Restraining Surface Charge Accumulation and Enhancing Surface Flashover Voltage through Dielectric Coating

Abstract

A conductive metallic particle in a gas-insulated metal-enclosed system can charge through conduction or induction and move between electrodes or on insulating surfaces, which may lead to breakdown and flashover. The charge on the metallic particle and the charging time vary depending on the spatial electric field intensity, the particle shape, and the electrode surface coating. The charged metallic particle can move between the electrodes under the influence of the spatial electric field, and it can discharge and become electrically conductive when colliding with the electrodes, thus changing its charge. This process and its factors are mainly affected by the coating condition of the colliding electrode. In addition, the interface characteristics affect the particle when it is near the insulator. The charge transition process also changes due to the electric field strength and the particle charging state. This paper explores the impact of the coating material on particle charging characteristics, movement, and discharge. Particle charging, movement, and charge transfer in DC, AC, and superimposed electric fields are summarized. Furthermore, the effects of conductive particles on discharge characteristics are compared between coated and bare electrodes. The reviewed studies demonstrate that the coating can effectively reduce particle charge and thus the probability of discharge. The presented research results can provide theoretical support and data for studying charge transfer theory and design optimization in a gas-insulated system.

Study on interface insulation properties of Al2O3 epoxy composites using plasma jet‐fluorinated etching/SiOx deposition

“…The flashover voltage along the surface is an essential indicator to assess the surface insulation properties, and many scholars have found a significant association between flashover voltage and interface charge 39 . The release of interface charge strongly correlates with the trap's energy level and density.…”

“…Scale data (kV) Shape data (%) The flashover voltage along the surface is an essential indicator to assess the surface insulation properties, and many scholars have found a significant association between flashover voltage and interface charge. 39 The release of interface charge strongly correlates with the trap's energy level and density. isothermal superficial potential dissipation (ISPD) uses a DC supply to accumulate a certain amount of charge on a material's surface.…”

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