Simultaneous Fault Examples
pu := 1 MVA:= 1000kW a:= 1ej 120 deg A012 1 1 1 1 a2 a 1 a a2
:= 13.8kV 100MVA ZS1 = j0.3 pu V = 1.0pu BUS 1 BUS 2 ZL1 = 0.8 pu 85o ZR1 = j0.3 pu RelayR1 24kV 100MVA RelayR2 V = 1.0pu 13.8kV: 230kV 100MVA X = 10% X/R = 15 -Yg BUS S 230:24kV 100MVA X = 10% X/R = 15 Yg- BUS R on 100MVA and 230kV ZR2 = ZR1 ZR0 = j1.0 pu ZS2 = ZS1 ZS0 = j1.0 pu ZL2 = ZL1 ZL0 = 3ZL1 Z2 = Z0 = Z1 Z2 = Z0 = Z1 VB1 := 13.8kV VB2 VB1 230 kV 13.8kV
:= VB2 = 230 kV VB3 VB2 13.8 kV 230kV
:= VB3 = 13.8 kVLocal source (no change of base needed):
· · Remote source (no change of base needed):
ZS1 := j 0.3 pu ZR1 := j 0.3 pu
ZS2 := ZS1 ZR2 := ZR1
Transmission line: ·
ZL1 := 0.8pu e j 85 deg ZL1 = (0.0697+0.797i) pu ZL2:= ZL1
ZL0 := 3 Z L1 ZL0 = (0.2092+2.3909i) pu
Transformer between BusS and Bus1 (no change of base needed) · θT1 atan 15 1
:= XT11 := 0.1pu mag_ZT11 XT11 sin(
θT1)
:= ZT11 mag_ZT11 e jθT1 := ZT11 = (0.0067+0.1i) pu- Negative and zero sequence impedances equal to positive sequence impedance: ZT12:= ZT11 ZT10:= ZT11
Transformer between BusR and Bus2 (no change of base needed) · θT2 atan 15 1
:= XT21 := 0.1pu mag_ZT21 XT21 sin(
θT2)
:= ZT21 mag_ZT21 e jθT2 := ZT21 = (0.0067+0.1i) puPositive sequence per unit, per phase, equivalent circuit: BusS 1.0 Bus1 Bus2 ZL1 Src1 Src2 BusR 1.0 ZR1 ZT21 ZS1 ZT11 +30 deg +30 deg N1
Negative sequence per unit, per phase, equivalent circuit:
BusS Bus1 Bus2
ZL2 BusR ZR2 ZT22 ZS2 ZT12 -30 deg -30 deg N2
Zero sequence per unit, per phase, equivalent circuit:
BusS Bus1 BusR
ZR0 ZT20
Bus2
ZS0
ZT10 ZL0
Define Zbus matrices, but the fault bus needs to be added as a function of M for now. ·
YBus1(M) 1 ZS1 1 ZT11 + 1 - e j 30 deg ZT11 0 0 0 1 - e-j30deg ZT11 1 ZT11 1 M Z L1 + 0 0 1 -M Z L1 0 0 1 1-M ( ) Z L1 1 ZT21 + 1 - e -j30deg ZT21 1 -1-M ( ) Z L1 0 0 1 - e j 30 deg ZT21 1 ZT21 1 ZR1 + 0 0 1 -M Z L1 1 -1-M ( ) Z L1 0 1 M Z L1 1 1-M ( ) Z L1 +
:= YBus2(M) 1 ZS2 1 ZT12 + 1 - e -j30deg ZT12 0 0 0 1 - ej 30 deg ZT12 1 ZT12 1 M Z L2 + 0 0 1 -M Z L2 0 0 1 1-M ( ) Z L2 1 ZT22 + 1 - e j 30 deg ZT22 1 -1-M ( ) Z L2 0 0 1 - e -j30deg ZT22 1 ZT22 1 ZR2 + 0 0 1 -M Z L2 1 -1-M ( ) Z L2 0 1 M Z L2 1 1-M ( ) Z L2 +
