Analysis of power loss of permanent magnet synchronous motors in more-electric-aircraft considering the impact of temperature

The permanent-magnet synchronous motor (PMSM) is playing an increasingly important role in the development process of more-electric aircrafts and all-electric aircrafts. The working performance and the temperature level of PMSMs are closely interacted and interact on each other. In this paper, loss models of the PMSM were derived based on the electromagnetic induction principles and taking consideration of the influence of temperature on the permanent magnet characteristics and other material properties of the motor. A simplified thermal network was developed to estimate the temperature distribution of the PMSM. Taking a typical small-size PMSM as an example, the impacts of temperature on the losses and working efficiency of the motor were analyzed under different working states and various convection cooling intensities. Results indicate that the higher temperature will lead to a larger thermal loss and a lower working efficiency of the PMSM which can be improved with a better cooling management system. The temperature was a non-negligible factor for the loss estimation during the design process of a PMSM.