基于三次谐波注入法的逆变器谐波抑制策略研究

Research on Restraint Strategy of Third Harmonics Inverter with SPWM

详细分析了三相电压型SPWM逆变器输出电压谐波及其产生规律,并提出了一种基于三次谐波注入法的谐波抑制策略,该方法生成的SPWM波形是通过在正弦波上注入三次谐波而形成的,然后用这个SPWM波形控制开关器件的通断从而使输出电压波形得以优化。理论分析表明该方法在提高输出电压幅值,提高直流电压利用率的同时,还可以降低输出电压的THD,仿真结果也证明了这种谐波抑制策略的正确性。

This paper analyses the harmonics in output voltage of three-phase SPWM inverter and the produce regular pattern. A restraint strategy of third harmonics inverter with SPWM are proposed, the method adopt an appropriate superimposed on the sinewave modulation harmonic to make it saddle-shaped wave. Producing SPWM waveform to control the inverter switching devices onand off to improve the output voltage waveform. Mathematical analysis shows that the method not only improving the output voltageamplitude and dc voltage utilization, but also reducing the THD of output voltage. The simulation results indicate the accuracy ofthe presented restraint strategy.