Title :
The Use of Underbuilt Wires to Improve the Lightning Performance of Transmission Lines
Author :
Visacro, Silverio ; Silveira, Fernando H. ; De Conti, Alberto
Author_Institution :
Lightning Res. Center (LRC), Fed. Univ. of Minas Gerais (UFMG), Belo Horizonte, Brazil
Abstract :
An unconventional technique to improve the lightning performance of transmission lines, consisting of the addition of grounded wires properly positioned below the phase conductors, is assessed. Overvoltages developed across insulator strings of existing 230-kV lines in response to direct strikes to the towers were simulated using an electromagnetic model. Minimum reductions of these voltages in the ranges of 19%-32% and 26%-44% were achieved for 20- to 80-Ω tower-footing grounding resistances due to the addition of one and two underbuilt wires, respectively. This practice was shown to be more efficient than reducing the tower grounding resistance to its half value.
Keywords :
lightning; lightning protection; poles and towers; power overhead lines; power transmission protection; wires (electric); electromagnetic model; grounded wires; insulator strings; lightning performance; phase conductors; resistance 20 ohm to 80 ohm; tower-footing grounding resistances; transmission lines; underbuilt wires; voltage 230 kV; Conductors; Grounding; Lightning; Poles and towers; Resistance; Surges; Wires; Lightning; lightning overvoltage; lightning performance of transmission lines; transmission lines;
Journal_Title :
Power Delivery, IEEE Transactions on
DOI :
10.1109/TPWRD.2011.2168546
