Essay on High Voltage Transmission Line Outdoor Insulations

        According to Author Hussain & et.al (2017), it is conducted that; Experiments have been conducted on insulation material with collective application of saline contamination and acid to copy and reproduce similar conditions. Investigative approach is adopted in the whole process.  There are different types of tests samples, which are in fact used for the investigation as well as for experiment. The test samples are enlisted as silicone rubber (SIR), ethylene propylene diene monomer (EPDM), and polyethylene (HDPE) that possess high density. These are usually used and referred to as reference. Material is the most primary and integral part of any solid thing. So, the material that is used in manufacturing of the product of those is just like those which are used in daily life. It has almost resemblance with the high voltage insulators. All samples are made up and tested in different chambers as well as in very different atmosphere as per desire and requirement of a product or tested object. 150 h for multiple saline contaminations, which are, combine with cold fog and acidic is fixed.

        They whole process is set up and related just for the sake of experiment. Different seasons have their own nature in which wires are prepared as per demands of weathers and seasons for better results. The findings are based on the experiments and analysis that has been extracted from research work and investigative methods. The analysis depicts some conditions, which exist near to the shoreline, which are exposed to saline and acid spray. Under the sway of acidic and normal cold fog, electric field and discharge current are deeply examined by not putting away polymeric samples. These samples have highly significance in the field of electronics that is the core reason that these are not ignored at all. There are different types of physic-chemical changes, which are usually used in order to investigate hydrophobicity recovery property in the post-testing condition. There are different types of infrared which are used in examine other things which are like Fourier transforms infrared (FTIR) spectroscopy and electron microscopic (SEM). These are used to probe or examine physicochemical changes and shifts. That is the comparative study that is conducted on the polymeric samples, which are exposed in fact to the acidic and normal cold fog. The data is based on the research and tests, which have been conducted on the base of the data to develop a sound and more comprehensive narrative. Research data is provided with different references so that readers could extract his own narrative on the base of sound footings by analyzing the existing data and research findings. The references which will be mentioned in the research for better prediction but not at all on the base of illogical but on logically consistent narratives. These are not only best for better material coating but also for designing of external insulation [1].

        Research is conducted by the Author Braini (2013), about “coatings he stated that it is all about coating for outdoor high voltage insulators. There is a link between voltage and pollution severity of site. There is dire need to comprehend the link and relationship between the both things. So, following the relationship, as the voltages are increased with the same ratio the pollution severity of sites becomes more important factor in this regard. Even, in determining insulation level of the system, these both factors in fact matter. There are certain types of threats to accuracy of the system that usually leads to system outrages as well as destruction. Particularly, flashover, which is polluted on insulators, poses serious threats to efficacy and reliability of the system as well as mechanism. Now the most important and significant question arises that how the constant and clouded threats can be proved redemptive or strove off the worst effects of flashover? In fact, there are many remedial measures, which can be taken to ramp out the enduring threat. One of the most important and highly significant methods is the application of hydrophobic coatings like room temperature vulcanizing silicone rubber and grease coasting on ceramic insulators [2].

        Author Jamaludin & et.al (2017) by analyzing deep on the research on the equator he stated that KSA is a country that is well-known because of its extraordinary feature of its highest lightening densities in the globe. Approximately, 70% of power outages in KSA is contributed by lightening. There are severe impacts of the outrage on different things, which are as affecting power equipment, automated network system that usually causes disruption in data. That is the reason that the stance is get projected with the sound arguments that insulator’s evaluation is under different lightening impulses can be crucial and difficult in order to address and overcome the issue in more comprehensive and effective manners. This paper is highly unique as it lead to pave the way for the approach in which the increase in electrical performance of polymer insulter are used by utilizing room temperature vulcanization coating.  There are three different types of settings which are as polymer insulator, namely uncoated, RTV type 1, and RTV type 2. The most surprising thing is that all the three insulators are tested under three conditions which are as dry, clean wet and salty. Even the voltage breakdown is recorded against each test. The record is maintained as the tests are made conducted. After the process of testing, the effectiveness of RTV coating application became visible and noted too [3]

