Analysis of Four-Switch Non-Isolated Non-Inverting Buck-Boost Converter Considering Non-Idealities

Non-inverting buck-boost converters are widely used in applications requiring voltage regulation with a constant output polarity. These include fuel cell systems, battery-powered devices, telecommunication equipment, and electric vehicle charging infrastructure. This paper presents a detailed analysis of a four-switch, non-isolated, non-inverting buck-boost converter, focusing on the impact of non-idealities such as switch resistances. The study derives expressions for voltage gain and inductor current ripple under different operating modes-buck, boost, and buck-boost-considering the influence of parasitic elements. The control of the converter is achieved through independent modulation of the switching duty cycles, enabling flexible operation across a wide voltage range. The proposed theory is verified in simulation using the MATLAB-Simulink platform.