A Novel Suppression Method for Input Current Zero-Crossing Distortion of the Vienna Rectifier Based on Negative-Sequence Current Regulation Under the Unbalanced Grid

Vienna rectifier with simple structure and high power density is widely used in industrial applications such as aviation power supplies and electric vehicle charging systems. The conventional control strategy is not effective in suppressing input current zero-crossing distortion when the Vienna rectifier is operated under the unbalanced grid. To solve this problem, based on analyzing the input current zero-crossing distortion mechanism and the duty cycle of the output voltage, the Vienna rectifier constraints of stationary operation region and the phase difference between the input current and the reference voltage are derived, and the interval clamping control strategy based on negative-sequence current regulation is proposed. The proposed method adjusts the phase characteristics of the input current and reference voltage by introducing the negative-sequence current regulation coefficient, the negative-sequence current regulation coefficient is calculated by combining the constraints of stationary operation region, and the negative-sequence current regulation is realized. By introducing a small amount of secondary fluctuation in active power, the input current zero-crossing distortion is suppressed, and the power quality is improved. Finally, the effectiveness of the proposed strategy is verified on the Vienna rectifier experimental platform.