Three-level converters with the input and output sharing the ground

The six nonisolated three-level (TL) converters proposed in (Xinbo Ruan et al., 2002) have two advantages: 1) the voltage stress of the switches is the half of that of their original converters; and 2) the energy-storage components such as inductances and capacitors can be reduced significantly. However, the applications are limited because the input and output do not share the ground. In this paper, these TL converters are modified so that the input shares the ground with the output, and in the meanwhile, all the advantages are remained. Buck TL converter is taken as the example to be verified by the experimental results.