Robust, harmonic-injection system for single-switch, three-phase, discontinuous-conduction-mode boost rectifiers

A single-switch, three-phase, discontinuous conduction mode, boost rectifier, comprising in combination:

• a three-phase, ac source comprised of phase a, phase b, and phase c, generating three-phase, line-to-line ac voltages V.sub.ab, V.sub.bc, and V.sub.ca, and line-to-neutral voltages V.sub.an, V.sub.bn, and V.sub.cn ;
• boost inductor means coupled to said line-to neutral voltages V.sub.an, V.sub.bn, and V.sub.cn ;
• a three-phase rectifier having an ac input connected to said boost inductor means and a dc output;
• a switch connected across said dc output;
• a load and a filter capacitor connected across said dc output and a rectifier connected in series between said switch and said load;
• a pulse-width-modulating controller having a control input connected to a modulating signal and an output connected to said switch to control an open-close duty cycle of said switch in accordance with said modulating signal;
• means for generating a signal proportional to an inverted, rectified, ac component of said three-phase, line-to-line voltages V.sub.ab, V.sub.bc, and V.sub.ca ;
• and
• means to couple said signal proportional to the inverted, rectified, ac component of the three-phase, line-to-line voltages V.sub.ab, V.sub.bc, and V.sub.ca to said control input to further modulate the open-close duty cycle of said switch.