Analysis on Operational Characteristics of Double Quench Flux Lock Type Superconducting Fault Current Limiter

The superconducting fault current limiter (SFCL) which has many advantages is being chosen as an attractive method for limiting fault current. To upgrade the performance of the SFCL, various configurations are reported. Among them, the double-quench type SFCL has been studied in order to reduce the power burden of the high-temperature superconducting (HTSC) elements. The double-quench type SFCL which consists of the two HTSC elements and the normal resistance is a method to improve the performance of the HTSC elements. The design of the normal resistance in the double-quench type SFCL for the control of distributed fault currents on both HTSC elements to reduce the power burden is very important. However, the double-quench type SFCL is difficult to change the specification of the component depending on changing the power system. To improve the disadvantage on the double-quench type SFCL, this paper proposed the double-quench-flux-lock type SFCL which combine the double-quench type SFCL and the flux-lock type SFCL. The conventional flux-lock type SFCL which consists of an iron core, two coils, and the HTSC element could control the operation current and the impedance of the SFCL depending on the turn ratio between two coils. The operational characteristics of the flux-lock type SFCL could flexibly respond to changes in the power system. The double-quench-flux-lock type SFCL proposed in this paper was verified through PSCAD/EMTDC.