Research on Soft Switching of Four-Switch Buck-Boost Converter

How to control the Four Switch Buck-Boost (FSBB) converter with high efficiency over the entire input voltage range is one of the hot topics of research. Four-switch buck-boost converters use an inductive current quadrilateral soft-switching control strategy to reduce switch losses has been reported in high-voltage and low-current applications. However, in the application of low voltage and high current, it is unclear whether the switching loss is still low with the inductor current quadrilateral soft switching control strategy or the three-mode hard switching control strategy makes the loss of the switch small. In this article, the losses of the switch in a four-switch buck-boost converter under the inductor current quadrilateral soft switching control strategy and the three-mode hard switching control strategy respectively.