Multi-physical Field Coupling Analysis of Flat Wire Motor

To further improve the accuracy of the complex multi-physics coupling system of flat wire motors, this paper presents an improved multi-physics field modeling method, which conducts a relatively comprehensive analysis of electromagnetic(EM), temperature, flow and stress field. And the multi-field coupling global model is simplified based on the analysis of two-field coupling relationships. First, each two-field coupling sub-model of four key physical fields is analyzed by bidirectional coupling and the weak coupling way is ignored. Secondly, based on the analysis results of the two-field coupling sub-model, the coupling relationship between electromagnetic field, temperature field and flow field is simplified and the global coupling model of electromagnetic field, temperature field and flow field inside the motor is established. Finally, because the stress field of the motor rotor is unidirectional influced by the temperature field, the rotor strength of the high-speed motor is analyzed based on temperature field to stress field coupling. Compared with the calculation results of EM and temperature two-field coupling, the accuracy of electromagnetic torque under multi-field coupling is increased by 4.4%, the calculation accuracy of electromagnetic loss is also increased by 2.1%. And the calculation accuracy of the motor temperature field is increased by 4.5%.