A Novel Dual-Side PM Machine With Decoupled Stator PM Topology

Dual-side permanent magnet (DSPM) machines have gained attention with their high torque density and high efficiency. However, the topologies of the stator PM and stator core are constrained in the regular design, limiting the utilization of the stator PM. Consequently, the torque production of the stator side is limited. To overcome this constraint, this article proposes a novel DSPM machine with a decoupled topology of stator PMs and iron core. The proposed design allows for optimal topologies of both components, enhancing the flux modulation effect in both the stator and rotor sides. This results in a generation of additional even-order harmonics of the equivalent stator magnetomotive force (MMF), thereby improving torque production on the stator side. Additionally, the placement of the stator split teeth can be evenly distributed along the stator bore, achieving an enhanced high-order harmonic of the stator permeance. Performance comparison between the conventional and proposed DSPM machines, following a global optimization, demonstrates that the proposed machine exhibits relatively high torque density and efficiency. Notably, the proposed machine achieves a 36.4% higher torque density while maintaining the same copper loss and PM usage. Finally, a prototype is manufactured and tested to validate the analysis.