Mechanical Refinements for the Stress Reduction of High-Speed Synchronous Reluctance Machines

This paper deals with the design of Synchronous Reluctance Machines for high-speed applications. In particular, this work is focused on the impact of different mechanical refinements made on the rotor lamination with the aim of reducing the maximum stress at high-speed operations. A synchronous reluctance machine, with rated speed equal to 50000 rpm, is firstly designed by means of an automated tool based on optimization algorithms; during the optimization stage, fast magneto-static finite element simulations coupled to an analytical model for the mechanical sizing of the rotor structure are adopted in order to quickly evaluate thousands of candidate machines. After the optimization procedure, different mechanical refinements are manually performed on the selected machine and their influence on the overall performance is evaluated by means of accurate structural and magnetic finite element analysis. The main steps of the design procedure as well as the influence of the geometrical variations on the Von Mises stress reduction within the rotor lamination are presented and analyzed.