级联型多电平逆变器控制方法的仿真研究

摘要

Cascaded multilevel inverter plays a very improtant role in the field of ac machines control.In recent year,for cascaded inverter,a lot of modulation methods and strategies are proposed and much progress has been achieved.To deal with 7-level cascaded inverter,the application of 2-level SVPWM in H bridge multi-level inverter is studied here,also the process and result of simulation are presented.Then,a direct torque control system based on the space vector pulse wide modulation is developed to solve problems of switching table and unstable switching frequency in traditional DTC system.The control is verified by simulation used MATLAB/SIMULINK software and the simulation result proves the feasibility and superiority.%级联型多电平逆变器在交流调速领域发挥着十分重要的作用.近年来,针对级联型逆变器提出了多种调制方法和调速策略,并取得了一定的成果.以级联七电平逆变器为研究对象,研究了如何将两电平空间矢量调制技术应用到H桥多电平逆变器的控制中,并给出了仿真分析的过程和具体结果.然后,将其与基于空间矢量调制的直接转矩控制方法相结合,从而解决了传统DTC在级联型多电平逆变器应用中存在的开关状态表难于形成、开关频率不固定等问题.通过MATLAB/SIMULINK搭建仿真模型,证明了此方法的可行性和优越性.