Insulator Contamination in Transmission Lines

Insulator Contamination in Transmission Lines

Harsha Shantappa Bagali1, Prof. Shakeer Ahmmad. Shaik2.

1,2 Department Of Electrical And Electronics Engineering,

A. M. C Engineering College, Bangalore-560083.

Prof. Nagaraj. P3

Associate Proffessor And Hod,

3department Of Information Science And Engineering, Channabasaveshwara Institute Of Technology, N. H. 206, Gubbi – 572216.

Abstract :-In today's reality, the interest for the electric power is becoming quickly; to beat this, numerous power era assets are building in everywhere throughout the globe. Yet the issue emerges when the new era is incorporated with the power system and dissemination, as the existed power system was not outlined by remembering the new reconciliation of era later on. The objective of this paper is to discuss some of the problems associated with insulators on the power transmission line.

Key Words- Insulator, Flash over, Leakage current, Contamination, Transmission line.

1. INTRODUCTION

   Of late, the enthusiasm of electric power has widened fundamentally. To fulfill this interest, electrical organizations have needed to enhance the effectiveness of their transmission lines. Likewise, with the liberalization of electrical markets, the individual customers will have the probability to pick the supplier organizations that give them a superior nature of administration.

   The effectiveness of the framework is built primarily with respect to the progression of the administration, staying away from blames that assume temperate misfortunes for organizations and clients. To keep up this progression, one of the principle issues that have been found is the impact delivered by contamination in the insulators of electric lines. This contamination is one of the fundamental driver of flashover in the insulators. The insulator starts to fizzle when the toxins that exist buzzing around settle in the surface of the insulator and consolidate with the moistness of the mist, downpour, or dew. The mixture of contaminations, in addition to the dampness structure a layer that can get to be conductor and permit passing ebbs and flows that will encourage the states of short out. This is because of an abatement of the safety of the insulator surface. Unless there is a common cleaning on the other hand a sufficient support, the electrical movement will be influenced by a conceivable flashover in the insulator.

   As such, the contamination debases the insulators and influences seriously to their electric qualities, being one of the primary driver of mis operation of the insulator. Along these lines, the electric organizations ought to keep the interferences of the administration, created by insulators tainted.

   The majority of the techniques for contamination control are based mostly in:

   • Dissecting the seriousness of the contamination, that is to say, to make "zones of contamination".

   • Controlling the circumstances of the contamination on the insulators, to focus when a cleaning or upkeep of the insulators is required for keep the issues because of contamination.

   • Comparing the behaviour of the different designs of insulators (form, length) and/or of the materials of the insulator that are going to work under contaminated environments.

     The likelihood of appearance of deficiency circumstance relies on upon the sort and material of the insulator, the climate of the zone, the sort and level of contamination, and also the working voltage of the insulator.

     Different issues identified with contamination are: erosion and disintegration of the insulator. Additionally in polymeric insulator, the marvel of dry groups, and the impact of pyrolysis, must be kept of breaking down the operation of the insulator.

2. SORTS OF POLLUTION.

   The level and the sort of contamination of a regions are connected with the wellsprings of contamination, and in addition with climate elements of the spot. Table 1, demonstrates the contaminations and the sources that deliver them.

   Contaminant	Wellspring of contamination
   Salt
   Cements/Bond	·Construction destinations
   Earth	·Earth proceeding onward development ventures
   Fertilizers/Composts
   Metallic
   Coal
   Volcanic ash /Volcanic fiery remains
   Defecation/ Poop
   Chemical/ Synthetic
   Smog/ Exhaust cloud
   Smoke

   • Coastal zones

   • Salt Industries

   • High courses with store of snow where salt is utilized to soften the snow

   • Cement Plant

   • Rock quarries

   • Plowed fields

   • Fertilizer plants

   • Frequent utilization of composts in developed fields

   • Mining taking care of techniques

   • Mineral taking care of techniques

   • Coal mining

   • Coal taking care of plants/warm plants

   • Coal smoldering/block furnaces zones

   • Volcanic movement regions

   • Roosts of fledglings regions.

