Redundant fault-tolerant Buck-Boost converter

The invention discloses a redundant fault-tolerant Buck-Boost converter, and relates to the technical field of power electronics. The invention provides an improved Buck-Boost converter based on a traditional TSBB circuit. According to the invention, the improved Buck-Boost converter is mainly improved and designed by changing an original topological circuit structure and adding an additional power switch tube, the improved topological circuit has an additional function of fault tolerance, the fault tolerance function of two original switch tubes of the topology can be realized by using one additional power switch tube, and the improved topological circuit can also work in any one of the Buck working mode, the Boost working mode and the Buck-Boost working mode; compared with a traditionalTSBB, the topology of the invention has a fault tolerance function, and fault tolerance can be carried out on any switching tube of the topology only through one additional power switching tube; and the two switch tubes are g