考虑火花放电的杆塔冲击接地特性计算方法  

Calculating Method of Impulse Characteristics of Tower Grounding Devices Considering Soil Ionization

作　　者：何金良[1] 孔维政[1] 张波[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

出　　处：《高电压技术》2010年第9期2107-2111,共5页High Voltage Engineering

基　　金：国家自然科学基金(50737001)~~

摘　　要：输电线路杆塔遭受雷击时,因杆塔接地电阻的存在,塔身上会产生很高的电位,过高的电位将引起杆塔对输电线路的反击,进而造成输电线短路。为了准确计算杆塔冲击接地特性,以便有效设计接地装置,基于电磁场和电路理论,通过等效半径的方法考虑了土壤中的火花放电效应,建立了杆塔接地装置的时域分析模型。计算结果显示,考虑土壤火花放电效应后的接地装置电位升更加符合实验测量结果,比没有考虑时电位升要低。该算法适用于大电流冲击下杆塔冲击特性的分析计算。Under lightning strike,the voltage of transmission tower can rise to an extremely high level,causing the back flashover from towers to transmission lines sometimes.Thus,it is important to identify the impulse characteristics of tower grounding device for calculating the potential of the tower.Based on the theory of electromagnetic fields and equivalent circuit method,the time domain model of grounding device with the soil ionization effect considered was introduced.The simulation result shows that the computational potential rise can be much closer to the measured result when considering the soil ionization effect.Therefore,the proposed model can provide much more accurate results in lightning overvoltage analysis of transmission line.

关 键 词：杆塔接地装置 冲击接地特性 土壤火花放电 电路分析法 时域模型 等效半径 

分 类 号：TM862[电气工程—高电压与绝缘技术]