4. Dasar Variable Speed Drives.pdf

Dasar Variable Speed DrivesMochammad RAMELI

Teknik Sistem Pengaturan - Jurusan Teknik Elektro FTI ITS

2014

Obyektif:

Mempelajari hubungan model motor induksi Karakteristik motor beban Teknik penyesuaian Pengaturan karakteristik motor beban

Mempelajari teknik dasar: pembangkitan gelombang sinus PWM Konverter elektronik

Konsekuensi penggunaan Konverter elektronik Teknik minimisasi pengaruh harmonisa

2

M. RAMELI: Control of Electric Drive

ABBMonth DD, YYYY | Slide 3

ASHRAE Rocky Mountain ChapterVFD FundamentalsApril 16, 2010Jeff Miller -

2010

Referensi:1. Jeff Miller, VFD Fundamentals, ASHRAE Rocky Mountain Chapter, April 16, 2010

3



04/08/05

Biodata Personel Nama: Mochammad RAMELI, DR. Ir. Tempat/tgl lahir: Surabaya, 27 Desember 1954 Pendidikan:

S1- Teknik Elektro ITS, 1979 S3- Control Engineering, Univ. Louis Pasteur - Strasbourg, France, 1990.

Pekerjaan : Dosen Teknik Elektro ITS Alamat rumah : Jl. Teknik Arsitektur J-6 Surabaya. Telephone : (031) 5931146 Mobile : 081 232 888 52 Istri 1 (satu), anak 2 (dua): laki-laki & perempuan Email: [email protected] atau [email protected]

Modeling dan Pengaturan Penggerak Elektrik(Control of Electrical Drives)

INDUCTION MOTOR DRIVES

Scalar Control Vector Control

Const. V/Hz is=f(r) FOC DTC

Rotor Flux Stator Flux CircularFlux

HexagonFlux

DTCSVM

5


Pengaturan motor induksi asinkron berdasarkan model steady-state (rangkaian ekivalen SS per-fasa):

Rr/s

+

Vs

Rs Lls Llr

+

Eag

Is Ir

Im

Lm


6


UV

W

pfns 2

.120=

+

+

==2

2'2

1

'2

23

eks

dd

Xs

RRs

RVPT


7


rs

Trated

Pull out Torque(Tmax)

Te

ssm ratedrotor

TL

Te

Titik potong (Te=TL) menentukan kecepatansteadystate.


8


Diberikan satu beban dgn karakteristik T,kecepatan steady-state dapat diubah dgn mengubah karakteristik T motor:

Mengubah Pole Kecepatan sinkron berubah sesuaidgn banyaknya polesPerubahan kecepatan secara Diskrit

Tegangan variabel (amplitude), frequensi tetapmenggunakan Trafo atau TriacTegangan diturunkan Slip menjadi tinggi efisiensi rendah

Tegangan variabel (amplitude), frekuensi variabel (V/Hz konstan)Menggunakan converter electronikBeroperasi di low slip frequency

pfns 2

.120=


9


Tegangan variable, frekuensi tetap

0 20 40 60 80 100 120 140 1600

100

200

300

400

500

600

Torq

ue

w (rad/s)

Kecepatan makin rendah slip makin tinggi

Efisiensi rendah pada kecepatan rendah

Contoh: 3phase squirrel cage IM

V = 460 V Rs= 0.25

Rr=0.2 & Lr = Ls = 0.5/(2*pi*50)

Lm=30/(2*pi*50)

f = 50Hz p = 4


10


Nilai V/Hz = konstan

Bila nilai Eag cukup besar air-gap flux mendekati konstan

Eag = k f ag

fV

fEag =ag = konstan

Pengaturan kecepatan dilakukan dengan merubah-rubah nilai frekuensi f mempertahankan nilai V/f konstan untuk menghindari kejenuhan flux.

