Operation of superconducting fault current limiter using vacuum interrupter driven by electromagnetic repulsion force for commutating switch

Abstract

SUMMARYUsing conventional high-temperature superconducting wire, a model superconducting fault current limiter (SFCL) is made and tested. Solenoid coil using Bi2223 silver sheath wire is so made that inductance is as small as possible and a vacuum interrupter is connected in series to it. A conventional reactor coil is connected in parallel. When the fault current flows in this equipment, superconducting wire is quenched and current is transferred into the parallel coil because of voltage drop of superconducting wire. This large current in parallel coil actuates magnetic repulsion mechanism of vacuum interrupter. Due to opening of vacuum interrupter, the current in superconducting wire is broken. By using this equipment, current flow time in superconducting wire can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of parallel coil.

Breakdown of YBCO thin films during current limiting and methods of improving current limiting performance

“…Previous investigations employed an electromagnetic repulsion switch using a Bi2223 silver sheath wire and bulk YBCO. Since the Bi2223 silver sheath wire and bulk YBCO have low resistance, a long length is necessary in order to obtain the specified resistance [8]. In order to reduce the size of the superconductor parts and to reduce the cost of SFCLs, a superconductor with high resistance after quench must be used.…”