Development Of A Superconducting Transformer For Rolling Stock

Having undertaken studies into a lightweight and highly efficient superconducting transformer for rolling stock, we developed a prototype with a primary winding, four secondary windings and a tertiary winding using Bi-2223 high temperature superconducting wire Its primary voltage is 25kV, which is widely adopted as the catenary voltage on the world's high-speed lines We adopted liquid nitrogen cooling, the weight being 1 71t excluding the refrigerator The maximum output available to maintain superconductivity is 3 5MVA We also introduce railways in Japan