Research of partial discharge characteristics in XLPE-insulated cables with single and multiple defects

This paper considers research on multiple partial discharge (PD) sources in a single XLPE-insulated cable sample. The electrical field was simulated in the field of the artificial defects of cables. Cable samples were prepared for experimental research. After that, artificial defects were created in them. PD measurements were performed from one to six cable artificial defects. Results showed similar phase-resolved PD patterns (PRPD). It is explained by the defects’ location in the field of the grounding electrode. The unexpected result is PD pulses form similarity. They have to differ because of the cable distributed-parameters line characteristics. However, the difference might be insignificant because of the small cable samples’ length. Besides, PD apparent charge and intensity also have no obvious dependence on defects’ amount. Therefore, multiple defects’ recognition is a complicated task. Probably, close defects’ location might complicate the recognition even in long cable lines.