Research on the Movement and Partial Discharge Characteristic of Free Metal Particles in GIS

Free metal particles are one of the main threats to the insulation reliability of gas-insulated switchgear (GIS). Under the action of electric field force and applied voltage, the presence of metal particles will cause the spatial electric field distortion of the GIS, which in turn leads to the degradation of the insulation performance of the GIS. In this paper, a simulation calculation model for charging, force, and movement of free metal particles in UHV GIS is established, and the movement and charging laws of particles under power voltage are studied. The results show that the spatial position distribution of particle movement is mainly in the middle area of the bottom of the GIS enclosure. The spatial position density distribution gradually decreases from the central area of the enclosure bottom to the surrounding space area. As the amplitude of the applied voltage increases, the horizontal and vertical displacements of the particles gradually increase. The maximum horizontal and vertical displacements of the particles gradually decrease with the increase of the particle radius. The particles will be charged and discharged at the full voltage phase. The particles discharge more concentrated at the voltage peak, and the discharge amount is the largest. The simulation results are basically consistent with the experimental results.