Insulation Design and Experimental Results for Transmission Class HTS Transformer With Composite Winding

In the response to the demand for electrical energy, much effort aimed to develop and commercialize high temperature superconducting (HTS) power equipments has been made around the world. In Korea, companies and universities are developing a power distribution and transmission class HTS transformer that is one of the 21st century superconducting frontier projects. The composite winding of transmission class HTS transformer is concentrically arranged primary winding (High)-Secondary winding (Low)-tertiary winding (High) from center. Primary winding is continuous disk type, Secondary winding is layer type and tertiary winding is Double pancake type. For the development of transmission HTS transformer with composite winding, the cryogenic insulation technology should be established. We have been analyzed insulation composition and investigated electrical characteristics such as breakdown of , barrier, kapton films and surface flashover on Fiber Reinforced Plastic (FRP) in Liquid nitrogen . We are going to compare with measured each value and apply the value to most suitable insulating design of the HTS transformer.