轴向磁通切换永磁电机双矢量合成模型预测磁链控制

为了减少轴向磁场磁通切换永磁电机(axial field flux-switching permanent magnet machine,AFFSPMM)的转矩和定子磁链脉动,提出一种磁链矢量跟踪误差最小化的双矢量合成模型预测磁链控制(two-vector synthetic model predictive flux control,TVS-MPFC)方法。首先,为了消除传统模型预测转矩控制(model predictive torque control,MPTC)价值函数中的加权因子,推导TVS-MPFC的等效价值函数;然后,根据无差拍控制估算参考电压矢量;接着,在一个控制周期内,采用双电压矢量的控制方法来提高控制系统的稳定性,其中第一个电压矢量直接选定为有效矢量,而第二个电压矢量在有效矢量和零矢量之间进行选择;最后,根据磁链矢量跟踪误差最小化原理,确定所选电压矢量的占空比。通过仿真和实验验证了所提控制策略的正确性和有效性。结果表明,与传统MPTC和DB-MPFC相比,所提TVS-MPFC改善了AFFSPMM控制系统稳态性能,特别是在低速和超低速运行的工况下效果更明显。

Two-vector Synthetic Model Predictive Flux Control of an Axial Field Flux-switching Permanent Magnet Machine

A two-vector synthetic model predictive flux control(TVS-MPFC) with flux vector tracking error minimization was proposed in this paper to reduce the ripples of torque and stator flux of axial field flux-switching permanent magnet machine(AFFSPMM). The equivalent cost function of TVS-MPFC was first derived to eliminate the weighting factor in the cost function of traditional model predictive torque control(MPTC). The reference voltage vector was then estimated on the basis of deadbeat control. A control method with two voltage vectors was subsequently applied during a control cycle to improve the stability of the control system. The first voltage vector was directly chosen as an active vector, whereas the second voltage vector was selected between active and zero vectors. Finally, the duty ratios of the selected voltage vectors were determined on the basis of the principle of flux vector tracking error minimization. The correctness and effectiveness of the proposed control strategy were verified by simulation and experiment. The results show that the proposed TVS-MPFC improves the steady-state performances of AFFSPMM control system compared with traditional MPTC and DB-MPFC, especially at low and very low speed operation.