On the development of a negative surface discharge model in air

A two-dimensional axisymmetric model has been developed for the simulation of a negative surface discharge in air. The finite element model is based on a set of continuity equations accounting for the movement, generation and loss of electrons, positive and negative ions and these equations are coupled with Poisson´s equation to take into consideration the space charge field. The surface charge density is calculated by integrating the charged particle current densities at the dielectric surface. The model shows some similarities and differences to the negative corona discharge case. The simulation surface charge density is consistent with experimental data in terms of the distribution form and magnitude.