A Boost-Full-Bridge-Type Single-Active-Bridge Isolated AC-DC Converter

A boost-full-bridge (BFB) concept is proposed in this paper. It improves the control dynamics of boost-half-bridge (BHB) converters, and makes the converters feasible for dc-dc applications as well as ac-dc. A BFB-type single-active-bridge (SAB) ac-dc converter is proposed and investigated in this paper, as an example case from the BFB family of topologies for the validation of the BFB concept. The proposed converter topology has high power density and galvanic isolation, thanks to its high-frequency (HF) transformer link. It also features dc-side short-circuit fault-blocking capability. This paper analyzes the operation principles of the converter and presents suitable modulation and controller schemes. Experiment results are also provided to demonstrate the start-up dynamics, steady-state waveforms, and the dc-fault-blocking capability of the converter.