Research on Direct Torque Control of Induction Motor with Low Torque Ripple

Focusing on the problem of torque ripple in direct torque control of induction motor,a torque ripple restraint method based on multi-segment was proposed.Through reducing the space angle of the spinning flux,the angle between flux and voltage vector included tends to continuous,thus the torque vibration caused by step cut of voltage vector is reduced.Meanwhile the voltage main vectors,which are employed to change stator flux amplitude symmetrically,eliminates torque ripple due to current distortion.Simulation results show that this method can reduce torque ripple of induction motors at a low speed and improve repose behavior for direct torque control systems.