Corona modeling in HVDC transmission lines based on a modified particle-in-cell approach

• An extension of HVDC lines study using particle-in-cell for model space charges.
• A dynamic simulation considering space charges, wind and voltage, obtaining electric field and ion current.
• Use of local mesh to solve the Poisson equation near the conductors prevents numerical singularities.

As the number of high voltage direct-current (HVDC) projects increases there is a growing interest in aspects related to the effects of the fields in the areas close to the HVDC lines. This work presents a study of corona phenomenon in HVDC transmission lines. Unlike AC overhead lines the presence of space charges is of paramount importance as the charge distribution is responsible for a distortion in the initial electric field. Although, the complete phenomenon demands a three dimensional (3D) approach, a simplified model is proposed using only 2 dimensions (2D). It is shown that the 2D model is capable of considering all the main phenomena related to the corona inception, namely, ionization, recombination and absorption in the vicinity of each conductor. A comparison of 3D and 2D models at the ground surface, for a charge free field, was carried out to asses the overall accuracy of the latter. A semi-Lagrangean modeling of space charges was also developed, considering the influence of particle displacement based on electric field and wind effects. This approach showed a suitable response for evaluation in semi-infinite regions, i.e., unbounded domains. The results are compared with experimental data presented in the literature as well as results from finite domain simulations.