基于虚拟磁链的PWM整流器模型预测直接功率控制

摘要

为了省去基于虚拟磁链定向的传统直接功率控制(DPC)中的滞环比较器和开关表以及基于电压定向的传统模型预测直接功率控制(MPDPC)中的交流电压传感器,提高系统的动态响应,实现功率的准确跟踪,在二者的基础上结合空间矢量脉宽调制(SVPWM),再引入延时补偿和重复控制,在两相静止坐标系下,以电网电压作为基本控制矢量,利用功率给定值与实测值的误差平方和最小建立目标函数,提出一种基于虚拟磁链的电压型PWM整流器的改进MPDPC方法.将传统DPC、传统MPDPC与改进MPDPC进行了仿真和实验对比研究.仿真和实验结果表明,所提改进MPDPC方法提高了功率跟踪精度,减小了功率纹波,降低了电流谐波畸变率.%To leave out the hysteresis controller and switching look-up table used in virtual flux oriented traditional DPC(Direct Power Control) and the AC voltage sensors in traditional MPDPC(Model Predictive Direct Power Control),improve dynamic response of control system,and achieve accurate power tracking,the delay compensation and repetitive control are integrated with SVPWM(Space Vector Pulse Width Modulation) to propose an improved MPDPC method for voltage-source PWM rectifier based on virtual flux that are also based on traditional DPC and traditional MPDPC method,which takes the grid voltage as the basic control vector and the sum of squared error between predictive power and measured power model minimization as the objective function in two-phase stationary frame.The traditional DPC,traditional MPDPC and improved MPDPC are compared by simulation and experiment,and the results show that the improved MPDPC method improves the accuracy of power tracking and reduces the power ripple and the harmonic distortion rate of current.