Adaptive TSK fuzzy sliding mode control design for switched reluctance motor DTC drive systems with torque sensorless strategy

This study proposes a novel Adaptive Takagi-Sugeno-Kang (TSK) Fuzzy Sliding Mode controller (abbreviated as AFSC) and investigates the application for a switched reluctance motor (SRM) direct torque control (DTC) drive system without a torque sensor. The sliding mode controller (SMC) is used for reducing the influence of uncertainties and external disturbances, and it performs fast responses. The parameters of the adaptive TSK fuzzy controller (AFC) are adjusted online for further reducing error residues after applying the SMC. Lyapunov stability theory is used for deriving the stability condition of the SMC and the adaptive update law of the AFC. The stability of the overall closed-loop system is also analyzed. To verify the performance and practicality of the controller developed for this study, the AFSC is employed as the speed controller in a SRM DTC drive system. The experimental results reveal that the steady-state speed error is maintained between ±2 rpm when the motor load torque is 1 Nm, and the motor operates at low, medium, high, and variable speeds. Comparing with the conventional SMC, a faster and smoother speed and torque responses are achieved. Moreover, the proposed control strategy is superior to the conventional SMC with respect to robustness for external disturbances.