Sinusoidal Harmonic Voltage Injection PWM Method for Vienna Rectifier With an LCL Filter

This article proposes a harmonic voltage injection pulsewidth modulation (PWM) method for a Vienna rectifier with an LCL filter. Existing PWM methods for Vienna rectifiers with full power factor can lead to resonance problems. It generates current oscillation at the resonant frequency. It is analyzed that why the resonance problem occurs in Vienna rectifier with the existing PWM methods. To solve these resonance problems, the proposed method injects a sinusoidal harmonic voltage into the sinusoidal reference voltage. The magnitude and phase of the injection voltage are determined by the power factor of the rectifier-side. Compared to other PWM methods, the proposed PWM method eliminates the possibility of resonant problems. Considering the operation characteristics of the proposed PWM method, this article suggests a design process for an LCL filter. The effectiveness and performance of the proposed PWM method and the design process for an LCL filter are verified by simulation and experiment.

I. Introduction

Vienna rectifiers have been used widely in various applications because of their many merits, such as the high reliability, reasonable cost, and small system volume [1]–[4]. Compared with the three-level topology, Vienna rectifiers have several advantages such as same quality of current, use of fewer switch devices, high power density, and low cost. Therefore, these rectifiers are attractive for use as grid-connected pulsewidth modulation (PWM) rectifiers in unidirectional power delivery systems [5], [6].