        According to Author GORUR (1991) it is conducted that; high voltage (HV) insulation technology is usually used for outdoor power transmission. Polymer material is given special type of status in this regard that is getting momentum in today’s highly competitive advanced market. Particularly, it is getting momentum and highly significance. A research is embarked on problems’ reviews with porcelain and glass which are being exercised and used for many years in the industry of field which are addressing many issues of the field of electronic with the help of outdoor application such as insulators, cable terminations and surge arresters [4]

        According to a research by Gubanski S. (2005), Electricity and power define contemporary society. Due to the increased role of electric power, new and improved methods of power generation and transmission are created, and devices that economize losses are researched upon. One such component that is used to reduce losses is high voltage insulator. They are made to work efficiently by altering geometry so their creepage increases or their self-washinf property increases. Dry brand arching’s reduction is another method sought. Various kinds of insulators that are more resistant to stress were proposed. Moreover, it is also focused on changing the material of already existing substances and to improve their performance. A composite insulator is of the following characteristics: It has a GFR, and a resin bonded rod that attaches metal ends. It has a protective covering of polymeric substances, which is termed as housing. Epoxies were the substances used, but hydrocarbons and silicones dominate the scene now. There is a severe lack of information available about the efficiency of these materials, and the testing methods aren’t reliable either and better testing methods need to be developed for better assessment. Solid coatings of RTV rubber are used with great success in improving the ceramic insulators’ efficiency. Its corrosion is quick when it faces DC voltage and sea contamination, and causes craters in glaze. [5]

    Power through a high voltage transmission line has a direct relationship with its current and voltage. Therefore, if we want to increase the power through a transmission line we are supposed to provide more current, as the potential difference stays constant across a transmission line. However, another law also states that power dissipation is proportional to current as well. Therefore, increasing the current would mean that power would be lost in form of heat, so we need to achieve a balance between the amount of current we increase. This also causes elongation of conductors. This paper would take a look at making a method that could calculate cheaply the amount of sag in a conductor and the mean temperature of the conductor core with a summary off the results. What is that method? It is taking two ends of a ground wire, which has high value of resistance, on a place on each of two towers of transmission line, and then measuring the induced current in the wire. The information that could be gained from this experiment is important in dynamic rating of these lines. The current generated is simply measured with an ammeter. [6]

        According to Corporate Author Powerlinesinc.com (2014), Electricity is not something that could be stored. Therefore, it has to be provided to where it is needed immediately. However, increasing the current would be detrimental as it would cause loss of power. Therefore, we use high voltage transmission lines, as increasing the voltage would not increase the energy dissipation. This makes it possible for us to send electrical power to faraway places. The national grid often passes through areas where these high voltage lines pass directly above the farmers and other humans. Although it is tried that they do not pass the areas inhabited, this is not possible on a full scale. There is little insulation done so there are some safety concerns with these. However, studies have not proven any link between high voltage transmission, no study since 1970 has found any ounce of evidence that there are any tangible harms of these transmission lines. This includes the Congress funded 1992 study that was due by the KSA Physical Society as well, which founded no link in these transmission lines and cancer. These transmission lines are very important in transport of energy. Although we do not often think about it, many skilled professionals work to ensure everything in this process, and all of this is very reliable despite being complicated. A lot of work is involved but we often don’t think about it. It is not very simply to get light by turning on a light switch. [7]

        As per writer Www.Siemens.Com(2018),  in order to transfer Electric power on the comparatively distances that are long, high voltage conduction lines needed to be there mostly via central broadcasting station to further substations. likewise, they ae also used for the broadcasting electricity via one main station to other for contribution of load. Both sectors residential and industrial now need more power, furthermore big cities accumulative development and renewables integration need more power for growth. It getting extremely difficult to ensure steady and safe flow of electricity that is tolerable in society and environment friendly, due to the separation of generations and their usage. Likewise it is a great obstacle for planners and project builder to have a high power electricity flow: as their main aim is to provide electric flow that is friendly for the environment and at competitive price as well as it is safe. There are sometimes challenges by society as lines of high voltage are not often much tolerated for this underground solution are best. In big cities where space in not suffice due to airports and other things high altitude lines are not feasible and here also underground solution is best.

