Analysis of the cooling performance based on the three-dimensional magnetic-thermal coupling in high-speed permanent magnet synchronous motor

The high-speed permanent magnet synchronous motors (HSPMSM) serve as the primary driving mechanism for the air compressor within the hydrogen fuel cell system; however, the heating problem is serious in HSPMSM and the heat is difficult to dissipate, which leads to severe challenges to the life and safety of the hydrogen fuel cell system. To solve this problem, an accurate indirect magnetothermal coupling analysis model was established to obtain the temperature characteristics of the HSPMSM. The loss of HSPMSM was analyzed initially, followed by an investigation into the interplay between the temperature and electromagnetic fields. Utilizing this model, the cooling efficiency of the axial channel and circumferential parallel channel were compared, and the temperature distribution considering the influence of the load and the high-temperature gas on the load side of the air compressor was analyzed. The findings suggest that, for the centrifugal compressor motors utilized in hydrogen fuel cell systems, the axial cooling waterway is recommended. • An indirect magnetothermal coupling analysis model of HSPMSM was established. • Axial cooling channel shows superior cooling efficiency at low water velocities. • Load and high-temperature gas significantly affect motor temperature distribution. • Cooling water flow rate increases stabilize motor temperature. • Bidirectional indirect coupling model enhances calculation accuracy.