Single-stage three-phase AC to DC conversion with isolation and Bi-directional power flow

An approach for three-phase AC to DC conversion is proposed, which consists of a single-stage while offering galvanic isolation, soft-switching, bi-directional power flow and a significant reduction of inductive and capacitive energy storage. Two elements enable this approach, namely a neutral voltage-lift capacitor and a Quad Active Bridge (QAB) converter. Moreover, a control strategy is described and a detailed converter analysis is given.