The Sensitivity of Electric Field Method on Detecting Faulty Porcelain Insulators

Electric field method is one of most efficient method to defect composite insulator. But it is not be used widely on porcelain insulator. In this paper, research of using the electric field method on porcelain insulators was made. A space electric field probe measured the distribution of electric field around the insulators. Several faulty insulators were place on the insulator string at every position. The relationship between the resistance of faulty insulators and the electric field distribution was studied. We found that the electric field distribution curve will appear descent at the position of faulty insulator. But the position and resistance of faulty insulators decided the extent of the distortion. According to the experiments at laboratory, we found that faulty insulator above 100 MOmega can´t be detected by the electric field probe