ELE 789 Special Topics in Electrical and Electronics Engineering:...

ELE 789: Special Topics in Electrical and Electronics Engineering; Electrical Power Quality

Dr. H.Bilge Mutluer

ELE 789 Special Topics in Electrical

and Electronics Engineering:

Electrical Power Quality

ELE 789: Special Topics in Electrical and Electronics Engineering; Electrical Power Quality 2

Course Outline

1. Power Quality (PQ) Definitions and

Objectives

2. Power System Modeling and

Simulation for PQ Analyses

3. Voltage Quality

4. Harmonics and Harmonic Elimination

5. Reactive Power Compensation

6. EMI, Grounding and Wiring


Reactive Power Compensation

• Power Factor

• Conventional Compensation Techniques

• Power Factor Correction of Unsymmetrical Loads and Phase Balancing

• Static Compensation Systems – FACTS Devices

– Reactive Power Compensation Solutions for Pulsed or Fast Varying Loads

– Case Study for Reactive Power Compensation

– Control System Design

– STATCOM


FACTS

• Flexible AC Transmission Systems

(FACTS)

• Various technologies that enhance the

security, capacity and flexibility of power

transmission systems


Problems in Transmission Lines


FACTS

• NGH = Hingorani Damper T

• CSC = Thyristor Controlled Series Capacitor

• PAR = Phase-Angle-Regulator TCVL = Thyristor Controlled Voltage Limiter

• SCCL = Super-Conducting Current Limiter

• TSBR = Thyristor Switched Braking Resistor

• BESS = Battery Energy Storage System

• HVDC = High Voltage Direct Current

• LTC = Transformer-Load Tap Changer

• SVC = Static Var Compensator TSSC = Thyristor Switched Series Capacitor

• STATCOM = Static Compensator

• UPFC = Unified Power Flow Controller

• TCPAR = Thyristor Controlled Phase-Angle Regulator

• SCCL = Super-Conducting Current Limiter

• SMES = Super-Conducting Magnetic Energy Storage


Steady State FACTS Solutions


Dynamic FACTS Solutions

Source:FACTS For Cost Effective and Reliable Transmission of Electrical Energy by Klaus Habur and Donal O’Leary


Solution Cost Estimation


Requirements in Transmission

Transmission Distribution

(Industrial)

Steady state voltage control; √ √

Voltage stability; √ -

System stability; √ -

Power Oscillation damping; √ -

Coordination of VAr contributions from

other equipment;

√ -

Fast VAr correction of variable loads; √ √

Fast correction of power factor; √ √

The correction of (line current)

unbalance;

√ √

Harmonic filtering; √ √


Line

v

FACTS

Controller

Series

Connection

Line

i

Shunt

Connection

a power electronic-based system and other static equipment that

provide control of one or more AC transmission system parameters

FACTS Controller


Reactive Power Compensation Solutions for Pulsed or Fast

Varying Loads

FACTS, Distribution Level

Solutions, LV Solutions


Saturated Reactor (SR)

• Shunt-connected iron core reactor. It is a

variable (nonlinear) susceptance that is

controlled by the terminal voltage. It is

connected in parallel to filters or capacitor

banks.

• SR is fixed in value and it is not a flexible

solution


Saturated Reactor (SR)

25MVAr 110kV shunt

magnetically controlled

(Saturated) reactor

connected to 32MVAr

Capacitor bank, installed

in Kudymar

Substain,Russia.

SR Installations in CERN


Thyristor Switched Reactor (TSR)

• Thyristor Switched Reactor is a primitive

TCR, which has the ability of controlling

the reactive power in steps, with just on/off

control.

• Only suitable for slowly varying loads with

fixed capacity, i.e. underground cable

compensation


Thyristor Switched Reactor (TSR)

Reactors of a Y-connected TSR installed for Bursaray, Turkey for

the compensation of underground cables installed for light railway


Thyristor Switched Capacitor (TSC)

• Connected as passive shunt filter that is

switched by back to back connected thyristors.

• TSC control is also stepwise as in the case of

TSR. When compared to the conventional

contactor type filter banks, TSC can be turned

on and off in a few operating cycles.

• In order to limit overvoltages and to balance the

load, TSC must be used with other types of

SVCs such as TCR or STATCOM


Thyristor Switched Capacitor (TSC)

Delta connected 500kVAr TSC system installed in TKİ BLİ

Enterprises by TÜBİTAK UZAY


Synchronous Condenser

• It is the Former technology for adjustable compensation. It consists of a synchronous generator and a field control circuitry.

