Analyzing DC Partial Discharge Characteristics of Voids Defect in MVDC Switchboard Cable Terminations

In DC power equipment, the switchboard is connected via a termination when the cable is connected from the outside. In the termination, multilayer interfaces are formed between XLPE and semi-conductive layer. Void defects occur between the multilayer interfaces due to various causes during cable connection, which causes damage due to partial discharge inside the termination. Therefore, this paper simulates the multilayer interface of XLPE-semi-conductive layer of switchboard cable termination to fabricated partial discharge simulation defect electrodes, and experiments were conducted under three different conditions by varying the size of the voids. The experiments were conducted at a temperature of 70 ° C to account for the rising temperature conditions at termination during operation. The discharge magnitude increases proportionally with both applied voltage and void size. In addition, discharges are larger and more frequently proportional to the applied voltage and void size. The characteristics of void partial discharges show that over time, the occurrence frequency increases, ceases at a certain point, and then increases again.