The eddy current loss segmentation model of permanent magnet for temperature analysis in high‐speed permanent magnet motor

Abstract

The rotor eddy current loss of high‐speed permanent magnet motor has an important influence on the temperature distribution of permanent magnet. In traditional method, the unbalanced distribution of eddy current in permanent magnet is ignored, and the eddy current loss is applied to the calculation of temperature field in the form of average heat density, which makes a certain error in the calculation of the temperature field in permanent magnet motors. This study proposes the 50 kW and 30,000 rpm high‐speed permanent magnet prototype and an eddy current loss segmentation model of permanent magnet. The unbalanced distribution of eddy current in permanent magnet is considered in this model, and the permanent magnet is divided into different regions. According to the eddy current loss segmentation model, the eddy current losses in different regions are obtained, then the heat density in different regions of permanent magnet is applied to the calculation of temperature field in the motor. The application of the proposed model is simple and convenient, and makes temperature simulation results closer to the actual situation. At the same time, in order to verify the accuracy of the model, the temperature calculation results using the proposed model are compared with the traditional method, and both the results are verified by relevant experiments.