抄録
It is needed to study the transient performance of electrical apparatus for lightning surges to ensure the electromagnetic compatibility (EMC) and to establish accident prevention. The electromagnetic transient program (EMTP) based on circuit theory has been applied to resolve the transient performance of electrical apparatus consisting of cables and conductors which are parallel to the ground surface, in which the propagation of TEM waves that are plane waves is implicated, and devices such as surge arresters represented by lumped elements. However, for example, vertical conductors, which are familiar in electrical apparatus, have not been modeled because TM waves propagate on such conductors. Furthermore, transient performance of almost all types of grounding electrode buried in the lossy ground, except buried wires parallel to the ground surface, is not clear. Then, full-wave computational analysis based on the finite difference time domain (FD-TD) method, which is familiar as numerical electromagnetic analysis method, have been used to calculate transient performance recently. The present article discusses the full-wave computational analysis method.
