Analysis on Three-Phase Ground Fault Current Limiting Operations of Three-Phase Transformer Type SFCL Using Two Superconducting Modules

Three-phase transformer type superconducting fault current limiter (SFCL) using two superconducting modules (SCMs) between secondary windings, which consisted of three-phase transformer windings wound on three legs of E-I iron core, one SCM with insulated connection with one secondary winding and another SCM with non-insulated connection between other two secondary windings, were suggested. For the suggested three-phase SFCL using two SCMs, its three-phase ground fault current limiting operations were analyzed through phasor diagram from electrical equivalent circuit. To verify three-phase ground fault current limiting operation of three-phase transformer type SFCL using two SCMs between secondary windings, three-phase ground faults were applied into three-phase power simulated system with the suggested SFCL. Through analysis on the test results, three-phase transformer type SFCL using two SCMs between secondary windings was confirmed to have effective three-phase ground fault current limiting operations through quenches of two SCMs.