Finite Element Modeling of Fields Distributions in a Three-core XLPE Cable with Multiple Cavities

Abstract

Three-core cross-linked polyethylene (XLPE) power cables are widely deployed for underground power distribution and transmission. The presence of cavities within the cable insulation serves as field enhancement regions which may lead to partial discharge capable of causing failure. In this paper, the distribution of electric and potential fields in a three-core XLPE power cable without and with cavities using finite element approach in COMSOL are presented. The results indicate a clear variation in the fields (electric and equipotential line) across the insulations of the cable cores without and with cavities. The highest field intensity across the healthy and defected model are contained in the upper core as compared to the right- and lefthand cores respectively. For the unhealthy cable configuration, the maximum electric field magnitude obtained in the upper core with three arbitrary cavities 1, 2, 3, was approximate 12. 1371 kV/mm. As such, increasing the overall average cable field strength by 88.06% as compared to the default field magnitude (1.3371kV/mm). The introduction of cavities, is observed to cause a significant increase in electric field magnitude within the cable.