A High Power Factor Three-Phase Three-Level Rectifier

Multilevel power converters have received much attention in recent years due to their high power and high voltage capability. However, a drawback of that structure is its large number of power devices and complexity of the control circuit. This paper proposes an inexpensive three-level three-phase rectifier, which improves the mains power factor and is free from inrush current; and from diode reverse recuperation and turn-on losses as well. The proposed rectifier employs only one three-level leg that operates at both constant switching frequency and constant duty cycle. Also, the proposed rectifier allows sharing the three-level leg, which makes it suitable for topology integration. The performance of the proposed rectifier is verified by theoretical analysis, and simulation and experimental results.