A Study of Partial Discharge Behavior of Multiple Cavity Defects in Epoxy Insulation Material

Electrical insulation is one of the most critical parts of most of high voltage power system equipment, and its quality plays a significant role in determining the reliability of the equipment. Most common problems of power equipment are associated with insulation failure. Partial discharges are common problems in electrical insulation. Measurement of partial discharge is therefore widely used to diagnose the condition of the insulation system. Hence, it is imperative to study how partial discharge activity can be analyzed in insulation material containing multiple cavities. The objective of this paper is to apply the Phase-Resolved Partial Discharge Analysis (PRPDA) technique to insulation with single and two cavities close to each other in order to investigate the behavior of the partial discharge activity. Through the analysis of the experimental results, it was established that phase-resolved partial discharge pattern for two cavities is different from that of the single cavity pattern.