500kV氧化锌避雷器上节单元0.75U_(1mA)泄漏电流测试误差分析  

Test Error Analysis of 0.75U_(1mA) Leakage Current at 500 kV MOA Top-Element

作　　者：吴冬文[1] 

机构地区：[1]江西省电力公司超高压分公司,南昌330009

出　　处：《电瓷避雷器》2012年第6期62-66,70,共6页Insulators and Surge Arresters

摘　　要：500 kV瓷外套式氧化锌避雷器受现场停电检修条件限制,上部金属均压环连接接地。测量避雷器上节单元直流0.75U1mA下泄漏电流值时,受均匀环接地影响,空间电离电流较大,影响了该测量值的精度,甚至产生结果误判。针对该问题的提出,建立合理的有限元计算模型,设置电压值0.75U1mA为150 kV为强制边界条件,再由相应的变分方程计算出避雷器的各单元电位、电离电流密度和空间电离电流。因此在测量避雷器上节单元直流0.75U1mA下泄漏电流值时,应适当地考虑测量值减去空间电离电流值。The maintenance condition of 500 kV porcelain-housing MOA is limited,the top metal grading ring is grounded.Measuring 0.75U1mA leakage current of the top-element of Oxide arrester is restricted to the grounded balance slices,so the ionization current is large,and affect the measurement accuracy,even lead to result misjudge.Thinking of this condition,this paper create rational finite element analysis model,let 0.75U1mA voltage value 150 kV as the essential boundary conditions,and use corresponding variational equation,to calculate the result of electric potential,ionization current density and spatial ionization current of each element to the Oxide arrester.So we should think of the measurement result to subtract spatial ionizing-current,when do the test of measuring 0.75U1mA leakage current of oxide arrester top-element.

关 键 词：氧化锌避雷器 0 75U1mA 试验误差 有限元 电离电流 

分 类 号：TM862[电气工程—高电压与绝缘技术]