水平安装支柱瓷绝缘子断裂故障及弯曲负荷分析  

Breakage Failure and Bending Strength Analysis of Porcelain Post Insulators in Horizontal Installation

作　　者：韦晓星[1] 孙勇[2] 陈如龙[3] 吕刚[3] 李东[3] 瞿少君[3] 

机构地区：[1]中国南方电网超高压输电公司检修试验中心,广州510663 [2]中国南方电网超高压输电公司,广州510663 [3]中国南方电网超高压输电公司贵阳局,贵阳550003

出　　处：《电瓷避雷器》2017年第2期156-163,共8页Insulators and Surge Arresters

摘　　要：由于运行环境恶劣,管型母线用瓷支柱绝缘子断裂事故时有发生,严重威胁着电网安全可靠稳定运行。介绍了一起500 kV变电站35 kV融冰管母户外瓷支柱绝缘子发生"多米诺骨牌"式断裂,导致管母大面积脱落的事故。现场勘查发现,融冰管母支柱绝缘子为水平安装方式,B、C相绝缘子全部断裂,管母脱落,A相1只绝缘子断裂,管母未脱落。随机抽检A相未断裂的4支柱绝缘子的抗弯曲负荷强度,分别为7.96 kN、10.89 kN、9.72 kN和10.89 k N,未达到设计要求12 kN。另外,瓷支柱绝缘子存在无露砂、无胶装缓冲层、水泥胶合剂有大气孔以及法兰铸铁强度低等质量问题是造成管母大面积脱落的主要原因之一。计算分析了不同工况下水平安装支柱绝缘子的抗弯曲负荷。计算结果表明:水平安装对支柱绝缘子的抗弯曲负荷要求高,12 kN的抗弯曲负荷设计要求无法满足"N-1"(1个支柱绝缘子断裂)故障情况下的应力要求,建议选用支柱绝缘子垂直安装的方式。Since the bad operating environment, the breakage of post station insulators supporting the tubular bus happened occasionally, and brought a big threat to the safe operation of power grid. An accident of Dominoes effect breakage of 35 kV post station insulators located in a 500 kV transformer substation was introduced. These insulators were used to support the melting tubular bus. The investigation at the scene showed that the insulators were in horizontal installation; all the insulators in Phase B and C dropped off, and then the tubular buses of the same phases; only one insulator dropped off from the tubular bus of Phase A, and the bus also in the right position. Randomly sampling 4 insulators from phase A, the actual bending strength were 7.96 kN, 10.89 kN, 9.72 kN and 10.89 kN respectively, which didn＇t meet the design value 12 kN. Additionally, most of the insulators were with no or lack of sand, no asphalt buffer layer, abnormal porosity of cement compo and lower strength of cast iron. The poor product property was one of the main causes of the accident. The bending strength of the insulators in horizontal installations was calculated under different conditions. The computed results showed that a higher bending strength is required when the insulators are installed in horizontal direction, and then especially the design value of 12 kN can＇t meet the bending strength demand when ＂N-1＂ failure （one insulator dropped）. In the end, the vertical mounting of station post insulators when supporting tubular bus is strongly recommended.

关 键 词：支柱瓷绝缘子 断裂 抗弯曲负荷 水平安装 “N-1”故障 

分 类 号：TM216[一般工业技术—材料科学与工程]