杆塔接地冲击特性的模拟试验研究  

Simulation Test Study of Grounding Impulse Characteristics of Transmission Line Tower

作　　者：邓长征[1,2] 周文俊[3] 杨迎建[4] 喻剑辉[3] 夏长征[3] 王鸿[1,2] 

机构地区：[1]三峡大学电气与新能源学院,宜昌443002 [2]中国电力科学研究院,武汉430074 [3]武汉大学电气工程学院,武汉430072 [4]国网电力科学研究院,南京210003

出　　处：《高电压技术》2014年第9期2917-2922,共6页High Voltage Engineering

基　　金：国家电网公司科技项目(GY71-12-025);Project supported by Science and Technoligy Project of SGCC(GY71-12-025)

摘　　要：为研究输电线路杆塔接地体的冲击特性,获取大尺寸接地体冲击系数的试验数据,采用模拟试验的方法,得到了4种接地体的冲击系数随冲击电流峰值的变化曲线。冲击系数呈现出随冲击电流峰值增大而减小的变化规律;通过与其他学者研究结果的对比验证了模拟试验的有效性,并根据粘土与细沙的临界击穿场强差异揭示了土壤颗粒的尺寸和均匀性对冲击特性的影响机理,初步得出采用细沙模拟土壤的试验方法将高估冲击特性的结论。最后通过不同型式接地体试验结果的比较,建议在低电阻率地区优先选取方框射线型接地体。In order to study the lightning impulse characteristics of grounding bodies and to obtain the test data of impulse coefficient for large-size grounding bodies, we acquired the curve of impulse coefficient versus the peak of impulse cur- rent of four grounding bodies through small-scale tests. It is found that the impulse coefficient decreases with the increase of impulse current peak. Comparison with some other researches proves the validity of the small-scale tests. Moreover, the influence mechanism of impulse characteristics caused by dimension and uniformity of soil particles is revealed by the difference between clay and silver sand in their critical breakdown field strengths, and a preliminary conclusion is drawn that using silver sand to simulate real soil in impulse tests of grounding devices will overestimate the impulse characteris- tics. In addition, by comparing the test results of grounding bodies of different figures, it is suggested that the grounding bodies including square and ray conductors should be selected for the areas with low resistivity soil.

关 键 词：模拟试验 冲击特性 冲击电流峰值 火花效应 土壤颗粒 低电阻率地区 方框射线型接地体 

分 类 号：TM862[电气工程—高电压与绝缘技术]