   • Wide mixed bag of concoction/ process commercial ventures, oil refineries…

   • Automobile outflows at roadways crossing

   • Diesel motor discharges at route crossing/ yards

   • Automobile outflows at roadways crossing

   • Diesel motor discharges at route crossing/ yards

   Table I. Contaminants and their sources.

   Autonomously of the current contamination sort, the typical stages in which a flashover can show up in the encasing by contamination are:

   • The contamination is put on the surface of the insulator and a contaminant layer shows up. The contamination can be created by an incredible assortment of sources, (ocean salt, businesses, fiery remains ). The wind the principle bearer of the particles, having an optional part the gravity and the electric field.

   • By the activity of downpour, mist, and so on… the layer at first glance is hosed and amplifies the conductivity.

   • The contaminant layer dries. In this manner, there is an increment of conductivity and spillage current.

   • Dry groups are structured as an outcome of the warming-up of the layer on the encasing surface.

   • Partial curves show up through the dry groups.

   • Partial releases are delivered, these releases produce capable of being heard clamor.

   • Finally, the total discharge is produced.

   So that the flashover can be delivered these stages have not to happen sequentially however that few stages can happen in the meantime.

   At the point when the debased layer is hosed, the safety decreases and the present of filtration that passes through it is expanded. With this build, the temperature of the contaminant layer is hoisted, and that reduce still more the safety. The safety will decrease until the temperature achieves the breaking point, starting to lose moistness. Starting here the layer safety starts to grow little by little until its aggregate drying. At that point will achieve the greatest estimation of safety. This wonder is a considerable measure more attainable in restricted parts of theinsulator where the thickness of current is higher. The increment of the safety makes the current reduce, however its development infers that most strains connected to the encasing show up through it, by being still moist the rest of the layer.

   An increment of contamination creates the increment in the spillage present and after that the flashover of the insulator is more likely. Yet in the event that we could circulate the contamination over all the insulator, the voltage would be compelled to be more lineal, so we would evade the electric fixation in any purpose of the insulator and the likelihood of flashover would lessen.

   In a few areas near to substantial wellsprings of contamination, the whole insulator is secured with the contaminant, yet this circumstance is a special case more than a tenet. In light of it, the most common rule is a not uniform dispersion. The surfaces uninsulatored or ensured of the insulator are influenced on distinctive routes by the constrains that are in charge of setting the contaminant and to clean the surface. Therefore by and large the most uninsulatored zones are more sullied than the regions ensured, however there are situations where the opposite is additionally sure.

   Albeit numerous variables can characterize the insulators contamination, three fundamental sorts of contamination can be highlighted: the industrial, marine and desert.

   1. Industrial Pollution.

      Individuals in their every day work produce smoke, clean or particles that are in suspension buzzing around. These particles essentially by the activity of the wind spread over zones where electric lines exist.

      The mechanical contamination of the encasings shows up with the businesses advancement and by the contaminants created and ousted to the environment, being conceivable assorted sorts: metallurgical, compound substances, dust, smoke, bond

      These substances will settle for the activity of the wind, weight, electric fields , on the insulators making a contaminant layer. This layer settled on the insulators is framed gradually amid a period that can a months ago or years. Amid this period will substitute dry ages with damp ages.

      The most administer approach to build the conduct of the insulator amid this sort of contamination is to control the conduct of the sufficiency of the spillage present with deference time, or the heap of the spillage current amassed amid a certain time of time. At that point it will be conceivable to see whether the movement of the contamination augments with the time furthermore the impact of the downpour (characteristic wash) will be seen. Along these lines, we will have the capacity to choose whether we need to do a manufactured cleaning (upkeep) or whether with the regular wash is sufficient to keep away from a perilous layer to be shaped.

      In the event that wouldn't we be able to utilize a system as the ESDD (Equivalent Salt Deposit Density) to control the conduct, that is a circuitous strategy, will be less certain. This happens in light of the fact that the danger of flashover in a particular encasing is straightforwardly identified with the release current abundancy (or to the estimation of the normal present by second); while the ESDD does not provide for us steer data of the conduct of the insulator and this would quit working. For the same ESDD the danger of flashover depends a ton on the configuration and of the material on the insulator utilized.

