Research on Optimization Method of Soft-Switching Range of DAB Converter Based on Saturable Inductor

Being difficult to achieve ZVS operation at light load is the inherent disadvantage of DAB converters, which also limits the promotion and application of the converter. In this paper, an optimized method of extending ZVS operation range is proposed to improve the efficiency at light load. To obtain the proposed method, the principle of DAB converter is studied, and its output power expression under the conventional phase-shift control is deduced, and the ZVS range of the DAB converter is presented and the influence of dead time and inductance parameters on the ZVS range is discussed in detail. The proposed method aims to change inductance value at different load, and the saturable inductor is applied into the circuit by analyzing its characteristics and effects. The experimental platform are used to study the proposed method. The results of experiment are in agreement with the theory, which verify the validity and correctness of the proposed method.