三电平逆变器静态直流输出时中点控制方法

Neutral Point Control Method on Static DC Output of Three-level Inverter

二极管箝位型三电平逆变拓扑在高压变频系统中得到了广泛的重视,但其存在中点电位不平衡的问题。重点分析了三电平逆变器在作静态直流输出时出现中点电位不平衡的原因,并提出了大矢量和小矢量分时调制的方法。该方法使中点电位得到控制的同时,提高了参数辨识中直流试验对输出电压的重构的准确性。最后用实验验证了该方法的有效性。

Topology of diode-clamped three-level inverter has been widely appreciated in high voltage inverter system, but it exist the problem of neutral point potential balancing. This paper analyses the reasons of neutral point potential balancing when three-level inverter is used for DC output and gives a method that large and small vector are modulated by time-sharing .This method gets the neutral point potential under control, besides improves the accuracy of the reconstruction of the output voltage in parameter identification during verified by experiment results. DC tests. Finally, the effectiveness of the proposed control approach is