Soft-switching analysis of a boost-integrated bidirectional dc/dc converter

The conventional dual active bridge (DAB) dc/dc converter can be appropriate for the systems with bidirectional power flow, but its output and input currents are discontinuous. Therefore, a boost-integrated soft-switching converter in which the output and input currents are continuous was proposed in this paper. The proposed converter has the advantages of symmetrical structure, galvanic isolation and simple control strategy, and it is suitable for the applications with low current ripple requirement. This paper analyzed the operation principle and zero-voltage-switching (ZVS) condition of the converter in detail. Specially, the ZVS condition was deduced on the basis of particular calculation and analysis of the resonant process that occurs at the moment of switching, which is in consideration of the junction capacitors of switches. Finally, a 1kW prototype converter was built to verify the theoretical analysis.