      Among the contaminants sources that portray this kind of contamination, we need to remember the qualities wellsprings of modern contamination and different sources that broaden the issue:

      • The regular contaminant sources are: the smoke of commercial enterprises, the one created by vehicles, structures

      • Industries that expend fossil fills, diesel, coal the overwhelming particles of the fuel stay in suspension in the nature.

      • Heavy commercial enterprises, for example, treating plants, oil refineries, organizations concrete works these can have extreme outflows of contaminants particles.

      • If the electric line is close to the coast, we need to remember the activity of the waves, breezes or winds originating from the ocean, the haze banks

        and the particles of salt that are in suspension in the edge of the zone where the insulator are found.

      • Agricultural ranges, the cultivating of the terrains, periodic flames, the harvest of composts, and so on..

   2. Marine Pollution.

      The insulator presented to seaside or marine situations, can get to be to be conductors because of the development of a conductive layer on its surface. This layer will be framed by virtue of the salted dew of the mornings in these zones near to the coasts. At the point when dried with the hotness created in the same insulator or with the nature temperature, is going to store in the encasing the vanished salt that had consumed some time recently.

      The particles put in the insulator are not perilous in dry climate yet, the issue emerges when the natural climate is damp, downpours, there is dew, mist then the layer can be come conductor. The conductivity of this layer will rely on upon the sort of salt that structure it. The climate conditions shift significantly from the seaside regions to the inner part territories and they assume an essential part in the contaminants testimony rate and in the operation of the encasing. The issue of the contamination depends chiefly on the nature's domain.

      Likewise we must remember the salt dissipated that is in the nature's turf. By the activity of the wind lands at the insulator, having the capacity to be put in their surface. With the progression of time this layer will be sufficiently thick to be hosed and to end up conductor.

      The risk of the contamination will rely on upon the sort of material and on the manifestation of the surface. Additionally the wellsprings of contamination must be researched and the method for testimony of the contamination. The wind is the primary bearer of the contamination, being others, the gravity and the electric fields. The contamination will depend likewise on the course of the wind for a more prominent or littler contamination of the insulators.

      The seriousness of the contamination in an area is evaluated as far as Equivalent Salt Deposit Density (ESDD) measure in units of Nacl mg/cm2, in which are considering, the accompanying five climate factors:temperature, moistness, weight, downpour and speed of the wind. This estimation of ESDD gives a base to do a characterization of the seriousness of the contamination of the zone considered and will serve for knowing the worth from which we need to do the support of the insulator, that is to say to create a legislative issues of right protection. The marine contamination is spotted not just in the encompassing region of the coast, additionally to extensive separations by the activity of the wind.

   3. Desert Pollution.

      In a few zones, the insulator of the electric lines are frequently subject to the affidavit of contaminants substances of the deserts. This can result in a genuine lessening in the adequacy of the insulator, having accordingly the flashover and the power supply need. Likewise the storms of sand must be remembered. The kind of ecological conditions will influence significantly to the insulator. The transcendent components in this sort of contamination are: the sand and the broad, salty tidy in a dry air. The desert atmosphere is described for dust storms and sea tempests that contain particles that move to a rapid. These particles strike to the surface of the insulator bringing about the material disintegration. The storms of sand are a paramount component that causes a lessening of dependability in electrical lines.

      In this kind of contamination the accompanying viewpoints are important:

      • The early morning dew speaks to the more noteworthy wellspring of wetting in the desert zones.

      • Stors of sand develop the contamination issues. The most exceedingly awful conditions happen when the storms are joined by a high mugginess or blustery climate.

      • Pollution layers gathered on the insulator amid the storms are of bigger grain and more prominent substance in salt than the layers framed amid the typical climatic climate of the desert. The contamination helped by the storms of sand is ordinarily conveyed by solid winds of far off locales.

        The execution of clay insulator under desert conditions is attractive contrasted and the execution in different zones with mechanical or beachfront situations. All things considered the utilization of insulator of Sir is not all that adequate because of the hydrophobic attributes change relying upon the states of climate and stickiness.

