Eddy Current Loss Analysis of High Speed Permanent Magnet Motor with Partial Shielding

The research on the eddy current loss of high speed permanent magnet motor(HSPMM) is very important to the temperature rise and efficiency of the motor. In this paper, the partial shielding method is used for reducing eddy current loss of permanent magnet, and the shielding layer exists only on the surface of permanent magnet. Through the finite element analysis, it is found that the partial shielding can effectively reduce the eddy current loss in permanent magnet, and the shielding effect is close to that of the shielding ring. Reasonable selection of the thickness of the partial shielding layer can effectively reduce the rotor eddy current loss. Meanwhile, the influence of slot opening on rotor eddy current loss is investigated, with the increase of slot opening, rotor eddy current loss increases gradually, especially the stator slot opening is larger than 3mm, the reason is that the air gap permeance is uneven due to slot opening.