基于载波相移 THI-PWM 技术的多电平逆变器研究

摘要

For the issue of low utilization rate of DC voltage on the traditional voltage source multilevel inverter , the idea of third harmonic injection ( THI) is introduced to the carrier phase shifting technique based on the mathematical analysis of carrier phase shifting SPWM modulation technique , and the carrier phase shifting THI-PWM modulation technique which is applicable to multilevel inverter is proposed , making form factor of the system rise from 1 .732 to 2 and the utilization rate of DC voltage increase by 15%.A three-phase five-level inverter simulation model is built in Matlab/Simulink , the simulation result demonstrates the correctness and the validity of the theory .%针对传统的电压型多电平逆变器直流电压利用率低的问题，在对载波相移SPWM调制技术进行数学分析的基础上，将三次谐波注入（ Third Harmonic Injection ， THI）的思想引入到载波相移技术中，提出了一种适用于多电平逆变器的载波相移THI-PWM调制技术，使得系统的波形系数从1．732上升到2，直流电压利用率提升15％左右。在Matlab／Simulink中搭建了三相五电平逆变器模型进行仿真验证，结果证明了该方法理论的正确性和可行性。