In order to improve the stability of low-speed and high-torque permanent magnet synchronous motor control in the shearer semi-direct cutting system under large load fluctuation and strong impact conditions, an improved model predictive torque control strategy based on duty cycle is proposed which can effectively reduce the flux and torque ripples and improve steady-state control performance. This method combines the separate process of the voltage vector selection and the duty cycle calculation through the predictive model combined with duty cycle. Then, the optimal voltage vector and its duration is selected simultaneously based on minimizing the cost function. In addition, in order to mitigates the computational burden of the proposed method, the voltage vectors in the finite control set is pre-selected using hysteresis comparator according to the motor operating status. Furthermore, the duty cycle pulse width modulation is introduced to obtain a fixed switching frequency of the inverter. The results of simulation experiments confirm that the proposed strategy can significantly reduce the flux and torque ripples and improve the steady state performance while maintaining fast dynamic response.

为提高采煤机半直切系统在大负载波动和强冲击工况下低速大转矩永磁同步电机控制的稳定性，提出了一种基于占空比的改进模型预测转矩控制策略。可有效降低磁通和转矩脉动，提高稳态控制性能。该方法通过结合占空比的预测模型，将电压矢量选择和占空比计算的分离过程结合起来。然后，基于最小化成本函数同时选择最佳电压向量及其持续时间。此外，为了减轻所提出方法的计算负担，有限控制集中的电压矢量是根据电机运行状态使用迟滞比较器预先选择的。此外，引入占空比脉宽调制以获得逆变器的固定开关频率。仿真实验结果证实，所提出的策略可以显着降低磁通和转矩脉动，提高稳态性能，同时保持快速的动态响应。