Assessment of Insulator Pollution Degree Based on Contamination Moisture With Temperature Change

For the safe operation of the power grid, online monitoring of insulator pollution degree is of great significance to the power system. Considering that the insulator contamination mostly is accumulated in the dry season with little rain, it is very valuable to assess the pollution degree with the small leakage current signal measured at low humidity. To this end, this article analyzed the moisture characteristics of contaminated insulators when the insulator temperature is lower than the ambient temperature and found that the water absorption rate of the contamination layer is proportional to the “apparent humidity” at the interface. Then, an assessment method for insulator pollution degree based on contamination moisture at unsaturated humidity (RH < 100%) was proposed, which has application prospects in arid areas.