Improved duty-ratio stator-flux eighteen-sector SVM-DTC system for new type TFPM

Abstract

On the basis of space vector modulation and direct torque control, the double six-phase transverse flux permanent magnet motor is taken as the research object. The eighteen-sector stator-flux subdivision method is proposed to reduce current harmonics and improve the characteristic of direct torque control. Control strategy of duty ratio is improved to decrease the torque ripple made by voltage vector mutation. The algorithm combination of the eighteen-sector stator-flux subdivision method and the improved duty ratio algorithm is built as the core of space-vector modulation direct-torque control. The static and dynamic characteristics of control system are simulated. The results show that the new control system can effectively improve the circular flux curve, stable rotate speed, suppress the torque ripple, and enhance the output characteristics of motor torque and rotate speed.