Page 32 - Practical Power System and Protective Relays Commissioning

28 Practical Power System and Protective Relays Commissioning

3.8 PROTECTION AND CONTROL PANELS
COMMISSIONING TESTS

3.8.1 Visual Check
Check that the panels are built as per the as-built approved drawing. Other
checks should include the earthing of each panel, and all external cables to
station equipment.

3.8.2 Electrical Tests

An electrical test can include any of the following:
1. Auxiliary relays tests.
2. Secondary injection tests.
3. Primary injection tests.
4. Scheme function tests.
5. On-load tests.
6. Tripping tests.
7. Metering panel tests.
8. Alarm and annunciators tests.
9. Fault recorder panel tests.
10. End-to-end test for line differential protection and distance schemes.
11. Stability of 380 V tests of transformer differential protection.
12. Remote taps-charger panel tests.
13. Bus transfer (ATS) system in 11 kV switchgear.
14. Scada signal operational and alarms test from station to master station.

3.9 FINAL ENERGIZATION COMMISSIONING PROCEDURES
Before energization these points should be confirmed:
1. Overcurrent commissioning setting is used on bus coupler temporary
which will accelerate the relay operation during first time energization
and the energization of any circuit will be through the bus coupler of the
station.
2. Remove all CT secondary shorting links.
3. All protection relays are working on their final setting.
4. All VT MCBs are closed and no abnormal alarms exist.
5. No engineers or technicians should be in the switchgear area during
energization.
6. No earthing exists in the primary circuits.
7. After energizing the new circuit, a phasing test should be done between
the circuit VT secondaries and existing reference circuit VT
secondaries.