1. Handling of Transformer Minor Gas Relay Action
(1) Immediately check and record the protective relay action signals and report to the dispatcher and station manager.
(2) Closely monitor the transformer’s voltage, current, temperature, oil level, oil color, sound, and cooler operation, and assign personnel to inspect the transformer externally.
(3) If the inspection reveals significant abnormalities, report to the dispatcher and take the faulty transformer offline. If no obvious fault signs are observed, escalate the issue to higher authorities for gas sampling and analysis and inspection of secondary circuits.
2. Handling of Transformer Major Gas Relay Action
(1) Inspect the relay protection action status, record and reset all signals, and immediately report to the dispatcher and station manager.
(2) For a single transformer in operation, request the dispatcher to immediately activate the backup transformer. For transformers operating in parallel, ensure that the operating transformer does not exceed its load capacity.
(3) Assign personnel to inspect the transformer for deformation, oil spray, oil level, oil color, etc. Report inspection results to the dispatcher and relevant departments, and conduct gas analysis and secondary circuit inspections.
3. Handling of Transformer Differential Protection Action
(1) Inspect the transformer body for abnormalities, check for flashovers or damage to porcelain insulators, and check for short circuits in the differential protection zone.
(2) If no visible faults are found within the transformer’s differential protection range, inspect the relay protection system and secondary circuits for faults or two-point grounding in the DC circuit. If no anomalies are detected, attempt to restore power after isolating the load. If the attempt fails, do not re-energize.
(3) If the action is caused by a relay or secondary circuit fault or two-point grounding in the DC circuit, disable the differential protection, re-energize the transformer, and then address the fault.
(4) If both differential and major gas relay protections are triggered, do not re-energize the transformer without internal inspection and testing.
4. Handling of Transformer Backup Protection Action
(1) Use protective action signals, indicators, and instruments to identify the fault location and scope of the power outage. Check for protective action signals or tripping flags on each branch circuit.
(2) Disconnect all branch switches on the de-energized bus and confirm that they are open.
(3) Open the line switches with protective actions or tripping flags in the affected circuits.
(4) Inspect the tripped bus and transformer switches for abnormalities.
(5) Check equipment connected to the de-energized bus for faults.
(6) If the fault point is identified, isolate it, restore other unaffected equipment to normal operation, and return the main transformer to service.
(7) Report inspection results to the dispatcher and relevant departments and maintain proper records.
5. Handling of Transformer Pressure Relief Protection Action
(1) Check the protection actions and record all signals triggered.
(2) Report the incident to the dispatcher, relevant departments, and leadership.
(3) Conduct a thorough external inspection of the transformer, focusing on whether the pressure relief device has sprayed oil or if the red button on the top has popped up. Report the inspection results to the dispatcher and relevant departments.
(4) If the pressure relief device has sprayed oil and the red button has popped up, it confirms the accuracy of the pressure relief protection action.