说明：  永磁同步电机的直接转矩控制，包含磁链观测，电压电流转速转矩等。很经典，很全面，功能完整.附带一个离散直接转矩控制下的模型
(Direct torque control of permanent magnet synchronous motor, comprising flux observer, voltage and current speed torque and the like. Very classic, very comprehensive, full-featured. Comes with a discrete model of direct torque control)