多电平逆变器空间矢量脉宽调制的简化算法

A Simple SVPWM Algorithm for Multi-level Inverters

提出了一种实现多电平逆变器空间矢量脉宽调制(Space Vector Pulse Width Modulation,SVPWM)的简化算法。该算法可以方便地根据参考电压矢量的幅度和相位选择3个邻近的基本空间电压矢量,并计算出这3个基本矢量的作用时间。该简化算法不但适用于三电平逆变器,而且对更多电平数的多电平逆变器同样有效。利用提出的简化算法对一个三电平逆变器进行了仿真和实验,仿真和实验结果验证了算法的正确性。

In this paper, a simple Space Vector Pulse Width Modulation （SVPWM） algorithm for multi-level inverters is proposed.A new coordinate is established which has two axes intersecting with the angle of π/3.In the new coordinates system,the original voltage vector is represented as the coordinate scale and the three nearest compound vectors can be selected easily.At the same time,the dwelling time of each vector can be simply calculated for either three-level inverters or inverters with more levels.What is more,it is easy to judge whether the SVPWM is in over modulation or not and easy to deal with over modulation with the proposed method.A three-level inverter lab prototype is completed to realize the proposed algorithm in which a DSP TMS320F240 is employed to control the inverter.The proper switching sequence is selected to keep the neutral point voltage balance.The simulation and experimentation results verify the validity of the proposed algorithm.