基于三次谐波注入的PWM调制技术仿真研究

针对传统载波移相SPWM调制技术调制下的级联H桥多电平大功率变流器输出电压利用率不高的问题，提出了三次谐波注入法，它能够在不影响逆变器负载电流和电压的情况下优化逆变器的输出，提高电压利用率15％且不影响输出电压谐波含量。本文详细分析了级联H桥三相多电平变流器的工作过程和三次谐波注入法的基本原理，并经分析得出了三次谐波注入PWM调制技术较之传统载波移相SPWM调制技术优越的结论。最后，通过Matlab／Simulink软件仿真验证了上述结论的正确性和可行性。

Simulation Study on PWM Modulation Technology Based on Third Harmonic Injection

In allusion to the problem of lower output voltage use ratio of the cascaded H-bridge multi-level high-power inverters by using the traditional carrier phase-shifting SPWM modulation technique, the third harmonic injection method is proposed, which can optimize the inverter＇s output without affecting the current and voltage of load, and improve the voltage utilization ratio of 15% but without affecting the harmonic content of output voltage. The working process of the three phase multi-level cascaded H-bridge inverter and the basic principle of the third harmonic injection method are analyzed in detail in this paper, furthermore the conclusion of which the third harmonic injection PWM modulation technology is superior to the traditional SPWM modulation technology is ob- tained by means of the analysis. Finally, the correctness and feasibility of the above-mentioned conclusion are verified through the software simulation of Matlab/Simulink.