A Buck-Boost Common-Ground Bipolar Rectifier With Controllable Short-Circuit Current

The AC–DC microgrid interface circuit faces key challenges in performance enhancement: Maintaining high efficiency across a wide input/output voltage range, suppressing common-mode leakage current, and controllable short-circuit fault current. To address these issues, this article proposes an interleaved buck-boost common-ground rectifier scheme with controllable short-circuit current capability. The proposed scheme reshapes the time-current curve (TCC) of the fault current by regulating the capacitor energy release rate, while suppressing common-mode leakage current through an AC–DC common-ground structure. The converter employs a dual-mode time-sharing operation to achieve high efficiency and a wide output voltage range, and it realizes bipolar voltage output by directly connecting the midpoint of the output capacitors to the AC ground. Experimental results from a 5-kW prototype show that the rectifier delivers excellent overall performance while maintaining a peak efficiency of 97.19%. This provides an effective interface solution for building high-performance DC power distribution systems.