The State Space Average Model of Buck-Boost Switching Regulator Including all of The System Uncertainties

In this paper a complete state-space average model for the buck-boost switching regulators is presented. The presented model includes the most of the regulator’s parameters and uncertainties. In modeling, the load current is assumed to be unknown, and it is assumed that the inductor, capacitor, diode and regulator active switch are non ideal and they have a resistance in conduction condition. Some other non ideal effects look like voltage drop of conduction mode of the diode and active switch are also considered. This model can be used to design a precise and robust controller that can satisfy stability and performance conditions of the buck-boost regulator. Also the effects of the boost parameters on the performance of the regulator can be shown easily with this model. After presenting the complete model, the buck-boost converter Benchmark circuit is simulated in PSpice and its results are compared with our model simulation results in MATLAB. The results show the merit of our model. KeywordsBuck-boost regulator; average model; SMPS; MATLAB; PSpice