Abstract

High-speed electric machines aim for compact, direct-driven elevated speed applications and highly efficient operation, especially when a gearbox can be avoided. The design of these types of machines is highly iterative, combining multiphysics optimization and leading to custom types of machines that fulfill the application-specific requirements. The Axially Laminated Synchronous Reluctance Machine (ALASynRM) with a solid rotor is one of the motor types that can be considered for high-speed applications. An axially laminated solid rotor structure combines magnetic and nonmagnetic layers rigidly bonded to each other by vacuum brazing, hot isostatic pressing, soldering, explosion welding, or even additive manufacturing. In this study, six nonmagnetic materials and nine magnetic materials are cross-compared. The results show clear differences in performance, efficiency, and physical properties of the rotor when made of different material combinations and can thereby suggest the best pairs when the application-specific performance criteria are known. The study is carried out on a 12 kW machine with a maximum speed of 24000 rpm.