Development of the lightning measure technique and applications using lightning electromagnetic impulse simulator

We have developed the electromagnetic impulse simulator by FDTD method (Finite Difference Time Domain Method), in order to analyze the situation of current diversion and the effects of electromagnetic field in the building by lightning strikes. Also we have experimented using the 1/4 scale model of a 3-story building. The situation of current diversion and the distribution of electromagnetic field were measured, and those results were compared with the calculation by the developed simulator. The results of calculation by the simulator and experimental results were agreed well. Furthermore, we applied this simulator to designing the lightning measures of an actual building. Although it has passed 3-years and half a year since the building was completed, the damage caused by the lightning strikes did not occur. By the way, the building layout planning described here is the “plane arrangement plan technique”. This is to move “the important room which uses ICT (Information and Communication Technology) equipments” such as a server room and “the important room which maintain the function of the building” such as a central control room, to safety areas which have no serious effect by the lightning strikes in schematic drawings.