Analysis of Partial Discharge in underground cable joints

The reliable operation of power network is greatly reduced by the cable joint failure. Most of the cable joint failure is due to poor workmanship and insulation degradation. During cable joint process, different types of insulating materials are used. The quality of insulation systems is important in the part of cable network. Partial discharge is a diagnostic tool for detecting problem in cable joint. This work has been carried out in a laboratory on 1.1 kV XLPE, 25 Sq.mm cable and cable joints with different insulations. Partial discharge under different conditions such as a piece of cable, cable joint without insulation, cable joint with insulation (tape insulation, epoxy resin insulation, epoxy resin grade 103 insulation) and cable joint with void are analyzed. Based on the results epoxy resin insulation has higher Partial Discharge Inception Voltage (PDIV) values and shows better performance than other insulations.