High Gain Buck-Boost Converter with Active Coupled Inductor Structure

Abstract

In order to improve the voltage gain of conventional Buck-Boost converter and reduce the voltage stress of switching tube, a high gain buck-Boost converter with active coupling inductor structure was proposed. The converter combines the traditional Buck-Boost converter with the equivalent Buck-Boost converter, adding the switching capacitor mixed group structure to greatly improve the voltage gain of the converter, and introducing the coupling inductor structure to reduce the voltage stress of the switching tube. The different working modes of the converter are analyzed and the expressions of voltage gain and voltage stress of the switching device and the critical working conditions of the excitation inductor are derived. Compared with conventional Buck-Boost converters, the voltage gain of the converter is increased by a factor of (5+D+2n)/D , and the voltage gain can be flexibly adjusted by the turn ratio n. The voltage stress of the switching device is reduced to 1/(5+D+2n) times the output voltage. Finally, the correctness of the theoretical analysis is verified by simulation and experiment.