Power Loss and Thermal Analysis of a MW High Speed Permanent Magnet Synchronous Machine

High speed permanent magnet synchronous machines (PMSMs) have attracted much attention due to their high power density, high efficiency, and compact size for direct-drive applications. However, the consequent power loss density is high and heat transfer is also deemed as a technical challenge. This is particularly the case for high-speed operation. In this paper, electromagnetic and mechanical power losses in a MW level high speed PMSM is comprehensively investigated by finite element analysis; the transient machine demagnetization performance is studied with the proposed rotor composite structure to improve the machine anti-demagnetization capability; the temperature distribution of the high speed PMSM is also analyzed by a fluid-thermal coupling method with calculated power loss. The high speed PMSM is prototyped and experimentally tested to validate the effectiveness of numerical models and calculated results