摘要
电气几何模型(electric geometry model,EGM)作为解决雷电屏蔽问题的工程模型,广泛应用于计算评估高压、超高压输电线路的雷电绕击性能。然而,随着特高压输电线路杆塔高度的提高和空气间隙的增长,运用现有EGM得到的绕击率和实际观测数据有较大出入。鉴于此,该文基于1~10m的棒-棒长空气间隙负极性20/2500μs操作冲击50%放电电压试验数据,并引入Idone的雷电通道回击速度概率分布,修正了现有击距公式;再根据棒-棒间隙和棒-板间隙的50%放电电压在4m处发生翻转的特点,结合试验结果修正了大地的击距系数,提出了一种适用于大尺寸输电线路的改进EGM。最后运用该文提出的改进EGM分别对日本500、1000和中国1000k V交流输电线路的绕击率进行计算,与日本长期的雷击观测数据对比表明:该文提出的改进EGM较现有EGM更加适合大尺寸输电线路,尤其是各相导线绕击比例和观测数据更加吻合。该文提出的改进EGM能为大尺寸输电线路雷电屏蔽设计提供参考。
Electric geometry model, as a kind of engineering model solving lightning shielding problems, has been widely used in assessing shielding failure lightning performance of HV and EHV transmission lines. However, with the increase of UHV line voltage level and the growth of the air gap, the results calculated by the previous EGM is not consistent with the observed data. Hence, this paper corrects the equation between the lightning current and the striking distance, based on the data of negative polarity 50% discharge voltage from the rod-rod gap -20/2500μs switching impulse test of which the distance of air gap ranges from 1-10m, and the return stroke velocity distribution obtained by Idone was newly applied. In addition, According to the character that, when the gap distance exceeds 4m, the size relationship of negative polarity 50% discharge voltage between the rod-rod gap and rod-plane gap changes, the striking distance factor of ground has been corrected based on the test data. With these improvements, an improved EGM applied to large-sized transmission line has been proposed, which is applied to calculate the lightning stroke rate of 500kV and 1000kV transmission line in Japan and the lightning stroke rate of 1000kV transmission line in China. It was found that the results calculated by the improved EGM are closer to the actual observations in Japan, especially the lightning stroke proportion of each phase conductor. Thus, this improved EGM is more suited for large-sized transmission lines and can provide a more reliable foundation for lightning shielding design.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第12期3654-3661,共8页
Proceedings of the CSEE
基金
中国博士后科学基金项目(2014M560624)
国家电网公司2015年总部科技项目(SGTYHT/14-JS-188)~~
关键词
特高压输电线路
绕击率
电气几何模型
击距
负极性长间隙冲击放电
UHV transmission line
lightning shielding failure
electric geometry model
striking distance
negative switching surge discharge tests of long air gaps
作者简介
王羽（1983）,男,讲师,主要从事电力系统防雷与接地、过电压保护、电网防灾减灾方面的研究,wy_20002@163.com;
邓冶强（1991）,男,硕士研究生,主要从事电力系统雷电过电压等方面的研究工作,dengyeqiang@whu.edu.cn;
文习山（1962）,男,教授,博士生导师,主要从事防雷与接地、过电压保护、电缆绝缘监测与电磁场数值计算等方面的研究工作,xswen@whu.edu.cn;
马宇晗（1995）,女,本科在读,武汉大学电气工程及自动化专业,923443228 @qq.com。
