An engineering model for transient analysis of grounding system under lightning strikes: nonuniform transmission-line approach
An engineering model for transient analysis of grounding system under lightning strikes: nonuniform transmission-line approach
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DOI：
10.1109/tpwrd.2004.843437
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发表时间：
2005-04
影响因子：
4.4
通讯作者：
Yaqing Liu;N. Theethayi;R. Thottappillil
中科院分区：
文献类型：
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作者：
Yaqing Liu;N. Theethayi;R. Thottappillil
本文采用非均匀传输线方法，基于时域有限差分（FDTD）技术求解电报方程，对不同类型接地系统在雷击作用下的暂态行为进行时域建模。接地线不同部分之间的电磁耦合包括使用有效的单位长度参数（l， c和g），这些参数与空间和时间有关。该模型能较准确地预测接地电极的有效长度和暂态电压，而采用电极长度依赖于单位长度参数的均匀传输线方法无法预测有效长度和暂态电压。与电路理论方法不同，该模型能够准确地预测大型接地系统的浪涌传播延迟。基于该模型的埋地水平导线和接地网的仿真结果与电路法和电磁场法的仿真结果吻合较好。从工程角度来看，本文所提出的模型具有足够的准确性、时间效率和易于应用的特点。
A nonuniform transmission line approach is adopted in this paper for modeling the transient behavior of different types of grounding systems under lightning strikes in time domain by solving Telegrapher's equations based on finite-difference time-domain (FDTD) technique. Electromagnetic couplings between different parts of the grounding wires are included using effective per-unit length parameters (l, c, and g), which are space and time dependent. The present model can predict both the effective length and the transient voltage of grounding electrodes accurately, while, an uniform transmission line approach with electrode length dependent per-unit length parameters fails to predict the same. Unlike the circuit theory approach , the present model is capable of predicting accurately the surge propagation delay in the large grounding system. The simulation results for buried horizontal wires and grounding grids based on the present model are in good agreement with that of the circuit and electromagnetic field approaches , . From an engineering point of view, the model presented in this paper is sufficiently accurate, time efficient, and easy to apply.