Surface Charging Models for Prediction of Dielectric Withstand in Medium Voltage Range

An engineering approach to the computational prediction of surface charging during dielectric tests of medium voltage devices is presented. It is based on a formulation of the saturation charge boundary condition applied to an iteratively estimated area on the insulation surface. The simulation procedure is explained for a simple case study including a rod electrode, shaped barrier, and grounded enclosure. Applications of this procedure to 3-D models of medium voltage devices are presented.