Analysis and design consideration of a unity power factor quasi-resonant rectifier

Existing ac-dc low harmonic rectifiers are costly and require complex control schemes to minimize input current distortion. Introduced here is a new class of low cost ac-dc high power factor/low harmonic rectifiers. With active zero current resonant switch (Z.C.S) added to the diode bridge rectifier, the converter is capable of drawing a high quality input current waveform naturally at nearly unity power factor, without switching losses and current line transducers. Thus, a simple single phase or 3 phases ac-dc high power factor rectifier is obtained. Full theoretical analysis is done. Simulation and experimental results are given to demonstrate the validity of the concept.