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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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Lightning is an electrical discharge between cloud and the earth, between clouds or between the charge centers of the same cloud. Where N DLS is the number of direct lightning stroke DLS on a line; P I l is the probability of lightning current likely to cause flashovers of the line insulation; P arc is the probability of a power are caused by an impulse flashover an insulator; and P rc is the probability of successful line breakers enclosures.

If you wish to download it, please recommend it lightninv your friends in any proyection system. 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 the insulators.

Share buttons are a little bit lower. Therefore, this arrester should be relatively short.

Long Flashover Arrester (LFA) Seminar Report

The lightning protection failed. The probability of PAF sharply decreases with a decrease in E. It is designated as LFA-M.

This negative charge however will be only on that portion on the line right under the cloud and the portion of the line away from it will be positively charged.

The physical phenomena associated with a direct lighting stroke on an unprotected power line causing line tripping. After the LFA A fully flashed over, the lightning current travels through the pole and its footing. Advertise on this site?? Then it can withstand very high over voltages. Thank you 5 months ago. It was also shown that, after the LFA A arrestors has successfully operated, the voltage rate of rise on phase B insulator and its arrestor becomes low and this facilities successful operation of the LFA B arrestor, at least, over the 10 to W grounding range.

Due to electromagnetic coupling between phases, the potential of the healthy outer phases also increases and it can be assessed from the conductor coupling factor. In the case, it is essential to coordinate the arrestors and the insulators on the lightning struck phase A. 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 over voltage and direct lightning strokes.

The cloud will induce a charge of opposite sign on the tall object. The rate of decrease of the critical gradient slows down for larger fault currents. Direct stroke Indirect stroke.

Lightning Protection Using LFA (Lightning Frequency Arrester)

Finally, the calculation is checked for completion. The next step is to calculate flashover voltages for the individual discharge components or lf-m. Then mail to us immediately to get the full report. Devices which capture the high voltage sparks resulting out of lightening. Thus, the number of outages caused by direct lightning strokes can be lowered with the use of LFA arresters by an order of magnitude or more even for high values of grounding resistance.

Seminar Report on Plastic Roads. A flowchart of the calculations is shown in fig6.

An LFA-M arrester consists of two cables like pieces. A new long flashover arrester model has been developed. LFA-Ls help avoid both conductor burnouts and overhead power lines outages caused by lightning induced over voltages. After a top phase LFA flashes over, lightning current will flow, through the affected conductor lightnin through the pole to the ground. As seen in fig 3. Due to a special inner structure the LFA impulse flashover voltage is lower than that of the insulator and when subjected to lightning overvoltage the LFA will flashover before the insulator.

From the short analysis presented above, it is protectuon that it is possible to improve the protection against lightning by increasing the length of lightning flashover path. Charge on the cloud Q is bound by cloud R. For a lightning stoke on a phase conductor, the lighting current propagates both ways from the stroke lightnint overcoming the surge impedance Z s of the line.


Can be applied for protection of distribution lines. Each cable piece has a semi conductive core of resistance R. Where I l 1 t is the lightning current steepness and it is the time. The pole does not get involved in the path of the lightning current until the insulator or the arrestors have flashed over.

This assures uninterrupted power supply of a LFA protected over head line. Share to Facebook Share to Twitter. Li-Fi is a wireless optical networking technology that uses light-emitting diodes LEDs for data tran There are two main ways in which the lightning may strike the power system.

The 3-D password is a multifactor authentication scheme that combines these various authentication schemes into a single 3-D virtual Go to Application Have a question? Provides a low-impedance path for the lightning current to lessen the heating effect.