Experimental assessment of induced voltage in a scaled building directly hit by lightning

The strike of lightning directly or even nearby an electrical installation produces electromagnetic pulses and consequently induces over voltages on equipment ports inside a building structure. From an electromagnetic compatibility point of view, knowledge of the magnetic fields in the internal structures is essential for the development of protective systems against surges. This paper presents an experimental evaluation of the shielding efficiency provided by different LPS configurations, to the magnetic field developed inside a structure hit by a direct lightning. Three different LPS settings were tested by changing the mesh sizes of the protection system. Measurements of the magnetic fields were carried out with a loop antenna. The building was made in a 1:20 scale wood structure. For the simulation of the lightning, a surge generator was used located at the top of the building. The measured values were compared with the ones calculated according to IEC 62305-4 and are in very good agreement.