Induced currents in cranes in electromagnetic field of MF transmitters

Abstract

Electromagnetic field of powerful MF transmitters induces currents in large-scale conductive structures which act as unintentional receiving antennas. Among such structures are construction cranes, tower cranes, portal-harbour cranes and reloading bridges, so that touch voltages and short-cut currents are experienced by their workers. Calculations are presented in this paper for cranes treated as wire antenna structures in plane-wave electromagnetic field of some frequency and propagation direction, using Point matching method for solving the system of electric field integro-differential equations (EFIE) of Hallen's type with current distributions approximated by polynomials. Possible solutions of this problem are given in the paper.