抄録
An equivalent circuit to calculate lightning-induced voltages on a distribution line, linked to a numerical method to calculate the electric field associated with a return stroke, is proposed. The electric field is first calculated in the frequency domain by decomposing the return stroke channel into numerous electric dipoles, then it is synthesized to yield solution in the time domain. Under the condition for a line of infinite length over perfectly conducting ground, it is shown that the proposed equivalent circuit is identical to that proposed by Rusck, which has been widely used.
In this paper, lightning-induced voltages on a line of finite length over perfectly conducting ground are analyzed by using the new model. The importace of the current wave generated by the vertical electric field at the termination of the line, which is newly taken into acount in this new model, is demonstrated. As a result, it is shown that the lightning-induced voltage on a line of finite length is greatly affected not only by the distance, but also by the direction to the return stroke.
