Mousalreza Faramarzi - Faculty of Electrical and Computer Engineering Babol University of Technology Babol, Iran
Mohammad Mirzaie - Faculty of Electrical and Computer Engineering Babol University of Technology Babol, Iran

Environmental condition such as pollution and humidity can influence on expected performance of insulators and change their electrical behavior. Pollution also reduces the efficiency of the insulators and increases the possibility of flashover occurrence which consequently results in transmission line outage. Therefore, forecasting the flashover and detecting the critical conditions are very important. This paper proposes a novel method for critical conditions detection and consequently preventing from flashover in porcelain and glass insulators by employing leakage current analysis Pollution also reduces the efficiency of the insulators and increases the possibility of flashover occurrence which consequently results in transmission line outage. Therefore, forecasting the flashover and detecting the critical conditions are very important. This paper proposes a new method for critical condition detection and consequently preventing from flashover in porcelain and glass insulators by employing leakage current and applied voltage analysis. The index (P.D%) which is defined here is the Cosine of the phase difference between the main harmonics of the leakage current and applied voltage. Also this index enables operators to have a better planning for optimal utilization of high voltage equipment. Experimental results have verified the validation of the defined index.

insulator, leakage current, flashover, main harmonic, Phase Angle Difference Indicator