In this paper

a typical insulation fault of 220 kV miniaturization GIS equipment is analyzed. Through detection and analysis of gas decomposition products

site inspection

disintegration investigation and three-dimensional simulation of electric field

the main reason of this insulation fault is found. Because of the low inside margin of insulation for the miniaturization GIS equipment

the poor quality

metal dust produced by interrupting process and metallic foreign body brought in during assembly process

the electric field is distorted and internal insulation is breakdown. Finally

combined with the operation condition and discharge reason

the preventive measures and suggestions for installation

experiment

operation and maintenance of miniaturization GIS equipment are proposed.