A Hybrid-bridge-based Dual Active Bridge Converter with Reduced Device Count

In this paper, a hybrid-bridge-based dual-active-bridge (DAB) converter with a three-level (TL) half-bridge and a two-level full-bridge is proposed, which can be utilized to interface the medium voltage and low voltage DC. In the proposed converter, there are only eight power switches in total. Compared with the traditional hybrid-bridge-based DAB converter with a neutral-point-clamped (NPC) type TL half-bridge, a fewer power device count and higher efficiency can be realized in the proposed converter due to removing clamping diodes. Thus, a more compact circuit structure and a lower cost can be obtained. Moreover, zero-voltage-switching (ZVS) of all switches in primary-side and secondary-side can be achieved in the proposed converter. The operating principle, performances, and characteristics of the proposed converter are analyzed in detail. Also, a specification design case with a detailed key parameter design is given. Finally, a 1-kW experimental prototype is established to validate the proposed converter, and obtained experimental results are highly consistent with the theoretical analysis.