基于分布式时变参数电路的接地网暂态研究

Research on Transient Model of Grounding Grid Based on Distributed Time-varying Parameter Circuit

为了准确、快速地分析接地网的冲击暂态特性,在考虑土壤电离特性的基础上,建立了接地网数值分析模型,利用电磁暂态分析软件ATP-EMTP研究了接地网在冲击电流下的暂态特性。讨论了不同雷电流注入点和不同地网结构对接地网的暂态特性影响。研究表明:雷电注入点在地网中心时比注入点在地网边缘更容易散流;水平地网每个节点添加水平接地体与只在地网周边节点添加垂直接地体的情况下注入点电位升相同;对于复杂地网,注入点处的电位升最大,注入点四周电位迅速减小直到为0。

In order to analyze the transient characteristics of the grounding grid accurately and quickly,a numerical analysis of grounding grid model is established based on the ionization characteristics of the soil.The electromagnet-ic transient analysis software ATP-EMTP is used to study the transient characteristics of the grounding grid under impulse current.The influence of different lightning current injection points and different grounding grid structures on the transient characteristics of the grounding grid are discussed.The research shows that lightning current is easi-er to scatter when the lightning injection point is at the center of the grounding grid than that the injection point is at the edge of the grounding grid;The horizontal grounding grid with horizontal grounding conductors added to each node has the same injection-point potential rise as the grounding grid with vertical grounding conductors added only at the peripheral nodes;for complicated grid,the potential at the injection point rises the most and the potential a-round the injection point rapidly decreases until it becomes zero.