Development of partial discharge measurement method for pre-mold cable accessories with separated-shielding layers

Most of the accidents on XLPE cable line are caused by defective construction of cable accessories. Thus the authors developed a method to measure partial discharges in pre‐mold cable accessories. The authors provided separated‐shielding layers as detection electrodes in accessories, and discriminate between partial discharge pulse and noise pulse using realtime comparison of pulse current magnitudes from both detection electrodes. This paper describes the principle of the noise discrimination method, portable partial discharge measurement apparatus, and the results of field test.