三电平APF直流侧电容电压控制研究

摘要

为了提高三电平有源电力滤波器(APF)的动态补偿性能,针对影响APF补偿性能的直流侧电压平衡问题,提出一种基于零序电压注入的直流侧中点电位平衡控制方法,建立了该方法的控制模型,揭示了控制输入的零序电压分量作为一个控制自由度对中点电位的影响.分析了中点电压不平衡的根本原因,并给出一种基于符号滞后判断的中点电位平衡控制算法.三相正序参考电压指令采用无差拍控制方法产生,最后采用SVPWM控制方法产生脉冲信号.通过对系统的仿真和实验,验证了该控制方法的有效性和实时性.%In order to improve the dynamic compensation performance of the active power filter(APF),a neutral voltage balance control method is proposed by injecting zero-sequence voltage and a control model of this method is established.The fundamental reasons of neutral voltage balance problem is analysed. In order to obtain the signs of modulation voltages,the paper also proposes a hysteretic sign calculation algorithm and proves the real-time property of the control method.Three-phase reference voltage instructions are made by deadbeat control method. Finally the SVPWM control method is used to make the pulse signal.The simulation and experimental results validate that the perfor-mance of the proposed approach is satisfactory and effective.