Condition monitoring of discharged ZnO surge arrester on temperature distribution under various design conditions

Surge arrester is a device for protecting electrical power system from harmful effect of lightning. There are many types of surge arrester in the world, which are categorised by different sizes, voltage ratings, varistors and housing material. In this work, the influence of various parameters in a 132 kV surge arrester design on its thermal distribution has been studied using finite element analysis software, which is COMSOL Multiphysics software. A 132 kV surge arrester model was developed and used to simulate the thermal distribution under normal condition and overvoltage condition using different surge arrester parameters. The surge arrester considered was a Zinc Oxide type. The parameters of surge arrester design that were varied include the arrester length, bushing thermal conductivity, bushing width, glass width and ZnO width. It was found that these parameters affect the thermal distribution within the surge arrester model that has been developed. From the simulation results, understanding on thermal distribution for various parameters of surge arrester can be enhanced. This study may also help in condition monitoring on surge arresters as the effect of different surge arrester designs can be evaluated.