有源电力滤波器定频模型预测电流控制

摘要

有限控制集模型预测控制(FCS-MPC)需以较高采样频率确保控制效果,且开关频率不固定,多应用于三相三线系统中.为此,给出一种针对四线制有源电力滤波器(APF)的定频模型预测电流控制(3D-FSF-MPCC)方法.在α,β,y坐标系下,8个离散电压矢量将空间划分为6个三棱柱,通过定位电网电压矢量,选择其所在棱柱内的4个电压矢量共同作为每个采样周期内的输出.根据电流变化率计算公式,以电流无误差跟踪为目标确定各矢量的作用时间,再经脉宽调制得到开关信号,实现四线系统中电流控制的定频运行.仿真与实验结果证明,与FCS-MPC相比,该控制方法有相同的动态性能,且开关频率固定,电流补偿精度更高.%Finite control set model predictive control (FCS-MPC) has some disadvantages such as the high sampling frequency and non-fixed switching state.It is generally used in three-phase three-wire system.For these reasons,a new method called model predictive current control with fixed switching frequency in 3D coordinate system(3D-FSF-MPCC) for four-wire active power filter(APF) is proposed.In 3D coordinate system,8 discrete voltage vectors are divided into 6 three prisms.By positioning grid voltage vector,the nearest voltage vectors are selected as the output of each sampling period.According to the calculation formula of current change rate and the goal of zero error tracking,the action time of each vector can be determined.Then switch signals are obtained by pulse width modulation to achieve current control with fixed frequency in four-wire system.Simulation and experimental results show that,compared with FCS-MPC,this control method has the same dynamic performance,and current compensation precision is higher with fixed switching frequency.