Two efficient three-mode control strategies for four-switch buck-boost converters

The bidirectional DC-DC conversion, as an important application scenario, places certain requirements on the topology structure. The four-switch buck-boost (FSBB) converter has received widespread attention due to its simple structure, flexible control and state switchability. However, the traditional control strategy makes it difficult to meet the requirements of high performance, high stability and high security at the same time. Furthermore, the control methods commonly adopted in domestic and international practical applications rely heavily on analogue control, which cannot maintain efficiency over a wide stability range. The use of digital control methods allows for optimized control algorithms, maintaining stable system operation and improving efficiency. Therefore, it is very important to use the digital control method to further improve the smoothness and steady-state efficiency of the system multi-mode switching while maintaining a wide input and output range, based on this, this study proposes two new three-mode control modes: interleaved bias control mode and dual-edge bias control mode.