Influence of ring bonding at the ground level upon current distribution between down-conductors

Present study considers distribution of currents and magnetic field in frame-type lightning protection systems (LPS). Influence of equipotentialization ring conductor (ERC) connecting vertical down-conductors at the ground level, as recommended by some normative documents, upon current distribution between mentioned conductors and magnetic field (MF) inside structures is numerically simulated. Analysis for a wide range of soils/water electrical conductivity(σg = 0.67·10-3 to 1 S/m) and various relative permittivity (εr = 4; 7; 15; 80) values is done. When one of the goals of LPS design is to achieve a uniform current distribution between down-conductors and MF reduction within structure, for large conductivities (> 0.1 S/m) the presence or absence of ERC do not make a significant difference. In case of lower conductivities (<; 4·10-3 S/m), advantages have structures without ERC.