Study the effect of contaminants on flashover performance of porcelain disc insulator by artificial pollution testing

Faults in high voltage insulator generally occur due to pollution flashover, which is one of the most crucial problem resulted by cumulative effect of both pollution and moisture. In this paper, the effect of contaminants on the performance of flashover voltage of porcelain insulator under various environmental conditions has studied by performing artificial pollution tests that nearly reflects the condition of natural deposition. Under natural conditions, a pollution layer has formed gradually which may contain a variety of chemical compounds of different properties. We have used many chemicals as contaminants to analyze their effect on flashover voltage of the discs by measuring the polluted surface conductivity and pH value for individual salts and their mixtures. ESDD is also determined in the work, to check the severity of pollution on insulator surface. Results of the present study also serve the information like the fluctuations of flashover voltage gradient with ESDD.