Investigations into the surface condition of silicone rubber insulation material using multiresolution signal decomposition

In the present paper, the tracking phenomena of silicone rubber material has been studied under ac voltages, with ammonium chloride as a contaminant. The characteristic changes in the tracking time of the aged specimens are analyzed through leakage current measurement. The observed trends in the leakage current during the tracking study are analyzed using a moving average current technique. The contact angle of the specimen varies with the type of aging. multiresolution signal decomposition technique was adopted to identify the characteristic change in the hydrophobicity levels of the specimens using the standard deviation multiresolution analysis curve. It is concluded that the material with less contact angle where the leakage current magnitude is high, allows tracking to occur early. © 2006 IEEE.