

For HIT

For Amorphous silicon

Figure4.2. Complete modified system

4.2. Changes in the hardware

1. PV Scanner-Of the six channel of the scanner three (1-3) were used to connect

arrayof each technology and 4th channel were used as output to connect to MPPT

electric load. To do that internal connection of the scanner were changed.

Figure4.3. Previous Connection Figure4.4. Modified Connection

2. MPPT electric Load

The three MPPT electric loads of the three systems are brought together and

connected to a single system. Each MPPT electric load of the three is connected to the

three output of the scanner. These loads are driven by DC supply. Each electric load

drives a current of almost 3.5A.Thus three loads require total of 3.5x3=10.5A of

current. The PV scanner could not supply this amount of current thus two loads are

driven separately from battery bank.

3. Battery bank

The battery backup of the battery bank was very poor. Thus replacement of the

battery was required. Initially there were 12 batteries each of capacity 35Ah;

12V.The battery bank was of 24V.Now we have replaced these batteries with two

batteries each of capacity x Ah and 12V, connected in series to make 24V.

Figure4.6. Initial battery backup Figure4.7. Modified battery backup

4.3.Changes in software Chanel configuration 1-4 was only used and rest of the channel was disabled as shown in figure.

Figure4.8.chanel 1-4 disabled

Timing for the daytime operation was changed from (4am – 20pm) to (5am – 19pm).

Figure4.9.Timing for daytime and night mode are changed

Tab304, 305,306 were disabled as shown in figure.

Figure4.10. Tables not used are disabled

Champter-5: Modified System operation

1. This system operates in similar fashion as it was operating in the earlier

condition with some changes. 2. Now only three of the PV scanner can be used to connect only three technologies. 3. In present situation all the three channels are utilized for Multicrystalline, HIT,

and amorphous PV Module. 4. Now rest of the three channels is giving output of PV Modules and is used by

MPPT electric load. 5. In this system only IV Data are recorded for the three technologies. 6. Nine of the fifteen thermocouples are used to measure temperature of the array.

In which three thermocouple are used for each array. 7. System of operation is still in two mode viz night mode and Daytime mode but timing

of the modes are changed. Now daytime mode is from 5am to 7pm. 8. Components of the daytime are also changed now it has only two mode i.e. IV

curve (array), MPPT Operation. 9. While switching of scanner takes place IV curve is traced at channel 1,2,3 and at

Chapter-6: Conclusion

Comparative study of different technology helps in predicting which technology is better

among various technologies. Using three different systems for performance monitoring may not

be an accurate solution since there might be synchronization error. Thus using single to monitor

various technologies removes the problem of synchronization.

Reference:

PV Measurement Document PV Measurement Software document Campbell Scientific LoggerNet help