Condition monitoring of outdoor polymeric insulators using wavelets and ANFIS

In the present work, laboratory based pollution performance tests are carried out on silicone rubber insulator under ac voltage at different pollution levels and relative humidity conditions with sodium chloride as a contaminant. Multi Resolution Signal Decomposition (MRSD) using Discrete Wavelet Transform (DWT) is employed to understand the time frequency characteristics of the leakage current signal. The surface conditions of the insulator such as normal conditions, short duration discharges and long duration arc were characterized by using the leakage current measurement, utilizing the multi resolution signal decomposition technique. The process of identification of surface condition of the insulator was automated using Adaptive-network-based fuzzy Inference system (ANFIS).