Lightning Response of a Grounding System Buried in Multiple Layers in Earth Using the PEEC Method Based on the Quasi-static Complex Image Method

摘要

A mathematical model of the partial-element equivalent circuit method is developed in this paper that can be used to accurately calculate lightning current along a high-voltage alternating current substation grounding system buried in multilayered soil. Combined with the fast Fourier transform (FFT), the conduction effect of the components of the current harmonics is analyzed, and the effect of capacitance and induction between layers of soil are examined. Furthermore, the effects of the frequency-dependent conductivity and permittivity of the soil are considered. To speed-up calculation, the quasi-static complex image method and a closed form of Green's function are used. Through the inverse FFT, the model can calculate the distribution of lightning current in any grounding system. This can be used to study the performance of the system's response to transient lightning.