特高压直流线路复合绝缘子悬挂方式对其冲击闪络特性的影响  

Influence of Suspension Patterns of UHVDC Line Composite Insulator on Its Impulse Flashover Characteristics

作　　者：韩永霞[1] 唐力[1,2] 郝艳捧[1] 黄之明[1] 廖永力 李立浧[1] 

机构地区：[1]华南理工大学电力学院,广州510640 [2]南方电网科学研究院,广州510080

出　　处：《高电压技术》2015年第4期1272-1277,共6页High Voltage Engineering

基　　金：国家自然科学基金(51177052);特高压工程技术(昆明;广州)国家工程实验室开放基金(NEL201306);中央高校基本科研业务费专项资金(2013ZM0035)~~

摘　　要：V串绝缘子在输电线路中得到了广泛应用,但其与I串绝缘子的冲击闪络特性差异尚不明确。为此,在特高压工程技术(昆明)国家工程实验室开展了V串和I串悬挂方式的±800 k V复合绝缘子在操作冲击和雷电冲击作用下的放电试验,并通过有限元仿真软件对2种悬挂方式下复合绝缘子附近的电场分布进行仿真分析。结果表明:当有效绝缘距离相同时,正极性冲击电压下的V串绝缘子50%冲击放电电压低于I串绝缘子,而负极性冲击电压下的V串绝缘子50%冲击放电电压高于I串绝缘子;V串缘子下均压环与横担间的空气间隙的电场分布更接近棒–板间隙,而I串绝缘子2个均压环间的空气间隙的电场分布更接近棒–棒间隙。因此,I串和V串绝缘子间冲击闪络特性的差异是由于电极结构的极性效应引起的。V-string insulators are widely used in transmission lines, but the difference of impulse flashover characteristics between V-string insulators and I-string insulators remains unclear. To this end, we carried out discharge tests of ±800 kV V-string and I-string composite insulators under lightning and switching impulses at the（Kunming） National Engineering Laboratory for UHVDC Engineering Technology. The electric field distribution around the tested insulators was calculated and analyzed using the finite element simulation software as well. The results show that, compared with I-string insulators with the same effective insulation distance, the 50% impulse discharge voltage of V-string insulators is higher under negative impulses, but is lower under positive impulse voltages. The electric field distribution of the air gap between grading ring and cross arm in a V-string is similar to that of a rod-plate air gap, while the electric field distribution of the air gap between two grading rings in an I-string insulator is similar to that of a rod-rod gap. It is concluded that the difference of impulse flashover characteristics between V-string and I-string insulators is caused by the polarity effect of different electrode structures.

关 键 词：复合绝缘子 悬挂方式 冲击闪络特性 电场分布 有限元仿真 特高压直流 

分 类 号：TM216[一般工业技术—材料科学与工程] TM75[电气工程—电工理论与新技术]