A Novel Converter Integrating Buck-Boost and DAB Converter for Wide Input Voltage
Changle Xu, Shuang Liu, Xiang Guo, Chun Xiao, Xudong Zou, Lingyun Zhang, Caifeng Liu, Weibin Jiang
Abstract
Dual active bridge (DAB) converters are widely used in new energy electric vehicles. However, the traditional DAB converter has limited soft-switching range and high circulating currents under wide input voltage especially when both-side voltages are mismatched. As a result, large power loss and low efficiency are undesirably obtained. In this paper, a novel converter integrated Buck-Boost and DAB (IBBDAB) converter is proposed for superior performances under wide input voltage. The IBBDAB converter combines the advantages of the Four-Switch Buck-Boost (FSBB) converter and the DAB converter. Besides, partial switches of the two converters are shared to reduce conduction loss and the number of switches. Moreover, an improved modulation strategy based on dual-edge PWM and single-phase-shift (DE-PWM- SPS) is applied to the IBBDAB converter. Combined with the modulation strategy, zero voltage switching (ZVS) can be easily achieved for all switches of DAB converter. Simulation results are finally presented to verify the performances of the proposed converter.