DQ-Frame Zero-Crossing Effect Modeling and Current Distortion Compensation Method for Vienna Rectifier

Vienna rectifiers are widely used as front-end rectifiers in many applications because of their high efficiency and high power density. However, this topology has a problem that its current is always distorted near zero-crossing points, especially when the converter-side current ripples are large. This article reveals and models the zero-crossing current distortion phenomenon, which is caused by nonshared vectors of adjacent sectors when the sector detection error occurs. Near the zero-crossing points, the inevitably sector detection errors will occur due to the presence of the switching current ripples and other factors such as the control delay. The errors can be divided into two types, namely, the lag error, and the lead error. The effects of the two types of errors are equivalently modeled in the dq frame in this article. When the detection error occurs, it is equivalent to applying additional interference terms to the control output. Based on the equivalent error model, this article proposes two compensation methods to eliminate the zero-crossing effect caused by the sector error. The proposed methods are effective and easy-to-implement. Finally, simulation and experimental results validate the theoretical analysis.

I. Introduction

The Vienna rectifier is one of the most popular topologies in telecommunication power systems, wind turbine systems and power factor correction systems because of its good performance [1]–[5]. The carried-based pulsewidth modulation (CBPWM) and the space vector pulsewidth modulation (SVPWM) are two basic modulation methods for the Vienna rectifier. Nevertheless, the two kinds of methods can be proved equivalent in essential [6], [7].