Prof. Samy Mohamed Ghania :: Publications:

For proper design of the transmission and distribution insulation systems, it is necessary to fully clarify the lightning phenomena characteristics. In this paper, two typical power transmission lines (500 kV and 220 kV) are modeled to compute the lightning electromagnetic fields around the transmission lines. The lightning electromagnetic fields around the different power lines are calculated using the finite difference time domain (FDTD) method with Maxwell’s equations. Two selected zones are used to capture the electromagnetic fields while lightning strike. The first zone is around the insulators and the second is at the ground level underneath the power line at 1 m above ground and at the power line right of way (ROW). The correlation between the induced magnetic and electric fields is verified in the free space inside the two selected zones. The induced electromagnetic fields at different positions of each power line phases are evaluated. The obtained results show that while lightning strikes the conductor, the waveforms of electromagnetic field obtained at the selected monitoring points are the same as the lightning current's waveform. The amplitude of the electromagnetic field intensities exhibits a stabile linear relationship with the lightning currents as the free air intrinsic impedance.