Investigation of Voltage Harmonics of Dual-Armature Flux-Switching Permanent Magnet Machines

This paper investigates the voltage harmonics of dual-armature flux-switching permanent magnet (DA-FSPM) machines under load condition, with particular emphasis on the influence of stator and rotor armature reactions. Firstly, the mechanisms of the generation of even and fractional order coil voltage harmonics are investigated. It reveals that the alternate-SP-wound winding, alternate-RT-wound winding, stator winding distribution factor smaller than 1, and rotor winding distribution factor smaller than 1 cause asymmetrical armature reaction flux distributions in the DA-FSPM machines, thus additional harmonics are generated in the stator and rotor coil voltages under load condition. Furthermore, the elimination of even and fractional order harmonics in phase voltages are realized by means of selecting proper numbers of SP and RT and changing the stator and rotor coil connections. It shows that the torque ripple of the machines are reduced thanks to the reduction of voltage harmonics.