永磁同步电机有限控集模型预测电流控制预测误差分析

Prediction error analysis of finite-control-set model predictive current control for PMSMs

在采用有限控集模型预测电流控制策略的永磁同步电机驱动系统中,预测模型使用的电机参数尤其是定子电感可能与实际值并不匹配,会造成模型预测控制算法存在预测上的误差,进而影响系统稳态控制性能。针对该问题,首先定义了预测误差作为评价指标,然后推导出电流预测误差的数学模型,理论分析表明预测模型使用的d、q轴电感值正向偏差和负向偏差对于d、q轴电流预测误差会产生不一样的影响,且负向偏差影响更大。实验结果验证了上述关于电流预测误差的理论分析,同时对相应的电流稳态跟踪误差进行了实验分析,显示出预测误差对于稳态跟踪性能的影响。得到的预测误差数学模型和分析结论能够为模型预测算法预测误差的降低和控制性能的提升提供理论指导。

For permanent magnet synchronous motor (PMSM) drive systems adopting finite-control-set model predictive current control (FCS-MPCC) strategy, the parameters used in prediction model may not be the same as the actual values during the operation,especially for dand q-axis stator inductances. Such parameter mismatches can result in prediction error for FCS-MPCC and further deteriorate the steady-state control performance of motor system. In order to solve this problem,the prediction error was firstly defined as an evaluation index and its mathematical model was then derived. The theoretical analysis shows that the same positive deviation and negative deviation of d-or q-axis stator inductance can lead to different effects on the prediction error of d-or q-axis current, especially the negative one. Finally, the experimental results verify the theoretical analysis of prediction error. Besides, the corresponding current tracking errors are also analyzed. It provides effective guidelines for reduction of prediction error and im-provement of control performance for model predictive control.