Influence of Metallic Particles on Flashover Characteristics of Basin-type Insulator Under DC Voltage in GIS/GIL

In this paper, the DC flashover characteristics of the insulators when the linear metal particles are attached to the surface of the basin insulator in GIS/GIL are studied. Firstly, the finite element numerical calculation method was used to analyze the electric field distribution of the surface of the basin insulator in the absence of metal particles. According to the calculation results, four positions were selected for the convex and concave surfaces of the insulator to manually place the metal particles. Meanwhile simulated the linear metal particles with the metal copper needle, and measured the flashover voltage of the insulator under the condition of metal particle adhesion by experimental means, the effects of gas pressure, particle position change and particle length change on the DC flashover voltage of the insulator were considered in the experiment. Results show that the electric field near the particle is severely distorted when the metal particles are present on the surface of the insulator, and the distortion effect decreases as the metal particles move away from the high voltage electrode. However, the flashover voltage variation of the convex and concave surfaces of the insulator is not completely consistent ,this is mainly due to the difference in surface electric field distribution between the convex and concave surfaces of the insulator. The experiment also found that the effect of metal particles on the flashover voltage of the insulator is more significant at high pressure. This study can provide reference for the development and maintenance of DC GIS/GIL basin insulators.