Design and Implementation of Disturbance Compensation-Based Enhanced Robust Finite Control Set Predictive Torque Control for Induction Motor Systems

Finite-control-set-based predictive torque control (PTC) method has received more and more attention in recent years due to its fast torque response. However, it also has two drawbacks that could be improved. First, the torque reference in the cost function of the existing PTC method is generated by the proportional-integral speed controller, so torque reference's generation rate is not fast and its accuracy is low especially when the load torque is given suddenly and inertia value is varying. In addition, the variable prediction of the traditional PTC method depends on the system model, which also has the problem of parameter uncertainties. This paper investigates a disturbance observer (DOB)-based PTC approach for induction motor systems subject to load torque disturbances, parameter uncertainties, and time delays. Not only does the speed loop adopt a DOB-based feed-forward compensation method for improving the system disturbance rejection ability and robustness, but the flux, current, and torque predictions are also improved by using this technique. The simulation and experimental results verified the effectiveness of the proposed method.