:=YBus0(M) 1 ZS0 0 0 0 0 0 1 ZT10 1 M Z L0 + 0 0 1 -M Z L0 0 0 1 1-M ( ) Z L0 1 ZT20 + 0 1 -1-M ( ) Z L0 0 0 0 1 ZR0 0 0 1 -M Z L0 1 -1-M ( ) Z L0 0 1 M Z L0 1 1-M ( ) Z L0 +
:= ZBus1(M) := YBus1(M)-1 ZBus2(M) := YBus2(M)-1 ZBus0(M) := YBus0(M)-1Simultaneous AG and BC faults 30% of the way from Bus 1 to Bus 2
I1 +I2 = 2 I 0 V1 = V2 1 -2 V0 = Vf := 1.0pu No load M:= 0.3
I1 Vf ZBus1(M) 4 4, 1 ZBus2(M) 4 4, 1 ZBus0(M) 4 4,
(
)
14 +
1 -+ := I1 = 2.055 pu arg I( )
1 = -86.871deg I2 -I1 ZBus0(M) 4 4,(
)
4 ZBus2(M) 4 4, ZBus0(M) 4 4,(
)
4 +
:= I2 = 0.55 pu arg I( )
2 = 91.613 deg I0 I1 2 ZBus2(M) 4 4, ZBus2(M) 4 4, ZBus0(M) 4 4,(
)
4 +
:= I0 = 0.752 pu arg I( )
0 = -86.316deg I1 +I2(
)
-2 I 0 = 0 V1 Vf I1 ZBus1(M) 4 4, -:= V1 = 0.211 pu arg V( )
1 = -1.196deg V2 -I2 ZBus2(M) 4 4, := V2 = 0.211 pu arg V( )
2 = -1.196deg V0 -I0 ZBus0(M) 4 4, := V0 = 0.423 pu arg V( )
0 = 178.804 degV0 -2 -V1 = 0 VABC A012 V0 V1 V2
:= VABC 0 0.634 0.634
= arg VABC 1(
)
= 178.804 deg arg VABC 2(
)
= 178.804 deg Very close to ATP IABC A012 I0 I1 I2
:= IABC 2.257 2.256 2.256
= arg I(
ABC)
-86.316 177.191 -2.809
deg =SLG or LL alone (without simultaneous):
SLG · I0slg Vf ZBus1(M) 4 4, +ZBus2(M)4 4, +ZBus0(M)4 4,
(
)
:= I0slg = 0.752 arg I(
0slg)
= -86.316deg IA_slg := 3 I 0slg ILL · I1LL Vf ZBus1(M) 4 4, +ZBus2(M)4 4, := IABCLL A012 10-15 I1LL I1LL
-
:= IABCLL 0 2.256 2.256
= arg I(
ABCLL)
0 177.191 -2.809
deg = IABCLL-IABC 0.145 - +2.253i 0 0
= IA_slg 0 0
IABCLL + -IABC 0 0 0
=VS BUSS V BUS1 R1 I BUSF V V SAT Y V BUS2 R2 I YSAT BUSR V VR IA IC I I B I I A I V
ATP System Model
·
Fault Currents (versus time): ·
(f ile Simult_AG_BC.pl4; x-v ar t) c:BUSFA -IA c:BUSFB -IB c:BUSFC -IC
0.00 0.02 0.04 0.06 0.08 [s] 0.10 -3.5 -2.5 -1.5 -0.5 0.5 1.5 2.5 3.5 [A]
Note that: IC = -IB ·
IA = 2.257A θA:= -86.24deg
IB = 2.257A θA:= -177.1deg
Voltages at the fault point: ·
(f ile Simult_AG_BC.pl4; x-v ar t) v :BUSFA v :BUSFB v :BUSFC
0.00 0.02 0.04 0.06 0.08 [s] 0.10 -0.9 -0.6 -0.3 0.0 0.3 0.6 0.9 [V] VAG = 0V VBG = 0.6339V θVB := 178.9deg VCG = 0.6339V θVC := 178.9deg