硅钢片磁致伸缩引起的铁心振动是变压器噪声的主要来源。为研究由该振动引起的噪声分布并为降噪提供依据,必须对硅钢片的磁致伸缩现象有一个清楚的认识。不同于以往通过实验数据拟合得到磁致伸缩经验公式模型的方法,该文从磁致伸缩的物理发生机制出发,建立了适用于晶粒取向性硅钢片的磁致伸缩本质模型,该模型综合考虑了磁场和外应力对磁致伸缩现象的影响,为准确模拟实际变压器铁心的磁致伸缩提供了理论依据。基于磁致伸缩本质模型,利用弹性力学相关理论,进一步建立了变压器铁心的振动模型,并利用有限元软件ANSYS进行了仿真分析。仿真结果表明,所建立的模型可准确模拟磁致伸缩引起的铁心变形,为后续的噪声分析打下了良好的基础。
Transformer noise mainly comes from the iron core vibration caused by the magnetostriction of silicon steel sheets. In order to study the distribution of noise caused by this vibration and provide the basis for the noise reduction, it is necessary to have a clear understanding of the magnetostrictive phenomenon of silicon steel sheets. Unlike previous empirical model of magnetostriction obtained by experimental data fitting, the magnetostrictive intrinsic model which is suitable for grain oriented silicon steel sheets was established in this paper. The model considered the effect of the magnetic field and the external stress on magnetostrictive phenomena, and provided a theoretical basis for the accurate simulation of magnetostriction of the actual transformer core. Based on the magnetostrictive intrinsic model and the theory of elastic mechanics, the vibration model of transformer core was established and the finite element software ANSYS was used to simulate the model. The simulation results show that the model can accurately simulate the deformation of the core caused by magnetostriction, and lay a good foundation for the subsequent noise analysis.