Samaan Short Circuit IEEE PSE09

7/30/2019 Samaan Short Circuit IEEE PSE09

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Modeling of Wind Power Plants for

Transmission Network

Nader Samaan Robert Zavadil J. Charles Smith Jose Conto

EnerNex Corporation

Knoxville, TN

UWIG

Reston, VA

ERCOT

Taylor, TX

Presented at

IEEE 2008 Transmission & Distribution Conference & Exposition


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Agenda

Objective

Modeling of Type 1 WTG for steady stateshort circuit anal sis

Calculating equivalent impedance for wind plantto e use n s ort c rcut ana ys s

t t h w th tr n i nt h vi r f

Type 1 WTG during fault conditions

Conclusions


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Objective

Procedures to calculate the contribution of WindPower Plants (WPP) to short circuits in the MV/HV

transmission network (steady state analysis)To characterize the asymmetrical induction

generator short circuit current to identify the

breakers momentary duty (transient analysis) As the input mechanical power to induction

generator is almost constant after the fault, the

s or c rcu curren o n uc on genera or maydecay in a different manner than induction motors


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Type 1 Wind Turbine Generator

Type 1 wind turbine generator (WTG) is a-

It is connected directly to the padmount

Gear Soft starter

Grid

SCIG


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Modeling of Type 1 WTG for Steady State Short

Circuit Analysis Induction generator in short circuit calculations is

re resented as a volta e source in series with the

direct axis sub-transient inductance

That means for a 3LG fault at the WTG LV

,symmetrical short-circuit current with a magnitude

current during the first cycle after the fault


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Procedures for Determining the WPP

Equivalent Impedance (1)A detailed model for the WPP is needed to determine theplant 3-phase to ground I and single line to ground

ZZ

ISLG short circuit currents at the plant main substation

ne nene

Isc Feeder

ne nene

Isc Feeder

ZWTGZWTG ZWTG ZWTG

Isc_9Isc_8 Isc_7 Isc_6

_

ZWTGZWTG ZWTG ZWTG

Isc_9Isc_8 Isc_7 Isc_6

_

VG9

VG8 VG7 VG6VVG9

VVG8 VVG7 VVG6

WTG=T

ZT Impedance of turbine step up transformer

WTG=T

ZT Impedance of turbine step up transformer

d


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Procedures for Determining the WPP

Equivalent Impedance (2)Using the E/Z simplified method, short-circuit currentsare then used to obtain the equivalent positive sequence

and zero sequence impedances of the plantLL

V 3 LNV1 2

33 * LGI0 1

SLGI

WPP +ve -ve se uence

impedanceszero sequence

impedance


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eneric Dynamic Model for Squirrel Cage Induction

Generator with Pitch Angle Controller

Pitch Angle

Controller

AeroDynamics

-massmodel for

q e ca einduction

model


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Case Study

A 50 MW wind farmconsists of 20 2.5

MW Type 1 WTG

n y ower ac orwith 1.35 MVAR

switched on

au as s or . sec(12 cycles)

Grid MVA SC duty 1500 MVA


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Case Study: (3LG Fault at WPP MV Bus)

Fault Duration

Injected current from the WPP to the substation MV bus


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Case Study (SLG Fault at WPP MV Bus)

Faulted phase

Fault Duration

Injected current from the WPP to the substation MV bus


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Case Study (Decay of WPP Short Circuit

Current)No. of

cycles

after fault

Current

peak

value

Percentage of

rated

current

No. of

cycles

after

Current

peak

value

Percentage of

rated current

eak value

peak value(1167 A)

fault

(1167 A)

Max value 6623 A 568%after fault

instant

a ter au tinstant

3 cycles

3 cycles 3331 A 285%

6 c cles 1560 A 134%

6 cycles 2524 A 216%

9 cycles 780 A 67%9 cycles 1618 A 139%

3LG Fault SLG Fault


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Case Study (WTG Short circuit current)

3LG fault

Generator instantaneous current waveforms


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SLG fault



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Line to Line fault



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Induction generator highest peak current values

during the fault-Phase A

12 3 phase to groundLine to line fault10

Line to line faultLine to gro und fault

68

46

1 pu

Short circuit

current in kA

020 P re -f a ult Af ter F a ult 3 cy cles 6 cy cles 9 cy cles


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Induction generator highest peak current

values during the fault-Phase B

18 3 p h a s e t o g r o u n d

141618

Lin e t o l in e f au l tL in e t o g r o u n d f a u l t

1012

1 pu

Short circuit

current in kA

468

024

P r e-f a ul t A f te r F a ul t 3 c yc l es 6 c yc l e s 9 c yc l es


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Induction generator highest peak current

values during the fault-Phase C

18 3 phase to ground

141618 Line to line fault

Line to ground fault

81012

1 pu

Short circuit

current in kA

468

024

Pre f ault After Fault 3 cycles 6 cycles 9 cyclesre-f ault After Fault 3 cycles 6 cycles 9 cycles


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Case Study (Short Circuit Calculations)

Description Before the After the Fault level

Description Detailed

Model

Equivalent

Circuit

SK'' (MVA short- 1616.882 1616.867

a t on o

the WPP

a t on o

the WPP

ncrease

MVA short-

circuit1500 1617 7.8%

c rcu power

Ik(Symmetri

cal Sub

PhaseA

4059 A


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Conclusions

Procedures have been developed to build anequivalence circuit for wind plant to be used in short

circuit studies Different comparisons show that the equivalent

circuit gives the same result as the detailed model

The contribution of Type 1 WTG during the initialcycle of the fault (asymmetrical current) can be ashigh as 6 or more times the rated machine current

or c rcu curren ra e o ecay epen s on efault type with the fastest decay rate in the case of a

- .


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Questions

Documents

Samaan Short Circuit IEEE PSE09