Discrete-time model predictive control for high performance speed control in an induction motor drive

Abstract

This paper proposes a discrete-time predictive controller for providing high performance speed control in an induction motor drive. Specifically, the conventional speed PI controller is replaced by a model predictive controller and the control law is derived by the optimization of an objective function that considers the reference and the real speed as well as the acceleration of the induction motor by using the state-space model. Thus, high dynamic performance can be attained at any load and speed conditions, whereas in a conventional speed PI controller, the parameters are optimally tuned only for a specific operating condition of load and speed. Furthermore, since the developed predictive control algorithm is based on the discrete model of the induction motor, it can be more effectively implemented in a motor drive microcontroller. Also, since the acceleration of the induction motor is considered in the control algorithm, fast dynamic response and satisfactory rejection of the load disturbances can be accomplished. The proposed discrete-time model predictive control system has been simulated in the Matlab/Simulink environment. Several simulation results have been presented in order to validate the effectiveness and demonstrate the operational improvements of the proposed control scheme.