Investigation of Effect of Transmission Line Arresters Verified by Lightning Surges at Substations

Abstract

In recent years, the transmission line arresters have been installed to protect an overhead power transmission line from a back flashover caused by lightning. It has been also expected that lightning surges in the substations incoming via transmission lines can be suppressed by them. However, the suppression effect by those with series gaps has not been investigated sufficiently. Author has measured lightning surges at two 77kV substations from 1990 to 1993. As the transmission line arresters have been mounted on the towers in this field since 1992, the lightning surges due to the sparkover of the series gap of the transmission line arresters can be observed at the substations. In this paper, the lightning surge waveforms due to the sparkover of them have been analyzed in detail at first. Next, the accurate EMTP simulation method considering the induced lightning surge voltages has been proposed. Finally, the suppression effect by them has been investigated by the simulation corresponding to each mounting method.