Lumped Parameter Thermal Model for Axial Flux Switched Reluctance Motors

Abstract

The accurate prediction of temperature rise in various parts of a machine plays a significant role in ensuring that the machine delivers the required performance avoiding failures that arise due to high temperatures. In this paper, a lumped parameter thermal model is presented for exterior-rotor axial flux switched reluctance motors. Depending on its geometry, each part of the motor is modeled as a thermal equivalent circuit based on general cylindrical or cuboidal components. A total thermal network is obtained by proper connection of these sub-circuits. The model was calibrated by a stationary test; then, running conditions were applied to the model. The sensitivity of the model to the heat transfer coefficients was investigated by considering the effect of the coefficient variation on the estimated steady-state temperatures. Results show that the winding temperature, as the hottest part of the motor, is the most sensitive to the frame-to-ambient heat transfer coefficients.

Keywords::

• axial flux motors
• lumped parameter thermal model
• switched reluctance motors

Additional information

Notes on contributors

Yousef Ebrahimi

Yousef Ebrahimi received the BSc degree in control engineering from Sahand University of Technology, Tabriz, Iran, in 2001, and the MSc degree in electrical engineering from Tabriz University, Tabriz, Iran, in 2008. He has been pursuing the PhD degree in electrical machine design since 2010 from the same university. He is also proficient in finite element analysis. His research interests include magnetic and thermal design and analysis of special electric machines with focus on SRMs.

Mohammad Reza Feyzi

Mohammad Reza Feyzi received the BSc and MSc degrees in 1975 from the University of Tabriz in Iran with an honor degree. He worked in the same university from 1975 to 1993. He started his PhD work in the University of Adelaide, Australia in 1993. Soon after his graduation, he rejoined the University of Tabriz. Currently, he is a professor in the same university. His research interests include finite element analysis, and design and simulation of electrical machines and transformers.