杆塔冲击接地电阻的探讨

Discuss on Tower Impulse Grounding Resistance

以电路理论为基础,采用传统的接点电压法分析杆塔接地网的冲击接地电阻;通过建立目标函数,利用最优化方法———变度量法,较精确求出了雷电流双指数函数中的参数;借助于付氏级数,把双指数函数转化为频率点,这样对于雷电流的处理就类似工频电流的处理。结果表明,冲击接地电阻随接地网导体半径的增大而减小,两点注入比一点注入时冲击接地电阻要小,对工程设计提供了一定的参考。

Based on the electric circuit theory, this paper analyses the impulse grounding resistance of tower grounding grids by using a conventional nodal analysis technique. By establishing object function, this paper uses an optimization method-the variable metric method, and accurately solves parameters of double exponential function of lightning current. By Fourier series, this paper transforms double exponential function into the sum of many sinusoidal functions, which is separated into many frequency points, so processing of lightning current is similar to that of power current. Though spark discharge is not considered, this paper draws some conclusions, which presents a reference for engineering design.