        We can call likewise leave contamination to one that happens in zones where there are semiarid atmospheres, where the floor is not secured totally by yard not one or the other by trees. Subsequently, the shallow layer of the area is exceptionally dry and the dust effortlessly is scattered for the activity of the wind. To high speeds, these strike the surface of the encasing bringing on the disintegration of the surface.

        The dry insulator have regularly low conductivity, yet rain or dew are going to hose the layer and they transform it into a conductor. The regions sullied are warmed, making dry groups. This is owed hotness produced by the leakeage current. Being a zone with little amount of downpour, these

        are not fit for washing regularly the encasing and to wipe out the contaminant layer.

   4. Different sorts of contamination.

   Inside the situations tainted where the insulator work, additionally it is fascinating to consider sticky zones by the spirit of natural components in the insulator, what is characterized as organic contamination. The normal contaminants are the microbes, green growth, mushrooms and lichens that can corrupt the surface of the encasing or can make a conductive layer. The mushroom development can be vital on the grounds that its establishes can infiltrate in the matter and make a permeable structure on the surface of the material.

   Lichens and green growth are going to free natural acids, particularly the oxalic corrosive, fit for harming the surface of the insulator. From the start, the damp layer shaped by these components has not motivation to impact the work of the insulator. The issues show up when this layer dried and structure an oily layer amid dry periods. The natural component kicks the bucket, yet a sleek layer is shaped on the surface of the encasing. On the off chance that this oily layer is hosed once more, without having been cleaned, a layer of dry groups creates the impression that let the flashover of the insulator.

   On account of green growth and particularly in some polymeric encasings, the development rate is low and a considerable measure of time is required with a specific end goal to stretch out over a huge territory, despite the fact that moistness and temperature were high. Green growth don't infiltrate in the material, whether we have a satisfactory preventive support, and the danger of flashover of the insulator by natural contamination in regular conditions, is lower.

   Other wellspring of contamination is salt, amid the winter months, in zones of extremely frosty atmospheres. The point is to keep the development of ice in walkways and the streets and to de-ice them as quickly as time permits. The utility of the salty substances is to plummet the point of solidification of the streets/walkways and subsequently to defer the development of ice. The amounts of salt used can be massive.

   A piece of this salt will be set on the surface of the encasing on account of characteristic operators, in the same way as wind and development of vehicles in these zones. A vital contamination is the gathering of an amount of salt of around 0'1 mg/cm2 on the surface of the insulator.

   To de-ice, different sorts of salts are used. The most widely recognized one is the rock salt (sodium chloride) because of its minimal effort; it reduces the point of solidification of the surface to a couple of degrees. Other

   concoction substances that are likewise utilized are: the calcium chloride and magnesium chloride.

   They act better than the sodium chloride. Case in point, the calcium chloride meets expectations under (-8

   ºc), and is compelling for lower levels of relative stickiness (42%) contrasted and the sodium chloride (72%). Likewise a mixture of salts is used, in the same way as rock salt with calcium chloride, calcium magnesium acetic acid derivation (CMA). They are more compelling, and they cause less consumption. Naturally, they are more average than the rock salt; all things considered they are more costly than rock salt.

   On the same way, the calcium chloride, magnesium chloride and CMA in fluid state are utilized. The experience has demonstrated that the fluid opposes more, sticks better to the surface and gives a more prominent span, other than it applies less demanding. Thusly to de-ice is backed plainly by powers along these lines the quantity of clients amplifies.

3. STRATEGIES FOR LESSENING THE IMPACT OF CONTAMINATION.

   To keep away from the impact of contamination on the encasings there are three choices: right decision of the encasing sort, support of the insulator and end of the wellspring of contamination.

   The impact of contamination will rely on upon the district and on the viability of the upkeep arrangements and the right decision of the encasing sort.

   1. Sorts of encasings.

      The models and regulations demonstrate that the encasings used in the overhead electrical lines can be made of porcelain, glass or an alternate material of sufficient qualities to their capacity. The most utilized insulator until a few years prior were produced with porcelain, glass or soapstone. Because of their dielectric attributes and their office of throwing, all the encasings have been fabricated for a long time with these materials. However formed materials do a hard ability to the customary one.

