A hybrid excitation flux-switching permanent magnet linear motor for urban rail transit

In this paper, a hybrid excitation flux-switching permanent magnet linear motor (FSPMLM) is proposed. The proposed motor can be used as urban rail transit drive motor. The key of this structure is to have the magnet, armature windings, and DC field windings all on the short mover, while the long stator is only made of iron. The air gap flux density can be regulated by changing the magnitude and direction of DC excitation current, so it can not only reduce the drive system cost but also offer controllable electromagnetic force and electromotive force (EMF). This is helpful to extend the motor speed range and improve the system efficiency at different loads and speeds. The finite element analysis results validated the claims.