Direct Torque Control for Induction Motor Based on Low-Speed Performance Improvement

The duty cycle direct torque control (DTC) method suffers from the stator current distortion due to the flux drop at low-speed operation. To solve the above problem, this paper proposes a duty cycle direct torque control method for induction motor (IM) based on low-speed performance improvement. By analyzing the influence of active voltage vectors on stator flux through duty cycle, the method prioritizes the selection of candidate voltage vector combinations that can increase the magnitude of the stator flux, solving the problem of current distortion caused by flux drop due to inaccurate voltage vector selection. Finally, the effectiveness of the proposed strategy is verified by experiments on a 2.2kW IM.