SUPERCONDUCTING FAULT CURRENT LIMITER DEVELOPMENT

The authors have developed and tested a 400V - 100A class fault current limiter wound with AC superconducting wire having ultra-fine NbTi filaments. The limiter consists of non-inductively wound superconducting trigger coils and a superconducting limiting coil which acts as a reactor. Excessive fault currents initiate quenching in the trigger coils and these currents, which have flown in trigger coils in non-fault condition, are commutated from the trigger coils to the limiting coil. In the experiment, the authors have succeeded in limiting a fault current level to 120A with the limiter whose terminal voltage at the limiting condition was 420V.