A novel control method for improving reliability of 3-phase induction motor drives under the stator winding open-circuit fault

Post-fault control of a 3-phase Induction Motor (IM) drive under the Stator winding Open-Circuit Fault (SOCF) has gained significant importance in recent years especially for safety-critical industrial applications. Nevertheless, most of proposed schemes suffer from low accuracy or high complexity. In this research, a novel control scheme for improving reliability of wye-connected 3-phase IM drives under the SOCF according to Direct Field-Oriented Control (DFOC) is proposed and evaluated. In the proposed system, different transformations are presented and employed to control the faulty system. The controller is achieved by minor modifications in the traditional control scheme structure. In the proposed system, an Extended Kalman Filter (EKF) is also used to estimate the rotor flux. The designed EKF-based DFOC (DFOCEKF) is verified using simulations and experimental tests conducted on a 0.75 kW 3-phase IM drive. Based on the results it can be calculated that the torque ripple is decreased clearly after the proposed fault-tolerant control approach is applied. The DFOCEKF strategy can control the faulty motor accurately, which can further improve the reliability of IM drive systems. The results also confirmed that the proposed controller after the SOCF has faster dynamic response and higher accuracy compared to previous published papers.