23-04-2012, 04:36 PM
LIGHTNING PROTECTION USING LFA
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INTRODUCTION:
A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using LFA.
A new long flashover arrester model has been developed, it is designed as LFA-M
It offers grate number of technical and economical advantages.
For the protection of lines against direct lightning strokes, the arresters are connected between the poles and all of the phase conductors in parallel with insulators
LIGHTNING:
Lightning is an electrical discharge between cloud and the earth, between cloud or between the charge centers of the same cloud
Lightning is a huge spark and that take place when clouds are charged to at a high potential with respect to earth
Because of this lightning undesirable aspects present in transmission line
TYPES OF LIGHTNING STROKES
DIRECT STROKE:
In direct stroke the lightning discharge is directly from the cloud to an over head line
From the line current path may be over the insulators down to the pole to ground
The over voltage setup due to the stroke may be large enough to flashover this path directly to the ground
CONCLUSION:
A long flashover arrester(LFA) comprising three flashover modules using the creeping discharge effect was presented in this report
To protect a line against induced over voltages a single arrester must be mounted on a pole
The condition for the efficient protection of medium head voltage overhead lines against direct lining strokes