Conceptual Design of a Saturated Iron-Core Superconducting Fault Current Limiter for a DC Power System

A superconducting fault current limiter can significantly reduce the stress on the DC circuit breaker in DC power systems due to its inherent physical characteristics that can quickly limit the fault current. This letter presented the conceptual design of a saturated iron-core superconducting fault current limiter (SI-SFCL) for DC power systems. First, the electrical characteristics of the SI-SFCL were investigated. Then, a detailed design process and corresponding configuration of the SI-SFCL for a 15 kV, 3 kA DC power system were presented. A PSCAD/EMTDC simulation model was built to analyze the operating and fault current limiting characteristics of the SI-SFCL. To demonstrate the effectiveness of the conceptual design parameters and configuration, a lab-scale SI-SFCL for a 500 V, 50 A DC power system was designed in detail. The fault current limiting capability of the lab-scale SI-SFCL was confirmed by the 3D finite element method. As a result, the lab-scale SI-SFCL has a high current limiting capability, which can reduce the magnitude of the fault current by up to 75%. This study results will be effectively applied to a large-scale SI-SFCL for HVDC power systems.