10-04-2012, 05:13 PM
LIGHTNING PROTECTION USING MODULAR LONG FLASHOVER ARRESTER
Seminar__Presentation_ 2011 MODULAR LONG FLASHOVER ARRESTER (LFA-M).pptx (Size: 972.96 KB / Downloads: 83)
INTRODUTION
To Study the Lightning Protection of Medium Voltage Lines (6-10kv) using Long Flashover Arrester (LFA), invented by G. V. Porkin and A. D. Sivaev ,the Senior Members, IEEE 1998
NEED OF LFA ARRESTER
Distribution Lines : The Backbone of Power System
According to St Petersburg Power Administration
in Russia: About 50% DL has been replaced or upgraded
Causes:-
insulation flashovers at lightning overvoltage
insulation flashovers at switching overvoltage
operating voltage insulation flashovers due to
pollution and wetting
lightning impulse puncture of insulators
Effect:- Utilities resigned themselves to an
"inherently low" lightning performance of DL
Remedy:-
Necessary to assure a high lightning performance
of such lines, LFA and then LFA-M was invented
What is Lightning?
An electrical discharge, a huge Spark between cloud and the earth, between clouds or between the charge centres of the same cloud
FLASH AND STROKE
The term flash is used to refer to a complete
lightning event.
The term stroke is used to refer to one discharge.
In a typical lightning flash, 1-15 strokes are common.
A complete flash can take as much as a 1/3 of a second
CONCLUSIONS
A long flashover arrestor (LFA) comprising three flashover modules using the creeping discharge effect was presented in this report.
The LFA-M is a simple, low weight and convenient apparatus.
The voltage-time characteristics of this modular arrestor assure reliable protection of medium voltage overhead lines against both induced over voltages and direct lightning strokes.
Its resistors assure application of the total arrestor-stressing voltage simultaneously to all the modules.