基于有限元模型的500 kV变压器直流偏磁特性分析  

Analysis of DC Bias Characteristics of 500 kV Transformer Based on Finite Element Model

作　　者：樊贝 杜龙 王大江 FAN Bei;DU Long;WANG Dajiang(State Grid Suqian Power Supply Company of Jiangsu Electric Power Co.,Ltd.,Suqian 223800,China;State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China)

机构地区：[1]国网江苏省电力有限公司宿迁供电分公司,江苏宿迁223800 [2]国网江苏省电力有限公司电力科学研究院,江苏南京211103

出　　处：《电力科学与工程》2022年第12期55-60,共6页Electric Power Science and Engineering

摘　　要：利用Ansys/Maxwell 2D建立了500 kV单相自耦变压器有限元模型。通过在中性点施加不同幅值的直流量,模拟了变压器直流偏磁状态。对变压器内部磁场分布、励磁电流变化规律及空载损耗进行了有限元仿真计算分析。在直流偏磁发生时,铁心铁轭磁感应强度增加明显,较容易进入半波饱和状态。随着直流偏磁程度加剧,一方面,励磁电流中基波及谐波持续增长,其中偶次谐波增幅较快,励磁电流波形发生严重畸变;另一方面,空载损耗逐渐增大且分布有所变化,但增速逐渐变缓,铁心柱受直流偏磁影响较大。以上结果可为进一步研究变压器直流偏磁特性提供参考。The finite element model of 500 kV single-phase autotransformer is established by Ansys/Maxwell 2D.By applying DC with different amplitudes at the neutral point,the transformer DC bias state is simulated.The distribution of magnetic field,excitation current and no-load loss in transformer are analyzed by finite element simulation.When DC bias occurs,the magnetic induction intensity of the core yoke increases obviously and it is easier to enter the half-wave saturation state.As the degree of DC bias intensifies,on the one hand,the base wave and odd and even harmonics of the excitation current continue to increase,and the even harmonics increase faster,which causes serious distortion of the excitation current waveform.On the other hand,the no-load loss gradually increases and its distribution changes,but the growth rate gradually slows down.The core column is greatly affected by DC bias.The above results can provide reference for further study of transformer DC bias characteristics.

关 键 词：自耦变压器 有限元分析 直流偏磁 励磁电流 空载损耗 

分 类 号：TM41[电气工程—电器]