A Detection Method of Lightning Damaged Distribution Surge Arresters Using Discharge Current Waveforms

Abstract

In Japan, many distribution surge arresters with an internal series gap have been installed on 6.6-kV overhead distribution lines for reducing lightning overvoltages. In contrast, surge arresters are sometimes damaged by direct lightning strikes to distribution lines, particularly in winter. Measurement of insulation resistance between terminals of the surge arrester and measurement of DC discharge voltage of the surge arrester are generally adopted to detect damaged arresters. However, if metal-oxide (MO) varistors are damaged and the internal series gap is not damaged, it is difficult to detect damaged arresters by the conventional methods.

Therefore, this paper proposes a new detection method of damaged arresters using discharge current waveforms. In the new method, first, the discharge current of the surge arrester is measured when a high DC voltage is applied to the surge arrester through an inductor. Then, the damaged arrester is detected by comparing the current waveform with that of a non-damaged arrester. The detection rate of damaged arresters by the new method is remarkably higher than those by the conventional methods.