Simulation analysis on microscopic discharge characteristics of the bipolar corona of a floating conductor

A floating conductor exhibits a bipolar corona phenomenon with microscopic discharge characteristics that are still unclear. In this study, a plasma simulation model of the bipolar corona with 108 chemical reaction equations is established by combining hydrodynamics and plasma chemical reactions. The evolution characteristics of electrons, positive ions, negative ions and neutral particles, as well as the distribution characteristics of space charges are analyzed, and the evolutionary flow of microscopic particles is summarized. The results indicate that the positive end of the bipolar corona initiates discharge before the negative end, but the plasma chemistry at the negative end is more vigorous. The electron generation rate can reach 1240 mol (m³ s)⁻¹, and the dissipation rate can reach 34 mol (m³ s)⁻¹. The positive ion swarm is dominated by O₄⁺, and the maximum generation rate can reach 440 mol (m³ s)⁻¹. The negative ion swarm is mainly O₂⁻ and O₄⁻. The O₂⁻ content is approximately 1.5–3 times that of O₄⁻, and the maximum reaction rate can reach 51 mol (m³ s)⁻¹. The final destination of neutral particles is an accumulation in the form of O₃ and NO, and the amount of O₃ produced is approximately 4–6 times that of NO. The positive end of the bipolar corona is dominated by positive space charges, which continue to develop and spread outwards in the form of a pulse wave. The negative end exhibits a space charge distribution structure of concentrated positive charges and diffused negative charges. The validity of the microscopic simulation analysis is verified by the macroscopic discharge phenomenon.