Cooling System Design and Temperature Field Analysis for High-Speed Switched Reluctance Motor Considering Multi-Field Coupling of Electromagnetic-Thermal-Flow

Given the problems of high loss density and heat dissipation difficulties in high-speed switched reluctance motors (HSRMs), it is essential to design an effective cooling system and accurately predict temperature rise. In this paper, a 3kW, 20000 r/min HSRM is investigated, and a cooling system design and temperature field analysis method for HSRM considering the coupling of electromagnetic-thermal-flow (EM-TF) is proposed. First, an electromagnetic simulation model is established, incorporating an AC copper loss calculation method based on fine winding modeling and a windage loss calculation method using full air-domain modeling to enhance accuracy. The calculated losses are then used as heat sources for thermal simulation. Subsequently, based on the unidirectional electromagnetic thermal-flow coupling (UEMTFC), the flow and thermal field performances of spiral, axial and circumferential waterways are compared, and the structural parameters of the optimal waterway are determined. Finally, the temperature rise is calculated using UEMTFC and BEMTFC, and the results are compared with experimental data. BEMTFC introduces flow field coupling, and accounts for the influence of temperature on the motor material and internal air properties during the iteration process, achieving higher accuracy. The deviations from the measured values are less than 4°C, demonstrating its effectiveness in HSRM thermal analysis.