ZVS operation of DAB converter based on triple-phase-shift modulation scheme with optimized inductor current

The dual active bridge (DAB) topology has been widely used in the industrial field, especially when bidirectional power transfer is required. However, the efficiency improvement of DAB converters is facing challenges and it is worthwhile devoting much effort to it. This paper presents a novel model based on the triple phase shift (TPS) modulation scheme to improve the efficiency of the dual active bridge (DAB) converter. According to the documentary proposed analytic expressions of six different modes of DAB converters, the constraints of zero voltage switching (ZVS) is achieved to further improve the efficiency of DAB converters. It is theoretically verified that almost full ZVS operation range for all the switching devices and quasi-minimum RMS value of the inductor current can be achieved for two operating modes. Finally, the simulating results from MATLAB/Simulink and the experimental results based on a hardware prototype were presented. By comparing the efficiency of the proposed all-ZVS operation and SPS operation, it can be concluded that the experimental results confirm that the novel proposed all-ZVS strategy can decrease the switching loss and increase the efficiency of the DAB converter simultaneously, which verifies the theoretic analysis.