The study of partial discharge generated from defects in XLPE insulation

The authors have developed of partial discharge measurement techniques for underground transmission lines. However, confirmation of the occurrence of partial discharges still depends on the experience of the maintenance staff. The authors studied the characteristics of partial discharges caused by failures in extrusion molded joints and investigated methods for distinguishing partial discharges from noises by evaluating the time, voltage and phase characteristics of the partial discharges. The occurrence phase characteristics of partial discharges have been investigated and are a useful index for distinguishing partial discharges from noises