Analysis on Fault Current Limiting Operations of Three-Phase Transformer Type SFCL Using Secondary Windings with Non-Isolation

Three-phase transformer type superconducting fault current limiter(SFCL) using secondary windings with non-isolation, which consisted of three-phase transformer windings wound on three legs of E-I iron core and three superconducting modules(SCMs), were suggested and its fault current limiting operations according to ground-fault types were analyzed. To verify the effective operation of three-phase transformer type SFCL using secondary windings with non-isolation, the unsymmetrical ground and the symmetrical ground faults were applied into three-phase power simulated system with the suggested SFCL. From the analysis on the experiment, three-phase transformer type SFCL using secondary windings with non-isolation showed lower power burden of three SCMs compared to the SFCL using secondary winding with isolation, especially in case of an unsymmetrical ground fault occurrence.