Effect Of Fog-haze On Flashover Performance Of Flat Glass Under AC Voltage

In recent years, fog-haze occurs frequently in most parts of China. When the fog-haze occurs, the relative humidity is large and the concentration of TSP(total suspended particulate) is high, which is a serious threat to the safe external insulation of power transmission, and causes lots of serious pollution flashover accidents. However, currently the research of the effect of fog-haze on flashover performance of external insulation of power system was rarely researched. Therefore, in this paper, the plate samples flashover test platform was built, on which temperature and relative humidity could be controlled and fog-haze environment was simulated by artificial fog and natural haze. And effect of fog-haze on flashover performance of flat glass under AC Voltage was researched in this test platform.Firstly, pollution tests under AC Voltage were carried out under fog-haze environment and normal days. The differences of contamination of insulators between fog-haze environment and normal days were obtained. Compared with normal days, the contamination particles of insulators under fog-haze environment are larger, the contamination of insulators are more serious, the ratio of NSDD to ESDD of insulators are smaller, the unevenness of the contamination of insulators are larger, and nitrate content in contamination is obviously larger. Secondly, the plate samples flashover test platform was built, on which temperature and relative humidity could be controlled and fog-haze environment was simulated by artificial fog and natural haze. Based on the differences of contamination between fog-haze environment and normal days, effect of the ratio of NSDD to ESDD and nitrate salt on flashover performance of flat glass under AC Voltage was researched in this test platform. Through analyzing those test results, the conclusion of that the flashover voltage of contamination of fog-haze is lower than that of normal days was obtained.Finally, effects of TSP concentration, relative humidity and contamination level on flashover performance of flat glass under AC Voltage were researched in this test platform. The experimental result shows that flashover performance of flat glass is affected by TSP concentration, relative humidity and contamination level. Wherein, the greatest effect factor is relative humidity, followed by contamination level and TSP concentration. And the three factors are not mutual independence.