Partial discharges multi-targets localization in power transformers based on spatial-estimation

A new partial discharges multi-targets localization method is presented in this paper, which is based on array signal processing. Two ultrasonic sensor arrays are located on the inner wall of the transformer tank and detect the ultrasonic signal emitted by the partial discharge sources. Spatial spectrum estimation technique is used in analyzing the signal characteristic information (number of signals, direction-of-arrivals et. al) and the number of partial discharge signal estimation, direction-of-arrival estimation and distance estimation are accomplished. The performance of localizations is given by computer simulations. It shows that the method processes with high resolution and good estimated accuracy and can effectively estimate the location parameter of multiple partial discharge sources in transformer.