Model Predictive Direct Speed Control of PMSM with Load Torque Compensation

In this paper, a free regulator model predictive direct speed control (MPDSC) is presented depending on accurate prediction of system status and selection of input voltage vectors using optimization criterion, i. e., a cost function. The research presents a good compensation for the load torque, which is an external disturbance in general, and the load parameters of PMSM, resulting in prediction inaccuracy. Since it is intended to implement the predictable model to a real system. Therefore, compensation is introduced to correct the error between the predictable model and the real system. The proposed control method is taken into account by tracking the maximum torque per ampere (MTPA) in the operating region below rated speed for high electrical efficiency, above the rated speed, field weakening is obtained in order to preserve the machine's power limit. The proposed control method was tested on a small PMSM at various speeds. Compared to the traditional direct torque control with an outer PI controller. The proposed MPDSC rapidly tracks the speed reference with good dynamic response and small offset and speed ripples.