• Fully controllable and has low harmonic generation. In a synchronous compensator, reactive power is varied by changing field current.

• Major drawbacks are high maintenance cost, slow response and balanced VAr generation capability


Synchronous Condenser

Armature Current versus Field Currrent for Synchronous Condenser


Thyristor Controlled Reactor(TCR)

Reactor

Thyristor

Stack

Reactor

Phase A Line

Phase B Line

Phase A Line

Phase B Line

Sn

ub

be

r

circu

it

Dyn

am

ic

Eq

ua

lizin

g c

ct

Sta

tic

Eq

ua

lizin

g c

ct

Ove

rvo

lta

ge

Pro

tectio

n

Ove

rvo

lta

ge

Pro

tectio

n

Single line diagram of a

polyphase TCR with, and

without series thyristor

operation


12- Pulse TCR Configuration

TCR 1 TCR 2

Supply Load

TCR 1 TCR 2

Supply Load

Main Objective: Cancellation of 5th and 7th harmonics (and some other higher harmonics)


TCR Currents

0 10 20 30

-1

-0.5

0

0.5

1

milliseconds

kV

/ k

A

TCR Phase AB Current

TCR Line AB Voltage

0 10 20 30

-1

-0.5

0

0.5

1

milliseconds

kV

/ k

A

TCR Phase AB Current

TCR Line AB Voltage


TCR Susceptance

0 20 40 60 80 100 120 140 160 1800

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Conduction Angle (degrees)

Suscepta

nce o

f th

e T

CR

(p.u

.)L

LX

B

sin)(


TCR Harmonics

I


L

VI

CVI

TCR or TSR: TSC:

SVC TCR V-I Characteristics


is a static self-commutated switching power converter which is

shunt-connected to an AC power system in order to produce

controllable capacitive or inductive currents to the AC power

system independent of the system voltage

STATCOM

STATCOM


X

Coupling

Transformer

System Bus

Ia

Exciter

V

If

Ef

X

Coupling

Transformer

System Bus

I

V

V0

VSC

Converter

+

Vdc

Rotating

Synchronous

Condenser

STATCOM

X

EVI fa

X

VVI o

STATCOM

STATCOM


STATCOM

29

Vo V

I

Vo

V

I

CapacitiveInductive

Vx

Vx


1. V-I characteristics

ILmax

ICmax

0

V

IC

2. Transient Stability

Regular SVC (Fixed capacitor + TCR) STATCOM

STATCOM maintain full capacitive reactive current at low system voltage

COMPARISON between SVC and STATCOM

STATCOM


3. Response Time

STATCOM is better than SVC due to the availability of fully

controllable power semiconductors in STATCOM.

4. Capability of Exchange Real Power

STATCOM in contrast to the SVC, can interface a suitable energy

storage (large capacitor, battery or super conducting magnetic

storage, etc) with the AC system for real power exchange

5. Operation in Load Compensation

Due to its better response time, STATCOM can also perform load

balancing or voltage regulation for voltage flicker problem more rapidly.


STATCOM


6. Loss versus VAr output characteristics

0

10

20

30

40

50

-600 -400 -200 0 200 400 600

Reactive Power (kVAr)

Po

wer

Lo

ss (

kW

)

TCR

STATCOM

Inductive

Capacitive

±500kVAr Current Source Converter based STATCOM vs.

SVC with 1MVAr TCR + 500kVAr Fixed Shunt Connected Harmonic Filter

STATCOM


7. Physical Size and Installation

For the same controllable capacitive and inductive reactive power

STATCOM has a relatively small energy storage in the dc-link

SVC has large capacitor and reactor banks


STATCOM is a shunt connected FACTS controller with

minimum energy storage

• significant reduction in overall size (30-40%), installation labor and cost

• improves the relocability of the system

STATCOM


Transmission STATCOM

♦ Midpoint voltage regulation to

increase transmittable power

♦ End of line voltage support to

prevent voltage instability due to

load having poor factor.

