机械应力对取向硅钢片综合磁性能影响的实验研究

Experimental Study on the Effect of Mechanical Stress on the Comprehensive Magnetic Properties of the Grain-Oriented Silicon Steel

变压器铁心在运行时长期承受外施应力和高频激励的影响,由此导致的振动噪声和铁损问题日益严峻。为深入研究取向硅钢片在不同频率和应力下的综合磁性能,该文搭建了软磁材料综合磁性能测量平台,首先利用单片磁特性测量装置和应力施加装置,得到了工频下拉应力和压应力对取向硅钢片磁致伸缩、磁滞回线及铁损特性的影响。进一步研究了应力和不同激励共同影响下硅钢片综合磁性能的变化趋势,得到了不同激励、应力对取向硅钢片磁特性、磁致伸缩特性及噪声特性的影响规律。测量结果及其分析表明,拉应力对硅钢片的磁性能影响相对较小,而压应力对其影响较大;在压应力作用下,随着频率的升高取向硅钢片的磁致伸缩量有所减小,但频率、谐波含量、谐波次数和压应力的增大均导致取向硅钢片噪声增大。

Transformer cores are subjected to external stress and high-frequency excitation for a long time during operation,which leads to increasingly severe problems of vibration,noise,and loss.To further study the comprehensive magnetic properties of the grain-oriented silicon steel sheet under different frequencies and stresses,a platform for measuring the comprehensive magnetic properties of soft magnetic material is established.Firstly,the effects of tensile and compressive stress on magnetostriction,hysteresis loop and loss characteristics of the grain-oriented silicon steel at 50Hz are obtained by using a single-sheet tester and a stress-controllable device.Furthermore,the variation of the comprehensive magnetic properties of the grain-oriented silicon steel sheet is studied,and the influence of stress and different incentives on the magnetic,magnetostrictive and acoustic characteristics is analyzed.The measured results show that compressive stress rather than tensile stress greatly influences on the magnetic properties of the grain-oriented silicon steel sheet.Furthermore,the magnetostriction decreases with the increase of frequency under compressive stress,whereas the noise increases with higher frequency,harmonic content,harmonic order,and more immense compressive stress.