Current-Limiting Characteristics of an Improved Flux-Coupling-Type SFCL

To suppress the short-circuit current more flexibly and effectively, this paper proposes an improved flux-coupling-type superconducting fault current limiter (SFCL) with multiple working modes. The proposed SFCL is consisting of a coupling inductance with superconducting and conventional coils, two high-speed switches, a shunt resistance and an additional limiting resistance. By controlling the statuses of the two high-speed switches, the proposed SFCL may show little impedance to not disturb the normal operation of a power system, and it will appear two-level limiting impedances to reduce the fault current into expected amplitudes. A precise simulation model of the proposed SFCL is created in the MATLAB platform, and the current-limiting performances under different working modes are verified. The digital simulation results prove the rapidity and availability of the proposed SFCL.