Analysis of Temperature Effects on Performance of Interior Permanent Magnet Machines for High Variable Temperature Applications

The purpose of this paper is to analyze and investigate the influence of temperature variation on the characteristics and performance of interior permanent magnet (IPM) machines. The impact of temperature variation on the materials of IPM machines is discussed to show the sources of performance variation. The flux linkages, torque output capability, and inductance variation as functions of the temperature are analyzed and discussed. This paper also shows the influence of temperature variation on key IPM machines performance including constant torque curves, voltage limit ellipses, maximum torque per ampere trajectories, and torque-speed curves. Experimental results of a traction IPM machine verified the analysis and theory. The results and trends shown in this paper set a foundation for developing control algorithm, which takes the temperature effects into consideration, especially in the applications where operating temperature varies significantly.