The aim of this study is to propose simple and reliable techniques to assess the condition of metal oxide arrester based on the dielectric response techniques. A number of modern electrical diagnostics for Metal Oxide Surge Arrester (MOSA) are discussed in this paper. The techniques included return voltage, decay voltage and polarisation/depolarisation current measurement. The single and multipulse current (8/20micros) was used to artificially degrade the MOSA. The before and after diagnostic ....etc

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powerpoint presentation on direct lightening strokes and induced over voltages using lfa-m ....etc

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Modern Surge Arrester plz
frwd fast ....etc

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Abstract
Outages of overhead power lines due to lightningstrokes are one of the main causes of shortages of electricsupplies and economic losses of power utilities. Pole-topmetal oxide arresters can protect distribution lines againstinduced over-voltages, but they can be destroyed in case ofdirect lightning stroke. Long Flashover Arresters (LFAs)have been developed and used successfully for this purposeand have no possibility of being destroyed because thecurrent flows externally along its surface. Since fieldexperience with 10 kV LFA ....etc

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Qudusia Amatun Nayeem


Lightning, is a form of visible discharge of electricity between rain clouds or between a rain cloud and the earth. The electric discharge is seen in the form of a brilliant arc, sometimes several kilometres long, stretching between the discharge points. How thunderclouds become charged is not fully understood, but most thunderclouds are negatively charged at the base and positively charged at the top. However formed, the negative charge at the bas ....etc

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Resistance Measurements and Interpretations Relating to Flashover
of Artificially Contaminated Ceramic Insulator Strings
Abstract
The flashover of insulator strings occurring at normal working voltages under contaminated/polluted conditions, obviously deserves serious consideration. Though much researchhas been gone into pollution-induced flashover phenomena but grey areas still exist in our knowledge.In the present experimental study the breakdown (flashover) voltages across gaps on insulatortop surfaces and gaps ....etc

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Line Arresters InTransmission Line
Jithin Lal K
S7 E2 RN:220
College Of Engineering, Trivandrum
2007-11 batch





CONTENTS
1)Introduction
2)TLA Components
3)Types of TLA
4)Working of TLA
5)Arresters Location
6)Problems in Applications of TLA
7)Transverse Discharge
8)Experiments
9)Impulse Voltage Waveforms
10) Results
11)Minimum Distance
12)Conclusion


INTRODUCTION
Transmission Line Arresters (TLA)
Any arrester that is applied on the lines of a power syst ....etc

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Abstract
A long flashover arrester (LFA), which comprises of three flashover modules using the creeping discharge effect, is described in this paper. In this design, 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. It assured reliable protection of medium voltage (e.g., 10kv) over head power line against both induced over voltages and direct lightning strokes. A single LFA per support or pole is found t ....etc

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....etc

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Akihiro AMETANI, Naoto NAGAOKA, Toshihisa FUNABASHI, Nagahiro INOUE


Abstract—
The paper has investigated a difference of flashover phases between extra-high voltage (EHV) and highvoltage transmission lines based on EMTP simulations. The number of ground wires and a tower footing resistance cause a significant effect on the three-phase archorn voltages. A higher probability of a back-flashover across the upper-phase archorn is very noticeable in the case of a tower with two ground wires and a lower f ....etc

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