Magnetic–Thermal–Fluid Coupled Heat Transfer Analysis of an MPMFM-AFM With Mixed Flow Fan

To solve the heating problem of a multiport magnetic field-modulated axial flux motor (MPMFM-AFM) used in hybrid electric vehicles (HEVs), a ventilation structure based on a novel mixed flow fan is proposed. Based on the magnetic–thermal–fluid coupled iterative method, the transient temperature of the MPMFM-AFM is calculated. First, the structure and working principle of the MPMFM-AFM are introduced. The core loss, eddy current loss, and copper loss of the MPMFM-AFM under different working conditions are calculated. Second, when the multirotor rotation is taken into account, the 3-D heat transfer model of the MPMFM-AFM is established. Then, the transient temperature of the motor under different working conditions is calculated. The effects of inlet air velocity and water velocity on the maximum temperature of the motor are studied. Compared with existing axial flow fans and centrifugal fans, the permanent magnets and windings can be cooled more effectively by the proposed mixed flow fan. Finally, the prototype and four mixed flow fans are manufactured. The winding temperature and wind speed are measured. The accuracy of the proposed temperature solution method and the effectiveness of the mixed flow fan cooling structure are verified.