变压器绕组热缺陷温度演化规律及其辨识方法  

Temperature Distribution Evolution of Transformer Windings Thermal Defect and Its Identification Method

作　　者：张弦亮 郝建 刘丛 王吉祥 吴洁 廖瑞金[1] ZHANG Xianliang;HAO Jian;LIU Cong;WANG Jixiang;WU Jie;LIAO Ruijin(State Key Laboratory of Power Transmission Equipment&Technology,School of Electrical Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]输变电装备技术全国重点实验室(重庆大学电气工程学院),重庆400044

出　　处：《高电压技术》2024年第4期1548-1559,共12页High Voltage Engineering

基　　金：国家自然科学基金(U1866603)。

摘　　要：近年来变压器因绕组发生热故障烧毁时有发生,严重威胁电网安全。为保障变压器的安全稳定运行,开展了变压器绕组热缺陷温度演化规律及其辨识方法研究。首先,基于有限元法研究构建变压器绕组电磁-温度-流体多物理场耦合仿真模型,并通过温升试验验证仿真模型的有效性;然后,仿真分析绕组不同过热位置、热缺陷严重程度和运行工况对绕组局部区域温度的影响规律;最后,应用绕组轴向油道多点温度突变分析研究提出绕组热缺陷位置和严重程度辨识方法。研究结果表明:基于该文多场耦合仿真模型计算的温度值与温升试验实测值的误差小于6%;绕组不同区域发生热缺陷时,过热区域热量会沿油流导向路径快速传递,绕组油道内多点温升值会随其下方区域过热温度的增大呈现线性规律增长;该文提出的热缺陷辨识方法对热缺陷位置辨识的准确度为100%,对热缺陷温度估计的相对均方根误差为6.1%。采用该研究成果能及早发现变压器运行过程中绕组上的热缺陷,避免由缺陷向更严重的故障发展,保障变压器的安全运行。In recent years,transformers have been occasionally burnt down due to thermal failure of windings,which has seriously threatened the safety of power grid.In order to ensure the safe and stable operation of transformer,this paper studies the temperature evolution law and identification method of thermal defects in transformer windings.First,based on the finite element method,a coupling simulation model of electromagnetic-temperature-fluid multi-physical field in transformer windings was constructed,and the validity of the simulation model was verified by the temperature rise tests.Then,the influences of different overheating positions,the severity of thermal defects and transformer operating conditions on local temperature of winding were simulated and analyzed.Finally,a method to identify the location and severity of winding thermal defects is proposed by using multi-point temperature mutation analysis of winding axial oil passage.The research results show that the error between the calculated temperature value based on the multi-field coupling simulation model and the measured temperature rise test is less than 6%.When thermal defects occur in different regions of the winding,the heat in the overheating area will be transferred rapidly along the oil flow guide path,and the multi-point temperature appreciation in the winding oil passage will linearly increase with the increase of the overheating temperature in the region below it.The accuracy of thermal defect identification model proposed in this paper is 100%,and the relative root-mean-square error of thermal defect temperature estimation is 6.1%.By using the research achievement of this paper,the thermal defects on the winding can be found early in the transformer operation process,so as to avoid the development from defects to more serious faults and ensure the safe operation of the transformer.

关 键 词：变压器 绝缘绕组 热缺陷 温度分布 辨识方法 

分 类 号：TM41[电气工程—电器]