大功率逆变器混合脉宽调制策略研究

Research on multi-mode pulse width modulation strategy for high-power voltage source inverter

对于大功率牵引传动系统来说,逆变器通常采用高压大电流开关器件,开关频率往往较低(<1 kHz),针对现有的过调制策略及中频区段采用中间60°SPWM调制方式的混合调制策略存在的不足,本文提出了一种中频区段采用优化同步SHEPWM调制方式的逆变器混合脉宽调制策略，且实现了SVPWM异步调制、分段同步调制、优化同步SHEPWM调制及方波工况之间的平滑过渡,仿真和实验结果验证了该调制策略的正确性和有效性.

When the high voltage and high current switching devices are applied to high-power traction system,the switching frequency is very low.In view of the deficiencies of the current overmodulation method and the intermediate 60°SPWM control,this paper proposes a multi-mode pulse modulation strategy which uses the Selective Harmonic Elimination Modulation for the intermediate frequency,and realizes the smooth transition between Asynchronous SVPWM,Synchronous SVPWM, SHEPWM and the square modulation.The results of simulation and experiment indicate that the inverter has good output characteristics in the entire modulation range.