In recent years, more stringent environmental protection requirements have led to increasingly higher voltage power equipment that adopt SF6 mixed gas as an insulation medium. In this paper, the streamer development in SF6 mixed gas and the distribution of each gas component were studied over time. Thus, a discharge model of the needle plate electrode with SF6 mixed gas was established. The hydrodynamic model for SF6 mixed gas discharge in uneven electric fields was created by coupling the Boltzmann drift-diffusion equation and Poisson's equation. The influence of different factors, such as the applied voltage, gas mixture ratio, and electrode spacing, on the streamer discharge of SF6/N2 mixed gas, and the influence of the type of mixed gas (air and CO2) combined with SF6 on the streamer development process were studied. The simulation results showed that the higher SF6 content in the mixed gas made breakdown more difficult, and a higher pressure led to a more concentrated streamer. Comparing and analyzing the discharge processes under different SF6 mixed gases (SF6/CO2, SF6/air, and SF6/N2) showed that the streamer for the SF6/CO2 mixture took longer to develop toward the plate electrode with a more difficult breakdown. The presented simulation results provide a microscopic interpretation for the needle-plate discharge defects that appear in power equipment that utilize SF6 mixed gas.

中文翻译：

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多组分SF6混合气体流注放电发展过程数值模拟

近年来，越来越严格的环保要求导致采用SF6混合气体作为绝缘介质的高压电力设备越来越多。本文研究了 SF6 混合气体中流注的发展以及各气体组分随时间的分布。由此，建立了SF6混合气体针板电极的放电模型。通过耦合玻尔兹曼漂移扩散方程和泊松方程，建立了不均匀电场中SF6混合气体放电的流体动力学模型。外加电压、气体混合比、电极间距等不同因素对SF6/N2混合气体流光放电的影响，以及与SF6结合的混合气体类型（空气和CO2）对流光放电的影响流光发展过程进行了研究。模拟结果表明，混合气体中SF6含量越高，击穿难度越大，压力越高，流注越浓。比较和分析不同 SF6 混合气体（SF6/CO2、SF6/空气和 SF6/N2）下的放电过程表明，SF6/CO2 混合物的流注需要更长的时间向更难击穿的板电极发展。所呈现的仿真结果为使用 SF6 混合气体的电力设备中出现的针板放电缺陷提供了微观解释。和 SF6/N2) 表明，SF6/CO2 混合物的流注需要更长的时间向更难击穿的板电极发展。所呈现的仿真结果为使用 SF6 混合气体的电力设备中出现的针板放电缺陷提供了微观解释。和 SF6/N2) 表明，SF6/CO2 混合物的流注需要更长的时间向更难击穿的板电极发展。所呈现的仿真结果为使用 SF6 混合气体的电力设备中出现的针板放电缺陷提供了微观解释。