基于开关序列的永磁同步电机模型预测磁链控制

Model Predictive Flux Control for Permanent Magnet Synchronous Machine Based on Switching Sequence

为了消除传统的模型预测转矩控制MPTC(model predictive torque control)算法中的权重因子,减小计算量并提高稳态控制精度,提出了一种基于开关序列的永磁同步电机模型预测磁链控制MPFC-SS(model predictive flux control-switching sequence)算法。首先,通过分析电磁转矩和磁链的关系,将对转矩和定子磁链幅值的控制等效转换为对d、q轴磁链的控制,避免了权重因子的设计。其次,采用定子磁链无差拍预测控制计算所需的参考电压矢量,并根据其所在扇区选择对应开关序列。然后,基于磁链无差拍预测控制原则,计算开关序列中基本矢量的最优作用时间,有效减小电流谐波和转矩脉动,实现定子磁链的准确跟踪。最后,对传统MPTC和所提算法进行了实验对比研究。结果表明:所提算法具有计算量小、电磁转矩脉动小、电流谐波含量低等优点。

To eliminate the weighting factor,reduce the computation complexity and enhance the steady-state control accuracy in the traditional model predictive torque control(MPTC)method,a model predictive flux control algorithm based on switching sequence(MPFC-SS)is proposed for permanent magnet synchronous machine in this paper.First,the relationship between electromagnetic torque and flux is analyzed,and the control of both the torque and stator flux amplitude is equivalently converted to the control of flux in d and q axes.Then,the deadbeat predictive control of stator flux is adopted to calculate the reference voltage vector,and the candidate switching sequence is selected according to the sector where the reference voltage vector is located.Afterwards,on the basis of the principle of deadbeat predictive flux control,the optimal duration time of basic voltage vectors in the candidate switching sequence is calculated,which can effectively reduce current harmonics and torque ripple,thus realizing the accurate tracking of stator flux.Finally,an experimental comparison between the traditional MPTC method and the proposed algorithm was carried out,and results show that the proposed algorithm has advantages such as light calculation burden,small electromagnetic torque ripple and low current harmonic content.