Impacts of contamination and hydrophobicity level on the leakage currents of composite insulators

For composite insulators, analyzing the relationships between leakage current and contamination/hydrophobicity level could be considered as an effective measure for forecasting pollution flashovers. Therefore, using experimental data in artificial climate laboratory, we simulated the impacts of contamination and hydrophobicity level on leakage current to reveal the relationships between them. The results show that, with the increase of contamination, the maximum effective value of leakage current and the number of high-amplitude pulses increase, the difference between phases of leakage current and applied voltage decreases from -33.19° to 0, and the fundamental harmonic content of leakage current decreases from 98.03% to 79.89% while the other harmonic contents increase. With the decrease of hydrophobicity, the maximum effective value of leakage current and the number of high-amplitude pulses increase, the difference between phases of leakage current and applied voltage decreases, and the fundamental harmonic content of leakage current decreases from 97.56% to 85.97% while the other harmonic contents increase.