A discrete current control for PWM rectifier

Applications of PWM rectifiers are very promising, since they are able to supply DC power while keeping a sinusoidal current with unity in the fundamental power factor simultaneously. Another important application for PWM rectifiers is as static VAR compensators, where they supply reactive power to compensate inductive loads connected on grid. In this paper, a microprocessor-based regulator is proposed for voltage-fed PWM rectifiers with sinusoidal input current to control both the fundamental power factor and direct voltage. The grid current is controlled through a discrete-time feed-forward regulator and a state feedback control, which provide a fast response without steady-state errors. A outer DC voltage loop is composed by a PI regulator. Simulation results are presented for load variations and reactive power control.