Study on Decreasing the Rotor Eddy Current Loss of Surface Permanent-Magnet Motors with Copper Sleeves

抄録

In high-speed surface permanent-magnet motors, eddy current loss in the rotor caused by magnetic flux harmonics is a significant problem. Although copper sleeves can reduce the eddy current loss of the rotor, the reduction effect on each eddy current harmonic component is not clear. In this paper, we calculate the eddy current loss in the rotor using finite element analysis, divide the losses into each harmonic magnetic flux component, and analyze the influence of copper sleeve on each harmonic component. Based on the knowledge obtained in the analysis, we propose the use of copper sleeve with holes as a method for reducing rotor loss further. The effect of the proposed method is verified using electromagnetic simulation.