三相逆变器高效调制下的谐波抑制

Harmonic suppression of three-phase inverter with high-efficiency modulation

为提高三相逆变器效率,本文提出一种新型分区间调制策略。该策略在同一时刻只有两相开关管工作在高频斩波状态,另一相开关管工作在低频开关状态,降低了开关损耗,从而提高了逆变器效率。分析过程中,将逆变器在各分区等效为buck变换器,使分析过程变得简单易懂。采用分区间调制策略后,输出电压电流波形在区间切换处产生畸变,通过分析产生畸变的原理,提出了抑制输出波形畸变的方法。采用仿真与样机实验的方法验证了所提分区间调制策略以及控制策略的正确性。

To improve the efficiency of three-phase inverter,a novel inter-partition modulation strategy is proposed in this paper.With the proposed strategy,only two-phase switching tubes work in a high-frequency chopping state at the same time,and the other switching tubes operate in a low-frequency switching state,which will reduce switching losses and improve the efficiency of the three-phase inverter.In the analysis process,the inverter is equivalent to buck converter in each time partition,which makes the analysis process easy to understand.With the proposed inter-partition modulation strategy,the output voltage and current waveforms change at the interval switching.The principle of the waveform distortion is analyzed and the method of restraining the distortion is proposed.The correctness of the proposed inter-partition modulation strategy and control strategy are verified by simulation and prototype experimental results.