Improved Analytical Estimation of Rotor Losses in High-Speed Surface-Mounted PM Synchronous Machines

Abstract

The prediction of rotor losses, primarily due to eddy currents (ECs) in either magnets or other rotor conductive parts, is of great concern for the design of surface-mounted permanent magnet synchronous machines. Particularly, in high-speed electrical machines, EC losses could be severe and seriously affect the machine performance in terms of thermal management and demagnetization, in turn influencing the efficiency. This paper proposes a novel and more comprehensive approach for analytically detecting rotor losses in such machines; broadening investigation techniques already well established by considering the slotting effect and its interaction with stator winding generated by magnetic field harmonics. Therefore, predicting the electromagnetic behavior of EC losses by means of the presented fast and accurate procedure represents a useful instrument for electromechanical designers to assess the machine performance.