Hybrid superconducting AC fault current limiter principle and previous studies

It is pointed out that one of the most promising uses of the low AC loss ultrafine wires in electrical devices is the fault AC current limiter. The superconducting AC current limiters may be separated into two kinds: resistive and inductive ones. For the resistive limiter, the superconducting winding triggers and assumes the limitation. For the inductive one, the superconducting winding plays only the role of trigger while the fault current is limited by another winding, superconducting or normal. In this case, a limited heating of the superconducting coil and then a very short recovery time may be anticipated. It will enable one to quickly restore the service. On the other hand, the current in the trigger coil may be chosen lower than the rated current so that the choice of the superconducting wire may be easier. The use of a judicious magnetic circuit improves the performance of the inductive current limiter as it decreases the voltage drop in rated operation and the heating of the superconducting coil during fault