基于参考电压分解的新型多电平逆变器空间矢量调制方法

A NEW SPACE VECTOR MODULATION METHOD BASED ON REFERENCE VOLTAGE DECOMPOSITION FOR MULTILEVEL VSI

提出了一种新的多电平逆变器的参考电压分解理论 ,将参考电压矢量分解成为基矢量和二电平矢量。针对目前多电平空间矢量调制方法计算十分复杂的问题 ,提出了一种新型的基于参考电压矢量分解理论的多电平逆变器空间矢量调制方法。该方法只需要将参考电压的二电平矢量用二电平的空间矢量调制方法合成 ,这样 ,多电平的空间矢量调制问题被简化成二电平的空间矢量调制问题 ,计算过程十分简单和快速。另外 ,通过归纳的多电平空间矢量的分布规律可以快速地找出所有的冗余开关状态 ,以便优化输出开关状态组合。提出的方法在理论上适用于任何电平数目 ,仿真结果验证了它的有效性。

A new theory of reference voltage decomposition is proposed. Based on this theory the reference voltage vector of a multilevel VSI is divided into two parts: base vector and two level vector. Then a new multilevel space vector modulation (SVM) method is presented. With the proposed method only the two level reference vector needs to be synthesized using conventional two level SVM methods. The computation of the proposed method is very simple and fast through simplification of the multilevel SVM issue into a two level SVM issue. In addition some important allocation laws of multilevel space vectors are presented which are very useful to find out all redundant switching states. The proposed method is applicable for any number of levels and its feasibility is verified by simulation results.