An Efficient Parallel 3-D FDTD Method for Calculating Lightning-Induced Disturbances on Overhead Lines in the Presence of Surge Arresters

In this paper, we propose an efficient modeling technique for incorporating surge arresters in finite-difference time-domain (FDTD) simulations of lightning-induced disturbances in power networks. Instead of using piecewise linear approximations for the V-I curve of an arrester, as usually done in the literature, we derive new updating equations for calculation of electric field components required at each FDTD time step. This is done in a semi-implicit manner where we first obtain a time-stepping relation of electric field based on the V-I curves of the arresters. The time-stepping relation in each time step is solved by the Newton-Raphson method to update the electric field components. The proposed technique is implemented into a nonuniform parallel FDTD code, which is used to simulate a three-phase distribution line of about 800 m equipped with lightning arresters and a neutral wire, installed at the International Center for Lightning Research and Testing at Camp Blanding Florida. The results of FDTD numerical simulations are found to be in excellent agreement with experimental data associated with triggered lightning.