直流偏置对磁致伸缩材料高频动态损耗及磁特性的影响分析

Impact Analysis of DC Bias on High-Frequency Dynamic Loss and Magnetic Characteristics for Magnetostrictive Materials

直流偏置磁场会造成磁致伸缩材料磁滞回环的畸变与不对称,影响材料的损耗数值与磁滞特性,且现有的磁能损耗模型无法对变直流偏置磁场下的损耗进行准确的表征和计算,因此有必要研究直流偏置对磁致伸缩材料磁特性的影响规律及数学表述,这对提高大功率磁致伸缩器件的输出性能具有重要意义。该文在变直流偏置激励条件下,测试了Terfenol-D样品在不同交流激励频率和磁通密度幅值下的动态磁滞回线,发现了其变化规律并提取了损耗特性和磁滞特性参数;基于Bertotti损耗分离理论和实测数据,采用Levebverg-Marquard算法,建立计及直流偏置影响的磁致伸缩材料高频损耗计算模型,该模型采用多元参数回归方法,通过引入直流偏置相关项对损耗系数进行修正;多种工况下的损耗计算值与实验值对比分析表明了计及直流偏置影响的磁致伸缩材料高频动态损耗特性模型的准确性。

The DC bias magnetic field caninducedistortion and asymmetry of the hysteresis loops for magnetostrictive materials,which affects the loss values and hysteresis characteristics,and the existing magnetic energy loss models cannot accurately characterize and calculate the losses under variable DC bias magnetic fields.Therefore,it is necessary to investigate the influence and mathematical expression on the magnetic properties of magnetostrictive materials when DC bias is applied,which is of great significance to optimizing the output characteristics for high-power magnetostrictive devices.In this paper,under variable DC bias,the dynamic hysteresis loops of Terfenol-D samples at different excitation frequencies and peak magnetic density fluxes are investigated,and the variation law is found when the loss characteristics and hysteresis characteristics parameters are extracted from these hysteresis loops.Based on Bertotti's loss separation theory and measured data,the Levebverg-Marquard algorithm is induced to establish a calculation model for high-frequency losses of magnetostrictive materials under DC bias.This model uses a multiple-parameter regression method to correct the loss coefficients by introducing the DC bias-related terms.The accuracy of the proposed model is verified by comparing the calculated loss values with the experimental values under various working conditions.