Influence of the Dielectric Film Height on the Charge Accumulation Characteristic in Uniform Ion Flow Field

摘要

Corona phenomenon occurs during the operation of HVDC transmission lines. The generated space charges will move to the surface of the dielectric film under the action of the electric field. The accumulation of surface charge causes distortion of the space electric field below the dielectric film. The height of the dielectric film above the ground will affect the charge distribution, which will have an effect on the ground-level electric field. It is necessary to study the effect of the height above the ground on the charge accumulation. In this paper, a parallel-plate ion flow generator is used to generate space charges. The ground-level electric field under the dielectric film at different heights is measured by a field mill, and the electric field is used to calculate the average surface charge density. The results show that as the height of the dielectric film increases, the ground-level electric field and the dielectric film charge density both show a decreasing trend.