Lightning induced voltages in simple configurations of underground cables

In this paper, the effect of the geometrical configuration of underground conductors and of the relative location of the lightning strike on induced voltages from lightning is studied. The position of the strike point that leads to the highest induced voltage is determined for buried cables for each configuration. The results show that the maximum voltages tend to appear at the extremities of the cables and at the point closest to the strike point. The overvoltages are lower for bare cables when compared to insulated cables. Overvoltage levels for typical negative subsequent return stroke currents used in this paper represent a risk for low voltage underground feeders and electronic, communication and control circuits.