Numerical Simulation of Charge Accumulation and Transport within Cross-Linked Polyethylene (XLPE) Subjected to High Electrical Stresses

Abstract

Accumulation of space charge is well identified to be a significant element affecting the performance of high voltage cable insulation system. In the area of polymeric insulation, space charge have been widely investigated under various electric stresses. The aim of this paper is to investigate the charge accumulation and bipolar charge transport within cross-linked polyethylene (XLPE) material through numerical simulation. The simulationestablished in this paper was designed based from previous work proposed by R M Hill and J M Alison. The simulation characterizes the injection, trapping, transport and recombination of electrical charges. The numerical model is driven by three fundamentalcalculations that described the characteristics of space charge which consist of Poisson’s, Transport and Continuity equations. In terms of its width, the XLPE sample used for the simulation is uniformly segregated in order to determine the electric field at each division. The electric field in the simulation is determined by using the direct discretization of Poisson’s equation. In the simulation, mobile electrons/holes and trapped electrons/holes are considered, while by applying Schottky injection algorithm, the charge is injected into the simulation with holes and electrons are at the anode and cathode respectively. Then different values of applied voltage are considered and preliminary results have shown that the variation of electric field would influence the dynamics and accumulation of space charge within the material.