      Porcelain is constituted basically with kaolin and quartz of first quality. The encasings are cooked to 1400 ºc and later they are secured with a layer of polish of silicate, bubble accordingly to acquire a coated in hot, doing them waterproofs and elusive, muddling along these lines the attachment of mugginess and dust.

      Glass is produced liquefying to temperatures among 1300 ºc and 1400 ºc, a mixture of salicylic corrosive with oxides of calcium, sodium, barium, aluminum, and so on. The glass utilized as a part of the encasings is a calcium glass basic, acquired by an extraordinary system by mean of sudden chilling through a chilly air present amid the

      procedure of combination. Thusly, a hard glass is gotten, of high mechanical safety and with great dependability for the progressions of temperature. In spite of the fact that this material is less expensive than porcelain, it has the burden of its coefficient of expansion which is, exceptionally influenced by changes of temperature. Plus, it can't be worked in muddled structures and the joining must be done by uncommon systems. However because of their littler expense and their straightforwardness, that encourages the visual control, they substitute much of the time to those of porcelain.

      Soapstone is utilized when the insulator ought to shoulder vast mechanical endeavors, on the grounds that its mechanical safety is roughly the twofold of the porcelain and its protecting properties are better. An alternate focal point is that the encasings of soapstone are moldings to weight in dry and their measurements can be more correct than those of the porcelain insulator, which are readied to weight in muggy. The fundamental impediment of soapstone is their high cost. This is readied from a glue with incredible substance of talc, that, by cooking, turns into a mass of precious stones of silicate of magnesium; the expansion of little iron oxide amounts, provides for it a trademark color light black or tan. Soapstone does not concede the lacquer.

      Identified with make materials, the groups of polymeric material more standard are: elastic or elastic of silicone and propylene ethylene rubbers (by and large EPDM). A few segments are added to these materials to enhance their properties. The encasings fabricated with these materials are referred to additionally as not clay insulator.

      Albeit utilizing the same polymer base, the plan can change of a considerable measure among the diverse sorts of encasings, since the mixes added can be dependent upon the 80% in weight of the insulatoring. Material of inlay is included, for the most part tri-hydrate of alumina or silica. It agrees to the twofold capacity of lessening costs and growing the imperviousness to disintegration and carbonization of the polymer, amid the shallow electric releases. Different mixes presented are: plastics, catalysers, cell reinpowerment, shades, balancing out UV (ultraviolet), postponing of fire, and so on.

      The focal points against the insulator of glass and porcelain are essential:

      • They are lighter, what assumes to lessen the costs of establishment, administration and substitution.

      • Greater imperviousness to vandalism, because of the innate versatility of the material.

      • Better conduct against contamination, which assumes littler need of cleaning in contamination conditions.

      • Smaller support costs.

        The complaints that can be cited are:

      • They are submitted to synthetic changes on their surface, because of the activity of natural specialists and electrical releases, which wrap up the properties of the insulator.

      • Compared with those of glass and porcelain, there is a littler involvement in administration, being hard to think about these differing sorts of insulators, since materials are distinctive and not generally known.

      • Despite its evident effortlessness, its last conduct relies on upon the outline and the methodology of creation. For instance the union of the metalwork to the core of fiberglass, the dispersion of the electric field in the insulatoring, the union of this to the core, and so forth.

      • Difficulty to distinguish deficient encasings.

        The utilized materials have differing details. The ones that have their base in elastic or elastic of silicone appear to have a more noteworthy acknowledgement, among others reasons by their ability of recuperation set against the loss of hydrophobicity. The term hydrophobicity alludes to the communication between the material of the encasing and water.

        In a hydrophobic surface, the water is set fit as a fiddle of remote drops. On the off chance that the help of water be nonstop, water forsake the surface of the insulator by the edge of their flippers. The hydrophobicity is an extremely esteemed property in light of the fact that enhances the conduct of the insulator against the contamination. This property diminishes the extent of the spillage present on the surface of the insulator furthermore the likelihood of dry groups appearance.

