Movement and Discharge Characteristics of Metal Dust in GIS under AC Voltage: Focus on a Special Luminescence Phenomenon

Metal particles near insulators are the main cause of insulation failure of Gas-insulated Switchgear (GIS), which seriously affects the stable operation of power grid. In this paper, the experimental platform of dust movement adsorption by AC GIS was built. The effects of applied voltage level, dust material, quantity and size on their movement behavior were studied. The special luminescence phenomenon induced by the movement of metal dust was analyzed. The results show that small size and large amount of metal dust have a greater influence on the insulation performance of the basin insulator. In the process of its movement, it is easy to form a series channel of multiple particles, which seriously distorts the electric field near the GIS basin insulator. In addition, when the charge polarity of the jumping particles is different, charge transfer will occur between the particles and a "luminescence phenomenon" will occur. The luminescence phenomenon may directly cause the insulator to flashover along the surface, which seriously affects its insulation performance. At the same time, the "luminescence phenomenon" increases the temperature in the laboratory, creating conditions for the reaction of metal dust with oxidizing gases. This work can provide data support and theoretical basis for the study of metal dust discharge in GIS, and the special phenomenon of "dust luminescence" found can provide new ideas for improving the reliability of GIS.