Monitoring of leakage current on HV surge arrester as pollution indicator of external insulation

Abstract

The pollution of external insulation of power equipment has a significant impact on the lifetime of electrical equipment. The paper is focused on the possibility of using monitoring leakage current through the external insulation of hv surge arresters as indicator of pollution. In the experiment the modified procedure for the preparation of the polluting layer was used. The leakage current on the surface of the external insulation of the hv surge arrester and the internal leakage current of the hv surge arrester was monitored. It was found, that the surface resistivity of a sample with polluting layer in wet conditions, decreased by almost two orders of magnitude. The experimental results show that monitoring of leakage current along the surface of the external insulation is a useful indicator of pollution. In addition, measurement of the leakage current on the surge arrester with pollution layer during wet weather can lead to significantly erroneous results.