8-14
T35 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
OVEREXCITATION INHIBIT TEST
CHAPTER 8: COMMISSIONING
8
8.4 Overexcitation inhibit test
8.4.1 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 transformer
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 8-4: Overexcitation inhibit test summary
8.5 Blank test tables
8.5.1 Differential restraint tests
Table 8-5: Differential characteristic test table
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
Test
Phase
Injected current
Displayed current
Status
W1 Current
W2 Current
Differential
Restraint
Balanced
Condition
A
Not Applicable
B
C
Содержание T35
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Страница 10: ...x T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Страница 14: ...1 4 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL FOR FURTHER ASSISTANCE CHAPTER 1 INTRODUCTION 1 ...
Страница 202: ...4 88 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL FLEXLOGIC DESIGN USING ENGINEER CHAPTER 4 INTERFACES 4 ...
Страница 472: ...5 270 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Страница 500: ...6 28 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL PRODUCT INFORMATION CHAPTER 6 ACTUAL VALUES 6 ...
Страница 514: ...7 14 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL TARGETS MENU CHAPTER 7 COMMANDS AND TARGETS 7 ...
Страница 580: ...A 16 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL FLEXANALOG ITEMS APPENDIX A FLEXANALOG OPERANDS A ...
Страница 588: ...C 6 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL COMMAND LINE INTERFACE APPENDIX C COMMAND LINE INTERFACE C ...
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