Numerical resolution of charge transport in cross-linked polyethylene by means of a bipolar model with a distribution of traps

Abstract

We present a bipolar model of conduction providing time-dependent solutions for charge densities under uniform DC field. The model assumes the existence of an exponential distribution of trap depth for electrons and holes, with an upper limit in trap depth. Charges are supplied through Schottky injection at both electrodes. Charges move within the insulation through a hopping mechanism. Space charge profiles and external current are simulated in the transient regime following voltage application/grounding in DC stress. The objective is to describe the behaviour of cross-linked polyethylene.