Overview of the Direct Torque Control Strategy in Switched Reluctance Motor Drives

Direct torque control (DTC) is a high-efficient variable frequency speed regulation technology, which has simple control structures, clear physical concept of signal processing, and good torque dynamic performance. The DTC is widely applied in high performance control of AC motor drives. In recent years, the DTC is also applied to ensure high performance torque control in switched reluctance motor (SRM). As the fundamentals of the SRM and its power converter are quite different from the traditional AC drives, significant improvements should be made in the DTC algorithms. In this paper, a systematic overview of the DTC strategies in SRM drives is presented. Firstly, the basic principle of DTC in SRM and its implementation are introduced. Secondly, the existing challenges and optimization schemes in current DTC schemes are discussed in detail. Then, a time-line of the research on DTC strategies and its comparison with other control strategies are analyzed. Finally, the future research trends of DTC in SRM drives are summarized.