变温条件下钐钴永磁材料损耗特性测量与定量分析

Measurement and quantitative analysis of loss characteristics of Sm_(2)Co_(17) magnets under variable temperatures

大功率永磁电机较高的工作温度会对转子永磁体的磁性能和损耗特性产生较大影响。本文通过自主研制的变温条件下永磁体交流损耗测试系统,对钐钴永磁体开展多磁通密度、宽频率、宽温度范围内的交流损耗测量实验,并基于测量数据在Bertotti损耗分离理论的基础上提出变温条件下交流损耗计算公式,对不同频率下交流损耗随温度升高的变化情况进行解释和验证。结果表明:钐钴永磁材料的磁滞损耗与温度呈正相关,而涡流损耗与温度呈负相关。且当交流磁场频率升高时,总损耗中涡流损耗占比增加而磁滞损耗占比下降,导致在不同频率交流磁场下总损耗随温度升高呈现出不同的变化趋势。研究结果可为实际工况下钐钴永磁电机的优化和设计提供重要参考。

The higher operating temperature of high-power permanent magnet motors will have a greater impact on the magnetic properties and loss characteristics of the permanent magnets in the rotor.In this paper,through the self-developed temperature-dependent AC loss measurement system,the AC loss of Sm_(2)Co_(17)magnets is measured in multiple magnetic densities,wide frequencies,and wide temperature ranges.Based on the measured data and the Bertotti loss separation theory,the calculation formula of AC loss under variable temperature conditions is pro-posed,and the variation of AC loss with temperature increase at different frequencies is explained and verified.The results show that the hysteresis loss of Sm_(2)Co_(17)magnets is positively correlated with temperature,while the eddy current loss is negatively correlated with temperature.When the frequency of the AC magnetic field increases,the proportion of the eddy current loss in the AC loss increases and the proportion of the hysteresis loss decreases,re-sulting in different changing trends of the AC loss with the increase of temperature under the AC magnetic field of different frequencies.The research results can provide an important reference for the optimization and design of Sm2Co17 permanent magnet motors under practical conditions.