杆塔冲击接地电阻的计算  

Calculation of Tower Impulse Grounding Resistance

作　　者：徐华[1] 吕金煌 文习山[1] 舒翔[1] 刘海燕[1] 

机构地区：[1]武汉大学电气工程学院,武汉430072 [2]泉州电力局,泉州362000

出　　处：《高电压技术》2006年第3期93-95,共3页High Voltage Engineering

摘　　要：通过数学模型,建立目标函数,利用最优化方程—变度量法,较精确地求出了双指数函数中的参数。借助于傅氏级数,把双指数函数转化为很多正弦函数和的形式。当高幅值的雷电流经接地装置注入接地网,接地网周围的土壤会发生火花放电。将土壤火花放电等效为接地分支等效半径的增大。当等效半径很大时,对分支埋深的影响作了论述。借助于场路结合的思想,采用节点电压法求得接地网在冲击电流下的参数。整个计算是逐步逼近的过程。计算的具体实例对工程应用有一定的参考。By mathematical model, using optimum method-variable metric method, this paper establishes object function, and accurately solves parameters of double exponential function. By Fourier series, this paper transforms double exponential function into the sum of many sinusoidal functions. And high amplitude lightning current is fed to grounding grids, spark discharge will be generated. The paper substitutes the spark discharge of soils with the increment of the equivalent radius of grounding branch. When equivalent radius of branch are very large, the paper introduces the influence of equivalent radiuses on the depth of embedment of grounding branch. By field-circuit coupling theory, the parameters in impulse current of grounding grids are obtained by using nodal voltage method. The whole calculations are a gradually approximate process. The paper computes some specific cases, and presents some reference for practical engineering.

关 键 词：雷电流 最优化 接地网 冲击接地电阻 火花放电 杆塔 

分 类 号：TM862[电气工程—高电压与绝缘技术]