Simulation Study on Positive Polarity Corona Discharge on the Surface of Transmission Line Conductors Ion Concentration Distribution

This paper establishes a coaxial cylindrical electrode model for transmission lines and conducts a numerical simulation study on the dynamic process of positive corona discharge on the conductor surface. The evolution patterns of electric field strength, spatial charge distribution, and discharge current are explored, and the transport characteristics of electrons, positive ions, and negative ions in positive corona discharge are analyzed. The results indicate that positive corona discharge exhibits periodic pulse current characteristics. Positive ions form a ‘shell’ distribution around the conductor, with their density decreasing as distance increases, and the concentration of positive ions dominates the discharge process. The photoionization mechanism plays a crucial role in maintaining the development of streamers and the oscillation of currents. Additionally, the propagation speed of streamers decreases over time, closely related to the distortion of the electric field caused by spatial charges. This study provides a theoretical basis for optimizing insulation and suppressing corona effects in high-voltage transmission lines.