局部放电测试对金属氧化物避雷器阀片缺陷的敏感度分析

一起金属氧化物避雷器故障分析中发现,对阀片存在缺陷的避雷器进行局部放电测试时未检出局部放电特征信号。对该现象进行深入分析,采用COMSOL Multiphysics?多物理场仿真软件建立金属氧化物避雷器模型,研究阀片柱中不同位置阀片存在缺陷时,以及不同缺陷类型时避雷器阀片表面的电场分布规律,通过对比存在缺陷时和无缺陷时的金属氧化物避雷器阀片柱的表面电场分布,研究局部放电测试对金属氧化物避雷器阀片缺陷的敏感程度,并针对仿真研究内容搭建试验进行验证,验证试验的结果与仿真得到的结论一致。研究发现:局部放电测试对金属氧化物避雷器两端的阀片缺陷较为敏感,对金属氧化物避雷器中间部位的阀片缺陷敏感度较低。研究结果为金属氧化物避雷器的局部放电现场测试提供技术参考。

Analysis on Sensitivity of Partial Discharge Test of Defects of MOA Valve Plate

It is discovered in an analysis of a metal oxide arrester(MOA)fault that the partial discharge characteristic signal is not detected when testing the arrester with defective valve plate.To deeply analyze this phenomenon,the model of MOA is established by using COMSOL multiphysics?simulation software.The electric field distribution law of MOA valve sheet surface is studied when there are defects at different positions and different types of defects.The surface electric field distributions of MOA valve sheet column with and without defects is compared,The sensitivity of partial discharge test to MOA valve defects is studied,and the simulation test is built to verify the results.The results of verification test are consistent with the simulation results.It is found that the partial discharge test is more sensitive to the defects of the MOA at both ends,and less sensitive to the defects of the MOA in the middle.The research results provide technical reference for the partial discharge field test of MOA.