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

Abstract

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.