A Novel Strategy for Current Distortion Suppression Based on Space Vector Modulation for Vienna Rectifiers Under the Wide-Range Unbalanced Grids

Vienna rectifier with high conversion efficiency and no bridge arm short connection is widely used in industrial applications such as wind power and electric vehicle charging systems. With the conventional space vector modulation (SVM), the input current of the Vienna rectifier is distorted near the zero-crossing point caused by the influence of non-ideal vector sequences, and the distortion of input current under the unbalanced grid condition will be more seriously. To solve this problem, based on analyzing the input current zero-crossing distortion mechanism and the vector operation trajectory of Vienna rectifier under the wide-range unbalanced grid, the stationary operation area constraints of Vienna rectifier are derived, and the interval clamped control strategy of SVM based on the negative-sequence current regulation is proposed. The proposed method adjusts the phase characteristics of input current vector and grid voltage vector by introducing the negative-sequence current regulation coefficient, which is calculated by combining the constraints of the stationary operation range to realize the negative-sequence current regulation. Finally, the interval clamp control based on SVM is accomplished to suppress the input current distortion. The effectiveness of the proposed strategy is verified on the Vienna rectifier experimental platform.