【目的】针对开绕组六相永磁同步电机模型预测控制(MPC)系统在单相上桥臂故障时存在的谐波电流和转矩脉动等问题,提出一种基于优化控制集的改进方法。【方法】根据矢量空间解耦理论,推导出单相上桥臂故障时的电压矢量及在基波平面和谐波平面的分布情况,并分析矢量特性。为了保证高电压利用率,进行虚拟矢量合成。针对传统凸包法难以选取合适基本电压矢量的问题,本文提出一种基于优化控制集的模型预测容错控制(MPFTC)方法。根据故障后的矢量特性分析,在G5组矢量中选取优化控制集,分析该控制方法对谐波电流和转矩脉动等性能的影响。在发生故障的情况下对传统MPC方法和本文所提基于优化控制集的MPFTC方法进行仿真对比分析。【结果】仿真结果表明,本文所提MPFTC方法将故障下电流总谐波失真由50.54%降至5.96%,3次谐波低于5%;电磁转矩仅出现1 N·m的瞬时跌落,并在10 ms内恢复,有效抑制了未处理时±50 N·m、50 Hz的振荡。【结论】本文所提MPFTC方法在谐波抑制和转矩脉动控制方面效果显著,验证了其强容错能力和工程应用价值。

[Objective] An improved method based on an optimized control set is proposed to address the issues of harmonic currents and torque ripple in the model predictive control (MPC) system of an open-end winding six-phase permanent magnet synchronous motor under single upper-arm faults. [Methods] Based on the vector space decoupling theory, the voltage vectors under single upper-arm faults and their distribution characteristics in both fundamental and harmonic planes were derived and analyzed. To ensure high voltage utilization, virtual vector synthesis was implemented. Addressing the challenge of selecting appropriate basic voltage vectors using conventional convex hull methods, an optimized control set-based model predictive fault-tolerant control (MPFTC) method was proposed in this study. Through post-fault vector characteristic analysis, an optimized control set was selected from the G5 vector group, and its impact on harmonic currents and torque ripple performance was evaluated. Comparative simulations between conventional MPC and the proposed optimized control set-based MPFTC method were conducted under fault conditions. [Results] The simulation results demonstrated that the proposed MPFTC method effectively reduced the total harmonic distortion of the current from 50.54% to 5.96% under fault conditions, with the third-order harmonic component suppressed below 5%. Additionally, the electromagnetic torque exhibited only a transient drop of 1 N·m and recovered within 10 ms, successfully mitigating the untreated 50 Hz oscillation with an amplitude of ±50 N·m. [Conclusion] The proposed MPFTC method demonstrates significant effectiveness in harmonic suppression and torque ripple control, verifying its strong fault tolerance and engineering application value.