Pollution accumulation characteristics of insulators under natural rainfall

Under natural environment, the washing effect of rainfall has great influence on the cleaning of outdoor insulators. To study the law of natural contamination on the insulator surface in the rainy weather. The natural contamination experimental study has been carried out for four 500 kV transmission lines in hundreds of sites and stations in Hunan Province for five years. The equivalent salt deposit density (ESDD) and non-soluble deposit density (NSDD) were measured monthly, and the meteorological data were statistically analysed. The results show that the residual ESDD and NSDD on the surface of insulators were affected by the rainfall intensity, duration and flushing angle. Meanwhile, based on the measured data of ESDD and NSDD, a cleaning model of insulators was established. The effects of splash on the bottom surface of insulators were studied by using the raindrop kinetic energy and Gaussian probability statistical distribution.