        In a surface needing of hydrophobicity, the water hoses the whole surface that, together to the contaminant components, structure a conductive layer. On the off chance that the encasing is sullied some dry groups show up. Despite what might be expected, in a hydrophobic surface, the layer of contamination hosed is broken, what make to be more troublesome the production of these dry groups and the flashover of the encasing.

        After eventually in administration, an encasing can see decreased their hydrophobicity, albeit in can be incidentally. There are a few conceivable reasons:

      • Pollutant layer: the presence of a layer of contamination assumes a loss of hydrophobicity.

      • Electric release, witch relies on upon the outline of the encasing, material of insulatoring and contamination of the surface.

      • Electric fields in zones of union of the distinctive materials that make up the insulator.

      • Environmental impacts: UV beams, wind, downpour, particles of sand, ice and snow.

      • Chemical impacts: convergances of acids, hydrocarbons and solvents consolidated with water.

        On account of encasings whose polymer base is silicone, the encasing could recoup its hydrophobicity, passed a period without outside hostilities. A few areas of polymer of low sub-atomic weight can be diffused through the central station vulcanized of polymer and material of inlay. These segments look like to the silicone oil and, because of their low atomic weight in connection to alternate particles of the central station, they move characteristically to the surface. When they get to the surface they structure a fine layer that restores the hidrofobicidad, including the materials that are found in it, for instance the contamination. The segments of polymer of low sub-atomic weight are found in the mass of the insulator, additionally they are delivered because of shallow electric releases, that corrupt the atoms of polymer in other littler. The loss of these chains on the surface of the encasing has subsequently the maturing of the insulator. To augment the hydrophobicity of insulator in defiled situations, a standout amongst the most used measures is the utilization of hydrophobic oils, being the most well- known the oil of silicon. It keeps the development of a nonstop film of water, which is the principle dependable of the flashover on the tainted surface of the insulator. This oil has give or take 4 years of action, despite the fact that this time relies on upon the level of contamination. An alternate oil that is expanding prominence is the layer of silicon RTV concerning the oil of silicon. The RTV has a more drawn out life from 5 to 14 years, which likewise relies on upon the way of contamination. The most vital property of the RTV is the movement of little atoms to the surface that keep up the encasing hydrophobic for additional time. A thickness of 0,25 mm. is the satisfactory one to acquire a

        palatable result. The RTV applies with a brush or splash.

        This practice has been used acceptably to decrease the danger of flashover amid long time. All things considered, this option is excessive and obliges an intermittent upkeep to evacuate and reapply the layer. The recurrence of this movement can shift from months to different years, contingent upon the sort, the level of contamination and the natural conditions.

   2. Upkeep of the insulator.

      In zones where there is contamination, other than a decent race of the insulator, is prudent to have a support plan. As it were, we have to wash or clean the encasing. This is more vital in regions with serious situations of contamination or low rain likelihood, being fundamental

      the end of the poison layer set on the encasing. This support can be completed with the framework energized, wash in hot, or de-energized. The later system is utilized when can't be connected an alternate strategy by specialized reasons or when the glue attributes of the poison, oblige the utilization of wash with concoction answers for recuperate the protection level. Commonly, the wash is done by hand.

      As a rule the most utilized routines are: the wash by water to high, normal or low weight, with dry air layered or with spurts of rough materials and all the more as of late the utilization of ultrasonic. Any of the methods utilized needs to ensure that the encasing won't endure harm, not one or the other that we are going to deteriorate the current circumstance.

      The wash with spurts of water is the best and monetary strategy, if the contaminant is clean, salt or land, or if these poisons are very little held fast to the surface.

      On the off chance that the contaminant component has a high bond, (for instance the concrete or poison starting from compound organizations or by-results of the petroleum) we need to wash the insulator with grating components. They can be smooth components, as smashed shell of cobs of corn or shells of nut, fine clean of lime, or more rough components as the fine sand. Continuously the supposition of the producer will be remembered for not harming the surface of the insulator.

      To keep the flashover amid the wash, the accompanying perceptions must be considered:

      • The wash of the encasing will start from least stage conductive.

      • When we wash, the water ought not fall straightforwardly on a filthy encasing.

      • We will start to wash from the lower piece of the encasing until completing in the upper part.

