Development of Direct Torque Control Technique of Induction Motor

Direct torque control(DTC)developed after the field-oriented control was a novel high-performance control strategy for AC variable-frequency drives.It was very popular for its merits such as quick and response of torque,structure simplicity,robustness and etc.Acquired many achievements in theory and application research,however as a new technique immature and imperfect problems that severe influence of stator respeed condition,large torque ripple under steady state.This paper summarized the current research status and existing problems for DTC and presented develop DTC technique.