Equivalent Circuit of Distribution Line for Lightning-Induced Voltage Analysis Using Analytical Formulas

This paper proposes an equivalent circuit at a transition point of distribution line for lightning-induced voltage analysis. The lightning-induced voltages caused by a piecewise linearly varying lightning current are expressed by analytical formulas. The equivalent circuit is represented by resistors and current sources, which are known from past history and given by the lightning-induced voltage on an infinite-length line. Transient voltages and currents at the transition point are accurately obtained in small computation time using the equivalent circuit. Thus, the proposed equivalent circuit is very convenient for analyzing the lightning-induced effect in complicated electric power networks. This paper presents an example of EMTP data cards to use the proposed equivalent circuit in the EMTP.