Thermo-Mechanical Analysis of High-Speed Brushless DC Motors with Phase Change Materials for Cooling Enhancement

Abstract: The work of this paper will provide a thermo-mechanical analysis of high-speed Brushless DC (BLDC) motors that are improved with Phase Change Materials (PCM) that require a better cooling performance. The widespread BLDC motors are affected by their thermal stress related to copper loss or magnetic hysteresis and mechanical friction that can lower the performance through degradation of insulation and efficiency. Historical air or liquid cooling systems are frequently unable to be used to stabilize temperature conditions during high-speed/varying load processes. Due to their use of a large latent heat storage capacity when changing phases, PCMs provide a passive and energy saving process in dealing with temperature rise. The findings and CFD simulations of experiments have proven that incorporating PCMs in BLDC motors bears potential of cutting the winding temperature by a half, which guarantees a higher thermal equality, as well as a longer lifespan of the motors. Also, the mechanical stress analysis showed that PCMs can reduce the thermo-mechanical strain due to the uneven thermal expansion, whereas sensitivity analysis helped to recognize the main parameters affecting cooling efficiency. Although PCMs have trade-offs in volumetric and weight and thermal lag aspects, the study reveals that PCMs significantly improve performance and reliability over the traditional methods of cooling. This study will point out the possibilities of PCMs as a thermo-sustainable thermal management solution to integrated electric motor uses on next-generation high-speed applications.