Improved direct torque control strategy for reducing torque ripple in switched reluctance motors

To reduce the torque ripple of a switched reluctance motor (SRM), this paper proposed a direct torque optimization scheme. To force the torque to better track the reference torque, the proposed method abolished the torque hysteresis control and a fuzzy controller was adopted to quantitatively analyze the difference between the reference torque and measured torque. Therefore, the torque reference factor that represents the torque under different conditions can be obtained, and the system should be controlled by different voltage vectors with different output torque capabilities at different torque reference factor values. In this way, the torque can better track the given torque. At the same time, the existing sectors were optimized in this paper. Under optimized sectors, the adopted direct torque control (DTC) scheme can drive the SRM better. To verify the effectiveness of the proposed scheme, it is compared with the current chop control (CCC) strategy and the traditional DTC control strategy on a 12/8 three-phase SRM by simulations and experiments. The obtained results show that the proposed method can effectively reduce the torque ripple of the SRM.