三电平四桥臂APF低运算量预测控制策略研究

四桥臂APF(active power filter)是解决三相四线制配电网电能质量问题的理想设备，三电平四桥臂APF因其充足的基矢量个数而具有较好的电流跟随性能，但模型预测电流控制应用于三电平四桥臂APF时预测运算量过大。提出一种基于空间分层思想的模型预测电压控制策略。基于无差拍控制思想及αβγ坐标系下离散数学模型，由参考电流预测出期望的参考电压，将多次电流预测转换为单次电压预测；并结合三电平四桥臂APF的电压矢量空间分布规律，采用空间分层思想，基于γ轴的空间位置进行优化矢量范围的选取，将寻优矢量范围从传统的81个降低至4~18个，实现了电压跳变限制和中点电位控制。仿真结果表明：该策略具有优良的控制性能。

Research on Low Computational Predictive Control Strategy of Three-level Four-arm APF

Four-arm active power filter(APF) is an ideal device to the power quality of three-phase four-wire distribution network. Owing to the sufficient number of base vectors, three-level four-arm APF has better current tracking performance, but the prediction calculation amount is too large when model predictive current control is applied. A model prediction voltage control strategy based on the idea of space stratification is proposed. Based on the deadbeat control idea and the discrete mathematical model in αβγ coordinate system, the expected reference voltage is predicted from the reference current, and the multiple current predictions are converted into the single voltage prediction. Combined with the law of three-level four-arm APF voltage vector space distribution, the idea of space stratification is adopted, and the optimal vector range is selected based on the spatial position of γ-axis. The optimal vector range is reduced from the traditional 81 to 4~18, and the voltage jump limit and the control of neutral-point potential are realized. Simulation results show that the strategy has excellent control performance.