Design and manufacture of a superconducting fault current limiter with bypass reactor by employing two different types of HTS wires

A resistive superconducting fault current limiter (SFCL) using Bi2223 wire and YBCO coated conductor has been developed. The SFCL has two coils; one is a bifilarly wound coil wound using coated conductor, and the other is typical inductive coil using Bi2223 wire. The bifilar coil plays the role of switching when a fault occurs, while it has a very small impedance in the normal operation. On the other hand, the inductive coil using Bi2223 wire has a very small resistance but a large inductance. The two coils were connected in parallel. Current flows mainly through the bifilar coil during normal operation. A partial fault current flows through Bi2223 coil because the resistance of the coated conductor bifilar coil rises. Two types of FCL were manufactured and tested; a conventional bifilar one, which has only one coil using a coated conductor, and the proposed one, which has two coils. The proposed one has a faster recovery than the conventional one.