Comparative Analysis of Isolated Bidirectional Dual-Active-Bridge DC-DC Converter Based on EPS and DPS

The dual active bridge (DAB) DC-DC converter not only results in greater backflow-power, but also produces greater current stress on the switch tube under the control of single-phase-shift. Two kinds of dual-phase-shift control methods are compared in detailed by the transmission power, backflow power and current stress in this paper. Current stress of the DPS was smaller under this strategy compared with the EPS. The strategy can not only make the requirements of switching devices lower, reduce the loss, but also improve the efficiency of converter. The advantages and disadvantages of them under optimal control are analyzed in terms of backflow power and current stress. The power characteristics of different phase-shift control methods are presented by establishing mathematical models. The analysis of the characteristics of the transfer function lay a foundation through the small signal modeling.