Sinusoidal internal model based control of a three-phase voltage source rectifier with buck-boost operation

A rectifier system having a DC voltage step-up and step-down characteristic is treated. The system consists of a PWM voltage source rectifier and a DC-to-DC buck converter connected in cascade. Theoretically, the system can produce a DC output voltage ranging from zero volts to infinity and a sinusoidal AC input current, and the displacement power factor can be kept at unity. The system can perform bidirectional power flow. Control strategy based on a sinusoidal internal model is proposed. Two PS regulators and two PI regulators for each control object is used. Experimental results confirm the validity of the proposed control system.