The large-signal SFG model of DC-DC buck-boost converters

This paper introduced the switching flow-graph (SFG) modeling technique for DC-DC switching converters. Based on the concept of virtual switching functions, the large-signal SFG models of DC-DC switching converters can be developed easily without complex mathematics. In this study, the large-signal SFG model of a basic buck-boost converter was implemented to explain the modeling procedure. By establishing the large-signal SFG model in MATLAB/SIMULINK, the circuit's dynamic behavior can be easily observed. In comparison with the experimental results and PSPICE simulation results, it demonstrates the SFG model can reveal some characteristics of buck-boost converters.