中点钳位H桥五电平逆变器空间矢量脉宽调制方法研究

Research on SVPWM Method for Five-level Neutral-point-clamped(NPC) H-Bridge Inverter

介绍了二极管中点钳位(NPC)H桥五电平逆变器的拓扑结构及其工作原理,提出了一种新的适用于五电平逆变器的电压空间矢量脉宽调制(SVPWM)算法.该算法利用12条规则来判断参考电压所在位置,为避免逆变器在扇区切换中输出矢量突变,采用了使两相邻小三角形区域输出矢量变化方向相反的方法.结果表明,本文提出的SVPWM算法是正确且有效的,与传统的SPWM方法相比,逆变器输出线电压的谐波含量明显减少,其基波电压的幅值也得到了明显的提高.

This paper introduced the topology of five-level neutral point clamped（NPC） H-Bridge inverter and its operating principle,and proposed a new algorithm of space vector pulse width modulation（SVPWM）,which can be applied to the five-level inverter.In this algorithm,the reference voltage position is located by twelve judging rules,and in order to avoid the abrupt change of output voltage vectors during the process of desired vector changing from one section to another,the method that made the output vector changes of the two adjacent triangles in the opposite direction is used.In this paper,the implementation approaches and concrete steps for the algorithm used to control the five-level inverter were studied with simulation.The simulation results have shown that the proposed algorithm is correct and effective,the harmonics of inverter output voltage are significantly reduced and the amplitude of fundamental voltage also increase significantly,compared with the traditional SPWM method.