Simulation of partial discharge sequences using fluid equations

Abstract

Simulation methods employing continuity equations to describe particle transportation are used to examine the process of single discharge. However, it is difficult to simulate partial discharge (PD) behaviour accurately by these methods, because it will take too much computation time to simulate consecutive PD sequences. In this report, in order to save computation time, a simple three-dimensional network is used to simulate PD sequences in a small void under ac voltage. The model considers charge generation, charge transport and charge disappearance, and electrical field redistribution in three dimensions. The continuity equations for electrons, positive ions and negative ions, including the effects of ionization, attachment, recombination, electron diffusion and the transport of charge under electrical field are solved simultaneously with Poisson's equation. With this model, the phase-resolved PD pattern and the current forms of each PD are obtained. Moreover, considering the propagation process of each PD and its influence on surface charge distribution, the fall part of PD current form and the effect of previous discharge on the subsequent one are also studied.