Research into the corona current characteristics of polluted insulators

The contamination influences the corona performance of transmission line insulator strings very much. Not only do they change the corona-originated voltage, but also change the quantity and amplitude of the corona pulses. This paper describes experiments into the corona current at diverse contaminating condition and various voltages. The experimental results show that the corona pulses conform to statistic rules and can be used to distinguish faulty insulators from transmission line insulator strings at the definite environmental condition. A fuzzy membership function is established according to the results which can be used as one of the preconditions to detect faulty insulators.