基于虚拟磁链DPC的电压型整流器控制系统研究

RESEARCH ON DIRECT POWER CONTROL OF VOLTAGE-TYPE RECTIFIER BASED ON VIRTUAL MAGNETIC FLUX MODEL PREDICTION

对电压型PWM整流器(VSR)的直接功率控制(DPC)系统进行研究,针对采用虚拟磁链实现无电压传感器电压观测存在的模型预测误差问题,提出一种基于牛顿插值原理对模型观测电压进行修正的虚拟磁链模型预测直接功率控制策略,通过牛顿插值法修正电网电压估算值,同时引入内模反馈校正环节对模型预测相邻时刻瞬时功率所产生的误差进行修正,以此改进整流器SVPWM控制电压,实现更稳定功率跟踪,减少启动和调节给定时产生的超调量,同时有效减少整流器网侧谐波,达到绿色整流的目的。仿真对比分析和试验结果表明,采用上述控制策略的VSR具有良好的直流侧电压输出质量、较强的抗干扰性和低网侧谐波,可有效实现绿色整流和高功率因数直流电压输出。

In this paper,a direct power control(DPC)system of voltage-type PWM rectifier(VSR)is studied. Aiming at the error of model prediction and estimation when using magnetic virtual flux to realize voltage observation without voltage sensor,a virtual magnetic flux model predictive direct power control strategy based on Newton interpolation principle to modify the model observation voltage is proposed. The Newton interpolation method is used to correct the estimated voltage of the power grid,and the internal model feedback correction is introduced to correct the errors generated by the instantaneous power model prediction at adjacent moments,so as to improve the SVPWM control voltage of the rectifier. The above method can achieve more stable power tracking,reduce the amount of overshoot caused by the start-up and regulation,effectively reduce the harmonic on the grid side of the rectifier to achieve the purpose of green rectification. Simulation comparison analysis and test results show that the VSR controlled by the above control strategy has good output quality of DC side voltage,strong anti-interference and low harmonics on grid side,and can effectively achieve green rectification and high power factor of DC output voltage.