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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The calculation is restarted as a new time step D t. Ligntning prevent transition of an impulse flash over to a PAF, the total flashover path L must be long. It is shown in the figure 5. Thus, t tr is larger than t cr. Charge on the cloud Q is bound by cloud R. Each cable piece has a semi conductive core of resistance R. As indicated before, the coordination of arrester LFA A is not depend on the grounding resistance because The pole does protectino get involved in the path of the lightning current until the insulator or the arrestors have flashed over.

Where k is the outage reduction factor of lightning outages caused by direct lightning strokes. We can increases the usig modules.

For a lightning stoke on a phase conductor, the lighting current propagates both ways from the stroke point overcoming the surge impedance Z s of the line.

If a flashover occurred on at least one of the insulators Ins A or Ins B. As seen in fig 3. An LFA mounted on the top phase must flash over before the top phase insulator. Phase-to-phase faults on a pole can give rise to fault current in order of a few kiloampers.

Li-Fi is a wireless optical networking technology that uses light-emitting diodes LEDs for data tran 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.

Don’t enter email or mobile no. Therefore, in order to protect the line against the direct lightning stroke. It offers a great protecgion of technical and economic advantages. The general pattern is as follows. Posted protectkon Sagar at lightnjng Finally, the calculation is checked for completion. If the number of flashover modules increases by increasing the cable pieces this LFA-M can be used for lightning protection of very high voltage lines.

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The induced over voltages can be counteracted by installing a single arrester on an overhead line support pole.

Long Flashover Arrester (LFA) Seminar Report

The direct lightning performance of the modular arresters was carried out using the equivalent circuits of fig 4. The LFA-M described here consists of three flashover modules.

Semiconductive core of upper piece, whose resistance is R ,applies the high potential U to the surface of the lower piece at its middle.

It offers great number of technical and economical advantages. Seminar Report on Plastic Roads. In stroke A, the lightning discharge is from the cloud to the subject equipment e. With the INS insulators the number of protevtion outages is lowered by a factor of five, the outage reduction factor K DLS being practically independent of the grounding resistance.

Modules1 and 3 flashover lightnung, followed by module 2 ,and thus, forming a rather long flashover channel along the LFA.

The cable pieces protectipn arranged so as to form three flashover modules 1,2,3 as shown in figure1. The direct stroke can be of two types. Probability of power arc flow PAF depends on many parameters: Induced over voltages can be counteracted by installing a single arrestor on an overhead line support.

Lightning is a huge spark that takes place when clouds are charged to a high potential with respect to earth object e.

LIGHTNING PROTECTION USING LFA-M

Then mail to us immediately to get the full report. Takes place when clouds are charged to a high potential Electrical discharge between a cloud and earth A huge spark If the cloud P shift too nearer to cloud Q,Then lightning discharge lfa-j occur between them and charges on both these cloud disappear quickly.

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If the cloud P shift too nearer to cloud Q,Then lightning discharge will occur between them and charges on both these cloud disappear quickly. The direct stroke can be of two types 1.

Long Flashover Arrester (LFA) Seminar Report

Finally, the overvoltage calculations are performed for a given lightning current steepness in order to determine the lightning protection performance. The arresters are connected between the pole and usinv of the phase conductors in parallel with the insulators. 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 overvoltage and direct lightning strokes.

Therefore protsction 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.

Similarly, the semiconducting core of the lower piece of the same resistance applies prottection low potential 0 to the surface of the upper piece, also at its center.

Charge on the cloud Q is bound by cloud R.

This assures uninterrupted power supply of a LFA protected over head line. A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters LFA. Indirect stroke result from eletrostatically induced charges on the conductors due to the presence of charged cloud. The LFA principle, its main applications and some laboratory test results are presented. Types of lightning II.

Phase to phase lightning flashover is also highly probable to occur resulting to a power arc protechion by heavy short circuit currents, which causes immediate line tripping.