Fault-Tolerant Control Strategies for Dual Three-Phase Permanent Magnet Synchronous Machine with YASA Topology under Open-Circuit Faults

For the dual three-phase permanent magnet motor with yokeless and segmented armature (YASA) topology used for electric aircraft propulsion, reliability is a fundamental requirement. Two fault-tolerant control strategies under single-phase open-circuit faults were analyzed in this paper, one of which is based on constant magnetomotive force (MMF), and another one is based on a reduced-order decoupling mathematical model. Minimization of copper loss and maximization of output torque were employed as control objectives. Through simulation analysis, the motor speed and torque can be maintained at pre-fault levels by fault-tolerant control. However, the connection of the neutral line brings significant odd harmonics in the current, causing notable torque ripple. The torque ripple reaches 7.51% and 14.26% for the two control objectives under constant MMF-based strategy. However, the reduced-order decoupling model-based control strategy alleviated this issue by mathematical correction of the post-fault model of the dual three-phase YASA machine, reducing torque ripple to 3.19%-4.10%.