♦ Improvement of transient

stability margin by increasing the

maximum transmittable power

♦ Power oscillation damping by

exhanging active (real) power with

power system

● compensation of poor load power

factor

● suppression of harmonics in loads

● voltage regulation

● load balancing

TYPES OF STATCOM

Distribution STATCOM

STATCOM


All STATCOM applications are based on Voltage Source Converters

Single phase

two-level H-converter

Three-phase

two-level converter

Three-phase

three-level converter

STATCOM APPLICATIONS

STATCOM



EPRI – TRANSMISSION STATCOM – FIRST INDUSTRIAL APPLICATION

DC-link voltage=6.6kV

Switching frequency is 50Hz

By using complex transformer connection and 8 VSC

48-pulse voltage waveform is obtained

±100MVAr GTO based three phase two-level VSC STATCOM

STATCOM


EPRI – TRANSMISSION STATCOM – FIRST INDUSTRIAL APPLICATION

48m

90m

±100MVAr GTO based three phase two-level VSC STATCOM

STATCOM APPLICATIONS STATCOM



ABB – SVC LIGHT- FLICKER COMPENSATION AND ACTIVE FILTER

Switching

frequency

is 1000Hz

±22MVAr IGBT based

three phase three-level VSC STATCOMc

STATCOM


ABB – SVC LIGHT- FLICKER COMPENSATION AND ACTIVE FILTER


±22MVAr IGBT

based

three phase three-

level

VSC STATCOM

22

m

16m

STATCOM


Line

Current Source

Converter

+

Line

Voltage Source

Converter

Coupling

Transformer

Coupling

Transformer

Storage Elements

Reactor for CSC

Capacitor for VSC

Reactive Power depends

on storage elements in

conventional SVC

(such as TCR, TSC)

Reactive Power does not

depend on storage

elements in STATCOM

Static VAr Compensator with

“zero” or “minimum” energy

storage element

+

CSC STATCOM - VSC STATCOM

STATCOM


Line

Current Source

Converter

+

Line

Voltage Source

Converter

Coupling

Transformer

Coupling

Transformer

Power

Semiconductors

CSC

bipolar voltage blocking

unipolar current flow

VSC

unipolar voltage blocking

bidirectional current flow


STATCOM


Line

Current Source

Converter

+

Line

Voltage Source

Converter

Coupling

Transformer

Coupling

Transformer

Coupling Elements

CSC

AC capacitors provide

low impedance for the

current harmonics

VSC

Reactors provide

high impedance for the

voltage harmonics


STATCOM


cosδ M II dcS X

Mcosδ VVI dcS

LineV

Current Source

Converter

Idc

LineV

+

Voltage Source

Converter

Vdc

VSCCSC

indirect controldirect control

Q = 3 V Is


STATCOM


SVC Design


Design Methodology Contracting

Specification of

Requirements

Design by hand

calculation and

simulation tools

Compare

standards and

specifications

Subsystem

Manufacturing

meets

Subsystem

Lab Tests

Performance

Satisfactory?Integration

YesUnsatisfactory

0

Investigation of

current loads and

further investment

plans


Design Methodology (Cont’n)

Integration

Integrated System

Lab Tests

Performance

Satisfactory?

Type of

Corrective

Action

Yes

No

System

Integration

Design

Concept

1

0

2


Design Methodology (Cont’n) Transportation

Installation to the

site

Check wiring and

installation

Comissioning

Field TestsEvaluation of

Tests

Type of

Corrective

Action

System

Integration

Installation

1

Ready

Satisfactory

Unsatisfactory

2


Design Methodology (Cont’n)

