Study on the Characteristics of Surface Charging in a Vacuum Insulation System

Flashover along surface of a solid insulator is one of the important problems for vacuum insulation systems. In order to mitigate the electric field at the junction between an electrode and a solid insulator, which is a primary cause of surface discharge, shield rings are applied to the electrodes. This paper presents a study on the charge distribution on an insulator surface in a vacuum insulation system. The main objective of this work is to clarify the charging characteristics and the effects of the shield rings on the charge distribution. The configuration of study consisted of a hollow cylindrical alumina insulator set between parallel electrodes. The tip radius and the position of the shield rings were varied for investigating their effects. After an application of 25 kV potential to…