Title :
Backflashovers of Transmission Lines Due to Subsequent Lightning Strokes
Author :
Silveira, Fernando H. ; Visacro, Silverio ; De Conti, Alberto ; de Mesquita, C.R.
Author_Institution :
Lightning Res. Center, Fed. Univ. of Minas Gerais, Belo Horizonte, Brazil
fDate :
4/1/2012 12:00:00 AM
Abstract :
Lightning overvoltages across insulator strings of existing 138- and 69-kV transmission lines were simulated using the hybrid electromagnetic model. It was found that, though the reduction of tower-footing grounding resistance is very effective to decrease lightning overvoltages caused by first strokes, this reduction is saturated around 750-600 kV for typical currents of subsequent strokes. The lightning performance of these lines was estimated and subsequent strokes were found to be relevant cause of backflashovers in 69-kV lines.
Keywords :
earthing; flashover; insulators; lightning protection; power transmission lines; power transmission protection; backflashovers; hybrid electromagnetic model; insulator strings; lightning overvoltage; lightning strokes; tower-footing grounding resistance; transmission lines; voltage 138 kV; voltage 600 kV to 750 kV; voltage 69 kV; Grounding; Insulators; Lightning; Poles and towers; Power transmission lines; Resistance; Surges; Lightning parameters for engineering application; lightning overvoltage; lightning performance of transmission lines; subsequent strokes;
Journal_Title :
Electromagnetic Compatibility, IEEE Transactions on
DOI :
10.1109/TEMC.2011.2181851
