Studies on the effect of void geometry and location on electric field distribution and partial discharge in XLPE insulated power cable by finite element analysis using COMSOL multiphysics simulation

Presence of partial discharges is a serious issue in the maintenance and condition monitoring of power cables. Under the effect of excess electrical field, the voids present in the insulation may go through breakdown, giving rise to the phenomenon of partial discharges. Repeated occurrence of partial discharges through a long period of time may lead to complete insulation failure. The partial discharge activity is dependent on the applied voltage, shape, size and location of voids and presence of minor protrusions on the conductor surface. In this study, the effect of all these factors was studied using a simulation model based on Finite Element Analysis (FEA) software. Three different void geometries were considered and their effect on partial discharge inception voltage, both in the presence and absence of protrusions, was studied. The location of the voids was also varied in the simulation study. From this work, an improved understanding of partial discharge within power cable insulation as well as its relationship with void geometry and location can be obtained.