Numerical Investigation of Charge Packet Dynamics in Polyethylene Assuming Barrier Height-Electric Field Hysteresis Hypothesis

Abstract

Abstract Charge packet phenomenon is a sign of the impending breakdown of the dielectric materials. In order to discuss the formation mechanism of charge packets, space charge characteriscs in polyethylene under the electric field of 150kV/mm are simulated based on the bipolar transport model assuming hysteresis in the barrier height for holes. It is found that if hysteresis in the barrier height is not introduced, net charge densities in the vicinity of the electrodes increase with the increase of polarization time. However, charge packets could not be reproduced without hysteresis hypothesis. When hysteresis loop in the barrier height are incorporated, charge packets are generated and propagated with the velocity about 3μm/s. The dying away of charge packets is not observed, which disagrees with the experimental data.