基于ATP-EMTP的伸长接地体时变接地电阻仿真研究

The Simulation Study on Time-Varying Grounding Resistance of Extended Grounding Electrode Based on ATP-EMTP Simulation

运用电磁暂态分析软件ATP-EMTP搭建了单根伸长水平接地体的π型等值电路仿真模型,使用电路理论的分析方法对接地体雷电冲击特性进行了研究。仿真模型考虑了火花效应的影响。运用模型对不同条件的伸长水平接地体进行了仿真计算,有别于工程上广泛使用的冲击接地电阻的概念,得出了接地体在雷电冲击条件下实际接地电阻随时间变化的曲线,分析了其变化规律。同时从接地电阻变化曲线的角度研究了接地体长度、雷电流幅值、土壤电阻率对接地电阻的影响。

Set up π-equivalent circuit siroulation models of single extended horizontal grounding electrodes is established by electromagnetic transient analysis software ATP-EMTP, lightning impulse characteristics of grounding electrode is studied by using the circuit theory analysis method. The spark effect is taken into account for the model. Different extended horizontal grounding electrodes are simulating calculated by using the model, which are different from the widely used impulse grounding resistance concept in engineering, their time-varying grounding resistance curves are obtained and the variation law is analyzed. The effect of the length of the grounding electrodes, the amplitude of the lightning current and the soil resistivity on the grounding resistance are studied from angle of the grounding resistance varying curve.