WELCOME LIGHTNING PROTECTION USING LFA-M Submitted By:Somi.P. Chacko Class: S7-EEE Roll no: MCET CONTENTS. Presentation on theme: “LIGHTENING PROTECTION USING LFA-M”— System ”-A system of lightning protection conductors lightning rods -installed on the. effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters (LFA).
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A delta arrangement of conductors maximizes direct lightning strokes on the top center phase, which acts as shielding wire for the bottom outer phases.
Lightning Protection Using LFA-M | Seminar Report, PPT, PDF for ECE Students
Indirect stroke result ofa-m eletrostatically induced charges on the conductors due to the presence of charged cloud. It was shown by the calculation that a 1-m- long arrestors.
As illustration, let us consider the operation of phase A arrester. Thank you 5 months ago.
Long flashover arrestors are those devices which capture the high voltage sparks resulting out of lightening. It offers protextion number of technical and economical advantages. Before flash over, the total resistance of the arrester can be assumed to be infinitely large.
Probability of power arc flow PAF depends on many parameters: A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters LFA.
It is shown in the figure 5. First, the line parameters are entered, including the arrangement and radius of the conductors, the pole height, the grounding resistance, etc. The direct stroke can be of two types. The LFA principle, its main applications and some laboratory test results are presented. Lightning is a huge spark and that take place when clouds are charged to at a high potential with respect to earth object e. Due to long flashover path, a flashover does not give rise to a power arc as the arc extinguishes when the power frequency current crosses zero.
Therefore the total voltage U is applied to each flashover module at the same moment, and all three modules are assured conditions for simultaneous initiation of creeping discharges developing in to a single long flashover channel.
Direct stroke Indirect stroke. Types of Lightening Strokes Where U l is the maximum operating line voltage; E cr is the critical gradient of the power frequency voltage that rules out PAF.
LIGHTENING PROTECTION USING LFA-M
Similarly, the semiconducting core of the lower piece of the same resistance applies the low potential 0 to the surface of the upper piece, also at its center. In direct stroke, the lightning discharge is directly from the cloud to the an overhead line. A heavy impulse current flows through the flashover channel, the pole, and the pole footing resistance resulting into a large sharp voltage rise at the cross-arm. The lightning protection failed. Thus the total voltage is applied to each flashover module at the same moment, and all the three flashover modules 1, 2 and 3 are assured conditions for simultaneous initiation of creeping discharges which,with respective modules flashed over, develop a single long flashover channel PowerPoint Presentation: The over voltage set up due to the stroke may be large enough to flashover this path directly to the ground.
Aim is to reduce the number of air terminals required by a traditional Franklin-type system. The induced over voltages can be counteracted by installing a single arrester on an overhead line support pole.
The LFA-M described here consists of three flashover modules. Due to different propagation rates of flashover channels for lightning impulses of positive and negative polarity, the first module to flashover is module 1 with a flashover.
Devices which capture the high voltage sparks resulting out of lightening. Don’t enter email or mobile no. In direct stroke, the lightning discharge is directly from the cloud to the an overhead line. Where I l 1 t is the lightning current steepness and it is the time.
In stroke B the lightning discharge occurs on the overhead line as the result of stroke A between the clouds. It is designated as LFA-M.
Long Flashover Arrester (LFA) Seminar Report
Electricity Foundations of Physics. It is designated as LFA-M. The important feature of this modular long flashover arrester LFA-M is that it can be applied for lightning protection of overhead distribution line against both induced overvoltages and direct lightning strokes.
Early streamer emission Radioactive rod systems Laser induced systems Charge transfer systems. Therefore, this new lightning protection system is thought to feature simple design, low cost, and high reliability.
It offers great number of technical and economical advantages. It was assumed to be equal to zero.