连续雷电冲击下杆塔导电混凝土基础的热效应分析  

Thermal effect analysis of tower conductive concrete foundation under ontinuous lightning strike

作　　者：张牧桑 冯子阳 汤昕[2] 周力行[1] ZHANG Musang;FENG Ziyang;TANG Xin;ZHOU Lixing(School of Electrical&Information Engineering,Changsha University of Science&Technology,Changsha 410114,China;Department of Power Grid Technology,Changsha Electric Power Technical College,Changsha 410131,China)

机构地区：[1]长沙理工大学电气与信息工程学院,湖南长沙410114 [2]长沙电力职业技术学院电网技术系,湖南长沙410131

出　　处：《电力科学与技术学报》2024年第2期249-254,共6页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金面上基金(52177015)。

摘　　要：导电混凝土做输电线路杆塔基础接地已在国内多个工程中得到试点应用。但其连续雷电冲击作用下杆塔导电混凝土基础的温升特性目前尚需理论分析与试验研究。为此,考虑连续雷电冲击下土壤电离的火花效应及其累积效应,建立杆塔导电混凝土基础散流的ATP-EMTP仿真模型,计算导电混凝土的杆塔基础在受到连续雷电流冲击作用时的热稳定情况,为工程实际提供理论参考。结果表明:在雷电冲击下,导电混凝土基础的热效应改变了周围土壤的盐碱度和含水量,提高周围土壤的电阻率,使得接地电阻相较于雷击前提高了6.56%;当连续雷电冲击次数n≤2时,导电混凝土基础上产生的温升Δt=287.06<300℃,此时杆塔导电混凝土基础是安全稳定的。当n≥3时,Δt>300℃,导电混凝土基础的结构存在被破坏的可能,有可能给电力系统稳定运行带来安全风险。因此,在工程实际中采用导电混凝土基础作为杆塔接地装置,应当尽可能减小导电混凝土基础周围土壤的电阻率,增强其散流散热能力。Conductive concrete applied as power transmission tower foundation grounding has been piloted in many domestic engineering projects.However,the temperature rise characteristics of conductive concrete foundation under continuous lightning impact still need further theoretical analysis and experimental research.In this paper,the spark effect of soil ionization under continuous lightning impact and its cumulative effect are considered.An ATP-EMTP simulation model for the dispersion effect of conductive concrete tower foundation is established.The thermal stability of the conductive concrete foundation suffering continuous lightning strike is calculated,which provides theoretical reference for engineering practice.The results show that the thermal effect of conductive concrete foundation changes the salinity and water content of the surrounding soil under lightning impulse.Thus,the resistivity of the surrounding soil is improved,which results in 6.56%increase of the grounding resistance.When the number of continuous lightning impulse n≤2,the temperature rise of conductive concrete foundationΔt=287.06<300℃,the conductive concrete foundation of tower is safe and stable.Once n≥3,the temperature riseΔt>300℃,the structure of conductive concrete foundation may be destructed,which may bring safety risks to the stable operation of power system.Therefore,in actual engineering applying conductive concrete foundation grounding,the resistivity of the soil around the foundation should be reduced to improve the dissipative heat capacity.

关 键 词：连续雷电冲击 导电混凝土 热效应 ATP-EMTP 

分 类 号：TM862[电气工程—高电压与绝缘技术]