基于预测控制的PWM整流器控制策略研究

Control Strategy of PWM Rectifier Based on Predictive Control

脉宽调制(PWM)整流器控制策略常以电网电压平衡环境为基础。在此着重研究电网不平衡状态时三相PWM电压型整流器(VSR)特性及其控制策略,提出电网电压不平衡环境下预测电流控制算法,在一个PWM开关周期内,利用己知电流状态,预测下一个采样时刻达到预期电流所需的控制电压值。该方法因无需进行网侧电流正、负序分量计算,从而减少内环电流调节器数目,简化了控制算法,提高了系统计算速度。其暂态过渡过程仿真和基于RT-LAB半实物实时实验结果表明,该控制方法无论电网电压是否平衡,系统均具有动态响应快、功率因数高、输出电压稳定性好的特性,能显著抑制网侧电网不平衡对PWM整流器性能的影响。

pulse width modulation（PWM） rectifier control grid voltage balancing strategy often based on environment, this paper focuses on the characteristics and control strategies of three-phase PWM voltage-type rectifier（VSR） characteristics and control strategies in the unbalanced grid.The predictive current control is proposed under grid voltage unbalance, in a PWM switching cycle, the use of known current state, to predict the next sampling time to achieve the desired current control voltage values required, this novel control method requires no extraction of positive and negative sequence components of net side current, reducing the number of inner current regulator simplifies the control algorithms to improve the calculation speed of the system.Transition process simulation and the experiment of RTLAB hardware-in-the-loop results show this novel control method has advantages such as fast dynamic response ,good per- formance of output voltage stability and high power factor, can significantly inhibited the effects of the imbalance of power grid side PWM rectifier performance when the grid voltage unbalanced.