摘要
强暴雨常伴随雷电天气会导致输电线路、变电站和换流站绝缘子表面干、湿部位电场分布不均,易引发电场畸变,同时雷暴引起的雨柱会快速短接绝缘子伞间距,显著缩短电弧发展路径,致使线路跳闸并引起停电事故。为研究强暴雨条件下线路绝缘子雷电冲击放电特性和电弧发展过程,针对3种110 kV线路常用硅橡胶复合绝缘子开展了雷电冲击放电特性测试。结果表明:复合绝缘子雷电冲击电弧发展过程主要分为起弧、局部电弧发展、完全闪络,其放电发展时间及其持续时间均随降雨强度、雨水电导率的增大而降低;电弧平均发展速度随雨水电导率的增加呈幂指数关系上升,最大上升率高达43.8%,并随降雨强度增加呈指数式增大,且与绝缘子伞裙结构参数有关。复合绝缘子雷电冲击闪络电压随降雨强度增加呈负幂指数关系降低,伞间距较大的绝缘子闪络电压受降雨强度的影响愈加明显;雨闪电压随雨水电导率的增加而呈负幂指数下降。基于此,提出了降雨强度、雨水电导率综合影响的复合绝缘子雷电冲击闪络电压计算式,计算结果与试验结果一致性良好,偏差小于7%。研究结果为雷电活动频繁的强暴雨地区输电线路外绝缘设计、选择及防护提供了参考。
Heavy rainstorms, which are usually accompanied by lightning, can lead to an uneven distribution of the electric field in the dry and wet parts of the insulators of transmission lines, transformer substations, and converter stations, resulting in electric field distortion. Meanwhile, the rain streams caused by thunderstorms can quickly cause short-circuit between the insulator skirts and greatly shorten the flashover paths, resulting in line tripping and power failure accident. In order to study the lightning impulse discharge characteristics and arc development process of line insulators under heavy rainstorms, lightning impulse discharge characteristics of three types of silicone rubber composite insulators commonly used in 110 k V lines were tested in this paper. The results show that the development process of lightning impulse arc of composite insulator mainly includes arcing, local arc development, and complete flashover. The arc development time and the total flashover duration decrease with the increase of the rainfall intensity and rainwater conductivity. The average speed of the arc increases exponentially with the increase of rainwater conductivity, and the growth rate is as high as 43.8%. In addition, the average speed increases exponentially with the increase of rainfall intensity and depends on the structural parameters of the umbrella skirt. The lightning impulse flashover voltage exhibits a negative exponential correlation with the rainfall intensity. The flashover voltage of insulators with a large umbrella skirt spacing is more severely affected by the rainfall intensity. Furthermore, the flashover voltage decreases in a negative power exponential correlation with the increase of rainwater conductivity. Based on these results, fitting expressions for the lightning impulse flashover voltage with the combined effect of rainfall intensity and rain conductivity were proposed in this paper. The calculation results are in good agreement with the experimental results, and the errors are less than 7%. The results can serve as a reference for the design, selection, and protection of the external insulation of transmission lines in areas with frequent lightning activities and heavy rainstorms.
作者
董冰冰
宋家乐
李特
李建生
蒋兴良
DONG Bingbing;SONG Jiale;LI Te;LI Jiansheng;JIANG Xingliang(School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China;State Grid Zhejiang Electric Power Research Institute,Hangzhou 310014,China;State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China;State Key Laboratory of Power Transmission Equipment&System Security and New Technology,Chongqing University,Chongqing 400030,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2023年第2期525-535,共11页
High Voltage Engineering
基金
国家电网有限公司科技项目(J2022047)
高等学校人才引智计划项目(BP0719039)。
关键词
强暴雨
硅橡胶绝缘子
雷电冲击
放电特性
动态过程
heavy rain
SIR composite insulators
lighting impulse
discharge characteristics
dynamic process
