Space-vector /spl alpha//spl beta/ modulator and sliding mode control of the three-phase buck type rectifier with freewheeling diode

This paper presents a vector based sliding mode control method for three-phase buck type three-phase rectifiers with freewheeling diode. This fast and robust technique uses sliding mode to generate /spl alpha//spl beta/ space-vector modulation, which forces the input line currents to track a suitable sinusoidal reference. A near unity power factor operation of the rectifier is obtained using a sinusoidal reference in phase with the input source voltages. With this control strategy the input currents are actively shaped, being possible to maintain a near sinusoidal current even with high ripple DC inductor current. A proportional integral (PI) controller can, then, be designed to regulate the rectifier output voltage. The obtained results show the effectiveness of the proposed control method.