Direct torque control of synchronous reluctance motor in M-T reference frame considering magnetic circuit saturation and cross saturation

In this paper, a direct torque control (DTC) method in the M-T reference frame considering magnetic saturation and cross-saturation is proposed to improve the control performance, reduce torque ripple and solve the problems of complex system design. First, due to the special rotor structure of the synchronous reluctance motor (SynRM), the magnetic saturation of the motor is obvious. It is necessary to establish a magnetic saturation and cross-saturation model for the motor, and modify the maximum torque per ampere control (MTPA) curve according to the model. Moreover, conventional DTC has problems such as large torque ripple and unfixed switching frequency of the inverter. It is difficult to design the overall control system in the common space vector modulation direct torque control (SVM-DTC), so SVM-DTC under the M-T reference frame is adopted. The simulation results show that the proposed method has good tracking performance, and has smaller torque ripple in stable operation.