Transformer operation and maintenance and fault handling schemes

Transformer operation and maintenance and fault handling schemes

However, due to its structure, process and operation and maintenance, transformer faults play a very important role in power plants, however, due to its structure, process and operation and maintenance, transformer faults occur frequently in power plants, which greatly affects the normal production of power plants. Therefore, it is of great significance to strengthen the regular maintenance of transformers and take practical and effective measures to prevent the occurrence of transformer failures to ensure the safe and stable operation of transformers.

1. Classification and causes of common fault phenomena of transformers

(1) The problem of the transformer itself when it leaves the factory. Such as loose ends, loose cushions, poor welding, poor core insulation, insufficient anti-short circuit strength, etc.

(2) Line interference. Line interference is the most important of all the factors that cause transformer accidents. These include: overvoltage during closing, voltage peaks during low load phases, line faults, due to flashovers and other anomalies. This type of fault accounts for a large proportion of transformer faults. Therefore, the transformer must be regularly tested for impact protection to test the strength of the transformer's resistance to excitation inrush current.

(3) The aging rate of transformer insulation caused by improper use is accelerated. The average life of a general transformer is only 17.8 years, which is much lower than the expected life of 35~40 years.

(4) Overvoltage caused by lightning strike.

(5) Overload. Overload refers to the transformer that is in a working state that exceeds the nameplate power for a long time. Overload often occurs when the power plant continues to slowly increase the load, the cooling device is not operating properly, the transformer is faulty, etc., and finally the transformer is overloaded. The resulting high temperature will lead to premature aging of the insulation, and the strength of the paper will be reduced when the insulating cardboard of the transformer is aged. As a result, the impact of an external fault can lead to insulation breakage and failure.

(6) Dampness: If there is flooding, pipeline leakage, top cover leakage, moisture intrusion into the oil tank along the casing or fittings, and moisture in the insulating oil, etc.

(7) Proper maintenance is not carried out.