电网电压不平衡条件下Vienna整流器控制及电流过零畸变抑制方法

The Control and Current Over-zero Distortion Suppression Method for Vienna Rectifier Under Unbalanced Grid Voltage Condition

当电网电压不平衡时,Vienna整流器的直流侧和交流侧将分别出现偶次谐波和奇次谐波,并且电流的过零畸变将会加剧。因此,在电网电压不平衡时,该文建立Vienna整流器在双dq坐标系下的数学模型,计算电流与输出电压之间的夹角,分析基于不同控制目标的2种控制方法及其电流过零畸变,提出一种可以在全调制度范围内最大程度降低电流过零畸变的调制方法,称为垂足近似合成法,所提方法在电网平衡和不平衡时均适用。最后,搭建额定功率为4.6kW的Vienna整流器实验样机,实验结果验证所提方法的可行性和优越性.

When the grid voltage is unbalanced,even harmonics and odd harmonics will appear on the DC side and AC side of the Vienna rectifier,and the zero-crossing distortion of the current will be aggravated.Therefore,when the grid voltage is unbalanced,this paper establishes the double dq mathematical model of the Vienna rectifier,calculates the angle between the current and the output voltage,analyzes the current zero-crossing distortion of the two control methods based on different control objectives,and proposes modulation method that can minimize the current zero-crossing distortion in the full modulation range is called the vertical foot approximate synthesis method.This method is suitable for both balance and unbalanced power grids.An experimental prototype for Vienna rectifier with a rated power of 4.6kW is built,and the experimental results verify the feasibility and superiority of the method proposed in this paper.