1.南通理工学院 电气与能源工程学院;2.江苏海洋大学 电子工程学院 江苏 连云港
1.School of Energy and Power Engineering,Nantong Institute of Technology;2.School of Electronic Engineering,Jiangsu Ocean University
Project supported by the financial support of National Natural Science Foundation of China (51707078); Science and Technology Foundation of Nantong Institute of Technology (ZX202110)
Two-switch Buck-Boost converter has been widely used in step-down voltage applications; however, its hard switching has a bad effect on the efficiency under existing control or modulate methods. In order to obtain soft switching and simplify the control circuit, a three-switch interleaved Buck-Boost converter is proposed in this paper. The presented converter is derived from a two-switch Buck-Boost converter and a co-directional coupling inductor at boost side. Firstly, coupling process is analyzed under a large coupling coefficient. Then, the converter operating principle is given in detail, and it is concluded that the expended duty cycle and soft switching at boost side power switches can be achieved under DCM of two self-inductance currents. Thus, a very simple control circuit based a single dual-PWM chip maybe accepted, which does not include a synchronous circuit and a current-sharing circuit. Finally, the simulation and experimental results are given to verify the analysis results.