Design of a high temperature superconducting coil for a 8.3 MVA fault current limiter

In this study, a high temperature superconducting (HTS) coil is designed for a single phase 8.3 MVA fault current limiter (FCL) whose ratings are 13.2 kV in voltage and 630 A in current. The coil is wound with the bifilar winding method to limit the fault current only by resistance. The wire used in the HTS coil is YBCO coated conductor (CC) with metal stabilizer such as copper or stainless steel. In order to design the HTS FCL, the thermal and electrical analyses are performed considering the transient thermal conduction and the resistance development according to the temperature. The HTS coil is designed with a temperature limit of 300 K. The stainless steel stabilized wire is desirable than the copper stabilized wire because of the high resistance and the low temperature rise. As the design result, the total length of the wire is calculated as 2.56 km with 25 μm stainless steel stabilizer. The parallel number of wires is 8 and the quench current of the coil is approximately 1200 A at 65 K. The height and the outer diameter of the coil except the terminals and the connection parts are 0.5 m and 0.9 m, respectively. The HTS coil is composed of 7 concentric solenoid coils and each coil has 19 turns of clockwise winding and same turns of counter-clockwise winding for non-inductive property.