Evaluation and Suppression of Windage Loss for High-Speed Flux-Switching Permanent Magnet Machine

In this paper, the issue of high windage loss caused by the salient-pole rotor of a 6-stator-slot/4-rotor-pole (6/4) high-speed flux-switching permanent magnet (HS-FSPM) machine is investigated, where a variety of windage loss suppression methods are proposed from both design and manufacturing process, respectively. Firstly, based on the hydrodynamics method, an analytical model for calculating the rotor windage loss of the HS-FSPM machine is established and the effects of both rotor tooth and slot shaping are evaluated. Secondly, the sensitive factors affecting windage loss, such as stator slot shape and the rotor outer frame size and shape, are analyzed to quantify the impact of each factor on windage loss. These sensitive factors affecting windage loss are classified, and the targeted suppression methods for windage loss are proposed. Validation is conducted using the computational fluid dynamics method. Then, to verify the rotor temperature rise and mechanical stress for the proposed windage loss suppression method, a multi-physics field coupling method is employed. Finally, different stator and rotor structures are manufactured and a prototype testing platform is built. Consequently, the windage loss separation experiments are conducted, which verifies the feasibility of the suppression method for windage loss of HS-FSPM machines.