Potential distribution analysis of suspended-type metal-oxide surge arresters

Nonuniformity of potential distribution of metal-oxide (ZnO) surge arresters reduces service lifetime of the arresters. The metal-oxide surge arresters of polymer housings developed can be suspended in different places. A combined method of electrical field and electric circuit is proposed to analyze the potential distribution of the suspended arresters. The equivalent electric circuit is obtained from a charge simulation method (CSM) and matrix transformation, and the potential distribution is solved from the electric circuit analysis by the first law of Kirchhoff. The complicated electromagnetic field problem is then converted to a simple electrical circuit problem. The calculation results show a good agreement with experimental results. Potential distributions of surge arresters suspended on a conductor by a wall, on a framework, and on a transmission-line tower are presented.