Voltage-Fed Dual Active Bridge Bidirectional DC/DC Converter With an Immittance Network

A new voltage-fed isolated bidirectional dc/dc converter (BDC) based on immittance network (IMN) is proposed. The operations of the BDC are analyzed in the buck mode and the boost mode, respectively. Compared to the conventional dual active bridges (DAB) BDC, the proposed converter can obtain unity power factor at both ac terminals of the high voltage side (HVS) bridge and the low voltage side (LVS) bridge. The unity power factor working is resulted from the characteristic of the IMN and it is helpful to improve the converter's efficiency. The quantitative relationship of the proposed converter is deduced. The optimal design guidance of transformer and IMN is presented. The analysis is verified by the experimental results from a 500 W prototype.