As the core equipment of power grid transmission and distribution,
Power Transformers directly affect the safety of the power system. During operation, faults such as overheating, abnormal noise, oil leakage and insulation damage often occur. Mastering efficient troubleshooting methods is crucial to reducing downtime losses.
Overheating is one of the most common transformer faults, mainly caused by poor heat dissipation, overload operation or abnormal core loss. During troubleshooting, first observe the oil temperature indicator. If the oil temperature exceeds 85℃ and continues to rise, check whether the radiating fins are clogged with dust and whether the forced cooling fans start normally. At the same time, verify the load data to confirm if there is overload operation. If necessary, use an infrared thermometer to detect the temperature distribution of the core and windings to locate local hot spots.
Abnormal noise faults need to be judged based on sound characteristics: a uniform "buzzing" sound is the normal operation sound. If a sharp abnormal noise occurs, it may be due to loose core or deformed windings. It is necessary to shut down the machine to check the core clamping bolts and winding insulation conditions. If accompanied by "crackling" discharge sound, it is mostly caused by damp insulation oil or aging insulation. It is necessary to test indicators such as oil dielectric loss and breakdown voltage, and replace unqualified insulation oil in a timely manner.
Oil leakage faults are likely to cause insulation degradation and fire risks. During troubleshooting, focus on checking the oil tank welds, gaskets, valves and other parts, and use the soapy water application method to find leakage points. For slight leakage, sealant can be used for repair. For severe leakage, it is necessary to drain the oil before replacing the seals or repairing the oil tank. After treatment, qualified insulation oil must be refilled and air exhausted.
Insulation faults are mostly manifested by decreased insulation resistance and excessive partial discharge. It is necessary to use a megohmmeter to measure the insulation resistance between windings and ground, and between windings, and combine methods such as dielectric loss test and partial discharge detection to locate fault points. If the insulation is severely aged, the windings need to be dried or insulation components replaced to avoid developing into short-circuit faults.
Troubleshooting must follow the principles of "external inspection first, then internal inspection; electrical inspection first, then mechanical inspection; no-load inspection first, then load inspection". Operators must take safety protection measures and strictly follow the operating procedures. Regular inspections and preventive tests can detect potential problems in advance. Combined with scientific troubleshooting methods, the operational reliability of transformers can be effectively improved, laying a solid foundation for the safe and stable power supply of the power grid.
