Inverse application of charge simulation method in detecting faulty ceramic insulators and processing influence from tower

Suspension insulators are widely used in power systems to provide electrical insulation and mechanical support for high-voltage (HV) transmission lines. To detect and replace the faulty insulators on power transmission lines is of great importance for the safe operation of the power system. A nontouch electric-field measurement method to detect faulty ceramic insulators is presented, which involves measuring the electric-field of measuring points in the vicinity of insulator strings and calculating the potential distribution along HV outdoor insulator strings. It also suggests a way to process the influence from the tower. The salient feature of this method is the significantly smaller number of measuring points and the greater distance between measuring points and insulator strings. Ceramic suspension insulators of 110-kV voltage ratings have been modeled under clean and dry surface conditions. Good agreement is obtained between the present calculations and the actual value, which demonstrates the practical viability of the technique