Analysis of parallel-serial dual active bridge converter

A parallel-serial dual active bridge (PSDAB) circuit is presented in the paper to improve the efficiency under the circumstances of high-voltage ratio transformation. The proposed PSDAB circuit is constructed by the paralleled low-voltage terminals of the two dual active bridges (DABs) and the serial high-voltage terminals of the DABs. Just like the DAB circuit, the zero voltage switching (ZVS) is easy to be realized only by phase-shifted control. The design method of resonant inductor is discussed and the main parameters are presented in the paper. Additionally, the power loss of this circuit is also analyzed in details. Finally, the simulation and the experimental results verify the design method based on the parallel-serial converter. The proposed circuit can be applied to realize high efficiency and high power density and will be a novel technology for renewable energy and energy saving.