Fractional-Slot PMSMs with One Coil Parallel Branches Made Phases: Topological Characterization and Circulating Harmonic Currents Rejection

The paper deals with fractional-slot permanent magnet synchronous machines

(FSPMSMs) equipped with phases made up of one coil parallel branches, with emphasis on their

faculty to reject the harmonic currents circulating in the loops yielded by the phase parallel branches.

These exhibit attractive potentialities, especially their enhanced open-circuit fault tolerance capability.

Furthermore, these topologies are suitably-adapted for low-voltage power supply that makes them

viable candidates for possible integration in the 42V automotive technology. This potentiality is

further highlighted in battery electric vehicles where the passenger safety is greatly improved in case

of accidents thanks to the reduction of the DC bus voltage. The study is initiated by a star of

slots-based topological characterization of the FSPMSMs that make it possible the arrangement of the

armature phases according to one coil parallel branches, considering the cases of odd and even num-

ber of phases, arranged in double and single layer slots. Then, the star of slots approach is extended

to the investigation of the back-EMF harmonics in order to check the possible circulating harmonic

currents.