Motion and adsorption: dynamic characteristics and spatial distribution of metallic particle in dry air DC-GIS

Abstract

Metallic particles within gas-insulated switchgear (GIS) can distort electric fields, leading to gas discharge. Their adsorption onto insulator surface is particularly hazardous, as it can cause flashover and seriously compromise insulation safety. In this study, a transparent conductive scaled GIS busbar is used combined with an object detection model to investigate the motion and adsorption characteristics of linear metallic particle in dry air. Results show that, compared to SF6 gas, the metallic particle in dry air exhibits higher velocity and a wider range of movement. However, it shows a lower probability of engaging in firefly motion and adsorbing onto insulator surfaces. Under positive polarity, the primary pattern is reciprocating movement. In contrast, under negative polarity, the particle exhibits prolonged swaying firefly motion on the conductor surface. Furthermore, increasing voltage enhances velocity and reduces the likelihood of firefly motion. Additionally, increasing the particle radius decreases firefly motion probability, whereas increasing length leads to the opposite result. Finally, the lifting position has no significant impact. This study supports suppressing metallic particle contamination and optimizing insulation design in dry air DC-GIS.