三电平逆变器空间矢量调制及其中点控制的研究

论述一种中点钳位式三电平逆变器SVPWM原理及其实现方法。为避免三电平逆变器在扇区切换中输出矢量突变,采用一种首发矢量全部采用正小矢量或负小矢量的空间矢量调制算法,给出了合成矢量的相应输出电压矢量,推导出三角形顶点工作矢量的作用时间。提出一种充分利用冗余小矢量的中点电压控制方法,实现了电容电压的平衡。实验研究结果证实了提出的调制算法是正确且有效的。

Research on SVPWM Method and Its Neutral-point-potential Control for Three-level Neutral-point-clamped (NPC) Inverter

In this paper,SVPWM pattern and implement method is addressed for three-level NPC inverter.In order to avoid the abrupt change of output voltage vectors during the process of desired vector changing from one section to another,a novel space vector modulation(SVM) algorithm is proposed,in which positive or negative small vectors are adopted as first active ones.Output voltage vectors to synthesize the desired vector are given and the duty time of active vectors for corresponding sub-triangle vertex is deducted.The neutral point potential stability is realized by detecting the direction of load currents and neutral point voltage and designing the real duty time of positive and negative space vectors in reason.Finally,the validity and correctness of proposed SVM method is confirmed by experiment results.