Energija, Vol. 60 No. 1-4, 2011.
Izvorni znanstveni članak
Lightning Protection of Electric Power Overhead Distribution Lines by Long-Flashover Arresters in Russia
G.V. Podporkin
E.S. Kalakutsky
V.E. Pilshikov
A.D. Sivaev
Sažetak
A simple and effective method for lightning protection of power overhead distribution lines
by long flashover arresters (LFAs) is presented. Even large lightning currents do not pose any
threat to these arresters because the discharge develops in the air and not inside the device.
LFAs, which are based on the creeping discharge effect, increase the lightning flashover
length significantly and thus eliminate Power Arc Follow (PAF). To protect a line against
induced overvoltages, a single arrester should be mounted on a pole. To protect a line against
direct lightning strokes, LFA-M arresters should be mounted in parallel with each insulator.
For covered-conductor overhead lines (CCL) using conductors with three-layer insulation a
new lightning protection approach is suggested, involving use of antenna-type long flashover
arresters whose essential component is the protected conductor itself. The essence of antennatype
long flashover arresters (LFA-A) is that the arrester which is connected to the antenna
gets flashed over well before the lightning leader comes in immediate contact with the line.
The toroid-shaped antenna made of a metal tube is mounted on the covered conductor’s
surface midway between the protector’s edge and the piercing clamp with the help of the
toroid fixation unit. As the lightning leader progresses from a thunderstorm cloud to the CCL
a high potential gets induced on the LFA antenna. A voltage drop that develops between the
electrode and the zero-potential conductor core gives rise to development of a creeping
discharge. Even before the lightning leader hits the line the creeping discharge channel flashes
over the covered conductor’s surface Thereby the conductor insulation get bypassed by the
discharge channel and thus protected against puncture.
LFA’s main applications and field experience are presented.
Ključne riječi
Lightning overvoltage; power arc follow; long flashover arrester
Hrčak ID:
198511
URI
Datum izdavanja:
20.6.2017.
Posjeta: 660 *