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EFISIENSI DAYA LISTRIK

DENGAN MENGGUNAKAN

VSD/INVERTER

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Kegunaan Inverter

• Mengurangi arus start pada starting motor di

sistem pompa, konveyor, fan dll

• Mengurangi tekanan hidrolik pada

permasalahan start stop pompa, sehingga

menghindari masalah getaran pada pipa dan

kerusakan pada peralatan

• Menghindari terjadinya water hammer pada

sistem penyaluran pompa fluida dengan head

yang tinggi

• Pada pemakaian beban variable torque seperti

pompa dan fan, pengguanaan inverter bisa

mengefisienkan pemakaian daya sampai 50%

• Dibandingkan dengan soft start inverter

Electricity consumption

• For processes and building utilities

– 72% of electricity consumption goes to turn motors

– 63% of this energy is used to circulate fluids

Compression

30%

Pumping

20% Ventilation

13%

Process

37%

Relevant applications

• Pumping

• Ventilation

• Compression

• Benefits from use of the Inverter:

– no more electricity

consumption than just

necessary

– enhanced performance

– user comfort

• At present only 5% of installations

are equipped with variable speed

drives

Contoh penempatan VSD pada sistem Air

Conditioning

A conventional installation

• Motor supplied directly by the line supply

• Motor speed of rotation = nominal speed

• Variation of flow by means of a restriction or load

loss device - valve, incliner, etc

• The reduction in flow causes the absorbed power

to drop very slightly

• Example of a Fan:

– flow regulation by an outlet valve

– at 80% of nominal flow - power consumption

95% of nominal power

Low-cost installation with a drive

• Motor supplied by a variable speed drive

• Elimination of the restriction device

• Variation of the flow is obtained directly by varying

the motor speed

• The reduction in flow causes the absorbed power to

drop considerably

• Example of a Fan equipped with a drive:

– flow regulation by the drive

– at 80% of nominal flow - power consumption

50% of nominal power

The fan power curve

10 20 30 40 50 60 70 80 90 100 Flow

Power

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Outlet valve

Suction valve

Drive

The fan power curve

Outlet valve

Suction valve

10 20 30 40 50 60 70 80 90 100 Flow

Power

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Variation in flow obtained by a

load loss system

The fan power curve

Outlet valve

Suction valve

Variable speed drive

10 20 30 40 50 60 70 80 90 100 Flow

Power

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Variation in flow obtained by varying the

motor speed

Variable

speed

The pump power curve

Control valve

Drive

10 20 30 40 50 60 70 80 90 100 Flow

Power

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

Example: 15 kW / 90 kW ventilation

TEMIC Semiconductors - Nantes, France

Recycled

air

Recycled

air

New air

• Central unit handling air destined for the

production factory

Output

without drive with drive

m3/hr kW kW

125000 90 90

92300 73 54

76800 71 21

68000 71 20

Power consumption

Example: 3 … 37 kW ventilation

Thomson Multimedia - Villingen, Germany

• Preparation of air destined for clean rooms

with 7 fans

• Energy savings: 500 kWh/year

320 kF/year

• Investment: 425 kF

• Return on investment: 16 months

Output

without drive with drive

m3/hr kW kW

45000 37 37

22500 31 4.6

Power consumption

Filter + air conditioning

Example: 55 … 110 kW pumping

Water authority - La Rochelle, France

• Drinking water distribution plant

– 10 recirculating pumps

– Flow regulation based on subscriber consumption

• Energy savings: 20 … 25%

Applications - Ventilation

• Thermal protection of drive and motor, alarm

on logic output

• Catch on fly restart with speed search

• “On or slowdown” function for tunnel smoke

extraction

• Configuration of type of stopping on external

fault

• Speed maintained on loss of 4-20mA signal

• Energy-saving function

Applications - Pumping

• Pump switching option card

– Control of an entire pumping installation

with a single drive

– Configurable changeover

• Limited number of starts

• Integral PI regulator

– Constant pressure maintained throughout

the network

– Preset flow references

– Change from Auto to Man

• Jump frequencies

– Protection of the mechanism

Perbandingan Inverter dan Soft Start

• Inverter bisa menekan arus start menjadi 1,2

kali Inominal, sedangkan soft start hanya 1,6

sampai 2 kali Inominal, Y/Δ 3 sampai 4 kali

Inominal

• Inverter bisa menghasilkan penghematan

daya sedangkan pada soft start tidak bisa

Aplikasi Inverter Pada Sistem

Distribusi Air Pada Gedung Bertingkat

• Aplikasi inverter cocok digunakan untuk

mendapatkan pengaturan flow yang baik

meskipun tempat yang tinggi dan jauh

• Inverter bisa mempertahankan tekanan aliran

tetap terjaga pada sistem penyaluaran fluida

dengan pompa

Aplikasi Inverter Pada Milling Sistem

• Mengganti motor DC dengan motor induksi 3 phasa, sehingga diperoleh keuntungan bebas pemeliharaan terhadap motor

• Diperoleh arus start yang kecil, hanya sekitar 1,2 kali Inominal

• Untuk pemakaian kecepatan dibawah nominal maka diperoleh efisiensi daya yang signifikan

Prinsip Pengaturan kecepatan

motor

• Stator control

• Rotor control

Stator control

• Contant frequency, varible voltage

(soft start, Y/D, Autotrafo, Rheostat,

prinsipnya mengontrol tegangan

sehingga slip bisa diatur dan rpm rotor

akan diatur)

• Variable frequency

(VSD/VFD/Inverter)

Variable frequency

• DC link convertion (dari input ac ke dc

kemudian ke ac lagi)

• Cycloconverter drivesn (ac diubah ke

ac juga tanpa melalui rangkaian dc)

DC Link inverter

• PWM inverter (VSD/VFD/Inverter)

• Square inverter (UPS atau power

suplai 1 phasa)

T/S Characteristic

Variable voltage T/S

Characteristic

Variable frequency T/S

Characteristic

• E = 4.44 f n ϕ

• E/f = Constan = 4.44 ϕ

• Pada saat menurunkan f maka V juga turus

• Pada saat V turun, maka P = V x I x

3phase, sehingga akan diperoleh

penghematan