Research Of Air And SF₆ Discharge Based On The Fluid-Chemicat Reaction Model

With the development of the ultra-high-voltage(UHV)transmission,its reliability service depends on insulation level of electrical equipment.And gas dielectric has multitudinous superiorities,so the mechanism and characteristics of gas discharge have drawn more and more attention.In the insulation structure,the non-uniform electric field caused by electrode surface defects or other factors has a serious influence on the gas insulation properties.It is necessary to study the mechanism and characteristics of main gas dielectric air and SF6 discharge.To deeply explore the air and SF6 discharge,the microscopic physical mechanism of gas discharge is revealed by numerical simulation and experiment of gas discharge.In this dissertation,a model of 5mm rod-plate gap gas discharge is established by the mixed model combined hydrodynamic theory and chemical reactions of species.The finite element is used to solve the numerical simulation model.The electron density,some main positive and negative ions densities,electrical field distribution and electron temperature distribution are obtained from the numerical analysis.In this dissertation,an experimental platform with air dielectric is set up to detect the discharge optical information.Spectrum and image of gas discharge are collected by spectrograph and ICCD under the condition of numerical simulation.By analyzing the spectrum of discharge,particles production and energy transfer can be observed and active material can be diagnosed.And the spectrum information also can be used to calculate the electron density and temperature.By the discharge image,the shape of streamer discharge is cognized intuitively.Comparing the simulated results with the experimental information,the correctness of conclusions can be verified.