Surface charge distribution pattern of basin insulator under metal particle contamination

Adhesion of metal particles on the insulator surface can easily lead to gas ionization and rapid accumulation of surface charge. However, the influence of metal particle shape on the surface charge distribution pattern is still lacking. In this paper, a charge test platform is established for basin insulators, and the surface charge distribution is measured based on the Kelvin electrostatic probe. The results show that the measurement process of surface charge takes about 2 minutes. The resolution of the circumference and radius directions is 1.3° and 1.3mm, respectively. When there is no particle contamination, 92% of the surface area of the insulator is the same polarity charge, and the conduction current through the insulator body is the main reason for the charge accumulation. For a small aluminum block of 1mm, the insulator surface rapidly appears bipolar charge spots. However, the charge distribution under the triangular aluminum sheet's adhesion condition is unipolar. Therefore, when particulate pollution occurs, the source of charge accumulation on the insulator surface changes to partial discharge on the gas side. This shows that the pattern of surface charge distribution depends on the geometry of the metal particle. The work in this paper can provide a reference for revealing the characteristics of surface charge accumulation under metal particle contamination.