一种新型基于矢量空间解耦的多相三电平逆变器空间矢量调制策略

A Novel Vector Space Decomposition Based Space Vector Modulation Strategy for Multiphase Three-level Inverter

该文以中压大功率交流电机驱动器为背景。针对多相电机驱动,提出一种基于矢量空间解耦（vector space decomposition,VSD）的中点箝位型多相三电平逆变器空间矢量调制策略。以五相三电平逆变器为例,利用VSD将变量解耦和映射到？-？基波平面和x-y谐波平面。将逆变器243个电压矢量进行精简和合成,得到基波平面和谐波平面解耦的两组电压矢量,分别用来合成基波分量和谐波分量。利用冗余矢量进行直流侧中点电压的控制。通过计算输出电压向量的作用时间,将各相输出电压状态进行合并以减小开关频率。最后通过实验验证提出的策略的正确性。

This paper was based on medium-voltage high- power AC motor drives. A multiphase neutral-point-clamped （NPC） three-level inverter space vector modulation （SVM） strategy based on vector space decomposition （VSD） was proposed for multiphase motor drives. Taking a five-phase three-level inverter as an example, the physical variables were decomposed and mapped onto fundamental a-fl subspace and harmonic x-y subspace with VSD. The 243 voltage vectors were selected and synthesized, in such way that two sets of voltage vectors were obtained for synthesis of voltage references on fundamental subspace and harmonic subspace, respectively. The control of the midpoint voltage in DC link was performed by using redundant voltage vectors. By calculating dwell time of output voltage vectors, the sequence of voltage vectors of each phase was rearranged to reduce the switching frequency. Finally, the experimental results were given to verify the mentioned strategy.