雷电冲击下稍不均匀电场中SF_6/N_2混合气体的协同效应  

Synergistic Effect of SF_6/N_2 Gas Mixtures in Slightly Non-uniform Electric Field Under Lightning Impulse

作　　者：郭璨[1] 张乔根[1] 文韬[1] 游浩洋 秦逸帆 马径坦 

机构地区：[1]西安交通大学电气工程学院,西安710049

出　　处：《高电压技术》2015年第1期69-75,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(JSKF[2013]43)~~

摘　　要：近年来,在气体绝缘金属封闭输电线路(GIL)中开始使用低SF6体积分数的SF6/N2混合气体作为绝缘介质,但对这种混合气体的协同效应相关研究还不多。为此,在稍不均匀电场、正负2种极性雷电冲击(LI)下,研究了较低SF6体积分数的SF6/N2混合气体的击穿特性及协同效应受电压极性和气压的影响。结果表明:在较低气压和负极性雷电冲击下的击穿电压高于正极性;当气压超过某一临界值后,正极性下的击穿电压将高于负极性。引入协同效应系数对混合气体的协同效应进行了分析,发现:负极性雷电冲击下协同效应系数<0.1,且受气压影响不明显;正极性下的协同效应相对较弱,但随着气压升高协同效应增强。SF6/N2 gas mixtures with low SF6 volume fraction are increasingly adopted as insulating media in gas-insulated metal-enclosed transmission lines（GILs）, but the synergistic effect of the gases is seldom researched. Thus, we studied the synergistic effect and breakdown characteristics of SF6/N2 gas mixtures with low SF6 volume fraction in slightly non-uniform electric field under both positive and negative lightning impulses, and studied how they are affected by im- pulse polarity and pressure. It is found that, under a low-pressure condition, the breakdown voltage trader negative lightning impulse is higher than that under positive lightning impulse, whereas, when pressure exceeds a certain value, the breakdown voltage under negative lightning impulse becomes lower than that under positive lightning impulse. Moreover, we introduced a coefficient to determine the synergistic effect. The synergistic effect under negative lightning impulse has a coefficient less than 0.1, and it is hardly affected by pressure. Meanwhile, the synergistic effect under positive lightning impulse is less remarkable than that under negative lightning impulse, but it gets stronger with the increase of pressure.

关 键 词：雷电冲击 稍不均匀电场 SF6/N2 混合气体 极性效应 协同效应 

分 类 号：TM75[电气工程—电力系统及自动化]