Investigation of the Self-Cooling Characteristics of a Novel Flux-Switching Permanent Magnet Machine

The objective of this paper is to investigate the self-cooling performance of a novel integrated flux-switching PM (FSPM) machine with the airfoil-shaped rotor. The rotor of the proposed integrated machine is functioning as both a rotor of the motor as well as an axial fan. It rotates to draw air from the ambient into the rotor and accelerate the flow through the rotor stage. The high-speed flow provides forced convection to the rotor, stator, windings, and magnets. Therefore, self-cooling is achieved. Accounting for manufacturing challenges of the airfoil blades, 3-D printed blade caps are designed and assembled over the laminated rotor poles for the airfoil-shaped rotor. In this work, electromagnetic performance is verified by 3-D finite element analysis (FEA). The convective heat transfer coefficients are calculated by analytical methods using Taylor-Couette flow and numerical simulations by 3-D computational fluid dynamics (CFD). The effect of encapsulations on the windings will also be investigated accounting for effective thermal conductivity and in-slot heat transfer from the winding to the stator.