A Magnetically Integrated Adaptive Fault Current Limiter for Low-Voltage DC Distribution Systems

Low-voltage direct current (LVDC) distribution system facilitates the efficient integration of renewable energy sources (RESs) and various DC loads. However, it is susceptible to DC faults due to the mismatch between the VSC blocking time and the tripping time of DC circuit breakers (DCCBs). To this end, this paper proposes the magnetically integrated adaptive fault current limiter (MIAFCL) for LVDC distribution systems, which resolves two major issues in current research: (ⅰ) inadequate adaptability to changing operational conditions, and (ⅱ) incompatibility in space-constrained installation scenarios. First, a novel fault current limiter topology is presented, and the stage-topology adaptive adjustment mechanism is developed to make it exhibit low intervention under normal conditions and effective current limitation during fault events. Subsequently, a high- and low-frequency reactor integration scheme for MIAFCL based on non-orthogonal decoupling method is proposed. This scheme mitigates core saturation, improving current-limiting performance and significantly enhancing component integration. Additionally, a detailed parametric design approach is proposed for the magnetic integration and circuit configuration of the MIAFCL. Finally, the effectiveness and superiority of the proposed method are validated through simulation and experimental verification, as well as comparisons with existing studies.