说明：  改进直接转矩DTC控制的永磁同步电机控制策略，比传统的矢量控制效果更好，变换负载转速和电流波动更小
(Compared with the traditional vector control, the improved direct torque DTC control strategy of permanent magnet synchronous motor (PMSM) has better performance, and the speed and current fluctuation of the transformed load are smaller)