Partial discharge characteristics in polymeric cable accessories

In order to detect partial discharges (PDs) in cable accessories, it is necessary to investigate and understand the generation processes of PDs along insulation surfaces and the signal characteristics of such PDs. Electric field analysis is used in this paper to find the effect of a void produced by a poor termination of cable. Such discharge signals were detected using a measurement system with a high frequency response in the GHz region and analysed both in the time and frequency domains. Based on the features of such signals a detection technique was developed and applied to an experimental model and an actual cable. The results obtained are encouraging. They indicate that practical PD detection in the field using this technique is feasible