A new three-phase single-switch rectifier with stepped down output voltage near unity power factor and extended operating range

A new three-phase, single-switch buck converter that can perform input power factor correction over a wider input voltage range than the conventional buck converter is proposed in this paper. In the paper, the operation of the conventional buck converter is first reviewed and the reason for the restriction in input voltage range is identified. A mechanism that can be used to overcome this restriction is then introduced and discussed in detail. The implementation of this mechanism in a three-phase, single-switch buck converter is explained and general design guidelines are given. Finally, the feasibility of the new converter is confirmed with results obtained from computer simulation and from an experimental prototype.