直流偏磁条件下电力变压器振动特性研究进展

Status and progress of research on transformer vibration characteristics with DC bias

基于电力系统中直流偏磁成因及变压器振动机制的分析,结合演绎铁磁材料本构关系的基础理论,从磁畴理论、现象学理论、热力学关系及弹性力学4个角度对磁致伸缩的建模机理与存在的问题进行了分析。在此基础上,对发生直流偏磁时磁致伸缩的现有计算模型进行对比,并讨论了发生直流偏磁时的硅钢片实验与变压器现场测试等研究中的不足,继而探析变压器振动的实验研究中直流电源的引入方式。综合分析现有研究进展后指出,为了给评估变压器承受直流偏磁能力与指导变压器的设计等提供参考,亟需研究直流偏磁时铁磁材料的磁化特性与磁致伸缩的模型这2个科学问题。

Based on the analysis of the forming reason of DC bias and the vibration mechanism of transformer in power system and combined with the fundamental theory of ferromagnetic material constitutive relation deduction,the modeling mechanism of magnetostriction and corresponding problems are elucidated from aspects of the magnetic domain theory,thermodynamic relationship,phenomenological theory and elasticity.On this basis,the existing computing models of magnetostriction with DC bias are compared,and the inadequacies of silicon steel sheet and onsite transformer tests when DC bias occurs are discussed.Furthermore,the inducing modes of DC power source during the experimental study of transformer vibration are explored and analyzed.According to the comprehensive analysis of the current research progress,it is pointed out that special attention should be paid on science problems such as ferromagnetic material magnetization characteristics and magnetostriction modeling,so as to provide a reference for evaluating the transformer withstand ability of DC bias and guiding the transformer construction design.