Isolated bidirectional converter with minimum active switches for high-voltage ratio achievement and micro-grid applications

Abstract

[[abstract]]This study proposes a novel isolated bidirectional DC/DC converter for micro-grid system, which can fulfil battery charging and discharging. Even though the proposed converter only employs four active switches and a coupled inductor, it can achieve high-voltage ratio without excessive duty ratio or high transformer turns ratio. The power stage of the converter is mainly developed by integrating a three-winding coupled inductor, three-switched capacitors, and a flyback-behaviour converter into a novel structure. The energy stored in the leakage inductance can be totally recycled for efficiency improvement. The operation principle, steady-state analysis, and design considerations of the proposed converter are described in detail. Finally, a laboratory prototype is built to validate the converter. The measured results have verified the correctness and the theoretical analysis