Ultra-High Strength Suspension Insulators and Insulator String Assemblies for UHV Transmission Line

This paper describes the development of ultra-high strength 70- and 84-ton suspension insulators, and the results of various tests to confirm their performances. Also, the investigations into electrical characteristics were made on the insulator string assemblies consisting of them. For the future UHV transmission lines in Japan, 42- and 54-ton suspension insulators are mainly considered to be used. However, high mechanical stress due to snow/ice and strong wind will be imposed on the insulator assemblies in the heavy snow areas. These insulators can be used successfully in such severe areas.