Operation of Superconducting Fault Current Limiter Using Vacuum Interrupter Driven by Electromagnetic Repulsion Force for Commutating Switch

Using conventional high temperature superconducting wire, 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 of it. In parallel of these, a conventional reactor coil is connected. 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.