Study on three-phase superconducting fault current limiter

Superconducting Fault Current Limiters (SCFCLs) have been intensively developed around the world these years, and the commercial SCFCL is expected to be available in near future. The main target of SCFCL include not only negligible small impedance under normal operation, but also fast and effective suppression of large fault current within the first current rise, and moreover repetitive operation with fast and automatic recovery. We designed a new type of three-phase SCFCL which is composed of a three-phase winding reactor type FCL and a magnetic shield type superconducting FCL. The proposed SCFCL is effective for symmetrical fault as well as unsymmetrical faults. In order to verify functions of the proposed SCFCL, we fabricate a small device and carry out the experiments. It is found from the test results that the proposed new type of three-phase SCFCL works to restrict the fault currents in all kinds of fault conditions. Moreover, the simulation results of EMTP have good agreements with the test results.