Transformer Partial Discharge Detection Using Electrical-Ultrasonic Technology

Partial discharge (PD) is usually happened caused by flaw and deterioration of transformer insulation. It is the main reason of the accident of transformer and power system. Therefore, it´s necessary and important to detect the partial discharge of transformer while operating and manufacturing. When PD of transformer internal insulation occurs, electromagnetic waves, sound waves and other signals are produced. According to supersonic signal, we can detect the location of PD. But this method can not test the number of charge. With electical-ultrasonic detection method, it is easy to locate PD and test the number of charge. In this paper, a method of electical-ultrasonic detection is presented, which is based three-dimensional scatter point and ultrasonic hit to time. The method is effective to locate fault of transformer insulation. To validate the approach, a case is introduced.