A Novel Buck-Boost Converter with Two Independently Controlled Switches

The paper proposes a new buck-boost converter with two independently controlled active switches that can work as a boost or as a buck converter depending on the input-output conditions, while it still operates at moderate duty cycles. Compared to the traditional buck-boost topology, the proposed converter exhibits a second order LC filter at the output. Moreover, using the integrated magnetic concept developed by professor Cuk, the two inductors of the converter can be coupled thus resulting a nearly dc output inductor current that implies low filtering requirements. A DC analysis is performed in order to obtain the static characteristics of the converter. Design equations are provided and the converter is simulated in order to prove the feasibility of the proposed buck-boost topology. Finally the experimental results confirmed the theoretical considerations and the simulations.