Study On Effect Of Haze On Pollution Characteristics And AC Discharge Performance Of Insulators

In recent years, with the rapid development of China’s industrialization process, the environmental pollution problem is increasing. The haze weather has shown a tendency of long duration and large scale. And the effects of haze weather on external insulation of power grid have attracted much attention. Lots of researches about fog’s effect on external insulation characteristics have been carried out. However, most of these researches ignor the effects of particles in haze enviroment on external insulation, i.e. these researches do not consider the differences between fog and haze weather. For now, research about the effects of haze particle on external insulation of power grid is still at the starting stage. Therefore, through field and simulation tests, this paper mainly explores the effects of haze weather on the contamination depositing characteristics of porcelain/composite insulator and the discharge characteristics of typical porcelain insulator on transmition line.The main composition and particle size distribution of haze can be obtained by searching the data. The aerosol generator and ultrasound fog generator are used to simulate the haze weather in artificial fog chamber. This paper has carried out the natural contamination test and simulated contamination test about porcelain and composite insulator. The contamination tests mainly analyse the influences of duration、serious degree、particle size and the relative humidity of the environment(RH) on the contamination depositing characteristics of porcelain and composite insulator. And the differences of contamination characteristic between porcelain and composite have been studied. In order to study the influences of component、particle size and conductivity of water fog on the discharge characteristics of insulator, AC discharge tests in the simulated haze environment have been done for XP-70 porcelain insulators.The results of natural contamination test show that: The influence of haze environment to contamination depositing embodies in wet sedimentation caused by gravity. The pollution degree on the up side surface is much higher than the down side area. In haze environment, the pollution on the up side surface of porcelain and composite insulator has a periodic trend over time. At the beginning of depositing, the quantity of pollution on the up side surface of composite insulator is 1.5 times of that porcelain insulator, with the sustained effects of haze, the saturated contamination degree of porcelain and composite insulator is pretty close. The saturated contamination quantity is determined by the severity of haze haze. Higher the AQI index, larger the saturated contamination quantity.The simulated depositing test results show that: The smaller the particle size of haze, the greater the degree of contamination. Compared to porcelain insulator, the large size particles are more easily to adhere on the up side surface of composite insulator. The environmental relative humidity will also promote the contamination depositing.The results of insulator AC discharge test show that: In the simulated haze environment, the flashover voltage of insulators is lower than in the fog environment. The difference of particle component affects the flashover voltage. The salt aerosols cause insulator flashover voltage decreased greatly. The flashover voltage becomes higher as the particle size growing. And the increase of water fog conductivity will lead to the drop of flashover voltage. With the increase of insulator contamination degree, the impacts of haze component、particle size and water fog conductivity on insulator flashover voltage become weak.