220kV金属氧化物避雷器带电测试异常的处理  

Dealing with an Abnormal 220 kV MOA Revealed by On-line Detection

作　　者：苏文宇[1] 汪晓明[1] 胡宏宇[1] 刘军农 

机构地区：[1]江西省电力公司超高压分公司,南昌330006

出　　处：《电瓷避雷器》2008年第3期32-33,37,共3页Insulators and Surge Arresters

摘　　要：介绍了220kV金属氧化物避雷器(MOA)带电测试异常的处理情况,对异常MOA进行停电试验、解体检查发现,MOA的A相上节U1mA变化率为0.85%,0.75U1mA下的泄漏电流和绝缘电阻均符合《规程》的要求,没有故障;A相下节U1mA的变化率为22.4%,0.75U1mA下的泄漏电流为786μA,绝缘电阻值为0.411GΩ,存在故障。分析指出:测量阻性电流可及时准确发现MOA受潮情况;MOA在运行中要严格按照DL/T596—1996进行定期带电测试,以便及时发现缺陷;当MOA内部发生故障时,交流泄漏全电流、泄漏电流阻性分量都会增大,但泄漏全电流没有阻性分量的变化明显。An example of abnormal 220 kV MOA dealing revealed by on-line detection was described. After examination of the MOA after de-energized tests and de-assembling it was discovered that the top unit of phase A had U1mA variatcd by 0.85%, leakage current and insulating resistance at 0.75 U1mA well within specifications of “Revision” which proved no fault, and the bottom unit had U1mA variated by 22.4%, leakage current 786 μA at 0.75 U1mA and insulating resistance of 0.411 GΩ which proved faulty. It is considered that leakage current measurement can reveal MOA moisture ingress in time which shall be carried out periodically as stipulated in DL/T596-1996 in order to reveal defect in time. A faulty MOA may have increased A.C. summary leakage current and its ohmic component, with weaker increasement of the former one.

关 键 词：220KV金属氧化物避雷器 带电测试 阻性电流 

分 类 号：TM862[电气工程—高电压与绝缘技术]