Predictive direct torque control with reduced ripples and fuzzy logic speed controller for induction motor drive

The direct torque control (DTC) suffers from high torque and flux ripples due to the use of hysteresis comparators. In this paper, an alternative method is presented for induction motor drive known by the model Predictive Torque Control (PTC). This technique includes the inverter model in control design and does not use any modulation block. The optimal selection of inverter switching states minimizes the error between references and the predicted values of control variables by the optimization of a cost function. Consequently, it reduces ripples and solve DTC drawbacks. Furthermore, this paper proposes an improvement in the external speed loop for PTC scheme. A fuzzy logic controller replaces the traditional PI controller to ensure more accurate speed tracking and increase the robustness against disturbance and uncertainties. The effectiveness of the presented algorithms is investigated by an experimental implementation with the aid of real-time interface (RTI) based on dSpace 1104.