Performance analysis of a wedgy airgap disk coreless permanent magnet synchronous motor

A wedgy Airgap disk coreless PMSM (permanent magnet synchronous motor) is proposed, consisting of only stator (armature) winding and twin rotor system-a double sided rotor with internal stator. No stator and rotor ferromagnetic cores have been used. And the axial air gap thickness of this PMSM in inner diameters equals to 8mm, while the axial air gap thickness in outer diameters is 5.4mm. The FEM analysis has been done to prove that the peak value of the magnetic flux density can be about 0.7T. There are high efficiency of 92% and high power factor of 0.99 in this low speed 250W PMSM. There is about 30% higher efficiency in this motor than that of Y2-series three-phase asynchronous motor. The wedgy airgap disk coreless PMSM will be widely used in electric vehicle, hand-held electric tool, mechanical arm and so on.