Explore Lightning Protection Using LFA-M with Free Download of Seminar Report and PPT in PDF and DOC Format. Also Explore the Seminar Topics Paper on. 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. Presentation on theme: “LIGHTENING PROTECTION USING LFA-M”— System ”-A system of lightning protection conductors lightning rods -installed on the.
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The above calculation does not take into account the effect of near-by poise: Fig 4 As illustration, let us consider the operation of phase A arrester. The cable pieces are arranged so as to form three flashover modules 1,2,3 as shown in figure1. lightning protection using lfa-m
LIGHTENING PROTECTION USING LFA-M – ppt video online download
You do not have the permission to view this presentation. If a flashover occurred on at least one of the insulators Ins A or Ins B. Lightning protection using lfa-m 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.
Thank you for providing the great information on a Lightning Protection System The pictorial representation is very helpful for every new user.
The effect of the power frequency voltage of a kV line on discharge process on the arrester surface is negligible. A flowchart of the calculations is shown in fig6. Thus the total voltage is applied to each flashover module at the same moment, and all the three lightning protection using lfa-m 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.
About project SlidePlayer Terms of Service. Then it can withstand very high over voltages. Direct stroke Indirect stroke. In order to view it, please contact the author of the presentation.
The cloud will induce a charge of opposite sign on the tall object. In this uaing, the total arrester stressing voltage is applied simultaneously to all of the three modules so that the voltage-time characteristics of the arresters are improved.
Therefore, in order prottection protect the line against the direct lightning stroke. The result is that negative charge rushes along the line lightning protection using lfa-m both directions in the form of traveling wave.
When cloud lihgtning to earth, -ve charge rushes along both directions in form of travelling wave. Unit 4 Ch Lightning is an electrical discharge between cloud and the earth, between clouds or between the charge centers of the same cloud. There are three clouds P,Q and R having positive, negative and positive charge respectively.
The pole does not get involved in the path of the lightning current until lightning protection using lfa-m insulator or the arrestors have flashed over.
A single LFA per support or pole is found to be sufficient to protect an over head line against induced over voltages.
A new simple, effective and inexpensive method for lightning protection of medium voltage overhead distribution line is using long flashover arresters LFA. A long flashover arrester LFAwhich comprises of three flashover modules using the creeping discharge effect, lfa- described lightning protection using lfa-m this paper.
Lightning Protection Using LFA (Lightning Frequency Arrester)
The LFA’s length may be several times greater than that of an insulator string, etc. Since phases Lightning protection using lfa-m and Lfam and their arresters operate under identical conditions, it is practical to combine them in an overvoltage analysis.
It is designated as LFA-M. When the potential between the cloud and line exceed the breakdown value of air, the lightning discharge occurs between the cloud and the line. When lightning protection using lfa-m discharges to earth, -ve charge rushes along both directions in form of travelling wave.
If you wish to download it, please recommend it to your friends in kightning social system. As a result probability lightnnig PAF for wooden structures is sufficiently lower than for lightning protection using lfa-m or concrete supports. For an overhead line in delta configuration shown in fig2, the top center face is the most vulnerable. In direct stroke, the lightning discharge is directly from the cloud to the an overhead line. Don’t enter email or mobile no.
A new long flashover arrester model has been developed. Therefore, this new lightning protection system is thought to feature lightnng design, low cost, and high reliability.
Automatically changes to Flash or non-Flash embed. As shown by calculations, in the case lightning protection using lfa-m INS insulators, it is important to coordinate the performance of phase B arrester and insulator because the voltage rate of rise, and thus, the lightning protection efficiency at direct lightning strokes depends heavily on the grounding resistance. From the line, current path may be over the insulators down to the pole to the ground.
LIGHTENING PROTECTION USING LFA-M
Where n 0 is the number of lightning outages on an LFA protected line caused by direct lightning strokes on the phase conductors and P I lcr is probability of a lightning current with prorection greater or equal to I lcr. The voltage rate of rise U l is proportional to steepness of the lightning current.
To protect a line against induced livhtning voltages; a single arrestor must be mounted on a pole. To prevent transition of lightning protection using lfa-m impulse flash over to a PAF, the total flashover path L must be long.
Provides a low-impedance path for the lightning current to lessen the heating effect. The probability of PAF sharply decreases with a decrease in E. In stroke B the lightning discharge occurs on the overhead line as the result of stroke Rpotection between the clouds.
lightning protection using lfa-m
The suggested LFA accomplishes this principle. Finally, the overvoltage calculations are performed for a given lightning current steepness in order lightning protection using lfa-m determine the lightning protection performance. If a positively charged cloud is above the line and induces a negative charge on the line by electrostatic induction.
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.