Dynamic characteristics of the N ₂ discharge in short-gap with dielectric-covered electrodes

To reduce the purity of SF ₆ in mixed gas SF ₆/N ₂ insulation and also in order to better go on online monitoring between insulating partial discharge of air gap, nitrogen as the main ingredients was focused on, meanwhile establishing one-dimensional and self-consistent fluid model of the gas discharge and concluding the electron and ion continuity and momentum transfer equations coupled to Poisson's equation, then the discharge process of the N ₂ gas in the short gap and its dynamics characteristic were researched. The time evolution process of N ₂ gas discharge at different voltages is obtained by solving nonlinear gas discharge equations, and the relation of internal discharge parameter is expressed by two and three dimensional phase diagram. The spatial and temporal distribution of electric field and the density of electron and ion were simulated, the result shows that discharge current pulse will be formed in discharge space when electric field outnumber critical value, and time-frequency image describes short gap discharge characteristic through short-time Fourier transform.