FACTORS AFFECTING THE MECHANISM OF FLASHOVER IN METAL OXIDE SURGE ARRESTER

摘要

The paper describes the mechanism of an electric flashover on a boundary surface between a ceramic varistor and polyamide casing of a metal oxide surge arrester. The role of a surface charge in the development of surface discharge was shown. The surface flashovers lead to constant destruction of a varistor pile and to stratification of the surfaces which lower the electrical strength of the metal oxide surge arrester. It was found that this problem can be solved by means of covering the ceramic varistor surface with a semi-conducting layer which carry away the generated surface charge and compensate the distribution of a electric field along the boundary surface.