Method for realizing point voltage balance control in large-power three-level rectifier

A method for realizing point voltage balance control in a large-power three-level rectifier belongs to the field of control technology of a large-power three-level frequency converter. The method comprises the steps of simulation calculation of an initial phase angle, synchronous modulation and phase modulation, and middle-point voltage balance control. The method has advantages of increasing action time of small vectors through synchronous modulation and phase synchronization, improving control capability to middle-point voltage and improving balance control to the middle-point voltage. According to the method, on condition that a hardware circuit is not changed, the middle-point voltage in the three-level inverter can be well controlled. 种大功率三电平整流器中点电压平衡控制的方法，属于大功率三电平变频器的控制技术领域。包括：初始相角的仿真计算环节，同步调制和相位调制环节，中点电压平衡控制环节。优点在于，利用同步调制和相位同步的方法来增加小矢量的作用时间，增加对中点电压的控制能力，来改善对中点电压的平衡控制。该方法在不改变硬件电路的条件下，可以更好的控制三电平逆变器中点电压。