Adaptive Harmonic Decoupling Sensorless Control Strategy of a New Five-Phase Flux-Intensifying Permanent Magnet Motor Under Healthy and Faulty Conditions

Five-phase flux-intensifying fault-tolerant interior permanent magnet (FIFT-IPM) motor has high torque output, wide speed range, and strong fault tolerance, which is suitable for the drive control system of electric vehicles (EVs). To meet the high reliability under the complicated and variable operating conditions of EVs, the fault-tolerant sensorless control is applied when the five-phase FIFT-IPM motor faces unavoidable faults. Regarding fault-tolerant sensorless control strategies, previous studies almost ignored the strong mutual coupling between fault-tolerant control and sensorless control. In this article, an adaptive harmonic decoupling (AHD) strategy for the fault-tolerant sensorless control of the five-phase FIFI-IPM motor is proposed. First, a new sliding mode disturbance observer (SMDOB) with adaptive gain is designed for fault-tolerant control to reduce complex disturbances. Meanwhile, to suppress the extended back EMF harmonics, a gradient descent adaptive filter (GDAF) with a dynamic learning rate is proposed from the perspective of sensorless control, which can greatly improve the estimated performance. Finally, the feasibility and effectiveness of the proposed strategy are verified by the corresponding experimental results.