ALGORITHMS FOR CALCULATION OF LIGHTNING-INDUCED VOLTAGES ON DISTRIBUTION LINES

This paper reviews the uncertainties involved in evaluating induced vo ltage lightning performance of distribution lines, and outlines two al gorithms to facilitate computer simulation. These are: 1. A simplified surge impedance model of each wire section of the line, permitting th e coupled electromagnetic fields to be replaced by simple algebraicall y computed forward-backward (FB) current pairs, easily processed by co mputer to handle current reflections and refractions from transformers , arresters, taps and other discontinuities. 2. An algorithm for distr ibution line induced voltage lightning performance calculations that i ntegrates between a striking distance curve and a critical flashover-d istance curve. These algorithms have been successfully embedded in a c omprehensive digital line performance program, and results from this p rogram will be provided in a companion paper.