M. Baumann, J.W. Kolar:
"Analysis of the Effects of Non-Idealities of Power Components and Mains Voltage Unbalance on the Operating Behavior of a Three-Phase/Switch Buck-Type Unity Power Factor PWM Rectifier";
Talk: 33rd IEEE Power Electronics Specialists Conference, Cairns, Australia; 06-23-2002 - 06-27-2002; in: "Conference Proceedings", vol.4 (2002), ISBN: 0-7803-7262-x; 1607 - 1612.

According to the experimental analysis of a 5kW wide input voltage range three-phase three-switch buck-derived unity power factor PWM rectifier, the ideally constant DC output current does show a low-frequency distortion for open-loop control operation which is translated into low-frequency harmonics of the mains current. This distortion cannot be eliminated completely by closed-loop control since the controller bandwidth has to be limited for stability reasons and/or in order to avoid an excitation of the LC input filter. In this paper the parasitic effects being responsible for the low-frequency distortions of DC output voltage and/or current are analyzed analytically and quantified for different operating conditions. Furthermore, the minimization of the influence of the parasitic effects by proper pre-control is discussed. All theoretical considerations are confirmed by digital simulations.