Protective Effect of Shield Wires Against Indirect Lightning to Transmission Lines

The effect of one or two shield wires placed at the top of line, on induced currents and voltages generated by lightning on the horizontal and vertical configurations of both single circuit and double circuit transmission lines, for perfect ground, has been studied using the Transmission Line “TL” theory. In this paper, the lightning effect is included by two current sources located at the line terminations. The examples presented in this paper show that the presence of the shield wires reduces the overvoltage induced on the line which is related to several parameters.