500 kV SF6断路器复合绝缘套管绝缘介质液化电场研究  

Research on Liquefaction Electric Field Study of Composite Insulating Medium for 500 kV SF6 Circuit Breaker

作　　者：姚顺 YAO Shun(Inner Mongolia Power(Group)Co.,Ltd.,Inner Mongolia Power Electric Operations Control Company,Hohhot 010010,China)

机构地区：[1]内蒙古电力(集团)有限责任公司内蒙古电力调度控制分公司,呼和浩特010010

出　　处：《内蒙古电力技术》2024年第2期73-77,共5页Inner Mongolia Electric Power

摘　　要：为研究复合绝缘子套管中的SF6气体发生液化对套管内部电场分布的影响,采用电流场有限元法对内部电场进行了求解分析。基于某项目中复合套管参数建立了3D实体模型,假设在重要部位出现液滴进行工频瞬态电场计算,得出整体电场强度分布规律和液滴周围电场强度分布规律。研究发现,轴对称方法不再适用于SF6液化情况的分析。结果表明,液滴会导致附近电场强度增大,且液滴介电常数越大电场强度越高,电场强度随液滴参数变化最大可能变为原场强的3倍,当液态SF6的介电常数高且SF6填充压力低,产生过电压时可能会形成击穿。另外,在地电位屏蔽上发生液化并引起放电的可能性最高,需要额外的加热措施或更换填充气体为SF6-N2气体。In order to study the impact of SF6 gas liquefaction in composite insulator bushings on the internal electric field distribution,this paper analyzes the internal electric field by using the finite element method of current field.Based on the parameters of composite bushings in a certain project,a 3D solid model is established.It is assumed that droplets appeare in important parts for calculating the transient electric field at power frequency,and the overall electric field intensity distribution law and the electric field intensity distribution law around the droplets are obtained.It is found that the axisymmetric method is no longer suitable for the analysis of SF6 liquefaction.The results indicate that droplets will cause an increase in the nearby field intensity,and the larger the dielectric constant of the droplets,the higher the electric field intensity.The electric field intensity may increase up to three times the original field intensity as the droplet parameters change,and breakdown may occur when the dielectric constant of liquid SF6 is high and the SF6 filling pressure is low.Furthermore,liquefaction and discharge are most likely to occur on the ground potential shield,requiring additional heating measures or replacement of the filling gas with SF6-N2 gas.

关 键 词：SF6断路器 复合绝缘套管 液化 有限元法 电场分布 

分 类 号：TM85[电气工程—高电压与绝缘技术]