Investigations on leakage current and phase angle characteristics of porcelain and polymeric insulator under contaminated conditions.

none4nsulator in order to develop a better diagnostic tool to identify the pollution severity of outdoor insulators. In this work, laboratory based pollution performance tests are carried out on porcelain and 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. Fast Fourier Transform (FFT) is adopted to calculate the phase angle values of the applied voltage and leakage current. Reported results show that the pollution performance of silicone rubber insulator is far superior when compared with porcelain insulator. Pollution severity of outdoor insulators could be identified from the DWT STD-MRA (Standard Deviation Multi Resolution Analysis) Distortion Ratio pattern analysis of leakage current signals.noneS. Chandrasekar; C. Kalaivanan; A. Cavallini; G.C. MontanariS. Chandrasekar; C. Kalaivanan; A. Cavallini; G.C. Montanar