Calculation of eddy field and temperature field for u-shape single phase line-start permanent magnet synchronous motor based on 3D FEM

In order to restrain the fluctuation of speed, vibraton, and increase the ability of starting under load, a copper sleeve was mounted outside the permanent magnet rotor of U-shape single phase line-start permanent magnet motor. The eddy-current field was calculated by using A, φ-A 3D finite element method, and the eddy-current distribution and eddy-current loss were computed. Using the coefficient of heat emission obtained according to the theory of fluid similarity, the 3D temperature field was calculated. The curves between eddy loss, temperature and thickness of copper sleeve were gained. The experimental results show that the calculated results of temperature field can satisfy the demand of engineering computation.