An advanced method for detection of partial discharge in oil-paper insulated transformer bushings and current transformers
Partial discharge (PD) detection is an important method to detect the defects in high-voltage bushings. Existing PD detection methods for bushings still have some problems related to the sensitivity and the anti-interference capacity. In this paper, an advanced method for the detection of PD in capacitor bushings is proposed to overcome the disadvantages of the conventional PD detection methods. The PD signal is captured by an inductor attached to the tap of the bushing, and all pulses that appear in a certain period are recorded by the oscilloscope. This method is considered to be more sensitive compared to conventional methods, and with the available information such as the frequency spectrum and phase distribution, the interference signal can be eliminated. Experiments on PD due to typical defects in capacitor bushings are carried out to validate the proposed method, and the results show that this method is effective in detecting some typical defects in bushing.