Influence of ground conductivity on the over voltages induced on overhead power distribution lines due to an indirect lightning stroke

Computation of induced voltage on an overhead line due to an indirect lightning stroke involves calculation of electric field due to the lightning stroke as well as its coupling with the overhead line. The ground conductivity influences both the electric field as well as the coupling mechanism and hence the magnitude and waveshape of the induced voltage. In this paper, lightning induced voltages are calculated for 33 kV, 3/spl phi/ single circuit and double circuit overhead power distribution lines. It has been observed that the magnitude and wave shape of the induced voltage is influenced by the finite ground conductivity as well as the number of overhead conductors in a multiconductor system.