Analysis of Flux-Modulating Synchronous Motors

Abstract

This paper analyzes the electromagnetic performance of flux-modulating synchronous motors (FMSMs) when the rotor design or motor topology is changed. The following inferences can be made from the results of the finite element analysis. 1) By setting an offset on the salient-pole rotor, it is possible to suppress the harmonics in the back-EMF waveform and reduce the cogging torque and torque pulsation. 2) Even if the rotor design is changed from the salient-pole type to the flux-barrier type or segment type, their torque densities are almost the same. 3) In the outer-rotor configuration, a high torque can be obtained by effectively utilizing the inner space as compared with the inner-rotor configuration. In addition, the outer-rotor configuration makes it easy to reduce the losses and improve the efficiency while obtaining nearly the same torque density as that of the partitioned-stator configuration.