Coupled Electromagnetic-Thermal-Mechanical Analysis for Accurate Prediction of Dual-Mechanical-Port Machine Performance

The performance of an electrical machine depends not only on electromagnetic (EM) parameters but also on the cooling system, the mechanical deformation, and the control system, which are closely coupled with each other. In this paper, a coupled EM-thermal-mechanical analysis for accurate prediction of dual-mechanical-port (DMP) machine performance is proposed. A unified model for the coupled analysis with the same mesh is built, in which the material properties are nonlinear and adjusted on the basis of temperature distribution. Two-dimensional EM finite-element analysis is carried out with the temperature feedback from thermal analysis. The detailed temperature distribution is derived from the losses in the EM analysis. Then, with the force and temperature distributions, mechanical analysis of the surface-mounted permanent-magnet outer rotor with glass fiber is implemented to examine the mechanical deformation and testify the mechanical strength under rated working condition. Finally, with the coupled analysis, a prototype DMP machine is designed, fabricated, and tested in the laboratory. Experimental results are given to verify the accuracy of the proposed analysis.