Analysis of the leakage current pulses of outdoor insulators in different relative humidity

This paper investigated the leakage current characters of outdoor insulators in different relative humidity and provided an approach to evaluate the contamination levels by the numbers of leakage current pluses. Artificial pollution tests were carried out on a kind of widely used glass insulator. Leakage current waveforms in different contamination levels and different relative humidity (RH) were recorded by a leakage current monitoring system. The relationships between maximum values of leakage currents, ESDD and relative humidity were studied. Meanwhile, 80 levels of leakage current pulses were picked out from the waveforms. Principal components including most information of the pulses were extracted using principal components analysis (PCA). Analysis to the scores of comprehensive principal components shows that the principal components of the leakage current pulses are strongly relative to the contamination levels. They provide a good approach to evaluate the contamination levels.