Fast-Recovery Superconducting Fault Current Limiter Based on a Novel Skeleton Topology for Future Cryo-Electric Aircraft: Reclosing and Repetitive Fault Cases

Recovery characteristic of superconducting fault current limiters (SFCLs) is a critical factor during their design process. After a low impedance fault, an SFCL cannot return to the superconducting state abruptly, due to the large heat generation during fault and the resultant high temperature above critical temperature T_c. Fast recovery of the SFCL will ensure fast reclosing and continuation of power supply in the power distribution network of an e-aircraft. In this work, a skeleton-based design of the helical bifilar SFCL was proposed to achieve fast recovery. The new structure ensures a larger cooling surface area between the high-temperature superconducting (HTS) tape and the coolant, thus enhancing recovery performance and reducing the recovery time of the SFCL. Multiple fault current limitation characterization profiles, including limited current, voltage drop across the SFCL, and resistance and temperature of the SFCL, were analyzed and compared with those of the classic helical bifilar SFCL. Studies were conducted on different initial operating temperatures, different HTS tape length usages, and different reclosing time ranges. The results show that the recovery time has been shortened from 2.2 to 0.49 s by the proposed new SFCL, as compared to the classic helical bifilar SFCL. This skeleton-based fast-recovery SFCL provides new ideas for fault management in future cryo-electric aircraft.