A Novel Bipolar Rectifier with Output Short-Circuit Current Limitation for Microgrids

In microgrids, DC-side short circuits can produce high fault currents that threaten converter safety. Conventional converters often struggle to limit these currents effectively. This paper presents a bipolar single-phase AC/DC converter designed for microgrids, featuring inherent output short-circuit current limiting. To reduce fault current, a small DC bus capacitance is used, which poses challenges in suppressing voltage ripple. To address this, a ripple suppression control strategy is proposed, leveraging the converter's operating modes to maintain stable output under small capacitance conditions. The proposed solution improves system protection and enhances overall reliability.