A New Flashover Prediction on Outdoor Polluted Insulator Using Leakage Current Harmonic Components

Abstract

Investigating of insulator performance is a continuing concern within the power system, so the study of the insulator parameters is required. The present paper aims to use new criteria and approach to predict the occurrence of flashover of (100 * 60 mm) plates of silicon rubber insulator using harmonics component of leakage current. the signal of leakage current of insulator with different pollution levels was measured under different weather conditions. Furthermore, to evaluate the effect of weather variables, various values of water conductivity were used for the experiments. The new criteria (Ki) is ratio of sum of leakage current harmonics value at frequencies 0-100 Hz to sum of leakage current harmonics value at frequencies150-500 Hz have determined. The proposed criteria can be used as wireless diagnostic tools for contamination levels flashover can occurred. Test was conducted by two wetting methods of sample SIR insulator is spray and dipping, different voltages 7kV and 14 kV have been applied. Test results shown high performance of this method.