A Three-Phase Single-Switch Fly-Back Power Factor Correction Circuit With Lossless Snubber

AC/DC converter is the most widely used converter in the power system. But the traditional AC/DC converter's power factor is low and its current harmonic is large, that may be harmful to the converter itself and the surroundings. So improving the traditional AC/DC converter, increasing the power factor and eliminating the current harmonic are very important to us.The adoption of strict international standards, such as IEEE Std. 519 and the European Norm IEC 1000-3-2, and regulations concerning harmonic pollution has made the reduction of the harmonics contents of the AC lines power supplies necessary. For the medium and minimum switching power supplies, which are widely used in power system, the best way is using power factor correction (PFC) in the converters. It can eliminate the source of harmonic. At present, the single-phase PFC is already developed, but the three-phase PFC is still in the stage of library works.The technique of three-phase power factor correction in switch mode power supplies is still not mature and currently, most of the schemes are based on the combination of three single-phase power factor correction circuits with complex topology and control strategies resulting in high cost and low popularization.We surveyed the high power factor AC/DC converter around the world and propose a novel three-phase high power factor AC/DC converter based on the fly-back converter. The most important advantage of the converter is realizing the three-phase AC/DC conversion and simple control scheme using duty ratio control and...