Evaluation of

TestsAcceptance

Periodical

Maintenance

Limited Warranty

Period

End of

Project

Satisfactory


Case Study

A unified and relocatable TCR

based SVC system for open cast

lignite mining


Case Study

A unified and relocatable TCR based SVC system

for open cast lignite mining • Design Criteria

– Unified

– Relocatable

– Modular

• Possible SVC Types

– TCR + F

– TSC

– TSR

– STATCOM


Unification


Coupling Transformer

Dyn-11

34.5kV/1kV

1 / 1.5 MVA 2 MVA

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

0.577 //0.0577/

0.0577

Sn: 0.5 10VA

Auxillary Transformer

Yzn-11

1kV/0.4kV 7.5kVA

1x95 /

16mm2

XLPE

1x1

85

mm

2

XL

PE

2x(1x18

5) mm2

XLPE

1 / 1.5 / 2

MVAr TCR

2x(1x185) mm2

XLPE

1 kV 1600 A 20 kA

Circuit Breaker

36kV,630A

16kA

MV, +/-10%, 50Hz, Isc< 16kA

HF

250kVAr

BA

SIC

SV

CAdditional HF/TSC Additional TCR

Ad

dit

ion

al

MV

HF

1x95 /

16mm2

XLPE

36kV,630A

16kA

Detuned 5th HF

1.8MVAr, 38kV

C5 = 162uF C7 = 108uF

L5 = 903uH L7 = 674uH

HF

250kVAr

C5 = 162uF C7 = 108uF

L5 = 903uH L7 = 674uH

HF

250kVAr

0.5 MVAr

TCR

(1x185) mm2

XLPE

TSC

500kVAr

TSC

500kVAr


Relocation for Open Cast Lignite Mines


(a)

Load Identification


Load Identification

Data Acquisition system

NI DAQCard 6062E, SC-2040 S/H Card (0.5 Ms/s)


Load Identification

• Single line diagram

• Monthly electric bills

• Daily active and reactive power demands

• Detailed information about electric motor

drives, transformers

• An investigation of previously installed

shunt compensators, and capacitors

• Future production plans and machine

stocks


Single Piece / Two Piece Reactor

PA

PCPB

TCR1

TCR4

TCR6

TCR3

TCR2 TCR5

1

2

PA

PCPB

PA

PCPB


PSCAD Simulation Results

Case

Maximum 5th

Harmonic

Filter Current

(kA)

Maximum 5th

Harmonic

Filter

Capacitor

Voltage (kV)

Maximum 7th

Harmonic

Filter

Current

(kA)

Maximum 7th

Harmonic

Filter

Capacitor

Voltage (kV)

Maximum

TCR

Line

current

(kA)

Maximum

TCR

Thyristor

current

(kA)

1 0,4760 0,9582 0,4296 1,0245 26,7383 0,7590

2 0,1383 0,5457 0,0927 0,5009 33,7312 0,9013

3 0,1276 0,8337 0,0832 0,8152 27,5715 0,7833

4 0,2920 0,4659 0,2629 0,4559 39,4042 0,6918

5 0,1333 0,8257 0,0877 0,8005 1,4378 1,6126

6 0,1260 0,8171 0,0826 0,7959 1,7268 1,8834

7 0,1277 0,8336 0,0832 0,8151 1,0207 1,0602

8 0,1300 0,8090 0,0855 0,7799 2,5117 1,8673

9 0,1266 0,8253 0,0828 0,8054 1,1658 1,1886

10 0,1277 0,8336 0,0832 0,8151 1,0207 1,0602

11 0,1303 0,8294 0,0853 0,8070 1,0265 0,7659

12 0,1281 0,8252 0,0836 0,8029 1,2619 1,0690


Implemented System

C5 C7

L5 L7

15 or 34.5kV

Busbar

5th Harm. Filter 7th Harm. Filter

TCR

Coupling

Transformer

HV SF6

Breaker

LV Air Ballast

Breaker

1kV Bus


Reactors

1 MVAr TCR 2 x 4.7mH, 376A, 1kV, BIL 20kV

1.5 MVAr TCR 2 x 3.17mH, 563A, 1kV, BIL 20kV

2 MVAr TCR 2 x 2.35mH, 752A, 1kV, BIL 20kV

Air core, outdoor reactor group


Thyristor Stack Design

Single Switch

3.17mH

Phase A Line (1kV)

Phase B Line (1kV)

270snbR

FCsnb 33.0

DC

R1

47

6S

Y3

43

4

3.17mH

1.5 MVAr TCR (Phase AB)


Filters

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

1kV Busbar

C5 C7 C5 C7

L5 L7 L5 L7

Tuning Frequency: 240.25 Hz Tuning Frequency: 340.58 Hz


Filter Design Harmonics injected from TCR (1A)

7th

HF

Cur.

5th

HF

Cur.

S

upply

Cur.

