Characteristics of Model Windings of High‐TC Superconducting Transformer for Railway Rolling Stock

We investigated the possibility of applying high‐TC superconducting traction transformer to a rolling stock. In order to achieve a lightweight design, the traction transformer needs to have a special winding structure unlike the experimental high‐TC superconducting power transformers fabricated so far. The windings of the traction transformer need to be arranged as closely as possible in a high magnetic field. Then, we fabricated two high‐TC superconducting coils that simulated the winding of a high‐TC superconducting traction transformer. One is a multi‐layer solenoid coil that simulated the primary winding of the transformer. This coil has five layers of a single Bi2Sr2Ca2Cu3Ox (Bi2223) superconducting tape. The other is a close solenoid coil that simulated the secondary winding of the transformer. This coil has one layer of eight parallel Bi2223 superconducting tapes. In this study, we measured the voltage‐current, AC loss, current sharing and over current characteristics of these coils cooled by satur...