Design and Test of High-$T_C$Superconducting Coils for a Three-Phase 10.5 kV/1.5 kA Fault Current Limiter

The design and test of High Temperature Superconducting (HTS) coils for a three-phase 10.5 kV/1.5 kA HTS fault current limiter (FCL) are described. It is well known that the critical current (I
_c
) of HTS materials is very sensitive to the orientation of fields. In the design of HTS coils, the value of the perpendicular component of magnetic field (B
_perp
) should be reduced, and the coils should be wound and jointed easily. In order to enlarge the current carrying capacity of the coil, the double pancakes in the coils were connected in parallel. Based on the field distribution in the coil and the current distribution in each double pancake, the design of the coil was optimized. Three coils wound with Bi-2223/Ag tape have been developed and tested in liquid nitrogen