Design Methodologies of High Speed Surface Permanent Magnet Synchronous Machines

This paper investigates the challenges of designing high speed surface permanent magnet synchronous motors. In particular, the material selection of the permanent magnet retaining system is addressed considering all its multi-physics implication. First, a design methodology capable of accounting for electromagnetic, structural and thermal aspects is presented and then used to compare different sleeve materials, different current calculation criteria and airgap thicknesses. Adopting the proposed approach, the maximum electromagnetic performance for a given outer envelope and the machine thermal behaviour are deduced for all the considered design scenarios. Indeed, the convenience of adopting metallic or composite sleeve is eviscerated according to both airgap thickness and current’s calculation criteria leading to the definition of general design guidelines.