A family of three-level DC-DC converters

This paper presents the study of a non isolated family of dc-dc three-level converters generated from a commutation cell with two diodes, two active power switches and one inductor. With the proposed commutation cell, the basic dc-dc converter topologies, namely, Buck, Boost and Buck-Boost are obtained. Principle of operation, mathematical analysis, and design example are included in the paper, along with experimental results taken from a laboratory prototype rated in 500 W and 50 kHz. It is demonstrated that the proposed converter family subjects the active power switches to lower voltage, in comparison with the conventional dc-dc non isolated converters, as predicted by analysis.