WGR Equivalent Modeling

Keith SmithNetwork Model Engineer RARF Workshop IIIAugust 29, 2013

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• System Protection Model Equivalent– Aggregated turbines modeled at .69 kV– Turbine step-up transformers aggregated into one .69-34.5 kV transformer– Collector system represented as single line– Provides more accurate fault data than aggregate turbine modeled at 34.5 kV level – Grounded Wye-Delta connection very common for turbine step-up transformers, limits single line to ground fault current

contributions from turbine

WGR Equivalent Model

IC35.kV 1

BUS035.kV 2

GEN0.69kV 3

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• Calculating impedances for equivalent model– Equivalent turbine impedance calculated as N turbines in parallel– Equivalent transformer impedance calculated as N transformers in parallel– Equivalent collector system impedance calculated from collector system cable

data using the following equation:

– Where n = number of turbines feeding cable segment

N = number of total turbines

Equivalent Methodology

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3-Phase to Ground Fault Full System

10035.kV 100

10135.kV 101

BUS235.kV 102

10335.kV 103

10435.kV 104

10535.kV 105

10635.kV 106

10735.kV 107

10835.kV 108

10935.kV 109

9020.69kV 902

9030.69kV 903

9040.69kV 904

9050.69kV 905

9060.69kV 906

9070.69kV 907

9080.69kV 908

2255P-87

0.0P-90 0.3P-12

0.4P-12

0.3P-12

0.4P-12

0.5P-12

0.2P25 7893P-117

0.2P25

7859P-117

2255P93

1944P93 311P93 2255P-87

1789P93 1944P-87 155P93

155P93

311P-87 156P93

156P-87 156P93

1635P93 1789P-87

154P93

7893P-117

7859P-117

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3-Phase to Ground Fault Equivalent

IC35.kV 1

BUS035.kV 2

GEN0.69kV 3

2254P-87

0.0P0 1.0P-14

0.2P24

114355P-117

2254P93 2254P-87 2254P93

114355P-117

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Single Line to Ground Fault Full System

10035.kV 100

10135.kV 101

BUS235.kV 102

10335.kV 103

10435.kV 104

10535.kV 105

10635.kV 106

10735.kV 107

10835.kV 108

10935.kV 109

9020.69kV 902

9030.69kV 903

9040.69kV 904

9050.69kV 905

9060.69kV 906

9070.69kV 907

9080.69kV 908

1548@-86

10.0@178 9.8@180

9.7@-180

9.8@180

9.8@180

9.7@-179

0.2@-179 5452@-89

0.2@-179

5427@-89

1548@94

1334@95 215@91 1548@-86

1227@95 1334@-85 107@91

107@91

215@-89 107@91

107@-89 107@91

1121@95 1227@-85

106@92

5452@-89

5427@-89

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Single Line to Ground Fault Equivalent

IC35.kV 1

BUS035.kV 2

GEN0.69kV 3

1549@-86

9.9@178 9.4@-177

0.1@-176

78586@-86

1549@94 1549@-86 1549@94

78586@-86

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Collector System Example

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Collector System RARF Format

GENERATOR DETAILS Cable Type WIND SEGMENT DETAILSResource Name

(Unit Code/Mnemonic) Cable Type From To Circuit NumberVoltage Level

Cable Segment Length

Number of Turbines On Cable Segment

List List alpha/numeric alpha/numeric alpha/numeric kV in kft Integer

WIND_FARM 1000 kcmil 0 121 1 34.5 2.955 9WIND_FARM 1/0 AWG 121 18 1 34.5 .08 1WIND_FARM 1000 kcmil 121 111 1 34.5 3.205 8WIND_FARM 1/0 AWG 111 12 1 34.5 2.86 2WIND_FARM 1/0 AWG 12 11 1 34.5 1.305 1WIND_FARM 500 kcmil 111 17 1 34.5 4.05 6WIND_FARM 500 kcmil 17 16 1 34.5 1.105 5WIND_FARM 4/0 AWG 16 15 1 34.5 1.04 4WIND_FARM 1/0 AWG 15 14 1 34.5 1.155 3WIND_FARM 1/0 AWG 14 13 1 34.5 .94 2WIND_FARM 1/0 AWG 13 10 1 34.5 2.040 1WIND_FARM 1000 kcmil 0 211 2 34.5 11.095 9

GENERATOR DETAILS

COLLECTION SYSTEM DETAILED MODEL POSITIVE SEQUENCE DATA ZERO SEQUENCE DATA

Resource Name(Unit

Code/Mnemonic) Cable TypeVoltage Level

kV R/kft X/kft Charging Bc/kft R0/kft X0/kft

List   kV (p.u. on 100 MVA base)(p.u. on 100 MVA

base)(p.u. on 100 MVA base)

(p.u. on 100 MVA base)

(p.u. on 100 MVA base)

WIND_FARM 1000 kcmil 34.5 0.002016383 0.003184205 4.115E-07 0.012535182 0.004444444WIND_FARM 500 kcmil 34.5 0.003654694 0.003503466 3.161E-07 0.020037807 0.009090527WIND_FARM 4/0 AWG 34.5 0.008477211 0.004015963 2.361E-07 0.026347406 0.011048099WIND_FARM 1/0 AWG 34.5 0.016593153 0.004553665 1.595E-07 0.038479311 0.018239866

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Generator Data

• Required turbine data for system protection cases

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Current Limits

• Required for type 3 and type 4 turbines

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QUESTIONS?