Dynamic behaviours on discharge process of SF6-N2 mixtures in short gap with parallel-plane electrodes

The purpose of this research work is to reveal dynamic behaviors of particles, such as electron, positive ion, negative ion, which are produced, augmented, attached, recombined, including their drafting and diffusing under electric field, during the discharge process of SF₆-N₂ gas mixtures, and also to discover the discharge disciplinarian in micro-mechanism for reasonably utilizing the SF₆. The fluid model of SF₆-N₂ mixtures gas discharge is established by adopting particles continuity equation together with coupling Poisson equations. This model is composed of the electrons, positive ions and negative ions continuity equations coupled with the Poisson equation. Two-dimensional simulation of the streamer discharge in SF₆-N₂ gas mixtures, which contains 50%SF₆, is studied in this paper. A program based on the finite element method in its full two-dimension form is developed and employed for the solution of transport equations of charged species under the effect of space-charge electric field. Results of two-dimensional simulation of cylindrically symmetric streamer between parallel-plane electrodes are presented. The formation and propagation of streamer in numerically was observed. The space electric field distribution, space ions distribution and drift velocity were predicted by the model. Through the above results Analysis can help to more profoundly understand streamer discharge mechanisms and provide the theoretical support for electrical equipment designed.