Experimental study on the contamination deposition characteristics of insulators in a fog-haze environment

In recent years, the frequent occurrence of fog and haze in China has attracted increasing attention in the field of electrical insulation. Fog-haze weather is an extreme weather condition with high humidity, high concentrations of suspended particulate matter, and sometimes high conductivity. This exacerbates insulator surface contamination and moistens the contamination layer, which may lead to flashover incidents. Here, an experimental system was established to simulate the fog-haze environment under controlled and tunable conditions. Simulated contamination tests were then conducted using three typical insulators. The influence of insulator type and environmental parameters was investigated. Test results showed that higher humidity led to faster pollution accumulation for all three insulators. Moreover, equivalent salt deposit density (ESDD) on the surface increased linearly with increasing fog conductivity, and that on the upper surface rose faster. The ESDD increased significantly under AC voltage, especially on the lower surface. Finally, insulator contamination was studied in a real-world fog-haze environment with periodic measurement of the ESDD and environmental parameters. The ESDD showed a good correlation with the PM2.5 and PM10 concentrations. This work should have relevance for the external insulation of the power grid to resist the effects of fog and haze.