Amplification due to

Parallel Resonance


Measurement


Protection Protection Relays

36kV, 630A, 16kA SF6 Circuit Breaker

Protection circuits in

Control Panel


Transformer Design Conventional Transformers SVC Coupling Transformer

TDD Limits defined by [23,35,42] High if filters are mostly at the

primary side

Even Harmonics in the load

(and SVC)

Limits defined by [23,35,42] Higher than limits

DC Current None Depends on controller, may be

excessive in misfiring

conditions

Voltage Fluctuation Limits defined in [22,23] Depends on loadbus, mostly higher

than regular

Transformer Design IEC 76,ANSI C.57 [58,59] IEC 76,ANSI C.57; with minor

additions

Core Size and Physical

Dimensions

Regular Core and case dimensions are bigger

for the same MVA

Overloads Rare, depending on load busbar Usual, depending on load busbar

Load Fluctuation Low High, especially in arc furnace

applications

Saturation IEC 76 Needs extra precautions

Hot spot probability IEEE/ANSI C.57.91-1995 [59] IEEE/ANSI C.57.91-1995 [59]


Transformer Design

The ANSI/IEEE standard C57.110 [39] defines a K factor

h h

h

h

I

hI

K2

22 )(

REC

REC

RKP

PII

.

.

max1

1

B-H Characteristics of an M3 type Steel Core

Bop can be selected below 1.6Wb/m2 instead

of 1.8 Wb/m2 used normally for distribution

transformers


EMC Considerations

Avoiding Loops Magnetic Clearences


Environmental Conditions

Flashover due to

extreme pollution Heavy Weather Conditions


Reactive Power Compensation


Harmonics

Main

Transformer

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

40A / 5A

10VA

750A / 5A

10P1O / 5VA1000A / 5A

10P10 / 5VA

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

750A / 5A

0.5Fs5 / 10VA

1000A / 5A

0.5Fs5 / 10VA

250A / 5A

0.5Fs5 / 10VA

250A / 5A

0.5Fs5 / 10VA

250A / 5A

0.5Fs5 / 10VA

3.17mH

3.17mH

3.17mH3.17mH

3.17mH

3.17mH

TKİ I

ELİ Işıklar

34.5kV Busbar

Transformer

Primary Current

Filter CurrentReactor Line

Current

Reactor Phase

Current


Harmonics Transformer Primary Current Referred to 1kV

Time (sec)

15 33 51 69 87 105

A

+0

+100

+200

+300

+400

+500

Current Harmonics

15 33 51 69 87 105

A

+0

+20

+40

+60

+80

+100

Current Harmonics

15 33 51 69 87 105

A

+0

+4

+8

+12

+16

+20

Filter Current

Time (sec)

15 33 51 69 87 105

A

+0

+100

+200

+300

+400

+500

Current Harmonics

15 33 51 69 87 105

A

+0

+20

+40

+60

+80

+100

Current Harmonics

15 33 51 69 87 105

A

+0

+4

+8

+12

+16

+20


Harmonics Filter Current

Time (sec)

15 33 51 69 87 105

A

+0

+100

+200

+300

+400

+500

Current Harmonics

15 33 51 69 87 105

A

+0

+20

+40

+60

+80

+100

Current Harmonics

15 33 51 69 87 105

A

+0

+4

+8

+12

+16

+20

Reactor Line Current

Time (sec)

15 33 51 69 87 105

A

+0

+200

+400

+600

+800

+1000

Current Harmonics

15 33 51 69 87 105

A

+0

+20

+40

+60

+80

+100

Current Harmonics

15 33 51 69 87 105

A

+0

+4

+8

+12

+16

+20


Reactor Current

Harmonic Order

6- Pulse TCR Theoretical

(%)

Field Data (%)

1 100 100

3 - 1.52

5 5.05 5.02

7 2.59 2.56

9 - 0.35

11 1.05 0.95

13 0.75 0.72


Harmonics

Main

Transformer

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

25A / 5A

10VA

500A / 5A

10P1O / 5VA1000A / 5A

10P10 / 5VA

C5 = 162uF C7 = 108uF

L7 = 674uHL5 = 903uH

500A / 5A

0.5Fs5 / 10VA

1000A / 5A

0.5Fs5 / 10VA

250A / 5A

0.5Fs5 / 10VA

250A / 5A

0.5Fs5 / 10VA

3.17mH

3.17mH

3.17mH3.17mH

3.17mH

3.17mH

TKİ

BLİ 34.5kV

Busbar

Transformer

Primary Current

5th Harm. Filter

Current (Rogovsky)

Reactor Line

Current

7th Harm. Filter

Current (Rogovsky)


