Transient electromagnetic field radiated by grounding systems caused by lightning strike in a dissipative half-space

Abstract

In this work, a method is proposed for the calculation of the electromagnetic field radiated by a grounding system in a semi-infinite dissipative medium subjected to a current excitation generated by the lightning strike. The assessment of the induced current distribution on the grounding system due to a transient excitation is obtained by solving Pocklington’s equation using the method of moments. A new method for the calculation of the transient electromagnetic field following the injection of a lightning current or short circuit is also developed. This method is based on the concept of the hertzian dipoles and the asymptotic expansion of a single dipole. A MATLAB computer program has been developed for the determination of the induced currents. The program is validated by comparing its results with those obtained with the commercial software NEC 4.

Keywords

• lightning
• electromagnetic field
• hertzian dipole
• nec4
• transient
• sommerfeld integrals
• grounding