变电站接地网暂态建模方法

为提高接地网暂态模型计算效率及建模灵活性,保证其计算精度,基于场路结合思想推导了接地网暂态建模及数值计算方法。该方法有效计及了接地导体间电磁互耦作用,可准确计算接地网不同频率电流及冲击电流作用时的暂态响应。采用该方法对接地网不同频率电流作用下的接地阻抗进行了仿真计算,并对接地网雷电流作用下暂态电位分布进行了计算,绘制了三维电位分布图。经与电磁场模型计算结果及接地网现场暂态电位分布试验结果对比,验证了模型的正确性。

A Transient Modeling Approach of Substation Grounding Grid

To speed up the calculation of transient model of grounding grid and improve the flexibility of its modeling as well as to ensure the accuracy of the calculation,based on hybrid analysis of electric circuit and electromagnetic field an approach of transient modeling of grounding grid and its numerical calculation method are derived.The proposed method effectively takes the electromagnetic mutual coupling among grounding conductors into account,so it can be used to accurately calculate the transient response of grounding grid under the action of currents with different frequencies and impulse current.Using the proposed method,the simulation of grounding resistance of grounding grid under the action of current with different frequencies is performed,and the transient potential distribution in grounding grid under the action of lightning current is calculated and a three-dimensional potential image is drawn.The correctness of the proposed model is verified by comparing the results calculated by the proposed modeling approach with the results calculated by electromagnetic field model and on-site measured results of transient potential distribution test.