GE Multilin
T35 Transformer Protection System
9-13
9 COMMISSIONING
9.4 OVEREXCITATION INHIBIT TEST
9
9.4OVEREXCITATION INHIBIT TEST
9.4.1 OVEREXCITATION INHIBIT TEST PROCEDURE
The Overexcitation Inhibit Test requires a secondary injection from a source capable of producing an adjustable 5th
harmonic component. Use the appropriate commissioning tables at the end of this chapter to record values.
This procedure is based upon the example provided in the Differential Characteristic Test Example section. The trans-
former parameters are as follows:
Transformer: Y/y0°, 230/69 kV, CT1 (300:1), CT2 (1000:1)
5th Harmonic Setting = 10%
1.
Connect the relay test set to inject current into the Winding 1 Phase A CT input.
2.
Inject a current into the relay until the biased Differential element operates.
3.
Confirm that ONLY the differential element has operated.
4.
Increase the 5th harmonic content level until the element drops out. Record this value as the
Overexcitation Inhibit
Level Pickup
.
5.
Gradually decrease the harmonic content level until the element picks up. Record this value as the
Overexcitation
Inhibit Level Dropout
.
6.
Switch off the current.
7.
Repeat steps 1 through 6 for phases B and C.
8.
Repeat steps 1 through 7 for winding 2 (and windings 3 and 4 if necessary).
Table 9–2: OVEREXCITATION INHIBIT TEST SUMMARY
PHASE
INJECTED
DISPLAYED
STATUS
W1
CURRENT
W1 5TH
HARMONIC
W2
CURRENT
W2 5TH
HARMONIC
I
d
5TH
HARMONIC
I
r
A
1 A
∠
0°
8%
0 A
∠
0°
0
1 pu
8%
1 pu
Operate
1 A
∠
0°
10%
0 A
∠
0°
0
1 pu
10%
1 pu
Block
B
4 A
∠
0°
8.5%
2 A
∠
–180°
9%
2 pu
8%
4 pu
Operate
4 A
∠
0°
9.5%
2 A
∠
–180°
9%
2 pu
10%
4 pu
Block
C
2 A
∠
0°
9%
4 A
∠
–180°
8.5%
2 pu
8%
4 pu
Operate
2 A
∠
0°
9%
4 A
∠
–180°
9.5%
2 pu
10%
4 pu
Block
NOTE
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 ...
