40.5kV穿墙套管事故分析及其结构优化

Fault Analysis and Structure Optimization of 40.5 kV Wall Bushing

针对某35 kV变电站穿墙套管的爆炸故障,通过对变电站的运行环境的统计分析、穿墙套管的外观检查及站内其他未爆炸穿墙套管的电性能试验,判断此次故障的主要原因为套管设计存在缺陷,其电场分布比较集中;诱发此次故障的外因是套管的长期运行环境比较恶劣,湿度比较严重。提出了通过优化套管屏蔽网的结构来改善电场分布、通过在母线室增加加热器和排风扇降低柜内湿度的解决方案。该方案实施后的设备运行良好。

Based on the explosion fault of bushing used in a 35 kV substation, through analyzing operation environment, appearance of bushing and electrical test on other bushings operating well, the key causes which lead to this failure were found： design defects and high non-uniform electrical field distribution, simultaneously, heavy operation condition and high humidity are the exterior factors resulting in this explosion fault. The solutions which are improving the electrical field distribution by optimizing shield ring of bushing, and reducing the humidity inside busbar compartment of switchgear by adding the heater and fan in the compartment are proposed. These switchgears operate well after implementation of the solutions.