Reliable 3-phase PWM boost rectifiers employing a stacked dual boost converter subtopology

Abstract

This paper describes circuit topologies for three-phase pulse-width modulation (PWM) boost rectifiers that operate with a unity fundamental power factor and a low-distortion AC line current. Overlap delays between the switching of the upper and lower devices in a PWM rectifier leg are not critical and diodes eliminate the possibility of the DC-link capacitor discharging into short circuits and shoot-through fault conditions. The rectifiers are controlled using a "stacked dual boost converter cell" subtopology model that can be used in two current control modes. The dual current-control mode shapes two line currents and can achieve current distortion levels below 5%. The single current control mode shapes one line current and can achieve current distortion levels close to 5% with the rectifier output DC voltage at the standard level associated with a rectified mains voltage. The per-unit current ratings for the switches in the three-phase PWM switch networks are around 15-20% of the input RMS line current as compared to 71% for a standard three-phase PWM rectifiers. Circuit simulations and experimental results are used to demonstrate the performance and feasibility of the rectifiers described.