Improved power quality three phase AC-DC converter

Because of increasing applications of power electronic ac-dc converters, it´s necessary to implement the single stage converter that can reliably perform both buck and boost operations. Traditionally, this can be achieved by double stage conversion (ac/dc-dc/dc) but ultimately leading to less efficiency and complex control. The novel ac-dc impedance-source converter, abbreviated as Z-source rectifier, has high power quality level and can overcome those limitations. This paper describes Z-source rectifier operating principle, its concept and superiorities. Analysis and simulation results show that three-phase Z-source rectifier can both step up and step down voltage. Least output dc voltage ripple and high power factor at input ac mains are other advantages of this converter.