Harmonic Analysis of Low-Stator-Slot and Rotor-Pole Combination FSPM Machine Topology for High Speed

The high-speed machine design is becoming important due to advantages such as high-power density and small size. Flux-switching permanent magnet (FSPM) machines have a simple rotor design without any windings or PMs, which makes them apt for high-speed operation. A low-pole topology of the FSPM machine is desirable to keep the operational frequency to a minimum. The lowest slot-pole combination for a three-phase FSPM machine is the 6-stator slot 4-rotor-pole topology. This research aims at investigating and analyzing the cause of the unbalance in the flux linkage and the back electromotive force waveforms of such an FSPM machine. The influence of rotor-pole width, stator-tooth width, and the magnet length has been analyzed to find the optimum design variable. Results will be useful in making this low-pole FSPM topology amenable for high-speed operations.