Modeling and Analysis of Electric Field Variation across Insulation System of a MV power Cable

Cross-linked polyethylene (XLPE) has found wide application in high- and medium-voltage power distribution and transmission systems. Owing to its excellent properties, XLPE is highly deployed for insulation purposes in underground power cables. The presence of defects across the insulation systems serves as field enhancement and partial discharge initiation sites that may lead to equipment failure. In this paper, the finite element modeling of electric field variation across the insulation system of an XLPE medium-voltage (MV) power cable has been presented. A cross-section of the cable sector has been modeled in COMSOL without and with a single spherical cavity. Electric field strength analyses are performed for the healthy and defected cable, and their results are compared. The simulation results showed that the presence of the cavity has risen the electric field strength magnitude by 27.1 % as compared to the original value (without cavity).