Mempertahankan nilai V/Hz tetap konstan

+V_

+Eag_


11


0 20 40 60 80 100 120 140 1600

100

200

300

400

500

600

700

800

900

Torq

ue

50Hz

30Hz

10Hz



12


Vrated

frated

Vs

f



13


VoltageSource Inverter

RectifierSuplai3-fasa IM

Pulse Width

Modulators* +Ramp

f

C

V



14


Apa itu Penggerak Elektrik / Drive / VFD/ AFD?

0

230

460

Volts

Hertz30 60

460 V

60 Hz= 7.67

VHz

230 V

60 Hz= 3.83

VHz

Bila suplai 230 VAC:

15


Motor

L1

L2

L3

C

L

Input Converter(Diode Bridge)

Output Inverter(IGBTs)

DC Bus(Filter)+

_+_

+

_

+

_

+ +

_ _

Apa itu Penggerak Elektrik ?

16


Apa itu Penggerak Elektrik ?

17


Satu variable frequency drive mengubah energi listrik masukan 50 Hz ke bentuk arus searah DC,selanjutya diubah ke satu bentuk keluaran tegangan variabel frekuensi variabel buatan.

VFD Fundamentals

50 Hz Power

Electrical Energy

ABB

Zero - 100 Hz

keMotor

VFD

RECTIFIER(AC - DC)

INVERTER(DC - AC)

AC DC AC

VFD

Zero - 100 Hz50 Hz

18


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

19


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

20


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

21


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

22


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

23


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

24


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

25


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

26


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

27


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

28


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

29


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

30


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

31


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

32


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

33


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

34


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

35


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

36


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

37


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

38


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

39


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

40


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

41


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

42


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

43


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

44


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

45


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

46


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

47


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Luasan dibawah Pulsa-pulsa Gel Persegi (Square-Wave Pulses)mendekati luasan dibawah satu Gelombang Sinusoida

Frekuensi

Tega

ngan

48


49


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Berapa kali posisi saklar berubah dari Pulsa-pulsa Positipke Pulsa-pulsa Negatip Menentukan Frekuensi Gelombang

Frekuensi

Tega

ngan

50


Frekuensi = 25Hz

Frekuensi = 50Hz

51


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

52


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor53


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

54


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

55


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

56


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

57


RECTIFIER

PositiveDC Bus

NegativeDC Bus

+

-

INVERTER

Motor

58


tPWM pulse width modulation

Inverter PWMM. RAMELI: Control of Electric Drive

uv

w

u

w

v


uv

w

u

w

v

+Hs


+u

v

w

u

w

v

Hs


uv

w

u

w

v+

Hs


uw

u

v

w

v

+

Hs


uv

w

u

w

v

+

Hs


uv

w

u

w

v

+Hs


+u

v

w

u

w

v

Hs


uv

w

u

w

v+

Hs


uw

u

v

w

v

+

Hs


uv

w

u

w

v

+

Hs


Beban-beban Non-Linear ?

Beban-beban yang mengambil arus non-sinusoidal dari jaringan-listrik:

Bukan lampu-pijar (Non-incandescent lighting) Komputer Uninterruptible power supplies Peralatan Telekomunikasi Mesin-mesin Foto-Copy Battery chargers Electronic variable speed drives Semua beban yg bekerja dgn konverter elektronik

AC to DC73


M460VAC 3-fasa

650VDC

AC buatan(PWM)

Semua AC Drives menyearahkan AC ke DC, kemudian mengubahke bentuk AC buatan (PWM) dgn Tegangan dan Frekuensivariabel untuk mensuplai motor.

Konversi AC ke DC membangkitkan harmonisa!

