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?