    The growth of nonceramic insulators is increasing day by day as it has more benefits as compare to the traditional glass insulators and traditional ceramic insulators [8]

    In the year of 2007 an author Farzana had conducted a research. In this research he explains the advantages of traditional line insulator and further explains the methods of mitigation and selection which depends on the in service stresses.

        The technical structures of snow and icing flashover in contrast to flashovers of contamination are discussed in this research. It compares the performance of line insulators and stations by primarily focus on the insulation lines or on ice bridging but on the influence of insulator diameter, electric stress elevation other some other factors of several applications. Action ranges from coating of silicon, washing program of insulator and partial charge to replace the proper string insulator by adding a little number of extra insulator to suggested profile and ice – resistant insulators. There have been several researches, which are conducted on the strength of electrical flashover of the ice – insulators. In the outdoor conditions, several of them have used the acceleration of the artificial ice. Lately by using the indoor chambers with the wind, temperature and climate control it has been achieved to test the parameters in more enhanced way. Though in the moderate acceleration areas the polymeric insulators, which has the narrowly spaced sheds, will usually be slighter as compare to the insulators of cap – and – pin because of the ice – bridging. In the same way the designs of performance of the icing with substitute sheds of diameter will be more convenient as due to the more time and more space which is required for the ice bridging [9].

        In the year of 2003, a research has conducted by an Author Shi and et.al in this research it has been described that in the recent periods the KSA western region has been promoting their development work on large – scale dynamically. As development, work is going to be rapid with the passage of time so the KSA western region has been planning to create numerous high transmissions lines with the great altitude. The insulators flashover of the contamination does not base just on the kind and rigorousness of the contamination but at the same time it does base on the altitude at which point the insulators are located. The density of the air and reduced pressure merged with the high rate of altitudes and with low contamination scale by it voltage of the flashover gets decreases. The purpose of this study is to recognize the low air pressure influence characters of insulation of the lines of transmission by the experiment as well as by theory. In this study there is also a recommendation which is given for the assortment of insulator at outdoor which will be used with the Qinghai – Tibet railway along the 110 kV AC power of line of transmission. Consequently voltage of breakdown differs and directly proportional to the density of the air. On the other hand the breakdown voltage diverges to altitude in the direct proportion. The equation below estimates the decrease in the voltage of the flashover as the outcome the density of the air get decreased which is the reason of increase in the altitude. By considering, this fact that in the area which has the elevation at average of 4500 m power transmission line can work.  Moreover, it runs in this area but the area should have the light pollution severity for two kinds of insulators that are the test of artificial contamination is based on the 5 pressure cases corresponding to the elevation of 4000m – 6000m treaded by the 500m and ESSD of two typical types. The connection is among the altitude and pollution flashover is considered as under the multiple ESSD [10].

        According to the research, which is conducted in 2012 by an author, Parmar in this study the writer describes the elements, which affect the plants and people by high voltage transmission line. As population is increasing, day by day so there is need to expand the cities to fulfill the need of people, by expanding the cities number of buildings are increasing and built close to the high voltage lines of transmission. By maximizing the power requires the great amount of power over long reserves. Currently there is huge amount of magnetic field and electricity is producing to generate it large transmission lines conformation with current and it affects the people as well as the objects of the near areas placed at the pounded surface.  It is necessary to examine the influence of electromagnetic field on the health of human. The non-ionizing radiations caused by electromagnetic field, which is produced due to electricity, has influence the health of people in negative way. The electromagnetic field does not affect the human health only but also animals, plants, buried pipes, vehicles and many other objects [11].

