软开关高增益Buck-Boost集成CLLC型直流双向变换器

An Integrated Buck-Boost CLLC Bidirectional DC Converter With High Gain and Soft Switching

研究一种Buck-Boost集成CLLC直流双向变换器,适用于输入输出共地且宽输入电压范围场合应用。直流双向变换器通过Buck-Boost与CLLC电路原边集成、CLLC副边母线电容叠加到原边母线电容上实现高增益。半桥CLLC电路与Buck-Boost电路集成,通过定频PWM同步控制;有助于开关管在较宽输入电压和负载范围实现软开关、高功率密度。该文分析了变换器的拓扑结构及工作模式,理论推导出变压器匝比取n1：n2=1：1即可获得高增益,减小了高频谐振变压器的体积和原边的谐振电流。此外,研究Buck-Boost电感Lb对变换器的软开关特性影响,给出了软开关实现的工作条件。搭建了一台低压侧适用电压2080V、高压侧适用电压100400V,双向功率600W的实验样机,实验结果验证了理论分析的正确性及方案的可行性。

An integrated Buck-Boost CLLC converter used for wide input voltage and in common input-output environment has been researched. Through the integration of Buck-Boost with the primary side of CLLC, high DC gain can be obtained by bus capacitor on the secondary side superimposing on that primary side. The converter is integrated with the half-bridge CLLC via Buck-Boost and synchronously controlled by fixed-frequency PWM strategy, and the,MOSFET can be soft switching in wide input voltage range and load conditions that use for improve power density. This paper introduces the topology of the IBBCLLC and the operation mode, demonstrates that turns ratio of n1：n2= 1 ： 1 can produce high DC gain, the size of the transformer becomes smaller and the current stress of the transformer primary side reduces. In addition, this paper provides the soft switching conditions by analyzing the effect on the soft switching performance from Buck-Boost inductor. In conclusion, a prototype with 20-80V low voltage side, 100-400V high voltage side and 600W output power is established, which proves the theoretical analysis is correct.