Konfigurasi Tipikal AC Drive

74


Non-linear loads draw current in a non-sinusoidal or distorted manner

Harmonics or harmonic content is a mathematical concept implemented to allow quantification and simplified analysis of non-linear waveforms

Harmonics are typically present in both network currents and network voltages

Non-linear current draw creates non-linear voltage as it flows through the electrical network

Current harmonics Voltage harmonics

Definisi Harmonisa

75


FundamentalHarmonisa ke-5Harmonisa ke-7Harmonisa ke-11Harmonisa ke-13Harmonisa ke-17Harmonisa ke-19

50 Hz250 Hz350 Hz 550 Hz650 Hz850 Hz950 Hz

60 Hz300 Hz420 Hz 660 Hz780 Hz

1020 Hz1140 Hz

Frekuensi Harmonisa

76


0 0.005 0.01 0.015 0.02 0.025 0.031

0.5

0

0.5

1

i1 t( )

i5 t( )

i7 t( )

Fundamental 5th

7th

0 0.005 0.01 0.015 0.02 0.025 0.031.5

1

0.5

0

0.5

1

1.5

iT t( )

t

Komponen--komponen

Penjumlahan

Theory: Fundamental, Harmonisa ke-5 dan ke-7

77

Ingat! Deret Fourier


PWM Drive Harmonic Input Spectrum

5th

7th

Fundamental

11th13th

Harmonic Content, 6- Pulse Drive

78


Distorsi Arus Harmonisa Menambah panas di trafo dan kabel,

menurunkan kapasitas tersedia Dapat memicu satu kondisi resonansi

dengan Kapasitor Power Factor Correction Tegangan berlebihan (Excessive voltage) Overheating pada kapasitor koreksi PF Tripping pada PF protection equipment

Distorsi tegangan - Voltage Distortion mengganggu kerja (interferensi) sensitive equipment. Paling dikuatirkan!

Harmonisa Mengapa dikhawatirkan?

79


Harmonics produced by an individual load are only important to the extent that they represent a significant portion of the total connected load

Linear loads help reduce system harmonic levels TDD equals the THD of the nonlinear load multiplied by

the ratio of nonlinear load to the demand load:

DLNLTHDTDD NL =Where

TDD = TDD of the systemTHDNL = THD of the nonlinear loadsNL = kVA of nonlinear loadDL = kVA of demand load

(nonlinear + linear)

Harmonics A System Issue!

84


Table 10.2Low-Voltage System Classification and Distortion Limits

SpecialApplications

GeneralSystem

DedicatedSystem

Notch Depth 10% 20% 50%THD (Voltage) 3% 5% 10%Notch Area, Vs 16,400 22,800 36,500

Note: Notch area for other than 480 V systems should be multiplied by V / 480.

IEEE 519 - 1992

Harmonics By the Numbers

85


Table 10.3Current Distortion Limits for General Distribution Systems

ISC / IL

Reactors (Chokes) Passive Filters

Harmonic Trap Hybrid

High Pulse Count Rectification Active Filters

Drive Front End Stand Alone

Harmonics Attenuation Options

87


Simplest and least expensive harmonic reduction technique

May be included in base drive package

Often meet harmonic needs provided drive load is a small portion of total connected load

May be implemented with AC line reactors or with DC link reactors

AC line reactors provide better input protection

DC link reactors provide load insensitive drive output voltage

Both types provide similar harmonic benefits

Swinging choke design provides enhanced light load harmonic performance

Reactors (Chokes)

88


AC LineReactor

M

DC LinkReactor

M

Different design techniques

Equal harmonic reduction for same normalized% reactance

Typical full load THD (current) at drive input terminals28% 46%

Reactors, AC Line atau DC Link

89


Installs in series with drive input

May feed multiple drives

Improves power factor (may go leading)

Typical full load THD (current) at filter input terminals5% 8%

Relatively unaffected by line imbalance

Hybrid Filter

90


Typical configurations are either 12 pulse or 18 pulse

Phase shifting transformer is required Additional drive input bridge(s) is needed Typical full load THD (current) at transformer

primary 8% 12% (12 pulse), 4% 6% (18 pulse) Performance severely reduced by line imbalance

(voltage or phase) Excellent choice if step-down transformer is

already required

High Pulse Count Rectification

91


6 pulse rectifier

Transformer and cabling simple

Current very distortedIthd typically 45% with 3% reactor

DC/AC

DC/AC

Transformer and cabling complicated

Current distortedIthd 8% to 12% (depending on network impedance)

