Single open-phase fault detection and tolerant control for wye-connected three-phase induction machine drives

This paper proposes open-phase fault detection (FD) and tolerant control strategies for wye-connected three-phase induction machines (WCTPIMs). The FD mechanism is based on the comparison between predicted and actual values of stator currents, and the control approach is derived from the field-oriented control (FOC). In the proposed fault-tolerant control (FTC) method, an asymmetrical current transformation is used for stator current components, and the conventional symmetrical voltage transformation is employed for stator voltage components. It is shown that using these transformations, a modified FOC can be employed for the faulty WCTPIM. The suggested scheme is able to control WCTPIM drives under normal and single open-phase fault (SOPF) modes with minor adjustments. Experimental results achieved from a laboratory prototype confirm the possibility and good performance of the proposed open-phase FD and tolerant control for the WCTPIM under different operating conditions. In this paper, a novel field-oriented control for three-phase induction motors under a single-phase open-circuit fault is proposed. Compared to the standard field-oriented control, the post-fault control method designed in this paper only uses variable current PI controllers, and it includes a different d-q transformation. The validity of the proposed control strategy has been proven by several experiments. Based on the experimental results, the standard field-oriented control achieves high torque and speed ripples and unbalanced current amplitude after the fault, while the proposed field-oriented control demonstrates superior transient and steady-state performances. In addition, compared with previous studies, the proposed controller in this paper can suppress the torque ripple. image