Research on Wetting Characteristics of Insulator in Ultrasonic Fog

Pollution accumulation and wetting of insulator are the two prerequisites for the pollution flashover. In this paper, the wetting characteristics of artificial polluted insulators in the ultrasonic fog were analyzed. Firstly, a method to analyze the water absorption of the contamination layers on the insulator surface is presented in this paper, and then by measuring the surface conductivity of the test specimens in the salt fog, the saturated water absorption of the contamination layers under different NSDD and different angle of inclination is calculated. It has been found that in the ultrasonic fog chamber, both the NSDD and the inclination angles have influence on the saturated water absorption of the insulators. For the specimens with vertical arrangement, the saturated water absorption is in a range of 1.68-2.7mg/cm2, which is greatly influenced by the NSDD. However, for the test specimen with inclination degree at 45°, the saturated water absorption is 3.04-3.42 mg/cm2and less affected by NSDD.