Description of bipolar charge transport in polyethylene using a fluid model with a constant mobility: model prediction

Abstract

We present a conduction model aimed at describing bipolar transport and space charge phenomena in low density polyethylene under dc stress. In the first part we recall the basic requirements for the description of charge transport and charge storage in disordered media with emphasis on the case of polyethylene. A quick review of available conduction models is presented and our approach is compared with these models. Then, the bases of the model are described and related assumptions are discussed. Finally, results on external current, trapped and free space charge distributions, field distribution and recombination rate are presented and discussed, considering a constant dc voltage, a step-increase of the voltage, and a polarization–depolarization protocol for the applied voltage. It is shown that the model is able to describe the general features reported for external current, electroluminescence and charge distribution in polyethylene.

An improved model to estimate trapping parameters in polymeric materials and its application on normal and aged low-density polyethylenes

“…And J h is the injection current density from the anode. With high voltage applied, charge injection behavior at the metal-polyethylene interface was verified conforming to Schottky injection mechanism 9,20,21 , which has already been applied into some previous modelling works on polyethylene 18,22,23 . Such conduction mechanism demonstrates that barrier height at the electrode-dielectric interface is lowered by the applied field and image charge force so that enhanced current density from electrodes takes place.…”

“…In recent years, many approaches have been developed on determination or estimation of these trapping parameters for various insulation materials, especially polyethylene [13][14][15][16][17][18] . Chen proposed a trapping-detrapping model based on two energy levels.…”

Combined RKDG and LDG Method for the Simulation of the Bipolar Charge Transport in Solid Dielectrics

“…It has already been widely adopted by Le Roy and Belgaroui et al in [2,3,7]. The model is given as follows:…”

“…For the solution of the Poisson's equation, the local discontinuous Galerkin (LDG) method proposed by B. Cockburn et al [5,6] is adopted in this paper instead of the generally used boundary element method (BEM) [7], in order to replace the numerical quadrature with analytical formulas in the RKDG weak formulation of the convection-reaction equations. This combined RKDG+LDG method is verified by the simulation of the space charge transport in a low-density polyethylene (LDPE) sample under high dc voltage.…”

Physical and Numerical Modelling for Bipolar Charge Transport in Disorder Polyethylene Under High DC Voltage

“…For these problems, different techniques for the space charge measurements were developed in order to understand and overcome their effects on the electrical properties such as electrical breakdown and conduction mechanism [5,6]. During these last years, the theoretical modelling and simulation have been integrated for better understanding the space charge dynamics [7][8][9][10][11][12]. Previous works showed the existence of two charge dynamics corresponding to mobile and trapped carriers at high and low DC applied voltages, respectively [12,13].…”