Modeling partial discharge in a three-phase cable joint experiment with minimal adjustable parameters

A general physical model of partial discharge (PD) has been developed and used to simulate discharges within a void at the tip of a metallic spike defect within a three-phase 11 kV paper insulated lead covered (PILC) cable joint. Discharges are modeled by altering surface charge density at the void boundary using a logistic function distribution. The model was validated against experimental data, and a good agreement was observed with minimal free parameters. The model was then used to investigate the impact of single phase energization on PD activity in three-phase PILC cable joints. It was concluded that PD testing of three-phase PILC cable joints should be performed at raised temperatures with the cable fully energized as this results in a higher frequency of PD activity, and reduces the level of background PD from cable terminations. This research represents a further step towards developing PD models that can describe measurements taken from operational high voltage plant.