500kVZnO避雷器试验应注意的问题

Attention should be Paid to Some Problems When Testing 500kV MOA Arrester

通过对500kV ZnO避雷器与220kV ZnO避雷器进行比较,指出了由于避雷器存在对地杂散电容,500kV避雷器电压分布不均匀,表现更明显,因此须装均压环。为了减少均压环和试验引线的对试验结果产生的影响,根据现场试验经验,作者提出了一些相应的措施以供大家参考。

Differences were pointed out after comparing 500kV MOA arrester with 220kV MOA arrester.That voltage distribution of arrester is asymmetric because of stray earth capacitance was analysed.This asymmetry is more marked in 500kV MOA than in 220kV MOA arreste.So equalizing ring must be installed on the top of arreste,But the equalizing ring will influence the result of test with testing-lead simultaneously.Aiming at decling the influences,corresponding method was put forward.