Fault-tolerant control of modular linear flux-switching permanent-magnet motor

The modular linear flux-switching permanent-magnet (M-LFSPM) motor is a newly investigated brushless AC (BLAC) machine having magnets and armature windings in the mover. Due to its reduced cost, improved effiency and enhanced fault tolerance, this motor is very suitable for high reliability urban rail transit applications. This paper proposes and implements a new constant-total magnetomotive force (CTMMF) control strategy for fault-tolerant operation of M-LFSPM motor. The key is to keep total magnetomotive force constant before and after the fault. Based on its operation principles, the mathematical model of the M-LFSPM motor is built. By building a CTMMF-abc equation of the M-LFSPM motor in the a-b-c reference frame, the proposed fault-tolerant control strategy is developed. Finally, simulation at normal and fault-tolerant operations are performed. The results verify that the proposed fault-tolerant control method can maintain the output thrust capability while offering good dynamic performance during fault.