FDTD Analysis of the Electric Field of a Substation Arrester Under a Lightning Overvoltage

The electric field in and around a 2.6-m-long substation arrester, on which a 1 MV lightning impulse is imposed, has been analyzed using the finite-difference time-domain (FDTD) method. The arrester is represented as a combination of 10 mm × 10 mm × 10 mm cubic cells, each of which has a nonlinear resistivity (or conductivity) in each of the x-, y-, and z-directions, dependent on the electric field in each direction. This simple representation requires no iterative procedure, and is suitable and useful for the FDTD simulation of an overvoltage-imposed arrester. The transient electric field in and around the overvoltage-imposed arrester, and the spatial distributions of vertical and radial electric fields along the surface of the arrester are shown. The influence of a shield ring is also shown.