SF_6气体中极不均匀场正流注放电机制及其瞬态产物的仿真研究  

Simulation Study of Streamer Discharge Mechanism under Non-uniform Electric Field in SF_6 Gas and Its Transient Products

作　　者：杨佳鹏 赵立进 周海 黄军凯 张崇新 任明[2] 

机构地区：[1]贵州电力试验研究院,贵阳550005 [2]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《绝缘材料》2015年第7期44-51,55,共9页Insulating Materials

基　　金：国家自然科学基金资助项目(50907051)

摘　　要：为研究SF6气体中由极不均匀场引发的流注放电的微观机制以及放电过程中的瞬态产物,基于玻尔兹曼漂移扩散方程和SF6电子碰撞反应截面数据,对SF6气体中的流注放电进行有限元数值仿真。仿真模拟了流注发展过程中外部电流的3个阶段性特征,得到了SF6气体各发展阶段的微观过程,包括流注发展中电子、离子及电荷的密度分布;结合理论分析,揭示了外施电势与流注放电通道内外的电场分布的关系,并指出若使流注向前发展,外施电势不但要克服流注通道反向电场,还要维持流注头部电场大于电离临界场强。另外,通过该仿真模型还获得了SF6气体中电离瞬态产物的成分及各自比例,F、F+、SF6vib+、SF5+、SF4++、SF4+、SF3+和SF6+为流注放电过程中的主要瞬态产物。In order to study the micro-mechanism of streamer discharge caused by non-uniform electric field and the transient products during discharge process, the streamer discharge in SF6 gas was simulated by finite element numerical base on Boltzmann drift-diffusion equations（BDDE） and cross section data of electron collision reaction. Three characteristics of external current during streamer process were simulated, and the micro-process including the distribution of electron density, ion density, and charge density were obtained. The relationship between applied potential and electric field distribution inside and outside of streamer channel was revealed by theoretical analysis. It is pointed that if the streamer develops forward, the applied potential should be great enough not only to overcome the revised field along the streamer channel but also to keep the electric field intensity ahead of streamer greater than the critical electric field intesnity of ionization. Moreover, the ionization transient products and their proportions were obtained by simulation, and the F、F＋、SF6vib＋、SF5＋、SF4＋＋、SF4＋、SF3＋, and SF6＋are the main products during streamer process.

关 键 词：SF6气体 玻尔兹曼方程 流注放电 放电机理 

分 类 号：TM835.4[电气工程—高电压与绝缘技术]