Risk assessment of contaminated composite insulators in pre-flashover conditions

Abstract

In this paper, a novel approach for risk assessment of the outdoor polluted insulators is presented to predict dry band-arcing and flashover. Risk evaluation of the dry-band arcing and flashover are represented using leakage current (LC) behavior in order to understand pollution behavior of the pre-flashover conditions. Critical indexes of the dry-band arcing and flashover are extracted based on the presented risk assessment model using wavelet transform (WT). Then, the developed critical indexes are used for prediction of the operation risk of the composite insulators. In addition, the occurrence probabilities of the dry band arcing and flashover are calculated based on the analysis of critical indexes. Several sensitivity parameters including pollution level, wetting rate and geometry specification are considered in the presented model. Validation results show that risk of the insulator's service can be correlated to the represented critical indexes. The proposed approach can be adopted as an online monitoring tool in order to avoid pollution flashover of the outdoor insulators.