不同地表情况下Cooray-Rubinstein算法的应用及其精度检验  

Application and accuracy validation of the Cooray-Rubinstein formula for different soil conductivity

作　　者：樊艳峰[1,2] 张其林[1,2] 李东帅[1,2] 高金阁[1,2] 申元 

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室,江苏南京210044 [2]南京信息工程大学大气物理学院,江苏南京210044 [3]云南电网有限责任公司电力科学研究院,云南昆明650217

出　　处：《大气科学学报》2017年第1期118-126,共9页Transactions of Atmospheric Sciences

基　　金：电网雷电预警技术研究及雷电预警系统开发(K-YN2013-186);配电网综合防雷体系研究与工程示范(YNKJQQ00000274);国家重点基础研究发展计划(2014CB441405);国家自然科学基金资助项目(41275009;41575004)

摘　　要：将雷电水平电场Cooray-Rubinstein(C-R)算法推广应用于地表电导率垂直分层的情况,并利用时域有限差分(FDTD)方法对不同地表情况下C-R算法的精度进行检验。结果表明,C-R算法的适用条件为:距离回击通道为100~1 000 m、地表电导率介于0.001~0.01 S/m,最大误差小于10%。当土壤电导率均匀分布时,C-R算法的精度最好;对电导率水平分层的情况,当上层电导率小于下层电导率时,C-R算法的精度较优;当电导率垂直分层时,若观测点处的土壤电导率小于闪击点处的电导率时,C-R算法的计算精度较高,反之,精度较低;对任何光滑有耗地表而言,利用C-R算法计算的首次回击水平电场的精度优于继后回击。Lightning is a type of strong discharge phenomenon in nature which can radiate intensive electro magnetism pulses.The electro magnetism fields may couple into the overhead transmission lines or power installations lying underground and cause significant damage to power systems,so it is important to research the overvoltage caused by lightning.It is well known that there are three different yet equivalent field-to-transmission line coupling models,namely the model of Taylor,the model of Agrawal,and the model of Rachidi.Based on these models,the determination of induced currents and voltages requires the evaluation of specific field components depending on the employed coupling model.Among them,the accuracy of Agrawal coupling model has been proven by artificial triggering lightning experiments.In the model of Agrawal,the horizontal electric field component along the line is required.Considering the inherent difficulty in measuring lightning horizontal electric fields,namely for the observation points to be located on the ground or a few meters above the ground,the vertical electric field magnitude is much larger than that of the horizontal component（typically two orders of magnitude）,thus even a small tilt in the measurement sensor could render the measured horizontal field useless,and therefore it is necessary to create an accurate and efficient algorithm to obtain the results.The exact solution of the lightning horizontal field requires calculation of the Sommerfeld integrals for several elementary dipoles at many frequencies,which is very time consuming.The finite different time domain（FDTD） method is a numerical computation method which can be used to calculate the lightning-radiated horizontally electric field over different types of ground;however,the use of numerical calculations in this method will affect thememory,as well as time consumption.Therefore,it is necessary to develop a method to calculate the lightning-radiated horizontal electric field with high accuracy and rapid computation.The C-R f

关 键 词：C-R算法 FDTD 雷电水平电场 电导率分布 精度分析 

分 类 号：P427.32[天文地球—大气科学及气象学]