9-10
T35 Transformer Protection System
GE Multilin
9.2 DIFFERENTIAL CHARACTERISTIC TEST EXAMPLES
9 COMMISSIONING
9
9.2.4 TEST EXAMPLE 3
Yg/D30° TRANSFORMER WITH PHASE B TO C FAULT ON THE DELTA SIDE.
Transformer: Y/D30°, 20 MVA, 115/12.47 kv, CT1 (200:1), CT2 (1000:1)
Figure 9–4: CURRENT DISTRIBUTION ON A YG/D30° TRANSFORMER WITH AN a TO b FAULT ON THE LV SIDE
Three adjustable currents are required in this case. The Phase A and C Wye-side line currents, identical in magnitude but
displaced by 180°, can be simulated with one current source passed through these relay terminals in series. The second
current source simulates the Phase B primary current. The third source simulates the delta “b” and “c” phase currents, also
equal in magnitude but displaced by 180°.
TEST
PHASE
INJECTED CURRENT
DISPLAYED CURRENT
STATUS
W1 CURRENT
W2 CURRENT
DIFFERENTIAL
RESTRAINT
Balanced
Condition
A
0.25
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Not Applicable
B
0.5
∠
–180°
0.8
∠
0°
0
∠
0°
0.8
∠
0°
C
0.25
∠
0°
0.8
∠
–180°
0
∠
0°
0.8
∠
–180°
Min Pickup
change the
Min PKP to
0.2 pu
A
0.25
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Block
I
d
= 0.051 < Min PKP
B
0.5
∠
–180°
0.95
∠
0°
0.154
∠
0°
0.948
∠
0°
C
0.25
∠
0°
0.95
∠
–180°
0.155
∠
0°
0.950
∠
–180°
Minimum
Pickup
A
0.25
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Operate
I
d
= 0.102 > Min PKP
B
0.5
∠
–180°
1.05
∠
0°
0.253
∠
0°
1.049
∠
0°
C
0.25
∠
0°
1.05
∠
–180°
0.255
∠
0°
1.050
∠
–180°
Slope 1
return the
Min PKP to
0.1 pu
A
0.25
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Block
I
d
/
I
r
= 13.2%
B
0.5
∠
–180°
0.92
∠
0°
0.123
∠
0°
0.919
∠
0°
C
0.25
∠
0°
0.92
∠
–180°
0.123
∠
0°
0.919
∠
–180°
Slope 1
A
0.25
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Operate
I
d
/
I
r
= 15.9%
B
0.5
∠
–180°
0.95
∠
0°
0.153
∠
0°
0.948
∠
0°
C
0.25
∠
0°
0.95
∠
–180°
0.153
∠
0°
0.948
∠
–180°
Intermediate
Slope 1 & 2
A
2
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Block
I
d
/
I
r
= 84.3%
< 86.6% computed
B
4
∠
–180°
1
∠
0°
5.37
∠
–180°
6.37
∠
0°
C
2
∠
0°
1
∠
–180°
5.37
∠
0°
6.37
∠
–180°
Intermediate
Slope 1 & 2
A
2
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Operate
I
d
/
I
r
= 87.5%
> 86.6% computed
B
4
∠
–180°
0.8
∠
0°
5.57
∠
–180°
6.37
∠
0°
C
2
∠
0°
0.8
∠
–180°
5.57
∠
0°
6.37
∠
–180°
Slope 2
A
4
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Block
I
d
/
I
r
= 93.7%
< Slope 2 = 95%
B
8
∠
–180°
0.8
∠
0°
11.93
∠
–180°
12.73
∠
0°
C
4
∠
0°
0.8
∠
–180°
11.93
∠
0°
12.73
∠
–180°
Slope 2
A
4
∠
0°
0
∠
0°
0
∠
0°
0
∠
0°
Operate
I
d
/
I
r
= 95.7%
> Slope 2 = 95%
B
8
∠
–180°
0.6
∠
0°
12.13
∠
–180°
12.73
∠
0°
C
4
∠
0°
0.6
∠
–180°
12.13
∠
0°
12.73
∠
–180°
828738A1.CDR
Y
/d30° Transformer
F
I (f) = 0.5 pu
–270°
A
∠
I (f) = 0.866 pu
–90°
b
∠
I (f) = 0
a
I (f) = 0.866 pu
–270°
c
∠
I (f) = 1 pu
–90°
B
∠
I (f) = 0.5 pu
–270°
C
∠
A
B
C
A
B
C
Summary of Contents for T35 UR Series
Page 10: ...x T35 Transformer Protection System GE Multilin TABLE OF CONTENTS ...
Page 48: ...2 18 T35 Transformer Protection System GE Multilin 2 2 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2 ...
Page 314: ...5 192 T35 Transformer Protection System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 338: ...6 24 T35 Transformer Protection System GE Multilin 6 5 PRODUCT INFORMATION 6 ACTUAL VALUES 6 ...
Page 350: ...7 12 T35 Transformer Protection System GE Multilin 7 2 TARGETS 7 COMMANDS AND TARGETS 7 ...
Page 366: ...8 16 T35 Transformer Protection System GE Multilin 8 2 CYBERSENTRY 8 SECURITY 8 ...
Page 406: ...A 14 T35 Transformer Protection System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 540: ...D 10 T35 Transformer Protection System GE Multilin D 1 IEC 60870 5 104 PROTOCOL APPENDIX D D ...
Page 552: ...E 12 T35 Transformer Protection System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...
Page 560: ...F 8 T35 Transformer Protection System GE Multilin F 3 WARRANTY APPENDIX F F ...
