Influence Analysis of Damp Defect of Composite Insulated Zinc Oxide Arrester Based on Finite Element Calculation

Composite insulated zinc oxide arrester is important electrical equipment in power systems, and is prone to insulation failure during operation. For a case of abnormal leakage current and heat generation of zinc oxide arrester, the cause of the abnormality was identified as internal dampness through testing and disintegration analysis. The finite element analysis method was used to study the effects of zinc oxide valve plate moisture, insulating sheath moisture and insulating sheath cracking on the voltage distribution of arrester. The results show that when the resistivity of the arrester varistors and sheaths drops to a certain extent, it will lead to a significant change in the voltage distribution on the varistors, and the overall change trend is that the voltage of the varistors around the object is reduced, and the voltage of the other varistors is raised. It plays a certain a certain reference role in the analysis and disposal of the insulation moisture abnormality of the composite insulated zinc oxide arrester.