Research on the stator coil insulation system of a 20kV turbo generator

This paper investigates the insulation properties and design of VPI coils with 20 kV rated voltage for turbine generators. From the research of the VPI process and the internal grading structure in the coil as well as the end corona protection structure, the 20 kV VPI coil is successfully designed. The electrical and mechanical properties are evaluated in this paper. The design of 20 kV VPI coil insulation system lays a foundation for the future design of a 27 kV coil.