Effective Model Predictive Control Approach for a Faulty Induction Motor Drive

Abstract

The paper presents an effective model predictive control (MPC) technique to enhance the performance of the induction motor (IM) drive under open phase fault condition. The mechanism of the proposed MPC approach is based on the stator field oriented control (SFOC) principle in which the stator flux is aligned to the direct axis of the rotating reference frame. In order to apply the proposed MPC approach on the faulty IM drive; the mathematical model of the IM is reconstructed to take the fault effect into account and for this purpose the single phase IM equivalent circuit is utilized. In order to improve the stator flux prediction process, an effective flux estimator is presented as an alternative to that one which uses a low-pass filter (LPF). The finite control set (FCS) principle is used to select the optimal voltages to be applied to the motor directly from the specified eight voltage vectors, which enables the elimination of the pulse width modulation (PWM). To testify the effectiveness of the proposed MPC in enhancing the dynamic performance of the IM drive under the fault condition; the IM drive performance under the proposed MPC is compared with the drive performance when applying the traditional predictive torque control (PTC). The obtained results confirm and emphasize the superiority of the proposed MPC in reducing the accompanied mechanical oscillations in the rotor speed and in eliminating the ripple contents in the controlled variables and enhancing the ability of the IM drive in riding through the fault.