      • Is vital to remember the bearing of the wind.

   3. End of the contminant sources.

   By and large, inquire about has been coordinated around the contamination decrease techniques. It is owed to the way that the end of the wellspring of contaminant is just conceivable when the kind of contaminant is modern, in light of the trouble to kill other contaminant sources, for example, desert, ocean

4. CONCLUSIONS.

The abatement of contamination will rely on upon: the sort of encasing, the support, the increment of the quantity of components in the chains of encasings, the increment of the spillage line, a superior outline of the insulator, the new materials

They are subjected to conditions that rely on upon the spot in which they are introduced. These conditions can fluctuate widely from a spot to an alternate, contingent upon the attributes of the district considered. These qualities make conceivable that the level of protection needed can fluctuate in a same line, because of the states of the contamination are distinctive for all the line. The climate components impact in a critical manner on the development of the contamination levels in a district.

Typically the insulator demonstrate a critical change in their regular operation when they are presented to extreme natural conditions.

In the event that, amid the development of an overhead electrical line, we don't remember the contamination of the zone and we don't pick a sufficient encasing, we will be obliged a more noteworthy upkeep work to anticipate issues. This assumes an extra cost for the business.

REFERENCES.

1. Chris S. Richards, Carl L. Benner, Karen L. Butler- Purry, and B. Don Russell, Fellow. Electrical Behavior of Contaminated Distribution InsulatorsExposed to Natural Wetting.

2. Ahmad S. Ahmada, P.S. Ghosha, S. Shahnawaz Ahmedb, Syed Abdul Kader Aljunid. Assessment of ESDD on high-voltage insulators using artificial neural network.

3. Ravi Gorur and Sreeram Venkataraman. Insulators for cold urban areas: The problem of Road Salt.

4. Ramos Hernanz, José A, Campayo Martín, José J. Motrico Gogeascoechea, Joseba1, Zamora Belver, Inmaculada, Insulator pollution in transmission lines

5. http://www.powermaintenance.com/lines/part 1.htm

6. Gerardo Montoya-Tena, Ramiro Hernández-Corona,Isaías Ramírez- Vázquez. Experiences on pollution level measurement in Mexico.www.scientdirect.com

7. http://tdworld.com/mag/power_silicone_rubber_insula tors/

8. M.A.R. Manjula Fernando. Performance of Nonceramic Insulators in Tropical Environments

9. Abdel-Salam H.A. Hamza, Nagat M.K. Abdelgawad, Bahaa A. Arafa. Effect of desert environmental conditions on the flashover voltage of insulators.

AUTHORS.

HARSHA. SHANTAPPA. BAGALI.

He received his B.E(Electrical and Electronics Engineering) degree at Hirasugar Institute of Technology, Nidasoshi-591236. from Visveswaraya Technical University, Belgaum in 2013, and pursuing his M.

Tech(Electrical Power System) degree at A. M. C Engineering College, Bangalore-560083 in Visveswaraya Technical University, Belgaum. His area of interest is Generation, Transmission and Distribution, High Voltage transmission line, Overvoltage phenomena and Power Quality.

Prof. SHAKEER AHMMAD. SHAIK.

He received his B.Tech degree in Electrical and Electronics Engineering at MERITS Engineering College, Udayagiri from Jawaharlal Nehru Technological University, Hyderabad in 2008, The M.Tech degree in Electrical Power Engineering at

Narayana Engineering College, Nellore from Jawaharlal Nehru Technological University, Anantapur in 2011. He was working as Assistant Professor in EEE department at

A. M. C Engineering College, Bangalore. His area of interest is Power Transmission and Distribution systems.

NAGARAJA P

He received his B.E degree from Bangalore University and M.Tech from Visveswaraya Technical University, Belgaum studied at Sri sidhartha Institute of Technology, Tumkur-572102 in 1987 & 2009 respectively. He is pursuing his Ph.D on Fault Diagnosis of circuits at Rastriya Vidyalaya College of

Engineering , Bangalore affiliated to Visveswaraya Technical University, Belgaum. His area of interest is Power Systems, Protection systems,Embedded systems, Artificial Intelligence, Neural Networks .