某220 kV变电站气体绝缘金属封闭开关设备盆式绝缘子发生放电故障，采用宏观观察、渗透检测、X射线检测等方法分析了发生放电故障的原因，并利用仿真软件计算了高电压环境下不同浇注间隙对电场的影响。结果表明：浇注间隙会使盆式绝缘子的电场发生畸变，在间隙深度和弧长相等的条件下，浇注间隙宽度越小，电场的畸变越大，间隙越容易被击穿，从而使得盆式绝缘子极易发生闪络现象。

A discharge fault occurred on the basin insulator of gas insulated metal enclosed switchgear in a 220 kV substation. The causes of the discharge fault were analyzed by means of macroscopic inspection, penetration detection and X-ray detection. The influence of different pouring gaps on the electric field under high voltage environment was calculated by simulation software. The results show that the pouring gap would distort the electric field of the basin insulator. Under the condition of equal gap depth and arc length, the smaller the width of the pouring gap was, the greater the distortion of the electric field was, and the easier the gap was to be broken down, so that the basin insulator was prone to flashover.