摘要
近年来,国内发生多起GOE系列拉杆式套管拉杆底座缺陷导致的套管或变压器损坏事故,另外,该类套管还存在将军帽内部拉杆螺栓及拉杆头部放电烧蚀、绝缘油析气性导致主绝缘局部放电产生X蜡等问题,为消除拉杆式套管安全隐患,决定对GOE系列拉杆式高压套管进行替换。笔者结合一台500 kV自耦变压器高压套管替换方案,对替换套管电气性能参数选用原则、套管油中尺寸及升高座改造方案、套管尾端接线结构改造方案、套管油中绝缘距离进行了分析;利用ANSYS有限元软件,建立二维轴对称有限元模型,对替换套管尾部油中电场进行了仿真计算。仿真计算结果表明:替换套管尾部径向最大场强约3.94 kV/mm,双环屏蔽出线装置附近最大场强约3.51 kV/mm,电气绝缘裕度值约为5~6倍,套管替换方案能够满足变压器安全运行要求,该方案对同类型隐患套管的改造、替换具有借鉴指导作用。
There have been a number of accidents of bushing or transformer damage caused by defects in the GOE series tie rod type bushing,there are some problems in this kind of bushing,such as the electric discharge ablation of the tie rod bolt and the head of the tie rod in the general cap,the gas evolution of the insulating oil,the partial discharge of the main insulation and X-wax,etc.In order to eliminate the hidden trouble of the GOE series tie rod type bushing,it is decided to replace the GOE series pull rod type high-voltage bushing.A 500 kV autotransformer type high-voltage bushing replacement program is proposed,the selection principle of the electrical performance parameters of the replacement bushing,the modification scheme of the bushing oil medium size and the riser,the modification scheme of the bushing tail end connection structure and the insulation distance in the bushing are analyzed.A two-dimensional axisymmetric finite element model is established to simulate the oil electric field at the end of the replacement bushing.The results show that the maximum field strength in the replacement bushing is about 3.94 kV/mm,and the maximum field strength at the shield ring is about 3.51 kV/mm,the electrical insulation margin is 5~6 times,and the bushing replacement scheme can meet the requirements of transformer safe operation.The scheme can be used as a reference for the modification and replacement of the same type of hidden trouble bushing.
作者
王典浪
曹鸿
李国艮
刘晋孝
陈静
尹启
WANG Dianlang;CAO Hong;LI Guogen;LIU Jinxiao;CHEN Jing;YIN Qi(Qujing Bureau of CSG EHV Power Transmission Company,Qujing 655000,China)
出处
《电瓷避雷器》
CAS
北大核心
2021年第2期78-84,共7页
Insulators and Surge Arresters
关键词
自耦变压器
拉杆式套管
导杆式套管
升高座
油中绝缘距离
电场仿真
电气绝缘裕度
autotransformer
pull rod bushing
guide rod bushing
elevated seat
insulation distance in oil
electric field simulation
electrical insulation margin
