Development of Global Vacuum Pressure Impregnation Insulation System for Turbine Generators

Abstract

Global vacuum pressure impregnation insulation system exhibits various merits in insulation performance and reliability for operation including maintenance. Therefore, the system is suitable for ordinary turbine generators, especially, the generators for geothermal power plant. We have developed a global vacuum pressure impregnation insulation system (F-resin/G insulation system) for large size turbine generators and had put into practical use in 1993. In the process of evaluation of insulation system, we evaluated impregnating ability, electrical, and mechanical characteristics. From evaluation, we were able to achieve the improvement of heat cycle, heat resistance and V-t characteristics against usual insulation system, because of the utilization of internal electrical field relaxation layer, thermal stress relaxation layer, insulation tapes with excellent impregnation ability and epoxy resin with high heat resistance. As the insulation characteristics are affected not only utilized materials and their composition but also manufacturing process, it is reasonable to suppose that we can obtain the improvement of insulation performances and stabilization of quality by using the taping simulation technique.