变温条件下TbDyFe合金高频磁特性和损耗特性分析

Analysis of High Frequency Magnetic Properties and Loss Characteristics of TbDyFe Alloy under Variable Temperature

超磁致伸缩材料TbDyFe合金具有温度敏感特性,该文测量变温条件下TbDyFe合金在不同频率f和磁通密度幅值Bm时的动态磁特性曲线,结果表明,当励磁磁场频率f和磁通密度幅值Bm一定时,随着环境温度的升高(从10℃增加到80℃),振幅磁导率逐步增加,动态磁滞回线横向变窄,所需磁场强度减少,磁能损耗也逐步减少。在此基础上,针对现有损耗计算模型无法对温度进行有效表征,而导致损耗计算结果误差较大的问题,提出一种变温条件下磁致伸缩材料的高频损耗计算模型,模型通过引入温度有关项对损耗系数进行修正;并且综合考虑高频磁滞特性和趋肤效应的影响,引入损耗附加磁通密度项及损耗附加频率项,从而建立可以有效考虑温度效应的改进损耗计算模型,通过多组测量值及计算值的对比结果验证了该模型的准确性和可行性。

The giant magnetostrictive material TbDyFe alloy has temperature-sensitive characteristics.In this paper,the dynamic magnetic characteristic curves of TbDyFe alloy are measured under variable temperature conditions at different frequencies f and magnetic density amplitude Bm.When the frequency f and magnetic density amplitude Bm are fixed,with the increase of the ambient temperature(from 10℃to 80℃),the amplitude permeability gradually increases,the dynamic hysteresis loop becomes narrower laterally,the required magnetic field strength decreases,and the magnetic energy loss gradually decreases.Since the existing loss calculation model cannot effectively characterize the temperature effect that leads to errors in the loss calculation results,a high-frequency loss calculation model for magnetostrictive materials under variable temperature conditions is proposed.The model corrects the loss coefficients by introducing temperature-related terms.Considering the influence of high-frequency hysteresis characteristics and skin effect,the loss additional magnetic flux density terms and loss additional frequency terms are introduced.Accordingly,an improved loss calculation model that can effectively consider the temperature effect is established.The comparison of measured and calculated results verifies the accuracy and feasibility of the model.