Fault Diagnosis and Analysis of Abnormal Gas of Current Transformer Based on Multiple Methods

According to the the metal expander jacking accident caused by abnormal gas of oil-immersed vertical current transformer, through the methods of appearance inspection, electrical test, disintegration analysis, same batch comparison and production process tracing, combined with the operating conditions, weather conditions and other factors, it is judged that the cause of the accident is the low energy discharge in the oil paper insulation. Insulation paper moisture, insulating paper fold, bubbles in the fold cavity may lead to low energy discharge. According to the cause of the failure, some suggestions about operation, defect maintenance for the same type and batch current transformer are proposed.