Proposed Design for a Tunable Inductive Shield-Type SFCL

Superconducting fault current limiters (SFCLs) offer a good solution for the increased level of short circuits in power systems. Inductive shield-type SFCLs are one of the most promising categories of the SFCLs. A design has been proposed for a tunable fault current limiter, which has the capability to vary the level of current limitation via varying some control parameters. This increases the utilization flexibility of the SFCL and may result in economic gains. Regarding the ever-growing short-circuit level in the power systems that may demand upgrade or replacement of protection devices, if SFCLs are installed with the proposed structure, several current limitation levels may be available and selected due to the short-circuit level of the system and the nominal rating of different power system devices. The proposed design is verified calculating theoretically the through current of the SFCL and studying the impact of different control parameters on it. Furthermore, a prototype SFCL has been fabricated and has shown the desirable tunable current limitation characteristics.