Lightning Performance of Double-Circuit Transmission Lines

This paper presents further studies of lightning outage rates on double-circuit transmission lines. Satisfactory agreement with field data has been demonstrated for calculations of total and double-circuit outage rates and for prediction of outage types on high-voltage lines. An analysis of the parameters influencing double- circuit outage rates has enabled proposal of several line designs that should achieve a low proportion of lightning faults involving both circuits. Two configurations are of particular interest-a double-horizontal arrangement with one circuit above the other, and a double-triangular arrangement utilizing a conventional lattice tower with three crossarms.