基于等效电路模型的新型三电平逆变器载波调制方法的研究

A novel sine-triangle modulation method based on equivalent circuit model for three-level PWM voltage source inverter

提出了一种新型的基于三角载波水平移相的三电平逆变器PWM调制方法。通过分析三电平电压型逆变器主电路结构,建立了相应的等效模型,给出了一种提高等效开关频率的具有二重化特点的载波水平移相调制算法。该调制方法与三电平逆变器空间矢量方法相比,其具有计算简单、实现简单等优点,与一般载波垂直移相调制算法相比,其具有低次谐波小、等效开关频率提高一倍、容易滤波等优点。通过仿真研究,验证了该调制方法的可行性。通过建立等效模型为采用两电平三相逆变器各种调制算法来实现三电平逆变器的控制奠定了研究基础。

A novel sine-triangle modulation method based on horizontal phase shifted carrier for the three-level VSI is proposed. By analyzing the topology of circuit and founding the equivalent circuit model, the principle is detailed. Comparing with voltage space vector modulation, the method is realized easily without complex computa- tion;and comparing with vertical phase shifted carrier PWM, the low order harmonics are much less,and the switch frequency is equivalently boosted to two times, so the design of filter is more easily. The feasibility is veri- fied by simulation results. In addition, the Equivalent Circuit Model provides a research base for those modulation methods for three-level VSI realized by using the multiplex of the modulation methods of general three-phase VSI.