What are the faults of the transformer?

There are many types of transformer faults, which are generally divided into local overheating, arc discharge, low-energy discharge, partial discharge, and insulation deterioration according to the nature of the fault. According to the process of failure, it is divided into sudden obstacles. Faults and chronic developmental faults are divided into internal faults and external faults according to the location of the fault. Internal failure refers to the failure of the internal magnetic circuit, winding wire, insulation system, structural parts and components. External faults refer to faults in transformer auxiliary equipment. If it is late, it may develop into an internal failure.

According to the statistics of the power system in recent years, the main faults of the transformer in operation include overheating of the transformer, abnormal oil, failure of the cooling device, light gas relay, abnormal noise, transformer circuit breaker, emergency stop of the transformer, etc. In fact, most external faults of transformers are found on site by inspection of visible parts. Regarding internal obstacles, there are also phenomena reflected in abnormal phenomena that can be seen from the outside.

The cause of frequent failures. The overheating of the transformer is the main reason for the insulation damage of the power transformer, and the excessive temperature rise will reduce the voltage resistance and mechanical strength of the insulating material. It is pointed out that when the temperature of the hot oil of the transformer reaches 140 ℃, air bubbles in the oil will occur, which will reduce the insulation level, cause flashing lights, and cause insulation damage. Driving at 6°C, the effective life of the insulation is doubled if the temperature increases by 6°C in the temperature range of 80 to 140°C. Overloading, malfunction of the cooling unit (or driving not fully engaged), internal malfunction or damage to the temperature measuring device, are the reasons for the abnormal rise in oil temperature and overheating.