Study of the AC arc discharge characteristics over polluted insulation surface using optical emission spectroscopy

Flashover of contaminated insulators is one of the major problems for the power distribution. Laboratory experiments have shown that the arc characteristics have great influences on the study of flashover performance of contaminated insulators. In order to investigate the characteristics of AC arc discharge on the polluted insulation surface, an experimental system was designed. The emission spectroscopy of arc discharge was obtained by a CCD spectrometer, and lithium chloride was added in the artificial pollution to introduce lithium as the indicator element in the analysis of arc emission spectroscopy. Arc temperature was obtained by employing the relative line intensities method, and the electron density was determined by analyzing the Stark-broadening values of the profiles. It was indicated that the temperature of partial arc increased with the leakage current value, but electron density of partial arc barely changes with leakage current. Special attention was paid to the influence of gas pressure on the characteristics of partial arc. It was found that both the arc temperature and the electron density of the arc channel increased with pressure in the case of same leakage current.