Design of a Novel Axial Flux-Switching PM Machine Integrated with Centrifugal Compressor with Radial Impellers

The purpose of this paper is to design a novel axial flux-switching permanent magnet (FSPM) machine for driving centrifugal compressors. The rotor poles of the novel integrated axial FSPM machine function as the radial impellers of the centrifugal compressor. The radial impellers rotate and accelerate the flow to increase velocity before entering the diffusers. The novel integrated axial FSPM machine is capable of producing torque for accelerating the flow while eliminating the requirement of a separate motor. Therefore, the total size of the centrifugal compressor system is significantly reduced, and high power density can be achieved. In this paper, the design and working principles of axial FSPM machine and centrifugal compressor are provided. The design tradeoffs of the integrated axial FSPM motor-compressor are evaluated. Magnet bridges and rotor pole thickness optimizations are implemented in FEA to reduce the cogging torque. The thermodynamic performance is calculated by the velocity triangles.