Stability analysis of a power system with superconducting fault current limiter installed

As a process of developing high temperature superconducting fault current limiter (SFCL), the stability of a power system in which SFCLs were installed was analyzed. For the investigation into the effect of SFCLs to a power system, we have proposed a simple model power system that had SFCL circuits. The modeling parameters of SFCL are obtained by experiment of a prototype SFCL, which is 440 V class and a shielding type model. This electric circuit was solved for transient performance by numerical methods. In case the SFCLs are installed in a power system, it can effectively protect synchronization both in a symmetrical three-phase fault and a single-phase line to ground fault by maintaining synchronism of the synchronous machines for a long time. By this analysis, we found a quantitative effect of SFCLs to a power system. Limiting fault currents means not only an improvement of circuit breaker abilities but also a protection of synchronism. So its synchronism protection property must be considered for a design of superconducting fault current limiters.