Quantitative method for determining surface erosion of silicon rubber for outdoor insulator by the measurement of leakage current under artificial salt fog condition

This paper describes the performance of widely used polymeric insulating materials for outdoor insulation. Various methods to describe the surface aging of polymer materials such as peak and average of leakage current, the cumulative charge and the weight loss have been investigated. The relationship between surface current and time are plotted and discussed. The results of a laboratory evaluation of the contamination performance of silicone rubber shows that due to significant material differences, polymers cannot be evaluated using experimental conditions standardized for porcelain and glass. The results of this paper show that weight loss, average current and cumulative charge are better parameters to characterize the aging of insulators than the surface transition time, the peak of leakage current and first flashover time