Radiation characteristics of the electric dipole excited by surge impulse current

Surge is a kind of transient over-voltage or over-current with short duration and high energy in power system, which mainly conducts through wires, also produces electromagnetic radiation in space. It was obtained that the amplitude spectrum of surge impulse current principally concentrates within 1 MHz based on the spectrum analysis. The electromagnetic radiation model of the electric dipole excited by surge impulse current was deduced by using retarded vector potential and electromagnetic field theory, and the analytic expressions in time domain of the radiated electromagnetic fields were given. Moreover, results were acquired by software MATLAB. The results show that the amplitude of the radiated electromagnetic field of an electric dipole is proportional to the surge peak current; the radiated E-field and H-field attenuate with distance; and the radiated electromagnetic field amplitude changes with time in pulse shape at a field point.