Technique to examine the influence of voltage harmonics on leakagecurrent based MOSA diagnostic indicator

摘要

The degradation of Metal Oxide Surge Arresters (MOSA) in serviceis diagnosed by using the third harmonic content of the resistiveportion of the arrester leakage current as an indicator. The thirdharmonic content consists of two components, i.e., a component due tothe nonlinear volt-ampere characteristics of the MOSA and an errorcomponent due to the presence of voltage harmonics. In order to assessthe discerning ability of an on-site diagnostic method to the errorcomponent its indicator has to be compared with that of a benchmarkmethod. This paper discusses such a method