12 pulse rectifier

18 pulse rectifier

DC/AC

Transformer and cabling complicated

Current wave form goodIthd 4% to 6% (depending on network impedance)

High Pulse Count Rectification

92


LCL Filter (Sine Filter) removes high frequencies >1 kHz. (Current and voltage)

Full output voltage is available with 80% input voltage(400VIn = 480VOut)

Full regenerative capability No transformer required Not affected by line imbalance

LCL filter

Line inverter(rectifier)

Motor inverter Motor

L L

C

M

Active Filter Front End with LCL Filter

93


Remember!Even an 80% THD nonlinear load with a will result in only 8% TDD if the nonlinear load is 10% and the linear load is 90%.

(80%(10%/(10%+90%))=8%)

Harmonic Reduction Summary

Effectiveness of Harmonic Mitigation Techniques (Assuming 100% Nonlinear Loading, ISC / IL = 60)

Technique THD (Current) Harmonic Reduction

No mitigation (reference level) 72% 3% line reactors (or equivalent DC link reactor) 39% 45.8% 5% line reactors (or equivalent DC link reactor) 33% 54.2% 5% line reactors + 5th harmonic trap filter 12% 83.3% 12 pulse input rectifier with 5% impedance transformer 10% 86.1% Hybrid filter 7% 90.3% 18 pulse input rectifier with 5% impedance transformer 5% 93.1% 12 pulse input rectifier with 5% impedance transformer + 11th harmonic trap filter 4% 94.4%

Active harmonic filter 3.5% 95.1%

94


Summary Practical Advice

With a main distribution transformer, 20-30% of its load on non-linear loads will typically comply with IEEE 519-1992

Voltage distortion causes interference with sensitive equipment, not current distortion!

5% reactors address 90+% of typical applications. They also provide protection against line transients and keep input currents low to avoid oversizing power wiring to comply with NEC.

Make VFD vendor perform a harmonic distortion calculation with the submittals.

95


PEAK: 1,040 volts 96


Peak Voltage all at 50 of cable

Peak Voltage has many Contributing FactorsInverter Rated

Motors Help Minimize the IssueLess dV/dT

minimizes; problems with RFI/EMI Motor Insulation & Bearing Current

Drive Peak Voltage

1 1040

2 1110

3 1180

4 1290

5 1350

6 2454

97


Recommendations

Keep cable length short as possible Use a NEMA MG1, Part 31 motor (not inverter duty or inverter

ready Ensure that grounding is sound

98


99


100


Dasar Variable Speed DrivesObyektif:ASHRAE Rocky Mountain Chapter VFD FundamentalsApril 16, 2010Jeff Miller - ABBBiodata PersonelSlide Number 5Pengaturan motor induksi asinkron berdasarkan model steady-state (rangkaian ekivalen SS per-fasa):Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Apa itu Penggerak Elektrik / Drive / VFD/ AFD?Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44Slide Number 45Slide Number 46Slide Number 47Slide Number 48Slide Number 49Slide Number 50Slide Number 51Slide Number 52Slide Number 53Slide Number 54Slide Number 55Slide Number 56Slide Number 57Slide Number 58Slide Number 59Slide Number 60Slide Number 61Slide Number 62Slide Number 63Slide Number 64Slide Number 65Slide Number 66Slide Number 67Slide Number 68Slide Number 69Slide Number 70Slide Number 71Slide Number 72Beban-beban Non-Linear ?Slide Number 74Slide Number 75Slide Number 76Slide Number 77Slide Number 78Slide Number 79Slide Number 84Slide Number 85Slide Number 86Slide Number 87Slide Number 88Slide Number 89Slide Number 90Slide Number 91Slide Number 92Slide Number 93Harmonic Reduction SummarySummary Practical AdviceSlide Number 96Peak Voltage all at 50 of cableRecommendationsSlide Number 99Slide Number 100

4. Dasar Variable Speed Drives.pdf

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