A detailed model for discharge initiation in argon at atmospheric pressure in presence of dielectric barriers

A detailed model was presented to explain the dielectric barrier effects employed to improve the insulation performance. The simulations were carried out for the dielectric barrier in two forms; as coating on electrodes, and as insertion in the inter-electrode gap. The electron conservation was modeled by the electron number density continuity equation using the drift-diffusion approximation. The analogous equation was applied for electron energy conservation. For diffusive transport modeling of heavy particles (including ions, excited atoms and ground state atoms), the mixture-averaged evaluation was formulated. The source terms were extracted based on plasma chemistry related to Argon including volumetric and surface reactions. The model is based upon a simultaneous solution of all foregoing equations together with the Poisson´s equation. The simulation results for applying a standard lightning impulse voltage for both positive and negative polarities were presented and discussed. The impact of various parameters e.g. the thickness of the barrier, the position of the barrier, and the role of applied voltage polarity on insulation performance were simulated and analyzed.