ABSTRACT
As suggested in Chapter 1, the flux-reversal (FR) PMSM may be considered a kind of “flux modulation” single-airgap (single-rotor) machine similar to the switched-flux PMSM. However, at the time of FR-PMSM introduction, the main idea was to use it in doubly salient machine multiple alternate polarity PMs on wider stator poles that host nonoverlapping multiple-phase windings made of 2mk coils (m—number of phases, k—an integer). Only the passive rotor has the function of magnetic saliency with Nr salient poles. In an effort to use the PMs better (to make them all active all the time), spoke-shaped PMs may be placed in the rotor sandwiched between two magnetically anisotropic stators that are phase shifted with each other by a PM pole pitch.
