Reducing Torque Ripples for Switched Reluctance Motor via Robust Adaptive Direct Torque Control Strategy

This article presents a robust adaptive direct torque control (DTC) strategy to reduce torque ripple for switched reluctance motor (SRM). To realize high-precision torque control and take the high nonlinearity of torque variation with rotor position and current into account, a total torque dynamics model containing two nonlinear functions is established. Furthermore, an adaptive torque controller is proposed which realizes the estimation of nonlinear functions using the designed adaptive laws, and its stability is proved based on the Lyapunov function. In the meanwhile, the convergence of the adaptive parameters toward their optimal values is analyzed, and the selection rules of the design parameters are given. In addition, the mechanism for compensating the controller gain by the adaptive operator is discussed in detail. Finally, experiments are carried out on 3-phase SRM to verify the adaptive capability of control parameters, robustness to motor model uncertainty, and torque ripple reduction effect of the proposed DTC strategy.