ANALYSIS OF THE ELECTROMAGNETIC ENVIRONMENT ENGENDERED INSIDE A BUILDING BY A LIGHTNING PROTECTION SYSTEM (LPS)

摘要

This paper deals with the electromagnetic fields radiated inside a building protected by a lightning protection system (LPS). When a LPS is struck by lightning, it protects the building from direct impact of that last one. But the electromagnetic environment inside the building is very severe and the radiated electromagnetic disturbances can be dangerous to the equipments inside especially with the appearance of electronic systems of increasing sensibility. In this study, instead of the numerical methods used by the former researchers like the method of moment and the finite-difference time domain or the circuit analysis method, a semi-analytical method based on the Hertzian dipole is used to quantify the electric and magnetic fields against researchers who characterize the magnetic field only. It has advantages of implementing easily and saving the computing time and storage. The current through the LPS is simulated by the modified transmission line model. The computed results of electromagnetic fields were verified versus some experimental results. Besides, the benefits of having one or two down conductors are discussed. Furthermore, characterization of the zones that are most exposed to the electromagnetic fields inside the building is done.