Propagation Characteristics of Partial Discharge Pulses in the Cable

In order to determine the type and location of partial discharge in cable, the effect of partial discharge (PD) pulse propagation in the cable is studied. Firstly, pulses are injected to cables of different lengths so that input and output signal can be measured at both ends of each cable. Then the transfer function of pulse propagation path can be defined. Secondly, high-voltage test is done in the cable joint with man-made defects, and typical PD waveforms are gotten. Seven parameters of waveform characteristics are calculated, including edge times, waveform shape and statistical characteristics. They are used to distinguish different types of PD or distances of the pulse propagation. Thus the efficiency of PD recognition in cable can be improved.