大地分层结构条件下架空线路系统导线—地回路阻抗的计算分析  

Calculation and Study of Impedance of Conductor-earth Circuits for Overhead Line Systems with Layered Soil Structure

作　　者：朱军[1] 吴广宁[1] 龚宏奎[1] 吴静文[1] 张龙伟[1] 曹晓斌[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《高压电器》2014年第2期29-34,41,共7页High Voltage Apparatus

基　　金：国家电网公司科技项目(2011-WG-4);铁道部科技研究开发计划重点项目(2011Z01-D)~~

摘　　要：架空线路系统导线—地回路阻抗是输电线路过电压防护和电磁兼容研究的重要参数。笔者将大地视为水平分层结构,运用复数镜像法,给出了大地水平分层时架空线路系统导线—地回路阻抗的计算方法,验证了该计算方法的正确性;结合中国特高压输电线路实例,计算分析了大地分层结构条件下架空线路系统导线—地回路阻抗的变化规律。结果表明:文中方法克服了Carson公式计算结果频率性能较差的缺点,具有更高的计算准确度;架空线路导线—地回路阻抗随频率和第1层土壤厚度的增加而增大且有饱和趋势,第1层土壤的电阻率对导线—地回路阻抗有明显影响。The impedance of overhead line systems is of particular importance for the study on overvohage protection and electromagnetic compatibility for transmission lines. In this paper, considering the earth as horizontal layered model, based on the complex image method, the calculation method of impedance of conductor-earth circuits with layered soil structure is given. The correctness of this proposed method is verified. Finally, taking UHV transmission lines as an example, the regularities of impedance of conductor-earth circuits for overhead line systems with layered soil structure are analyzed by calculation results. The results demonstrate that this proposed method overcomes the disadvantage of Carson＇s formula which has poor frequency characteristics and its calculation result has a higher accuracy. The impedance of conductor-earth circuits becomes larger with the increase of frequency and thickness of the first-layer soil, but has a tendency to saturation. Meanwhile, the resistivity of the first-layer soil has obvious influence on the impedance of conductor-earth circuits.

关 键 词：大地分层结构 复数镜像法 导线一地回路 阻抗 频率 土壤电阻率 土层厚度 

分 类 号：TM751[电气工程—电力系统及自动化]