Modeling and simulation of a digitally controlled active rectifier for power conditioning

The authors describe a single-phase active rectifier that provides an input AC current with unity displacement power factor and 3% total harmonic distortion (THD). The goal is to devise a rectifier to compensate for current harmonics and to improve the power factor of the line current. A closed-loop current control is proposed which will force the AC line current to be nearly sinusoidal and in phase with the input source voltage. Thus average DC output voltage is controlled to the desired value. Two topologies for the rectifier are investigated-a standard boost topology and a modified boost topology with the inductor moved to the AC side of the rectifier. Computer simulations that implement closed-loop control of the models are presented. Simulation programs and results are discussed