Operational Characteristics of Flux-Lock Type SFCL With Series Connection of Two Coils

In this paper, we investigated the operational characteristics of the flux-lock type superconducting fault current limiter (SFCL) with series connection of two coils, which was suggested by us previously. This SFCL has the similar fault current limiting characteristics to the flux-lock type SFCL with parallel connection of two coils. The current limiting operation of the SFCL is performed by the generation of the magnetic flux between two coils when a fault happens and the fault current limiting characteristics of the SFCL are dependent on the inductance ratio and the winding direction of two coils. To confirm it, the operational characteristics of this SFCL were analysed based on its electrical equivalent circuit and the fault current limiting characteristics of this SFCL were investigated through the fault current limiting experiments. Through the analysis, it was shown that the limited fault current and the resistance of high-T_C superconducting (HTSC) element could be adjusted by two coils´ inductance ratio and the winding direction of two coils.