A Study on Influence of a Surge Arrester on Multiphase Flashover in Medium-voltage Line

This paper discusses multiphase flashover in a 6.6kV medium-voltage line in Japan caused by direct lightning strike to the top of a reinforced concrete pole. The multiphase flashover causes a short circuit in the line, and sometimes causes serious damages in power apparatuses and cables. The flashover on an insulator is judged using an integration method, which can consider an influence of voltage waveform on the flashover and can be used in the EMTP. Surge arrester suppresses line voltage and insulator voltage. No flashover occurs on an insulator where a surge arrester is installed on the phase. This paper discusses an influence of a single surge arrester in a non-grounded medium voltage line on multiphase flashover for various combinations of insulator types and the surge arrester.