三电平四象限变流器的控制仿真研究

针对单相三电平变流器采用瞬态电流方法进行四象限控制,使其既能工作在整流状态,又能工作在逆变状态;并且直流电压稳定,人端电压和电流是同相位或反相位的.同时,控制三电平变流器必须要考虑直流侧电压的中点平衡问题,控制方法是根据直流侧上下2个电容差及中点电流反馈值进行分析,然后对于那些不利于中点平衡的PWM脉冲进行矫正,从而控制中点电压的平衡.

Study on Control Simulation of Three-level Four-quadrant Converter

By way of transient current, 4q control is carried out for the single-phase three-level converter, so that it may work either as rectifier or as inverter, with stable DC voltage and with same or reverser phase of input voltage and current. The mid-point voltage balance of three-level rectifier must be considered for the control of three-level converter. The way of control is to analyze the capacitance difference in DC side and the feedback value of mid-point current. Then correction is done to the PWM pulses which are not good for the mid-point balance, so as to control the balance in mid-point voltage.