A comparative study of three-level DC-DC converters

The main focus of this paper is a comparative study of several three-level isolated dc-dc converters. The main feature of three-level converters is that the voltage stress across their switches is half the DC bus voltage so that they can have fewer switching losses than comparable two level dc-dc converters. In this paper, the efficiency performance of a three-level dc-dc converter is compared to ZVS three-level and ZVZCS three-level dc-dc converters. The basic concepts of each topology are reviewed, and a comparison involving the number of passive elements and active switches used, the stresses of the semiconductors devices, and efficiency measurements based on experimental results is made. Conclusions based on this comparison are presented as well.