基于四开关Buck-Boost的三模式平滑切换控制策略的

四开关Buck-Boost电路因其独特的优势适合应用在宽电压输入的场合。本文在传统的三模式切换控制策略中加以改进，提出一种带输入电压前馈的改进三模式切换控制策略，并推导了在各个模式下的前馈函数，使其可以在输入电压变化时能很好的稳定输出。通过检测输入电压自动判断使用不同的前馈回路。传统控制方法在Buck模式和Boost模式切换至Buck-Boost模式时，输出电压在切换点处会跳变，通过合理设置Buck模式和Boost模式的参考电压，使系统在模式切换时消除切换点处的电压跳变。在Matlab/Simlink中搭建仿真模型，验证改进型三模式平滑切换控制策略的可行性。

Research on three-mode smooth switching control strategy based on Four Switch Buck-Boost

The Four Switch Buck-Boost circuit is suitable for wide voltage input applications due to its unique advantages.In this paper, the traditional three-mode switching control strategy is improved, and an improved three-mode switching control strategy with input voltage feedforward is proposed.The use of different feedforward loops is automatically determined by detecting the input voltage.In the traditional control method, when the Buck mode and Boost mode switch to Buck-Boost mode, the output voltage will jump at the switching point. By properly setting the reference voltage of Buck mode and Boost mode, the system can eliminate the voltage jump at the switching point.The simulation model was built in Matlab/Simlink to verify the feasibility of the improved three-mode smooth switching control strategy.