Design Considerations for a PM Synchronous Motor with Rotor Saliencyfor High Speed Drives

Abstract—This paper proposes some novel designs of perma- nent-magnet synchronous motors for extending their flux-weakening capabilities. According to such a proposal, the motors are greater than one, whereas characterized by a saliency ratio classical designs exhibit a saliency ratio lower than one. The innovative and classical design solutions are deeply compared in the paper. In order to understand better the basic differences in the motor design, the same base and flux-weakening performance are fixed. The influence of the saliency ratio on inverter voltampere ratings, maximum feasible speed, and current control characteristics is highlighted and discussed.