变压器拓扑修正暂态模型及其在直流偏磁耐受评估中的应用  

Topology-correct Duality-based Transformer Transient Model and Its Application in DC Bias Assessment

作　　者：李金龙 李金忠 张书琦 LI Jinlong;LI Jinzhong;ZHANG Shuqi(China Electric Power Research Institute,Haidian District,Beijing 100192,China;State Grid Corporation of China,Xicheng District,Beijing 100031,China)

机构地区：[1]中国电力科学研究院有限公司,北京市海淀区100192 [2]国家电网有限公司,北京市西城区100031

出　　处：《电网技术》2019年第9期3439-3446,共8页Power System Technology

摘　　要：近年来,随着特高压线路建设及投运数目的增加高压直流输电系统引起的直流偏磁日趋严重,非常有必要对变压器进行直流偏磁耐受评估。而直流偏磁工况下变压器激磁电流计算是直流偏磁耐受评估的重要研究内容。因此,根据变压器的铁心结构、绕组布置、逆磁滞回模型利用磁路-电路对偶原理提出一种综合考虑其结构特征与铁心材料的非线性磁化特性的拓扑修正暂态模型用于变压器直流偏磁激磁电流的计算。数值计算结果与试验测量数据具有良好的一致性,验证了所提模型的有效性。分析解释了不同材料、铁心接缝气隙厚度和漏感参数对计算结果的影响。经验证,变压器铁心材料对直流偏磁激磁电流的影响较小,气隙厚度和漏感参数是影响计算结果的重要参数,需根据试验结果对初始估计值进行必要修正。所得结论可为变压器拓扑修正暂态模型在直流偏磁耐受评估中的应用提供必要参考。Recently,transformer DC bias was on increasing rise with construction and operation of UHV transmission systems in China.It is essentially important to assess the tolerance level of transformer under DC bias.It was a key issue to calculate the exciting current of transformer under DC bias condition.In this paper,a topology-correct transformer transient model taking into account the structural characteristics and nonlinear features of iron core was proposed within duality principle of magnetic and electric circuits to calculate the exciting current of transformer under DC bias.Numerical results demonstrated a good consistency between computed current and measured data.The impact of major parameters,e.g.material type,air gap between core and yoke,zero sequence impedance,and etc.on transformer exciting current under DC bias were verified.It was concluded that the influence of core material type could be neglected,while the air-gap distance and leakage inductance should be carefully chosen and adjusted during computing.The proposed model and conclusions of this paper can provide reference for transformer DC bias assessment in engineering application.

关 键 词：变压器拓扑修正暂态模型 直流偏磁 磁滞模拟 电磁暂态 

分 类 号：TM85[电气工程—高电压与绝缘技术]