Microgap Discharge Characteristics of Particles on Insulator Surface Under Humidity Environment

Ensuring the safe and economical operation of power systems necessitates the prevention of insulator degradation and flashover in high-voltage transmission lines. This study analyzes the discharge mechanisms associated with micron-level pollutant particles on insulator surfaces under high humidity and low salt conditions. Surface contours of long-term exposed insulators were measured, allowing the calculation of potential differences based on the stacked heights of pollutant particles. A particle discharge model was subsequently developed to elucidate the dynamic behavior of electrons during the discharge process of salt particles in humidity environments. The findings reveal that under humidity environments, the surface water film formed on salt particles exhibits a stronger charge-capturing effect. Furthermore, the electric field intensity on the electrode-facing side increases significantly, being approximately 1.67 times higher than that observed in dry conditions. As the discharge progresses, the electron motion range expands, leading to an increase in electron temperature on both particle and insulator surfaces, which poses a potential risk to the integrity of the insulator material. This research provides valuable theoretical insights into the discharge mechanisms of micrometer-scale gaps under multi-fogging conditions, offering a foundation for mitigating insulator degradation and ensuring the reliable transmission of electrical power.