Development of Surge Simulation Code Based on Finite-Difference Time-Domain ( FDTD ) Approximation of Maxwell ' s Equations

This paper presents the development of a surge analysis program named VSTL (Virtual Surge Test Lab.) based on the Maxwell Equations formulated by the FDTD (finite-difference time-domain) method. By use of the Maxwell Equations, VSTL is inherently able to take into account the three-dimensional geometrical features of a simulated structure unlike EMTP-type circuit-based transient programs. In terms of the handling of imperfectly-conducting medium such as earth soil, VSTL is more advantageous than MoM (method of moments) based programs such as NEC-2. This paper also presents comparisons between calculated and measured results to validate the accuracy of VSTL.