Postfault Strategy of Universal Control for Dual Three-Phase PMSM Under Single Open-Phase Fault Considering Current Amplitude

Dual three-phase permanent-magnet synchronous motors (PMSMs) are becoming more popular in safety-critical applications such as aircraft systems and electric vehicles, primarily due to their robust fault-tolerant capabilities. Recently, natural fault-tolerant control methods have drawn attention to their abilities to avoid the complexities of control structure reconfiguration, fault diagnosis, and current reference adjustments. However, the postfault performances, particularly regarding the stator copper loss and the current amplitude, have remained uncertain or uncontrolled in most reconfiguration-less control methods. Aiming to fill this gap, the postfault strategy has been investigated for dual three-phase PMSM with a single open-phase fault with a universal control structure. It is revealed that the postfault performance under open-phase fault can be determined by the positive-sequence current in harmonic subspace. The amplitude model of each phase current has been established as a function of the current amplitude ratio and the phase shift between dual three-phase windings. On this basis, the maximum torque (MT) can be achieved by the universal control method under postfault conditions. The experimental results are presented to illustrate the effectiveness of the proposed method.