500kV电力变压器直流偏磁损耗特性的仿真研究  

Simulation Study of DC Bias Loss Characteristics of 500 kV Power Transformer

作　　者：韩金华[1] 杨晓辉[1] 王丰华[2] 段若晨[2] 郑含博[1] 

机构地区：[1]河南省电力公司电力科学研究院,郑州450008 [2]上海交通大学电气工程系,上海200240

出　　处：《高压电器》2015年第5期40-46,共7页High Voltage Apparatus

基　　金：国家自然科学基金项目(51207090)~~

摘　　要：局部过热是变压器发生直流偏磁现象时的一个重要特征。为了较为准确地分析变压器直流偏磁时的损耗特性及其诱发的局部过热问题,文中基于电路—磁路模型计算了500 kV变压器直流偏磁时的励磁电流,然后以此为边界条件建立了变压器的有限元分析模型,仿真研究了500 kV变压器的漏磁场和结构件损耗随直流分量的变化规律。计算结果表明,直流偏磁时,励磁电流、漏磁场、夹件和油箱表面的涡流损耗均随直流分量的增加呈现增大趋势。当变压器铁心工作在磁化曲线的饱和段时,励磁电流、夹件和油箱表面的涡流损耗的增幅加剧,可能会出现局部过热现象。研究结果可为变压器直流偏磁耐受性能分析提供理论依据。Local overheat is one of the important features resulted from the DC bias of a power transformer. To accurately analyze the loss characteristics and the corresponding local overheat, an electric circuit-magnetic circuit combination model is built to calculate the magnetic current of a 500 kV power transformer. Then a finite element analysis model of power transformer is established in the software ANSYS by taking the calculated magnetic current as boundary condition to obtain the variations of the leakage magnetic field and the loss of structural parts with DC component for the 500 kV power transformer. Calculation results show that all magnetic current, leakage magnetic field, and eddy losses in clamp piece and oil tank increase when the DC component enters into the power transformer. When the core operates in the saturated segment of magnetic hysteresis loop, the magnetic current and the eddy losses in clamp piece and oil tank increase greatly, which may result in local overheat. This study may provide a theoretical reference for the analysis of DC bias endurance of power transformer.

关 键 词：电力变压器 直流偏磁 漏磁场 涡流损耗 有限元分析法 

分 类 号：TM41[电气工程—电器]