Proposal of a New Detection Method for Damaged Transmission Line Arresters using Frequency Characteristics of its Equivalent Series Resistance

Abstract

About 70% of overhead transmission line faults have been caused by natural forces. Above all, more than 60% of those faults are due to lightning. As transmission line arresters (TLAs) are effective to prevent the faults caused by lightning, we have installed them in many of our transmission lines. Nevertheless, TLAs have been damaged by a very large electric charge of lightning, particularly in winter. Through investigation of the damaged TLAs collected from our transmission lines, we found some of the internal zinc oxide (ZnO) elements of TLAs were damaged. But it is difficult to detect those damaged TLAs by the conventional measurement of insulation resistance between terminals of TLAs. Therefore, this paper proposes a new detection method for the damaged TLAs using the frequency characteristics of its equivalent series resistance. The detection rate of the damaged TLAs by the new method is remarkably higher than that by the conventional method.