Development of a surge simulation code VSTL REV based on the 3D FDTD method

The prediction of surge phenomena is required for the design of effective lightning protection methodologies. Traditionally, transmission-line-theory-based simulation techniques have been employed, but such simulation techniques based on the assumption of the transverse electromagnetic mode cannot rigorously treat surge phenomena in three-dimensional structures and grounding structures such as buildings and grounding grids. Recently, full-wave numerical approaches have been widely and successfully applied to such surge phenomena. Central Research Institute of Electric Power Industry (CRIEPI) has developed a surge simulation code, which is called VSTL REV (Virtual Surge Test Lab. Restructured and Extended Version), based on the three-dimensional finite difference time domain method, which is one of the numerical electromagnetic field computation methods used to solve Maxwell´s equations. In this paper, we present an outline of VSTL REV and some examples of its application to the surge analysis of a building, a grounding grid, and an overhead distribution line.