Calculation on induced over-voltage on low-voltage overhead lines

There are always very tall buildings next to the low-voltage transmission lines through the city centers. If the buildings are stroke directly by lightning, the extremely high transient electromagnetic field caused by lightning current through the lightning downward lead might induce high over-voltages on the low-voltage transmission lines. If the induced lightning over-voltage exceeds the withstanding ability of the insulators, lines will flashover to the cross arm of the tower. In this paper , the equation used to calculate the induced over-voltage on the low-voltage overhead transmission lines less than 65m far away from the lightning stroke point is deduced and the sensitivity studies are carried out to indicate how the parameters would influence induced over-voltage.