Study of kV Class Current Limiting Unit With YBCO Thin Films

Using a high temperature superconductor, we proposed a model superconducting fault current limiter (SCFCL) with the high-speed commutation switch. The high-speed commutation switch consists of the parallel coil, the electromagnetic repulsion plate and the vacuum interrupter. In this SCFCL, the current in the superconductor is interrupted within 0.5 cycles. By using this equipment, the current flow time in the superconductor can be easily minimized. We studied resistive type SCFCL with the high-speed commutation switch and use YBCO thin film. For applying to high voltage, it is a problem that the superconductors in series connection don´t quench immediately for the Ic variations of the various superconductors. In this paper, we conducted the series connection test using YBCO thin films without a metal layer. The research is aimed at the scalability of small models towards commercial size fault current limiter (FCL).