基于三维电-磁-热流耦合方法的±800 kV穿墙套管插接结构过热性故障分析  

Plug-Connector Overheat Fault of ± 800 kV Wall Bushings Based on 3D Coupled Electromagnetic-Thermal-Fluid Method

作　　者：雷战斐 吴鹏 郭伊宇 周仕贻 柴斌 刘廷堃 徐辉 彭宗仁[2] 刘鹏[2] LEI Zhanfei;WU Peng;GUO Yiyu;ZHOU Shiyi;CHAI Bin;LIU Tingkun;XU Hui;PENG Zongren;LIU Peng(State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan 750011,China;State Key Laboratory of Electrical Insulation and Power Equipment(Xi'an Jiaotong University),Xi'an 710049,China)

机构地区：[1]国网宁夏电力有限公司检修公司,银川750011 [2]电力设备电气绝缘国家重点实验室(西安交通大学),西安710049

出　　处：《电瓷避雷器》2021年第2期59-65,共7页Insulators and Surge Arresters

基　　金：国网宁夏电力公司科技项目(编号:SGNXJX00LZJS1900275)。

摘　　要：特高压直流套管是特高压直流输电的关键设备之一,但在实际运行中多次发生换流站穿墙套管载流连接过热故障,经分析主要是由插接结构接触缺陷、异常发热导致的。本研究针对某载流过热故障的±800 kV SF^(6)气体绝缘穿墙套管,建立了套管及触指结构精细化模型,考虑热传导、热对流、热辐射等条件,通过三维电磁热流耦合方法对特高压穿墙套管内两种典型导电杆支撑结构进行仿真研究。结果表明:三支撑与双支撑结构的±800 kV SF^(6)气体绝缘穿墙套管在正常运行时的温度分布规律基本一致,导杆中部及靠近法兰和支撑绝缘子处温度较高,支撑绝缘子高压端嵌件的交界面处出现最高温度,但均低于其环氧复合材料的玻璃化转变温度;同时发现不同接触电阻倍数下,双支撑结构的温升整体高于三支撑结构。研究建立了外护套表面温度与载流接触过热点温度的对应关系,可为特高压直流穿墙套管通过红外监测护套表面温升、发现载流连接缺陷的运维方法提供依据。UHVDC bushing is one of the key equipment in UHVDC transmission system. However,overheat fault of connecting structure of wall bushing happened many times in working condition,which is caused by the overheating and defect of plug connector. Taking two kinds of classical ± 800 kV pure SF6 gas insulated wall bushing as research subject,the models of wall bushing and contact finger is built properly and analyzed. A 3 D coupled electromagnetic-thermal-fluid analysis method has been adopted;processes including heat radiation,heat conduction and heat convection has been taken into account. The results indicate that the temperature distribution of ± 800 kV SF^(6) gas insulated wall bushing with three support structure and double support structure is basically consistent in normal operation,and the high temperature region is distributed in the middle of the conduct pole,closed to the flange and supporting insulator. The highest temperature of the support insulator is at the interface between the support insulator and the high-voltage end insert,which is lower than the glass transition temperature of the epoxy composite. Meanwhile,this research found that the temperature rise of the double support structure is higher than that of the three support structure under different contact resistance multiples. The results built the corresponding temperature relationship of sheath and the overheated contact point and obtained the sheath temperature rise as the reference for infrared monitoring.

关 键 词：穿墙套管 接触电阻 温度分布 耦合场 过热性故障 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM216.5[一般工业技术—材料科学与工程]