直流下SF_6中绝缘子的闪络特性  

Flashover Characteristic Along the Insulator Under DC Voltage in SF_6 Gas

作　　者：贾志杰[1] 张乔根[1] 张斌[1] 范建斌[2] 李金忠[2] 李鹏[2] 

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]中国电力科学研究院,北京100192

出　　处：《高电压技术》2009年第8期1903-1907,共5页High Voltage Engineering

基　　金：国家自然科学基金(50877073)~~

摘　　要：直流气体绝缘金属封闭输电线路(GIL)在特殊环境下可替代部分架空输电线路或电缆,提高输电走廊选择的灵活性。严重影响GIL绝缘水平的关键因素之一是直流下沿支撑绝缘子表面的电荷积聚。为了研究该问题,建立了一个锥板电极系统来模拟GIL中同轴圆柱结构的电场分布,通过试验研究了直流下SF6中绝缘子的材料和形状对其闪络特性的影响,并利用有限元分析软件对不同形状的绝缘子进行了电场计算。结果表明,直流GIL中绝缘子的表面电导率和充电时间常数均对其表面电荷积聚和沿面闪络有重要影响。同时还提出了基于锥板电极的直流GIL的绝缘子表面电导率选取原则和外形结构优化注意事项。In order to promote the flexibility about the selection of transmission corridor, DC gas insulated transmission line （GIL） can-be utilized to substitute part of the overhead line or cable in special environment such as cross connections inside of substations or connections between new remote generation areas and the load centers. One of the predominant factors that greatly threaten the insulation level of GIL is the accumulation of surface charges along the supporting insulators under DC voltage. Consequently, the cone-plane electrode system was established to simulate the electric field distribution of the coaxial cylinder configuration in GIL. Various kinds of insulators that had different geometry and surface roughness were placed between electrodes for test. Moreover, software was used to analyze the electric field distribution along the insulators＂ surface under DC voltage. Key factors that affect the insu- lator＇s flashover characteristics in SF6 under DC voltage were investigated mainly from the view of insulator＇s material and geometry. Results show that the insulator＇s surface conductivity and charging time constant both have remarkable influence on the surface charge accumulation as well as the flashover along the insulators in DC GIL. The selection principle about the insulatofs surface conductivity in DC GIL and point for attention in optimizing insulator＇s geometry are put forward.

关 键 词：表面电荷积聚 表面电导率 闪络电压 表面粗糙度 电场分布 形状 

分 类 号：TM85[电气工程—高电压与绝缘技术]