全尺寸超、特高压交流绝缘子串的覆冰闪络特性  

Icing Flashover Characteristic of Full-scale EHV and UHV AC Insulator Strings

作　　者：于昕哲[1,2] 周军[1] 刘博[1] 宿志一[1] 

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

出　　处：《高电压技术》2013年第6期1454-1459,共6页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2011CB209406)~~

摘　　要：线路绝缘子的覆冰闪络是影响线路安全稳定运行的重要问题。为此提出了基于恒压升降法获取交流绝缘子串覆冰闪络电压的程序和方法,通过此方法可得到绝缘子串的50%覆冰闪络电压。试验在中国电力科学研究院特高压直流试验基地污秽及环境试验室人工气候罐内(直径22m、高34m)进行,在全尺寸条件下,利用上述方法分别完成了交流500、750、1 000kV等级线路绝缘子串的覆冰闪络特性研究。提出了用统计覆冰桥接程度来评估带电绝缘子串覆冰严重度。结果表明:随覆冰时间的增长,在固定电压等级运行电压下覆冰的绝缘子串桥接程度首先急剧增加,之后达到一定的饱和值。在试验尺寸范围内,串长和闪络电压之间具有较弱非线性关系。结合泄漏电流典型特征分析,严重覆冰条件下绝缘子串闪络在带电融冰期可分为"调整阶段"和"危险阶段"2个阶段。Insulator icing flashover is one of threats to safe operation of transmission lines. Thus, by the up-and- down method, we proposed a new approach and its procedure for obtaining the 50 ~/00 icing flashover voltage of AC insulator string. Test was carried out in the artificial climate chamber （34 m high, with its diameter of 22 m）, and the icing flashover characteristics of the long full scale insulator strings adopted in 500, 750 and 1 000 kV AC transmission lines were obtained with the method mentioned above. Besides, we proposed an evaluation method for icing severity of insulator string through statistical analysis of icicle bridging degree. Test results show that, under a certain operating voltage, as icing time increases, the icicle bridging degree of insulator string increases sharply at first till it reaches and keeps at saturation. Within the scale of test dimension, there is a weakly nonlinear relationship between string length and flashover voltage. According to analyses of typical characteristic of leakage current under heavy icing condition, the flashover of insulator string can be divided to two stages during the process of charged melting, i.e. the ＂adjusting stage＂ and the ＂dangerous stage＂.

关 键 词：绝缘子串 冰闪 升降法 全尺寸条件 冰柱桥接 超高压 特高压 泄漏电流 

分 类 号：TM216[一般工业技术—材料科学与工程]