三电平SVPWM与双调制波载波PWM的等效研究

Research of the equivalence between three-level SVPWM and double modulation wave carrier-based PWM

三电平SVPWM具有直压利用率高、THD小等优点,但实现较复杂,通过注入特定的零序分量可使载波PWM与8段以下的SVPWM开关序列等效。本文针对单调制波载波PWM不能与8段以上的SVPWM开关调制序列等效的问题,引入了双调制波PWM法,并在此理论的基础上深入分析了开关调制序列大于8段时三电平SVPWM与双调制波载波PWM的等效关系。经过严格的推导,得出了参考矢量位于不同扇区的不同小区域时,6个子调制波与三相原调制波、直流电压的对应关系。实验验证了上述结论的正确性。

The three-level SVPWM has the advantages of high utilization rate of direct pressure,low THD,while its realization is complicated. According to the problem that single modulation wave carrier-based pulse width modulation isn＇t equal to space vector pulse width modulation when the switching sequence is more than 8 segments,this paper introduces a method of double modulation wave carrier-based pulse width modulation to solve it. The equivalence between three-level space vector pulse width modulation and double modulation wave carrier-based pulse width modulation was thoroughly studied in this paper. The relationship between the 6 sub-modulation waves and the three-phase original modulation wave,DC voltage is obtained when the reference vector is located in different areas of different sectors. The experiment result verifies the correctness of the proposed method.