Leakage Current Patterns Observed in Polymeric Insulators Rotating Subjected to Wheel and Dip Test

摘要

Present paper discusses the behavior of leakage becomes unfit to electrical applications [2]. current flowing through silicone rubber based polymeric insulators. These insulators are investigated experimentally using rotating wheel and dip test arrangement which is designed as per IEC/TR 62730. The test specimen used in the present study has creepage length of 725 mm and four of such specimens are employed on rotating wheel. These specimens rotate through contaminants and touches high voltages in a specific cycle that runs for 1000 hours. During the experimentation, leakage current is captured and recorded. This leakage current represents an interesting behavior which is reported in the present work. Further, to analyze the leakage current pattern, Fourier transform is employed to observe the changes in the specific frequency components. It is reported that the variation of power frequency component is exponentially decaying whereas the variation of third harmonics follows a double exponential pattern. The MATLAB curve fitting tool is used to determine the parameters that confines the changes.