基于磁-热-流耦合模型的变压器损耗计算和热点预测  

Numerical Prediction of Losses and Local Overheating in Transformer Windings Based on Magnetic-Thermal-Fluid Model

作　　者：李永建[1,2] 闫鑫笑 张长庚[1,2] 陈怡帆 盈文亮 Li Yongjian;Yan Xinxiao;Zhang Changgeng;Chen Yifan;Ying Wenliang(Hebei Province Key Laboratory of EFEAR Hebei University of Technology,Tianjin 300130,China;State Key Laboratory of EERI Hebei University of Technology,Tianjin 300130,China;TBEA Tianjin Transformers Co.Ltd,Tianjin 300450,China)

机构地区：[1]省部共建电工装备可靠性与智能化国家重点实验室(河北工业大学),天津300130 [2]电磁场与电器可靠性省部共建重点实验室(河北工业大学),天津300130 [3]天津市特变电工变压器有限公司,天津300450

出　　处：《电工技术学报》2020年第21期4483-4491,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51777055,51807048);河北省杰出青年科学基金(E2018202301)资助项目。

摘　　要：基于有限元法对一台2500kV·A干式变压器进行额定负载条件下的三维瞬态电磁场模拟仿真,计算中考虑了漏磁场对箔式绕组和结构件涡流分布的影响。将电磁损耗计算结果按照网格逐单元耦合至温度场,并以此为热源建立磁-热-流多物理场映射关系,考虑温度对材料损耗特性的影响,精确模拟变压器对流换热过程并实现变压器结构件温升计算和绕组热点预测。开展变压器温升试验,结果表明模型预测值与试验值误差控制在±6%,温升分布规律与实际吻合得较好。该文采用的多物理场双向耦合分析方法克服了传统磁路法损耗计算不准确的问题,在变压器产品研发初期可提供损耗预测方法和计算数据,显著提高相关电工装备的运行效率。Based on finite element method, the 3-D transient electromagnetic field simulation of a 2500 kV·A dry-type transformer under rated load condition is carried out. The effect of the leakage flux on the eddy current distribution in foil windings and structures is considered in the calculation. The magneto-thermal-fluid coupling model was established and the loss density on each mesh element was mapped into the 3-D thermal field as heat sources. Considering the influence of temperature on material loss characteristics, the convective heat transfer process is accurately simulated, and the calculation of transformer temperature rise and the prediction of winding hot spots are realized. The test of transformer temperature rise indicated that the error between the predicted value of the model and test results was controlled within ± 6%. The temperature rise distribution law was in good agreement with actual situation. The multi-physics two-way coupling anlysis method adopted in this paper overcomes the inaccurate of loss calculation by the traditional magnetic circuit method. It can provide loss prediction methods and calculation data at the initial stage of transformer product development, and significantly improve the operating efficiency of related electrical equipment.

关 键 词：箔式绕组 涡流损耗 磁-热-流耦合 温升计算 

分 类 号：TM412[电气工程—电器]