Analysis of Current Limiting and Recovery Characteristics of Superconducting Fault Current Limiting Transformer (SFCLT) With YBCO Coated Conductors

Superconducting Fault Current Limiting Transformer (SFCLT) is expected to function as superconducting transformer in steady state and superconducting fault current limiter in fault condition. We have designed, fabricated and tested SFCLT with YBCO coated conductors to be operated in liquid nitrogen (LN₂) at 77 K and verified its technological feasibility. In this paper, we developed a simulation model to analyze electrical and thermal behaviors of SFCLT by solving the circuit equation and the heat conduction equation. By the use of this simulation model, we could evaluate the transition of resistance and temperature of the YBCO coated conductors during the fault current limitation as well as after the fault clearance, and verified the recovery criteria of SFCLT.