Internal discharge properties for different solid insulating materials

Abstract

It is well known that the presence of a void affects the performance of insulating material and its life time. The properties of partial discharge (PD) occurring at a void inside a solid insulating material are effected by the void conditions, mainly its dimension, position, temperature and gas pressure, which determine the electric field distributions within the void site and in turn influence the properties of partial discharge. In this paper, the PD properties of interest were inception electric field, maximum PD apparent charge and repetition rate. Composite and traditional insulating materials like Silicon Rubber, Ethylene Propylene Diene Monomer Rubber, high density polyethylene and Polyvinyl Chloride were used. Two different models depended on the classical abc and the finite element analysis model were used to represent a cylindrical void within homogeneous insulating materials. These models are used to study the effect of dimensions and positions of the void on the PD properties. The obtained results show that the repetition rate and the inception electric field depend on the void height. On the other hand, the maximum PD apparent charge depends on the radius of the void. Changing the void position has no significant effect on the PD properties.