接地装置雷电冲击特性的大电流试验分析  

Experimental Analysis on Impulse Characteristics of Grounding Devices Under High Lightning Current

作　　者：张波[1] 余绍峰[2] 孔维政[1] 何金良[1] 

机构地区：[1]清华大学电机工程与应用电子技术系电力系统及发电设备控制和仿真国家重点实验室,北京100084 [2]浙江省电力试验研究院,杭州310014

出　　处：《高电压技术》2011年第3期548-554,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724504);国家重点实验室基金(SKLD09M34)~~

摘　　要：降低杆塔接地电阻是改善输电线路直击雷保护效果最为有效的措施。冲击大电流下杆塔接地装置的接地电阻并不是常数,而是一个时变的非线性电阻,其值受多种因素影响。为此,使用大型冲击电流发生器,通过埋设多种形式接地极,采用现场试验研究了不同注入电流下、不同规模下接地体的冲击特性。试验结果表明,接地体的冲击特性与接地体长度、冲击电流幅值密切相关。对于短接地装置,冲击电流幅值造成的土壤电离强度对其冲击特性的影响更大;随着接地体长度逐步增加,接地体纵向电感作用加强,电流注入点位置、接地体规模的影响越来越大。Reducing grounding resistance of the transmission tower is the most effective measure to improve the protective effect of cloud-to-transmission line strike.The impulse grounding resistance of tower grounding device under high current is not constant,but a nonlinear time-varying resistance,which is affected by many factors.We adopted a large impulse current generator,through burying various forms of grounding devices,to investigate the impulse characteristics with different injection current,different size of grounding device by the use of field experiments.The results show that the impulse characteristics are closely related to the length of the grounding device and the current amplitude.For short grounding device,the soil ionization characteristics determined by the current amplitude have greater impact on the impulse characteristics.With the increasing in the length of the grounding device,the role of the inductance along the grounding electrode is strengthened.Then,the effect of the location of the current injection point and the size of the grounding device become remarkable.

关 键 词：接地装置 雷击 冲击接地 冲击系数 土壤电离 接地测量 

分 类 号：TM862[电气工程—高电压与绝缘技术]