Harmonics

No TCR firing 0.5 p.u. of full conduction current

of TCR


Compared to Design Parameters

Filter

element

Max rms current, A

Total current

True rms, (A) 50 Hz 250 Hz 350 Hz

5th HF 110 / 65 26 / 16 1 / 0.8 115 / 67

7th HF 71 / 44 4 / 3 13 / 9 75 / 46


0 10 20 30 40-1500

-1000

-500

0

500

1000

1500

Time (ms)

Vo

lta

ge

(V

) / C

urr

en

t (A

)

Thyristor Valve Voltage and Current Waveform,Reactor current 0.25 p.u. of full conduction current

Thyristor Valve (Phase) Voltage and Current

Voltage

Current


0 10 20 30 40-2000

-1500

-1000

-500

0

500

1000

1500

2000

Time (ms)

Vo

lta

ge

(V

) / C

urr

en

t (A

)

Thyristor Valve Voltage and Current Waveform,Reactor current 0.95 p.u. of full conduction current

Max. 1.83kV Voltage

Current

Thyristor Valve (Phase) Voltage and Current


Control System Design

For SVC Systems


Feed-back

Measurement

Triggering Reactive

Power

P I

Set Error

+

-


Feed-Forward

Triggering Reactive

Power

Iline Iload +

-

P

ISVC


Simple P-I Control

Reactive Power

Measurement

Load Supply

Harmonic

Filter(s)TCR

P I

Regulator

LinearizingTrigger

Circuits


Control with Load Balancing

V I

Measurement

Load Supply

Harmonic

Filter(s)TCR

P I

RegulatorLinearizing

Trigger

Circuits

Negative

Sequence

Calculation

Positive

Sequence

Reactive Power

+

+


Complete Control System Design

V I

Measurement

Load Supply

Harmonic

Filter(s)TCR

P I

RegulatorLinearizing

Trigger

Circuits

Negative

Sequence

Calculation

Positive

Sequence

Reactive Power

+

+

+

+

P Regulator

Reactive

Current Comp.

Calculation

Flicker Compensation System with feed-forward and feed-back control


Response Time Simulation

• Proportional gain is

0.2,

• Integral gain is 0.45

• Feed-forward gain is

0.133

• PI time constant is

selected 38ms

Time (sec)

00.75 1.5 2.25 3 3.75 4.5 5.25 6-0.7

-0.41

-0.12

+0.17

+0.46

+0.75

+1.04

+1.33

+1.62

+1.91

+2.2Reactive Power After Compensation Active Power

00.75 1.5 2.25 3 3.75 4.5 5.25 6-1.4

-0.88

-0.36

+0.16

+0.68

+1.2Load Reactive Power TCR Reactive Power

Q (

MV

Ar)

Q (

MV

Ar)


Control System Response

• 1- Measurement delay

• 2- Firing circuit delay

• 3- PI + FF regulator delay

1 2 3

10mS0.1 - 10 mS

30 - 100 mS

Time (mS)

Re

sp

on

se


0 100 200 300 400-1.5

-1

-

0.5

0

0.5

1

1.5

Time (ms)

TC

R R

ea

ctive

Po

we

r (p

.u.)

Open Loop Response of TCR

TCR ResponseTCR Reference

1 2 3

10mS0.1 - 10 mS

30 - 100 mS

Time (mS)

Re

sp

on

se

Tr=13ms

Open Loop Response

Maximum

Capacitive Power

Reached

Maximum

Inductive Power

Reached


0 100 200 300 400-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Time (ms)

TC

R R

ea

ctive

Po

we

r (p

.u.)

PI Loop response of TCR, Feed-forward disabled


PI Regulator Only (FF disabled)

Tr=140ms


PI + FF Regulators

0 100 200 300 400-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Time (ms)

TC

R R

ea

ctive

Po

we

r (p

.u.)

TCR Response (PI time constant =38mS)


• Proportional

gain is 0.2,

• Integral gain is

0.45

• Feed-forward

gain is 0.133

• PI time

constant is

selected 38ms

Tr=120ms


Reducing the Response Time

0 100 200 300 400-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Time (ms)

TC

R R

ea

ctive

Po

we

r (p

.u.)

TCR Response (PI time constant =25mS)


Tr=90ms

PI Time constant =25ms

ELE 789 Special Topics in Electrical and Electronics Engineering:...

Documents

Transcript of ELE 789 Special Topics in Electrical and Electronics Engineering:...