Comparative Analysis of a Synchro nous Reluctance and a Solid-Rotor Induction Machine for High-Speed Applications

High-speed applications represent a challenge in electrical machine design due to the thermal, mechanical and electromagnetic factors involved. Consequently, a good selection of the machine topology is crucial to satisfy the requirements of these applications. Nevertheless, devising appropriate selection criteria requires comprehensive comparative studies between prominent topologies, in order to provide relevant information of their suitability for different operating scenarios. This article presents a comparative study based on the finite element analysis (FEA) of two high-speed electrical machines sharing a common stator design: a synchronous reluctance machine and a solid rotor induction machine. Both with a mechanical speed of 20,000 r/min. The results show that, for the same mean torque objective, the SynRM provides lower core losses and higher overall efficiency, at the cost of developing higher torque ripple. Additionally, the SR-IM suffers from significantly lower mechanical stress, creating headroom to withstand higher operation speeds without compromising the rotor structure integrity.