Generic Model of Three-Phase (RE)BCO Resistive Superconducting Fault Current Limiters for Transient Analysis of Power Systems

This paper presents the modeling and implementation of a generic three-phase resistive superconducting fault current limiter (r-ScFCL) for transient analysis of ac power systems. The r-ScFCL consists of series-connected noninductive coils made of insulated commercially available (RE)BCO tapes operated in a liquid nitrogen bath, in parallel with a resistive shunt at room temperature. The model allows the prediction of the thermal and electrical behaviors of the device prior to, during, and after a fault. It was used to evaluate the impact of a three-phase r-ScFCL on the transient stability of a synchronous generator supplying an infinite bus through a step-up transformer and a transmission line. More specifically, the impact of the r-ScFCL design on fault current magnitude, device voltage, temperature, and recovery time was studied. For the chosen case study, the r-ScFCL did increase the stability of the power system. It was also found that parameters such as the length of the superconducting tapes, the number of tapes in parallel, and the shunt resistance can balance or unbalance the response of the r-ScFCL over the three phases during a fault.