Investigation on flashover of polymer insulators caused by foreign bodies

The faults of composite insulator have been divided into three kinds including pollution flashover, lightening flashover and reason unknown flashover. Some flashovers have occurred in the field but the mechanism of flashover is still unknown. This paper presents experimental results of flashover of polymer insulators caused by foreign bodies. It was found that the nonuniform voltage distribution and the dropping down foreign bodies may cause flashovers. In this paper, in addition to experiments, the voltage distribution is analyzed using the finite element method. The factors influenced the flashover phenomenon is thus studied.