Review on aging characterization and evaluation of silicon rubber composite insulator

Silicone rubber composite insulators have been widely applied as the external insulation of electric power system because of their advantages such as light weight, anti-contamination flashover performance, convenient transportation and installation, etc. With the complicated effects of on-site contamination, ultraviolet radiation, discharge, temperature, humidity and other factors, the silicone rubber materials are gradually aged, and aggravated with operation time prolonging, which causes the significant decrease of operation reliability and threatens the stability and safety of power system seriously. How to characterize and evaluate the aging state of composite insulators has been the problem and research focus of both at home and abroad. In this paper, combined with the research results of the authors' teams, the aging mechanism of silicone rubber material is analyzed, and the artificial accelerated aging methods, the detection and evaluation techniques of aging state of composite insulators are summarized. The applicability and effectiveness of different methods are analyzed, and the related development trends are forecasted, so as to instruct the operation, maintenance and manufacturing of composite insulators for power enterprise and manufacturer.