摘要
电力变压器发生短路故障时会产生巨大的电动力,为研究电力变压器短路故障时的绕组变形情况以及影响绕组变形的因素,文中基于变压器多物理场耦合理论,搭建了三相变压器的有限元模型,通过MATLAB/Simulink平台仿真变压器发生短路时的短路电流,将该电流作为电磁场仿真的激励,计算出绕组的漏磁场和电动力分布,再采用电磁-结构场耦合的方法分析绕组的形变量大小和应力分布;运用相关理论分析不同温度条件对绕组变形的影响。结果表明,在辐向上,高压绕组受到向外膨胀的辐向电动力,中压和低压绕组受到向中间压缩的辐向电动力,在轴向上,各绕组均受到从端部向中间压缩的电动力,温度越高,绕组铜的杨氏模量越小,相同电动力作用下绕组变形量越大。研究结果对提高变压器抗短路能力具有一定的参考意义。
When a short circuit fault occurs in a power transformer,a huge electrical force is generated.In order to study the winding deformation and the factors affecting winding deformation during a short circuit fault in a power transformer,a finite element model of a three-phase transformer is built based on the coupling theory of multiple physical fields in the transformer.The short circuit current of the transformer during a short circuit is simulated using the MATLAB/Simulink platform,and this current is used as the excitation for electromagnetic field simulation.Calculate the leakage magnetic field and electrodynamic force distribution of the winding,and then use the electromagnetic structural field coupling method to analyze the size of the winding's deformation and stress distribution.Analyze the influence of different temperature conditions on winding deformation using relevant theories.The results show that in the radial direction,the highvoltage winding is subjected to radial electric force that expands outward,while the medium and low-voltage windings are subjected to radial electric force that compresses towards the middle.In the axial direction,each winding is subjected to electric force that compresses from the end to the middle.The higher the temperature,the smaller the Young's modulus of the copper in the winding,and the greater the deformation of the winding under the same electric force.The research results have certain reference significance for improving the short-circuit resistance ability of transformers.
作者
贺清锋
兰生
HE Qingfeng;LAN Sheng(College of Electrical Engineering and Automation,Fuzhou University,Fuzhou 350108,China)
出处
《变压器》
2024年第5期51-57,共7页
Transformer
关键词
电力变压器
短路电流
多物理场耦合
有限元法
温度
Power transformer
Short circuit current
Multi physical field coupling
Finite element method
Temperature
