Research On Asymmetrical Half-Bridge In Single-Stage Isolated PFC Converter

Along with the development of the power electronic technology, in small and medium-sized power converters, single stage than power factor correction technology two levels of power factor correction technology, higher ratio of power electronic fields become research hotspot. Meanwhile soft switch technology enables switch loss decreases, and improve the efficiency of the converter transformer and inductor. This paper studies the key is asymmetric half bridge converter achieve single level of power factor correction and realize the two switch soft switch, this paper mainly do the following:Firstly, the single level power factor correction technology introduced the development situation, through a lot of documents and material, analyzes all kinds of soft switch in single stage application of IC simplifies PFC circuit.Secondly, the asymmetric half bridge circuit topology, structure with single level preamp PFC function asymmetric half bridge converter, gives each work modal of state equation. According to the circuit ZVS conditions, design control circuit. After a detailed understanding and after comparing, chose to meet our requirements of control chip.Thirdly, according to the single grade IC simplifies PFC asymmetric half bridge circuit job characteristic, select the appropriate control circuit, the application of system software emulation Pspice simulation research and the main parameters of the selected.Finally, completed the experimental platform, the system load conditions in different tested and debugged. Test results show that the proposed topology theory analysis is absolutely correct, and achieve the expected effect, reflected the topological structure of superiority.