        In a research conducted by Author Gubanski (2010), it is suggested that in the outdoor high voltage insulation the utilization of porcelain and glass in outdoor insulation of the electric power lines is traced back to almost 150 years ago. The first porcelain insulator was presented in 1850 and in 1858 first glass pin type insulators were introduced. At the beginning of the 20^th century suspension insulators were introduced and the design of cap and pin was very common till that date and today. In between the years 1920 and 1950, world witnessed the mega development of various types of insulators. The basic aim of developing those insulators was to enhance the active performance under constrained polluted environmental conditions. In the mid-fifties a revolutionary idea came out in which the self-supporting block of porcelain or glass was replaced by a complex structure of support bearing rod and protecting housing, which was made up of polymeric materials. It was expected that the idea will bring economic savings on a great scale but it also needed a new way of thinking regarding the selection and designing measures for the materials in addition to assembling technologies. Epoxies were proved non-useful in the outdoor environments. The use of elastomeric began in the seventies. Silicone rubber insulators became dominated as a result of the discovery of the reputation of the housing hydrophobic properties and its recovery. Years and after years, the work done made selection of optimal material compositions and manufacturing the technologies accessible initiating the non-ceramic insulators turned out to be acceptable in the market as a substitute solution in the designing of high voltage power lines and substation components. [12]

        In the research led by Zhang & at.al, (2010) it is stated that: this study presents the characteristics of porcelain, glass and complex insulators when contaminated and their after results in natural high altitude areas (1970 m). in the test, solid layer method was used in which a contaminant solution consisting of sodium chloride, kaolin powder and water was utilized to cover the surface of insulator. Then in the fog chamber the steam fog helps in wetting the chamber. With the help of up and down method 50 % of withstand voltage was produced. The results of the experiment indicate that significant effect of insulator profiles have been seen on the flashover voltages. It came to know that tri-shed porcelain insulator’s flashover voltages are lesser than the voltages of bell-type porcelain. The glass insulator which has bigger spacing has more flashover voltage rather than the smaller spacing. By optimization of the shed parameters composite insulators can be improvised by about up to 20%. In addition, the suspension patterns (I-, V- and Y-string) also have a noteworthy effect on the porcelain insulator flashover voltages. The Y-string configuration seems to lead to lower flashover voltages than I- and V-string insulators. The flashover voltages for V-string insulators are inclined by the angle between two insulator strings. The flashover voltage for V-strings of 120 is highest, which is higher than the I-string for 7.5% [13].

        According to a research by Doshi & Gorur, (2011) it is suggested that; composite insulators are closely in relation with the surface electric field (stress) distribution. This study explains results of calculation of the electric field distribution for composite insulators up to 1200 kV by the use of a 3D software package based on the Boundary Element Method. The analysis of the effect of corona and grading rings, single and bundled conductors, insulator orientation (dead-end and suspension), single and double units, and surface condition (dry and wet) on the electric field distribution has been done. It is advantageous for UHV systems (higher than 750 kV ac) the use of dual insulators with individual corona rings at the line and ground end and a common grading ring at the line end. The presence of optimal dimensions of corona and grading arrangement was demonstrated on a 1000 kV insulator string. Observation was made that the dead-end insulators involve higher electric stress as compared to their suspension counterparts and when the system voltage increases this difference gets more prominent.

        Grading Rings design and corona have no standards as further suggested. The tower configurations, line and various insulators can be effectively compared by means of software tools. It is quite a difficult analysis that is done under wet conditions.  In order to allow full insulation modeling in acceptable time, there is more essential work is required. There was a comparison done amongst suspension environments and composite insulations that were used in dead end for voltages that were around 500 kv ac. When suspension settings were matched with dead end settings, it showed that dead end settings were higher when used with insulation for electric field and system voltages ratio was increased. Even under conditions that are even though clean, corona can be there under wet situations. As a result, the material that should be used for housing should have proper endurance to corona. Detailed preparations may be required like several units with corona further grading rings may also be needed so that reasonable action of UHV insulators composite. [14].

        Guan & atal (2014) have addressed the causes associated with the outdoor insulation accidents of high-voltage transmission lines of DC and AC. In this reagrd, the researcher used the statistical analysis to describe the causes in China. This research paper was focused on the lightyning strike, birdes caused damaged, icing,  pollution flashover other factors having the potenial to affect the safe opertions of the high voltage transmission lines. Morever, the service situation of insulators was analyzed along with the reasons of damage and development tendencies of diferent insulatores within the transmission lines. As per the results of this research lightning strike,birds-caused damage, pollution flashover, windage-caused tripping, icing and external mechanical damadge are the main reasons behind the emergency shut-down rate and line tripping rate. However, the birds caused damaged and line tripping rate of the lighting strike have the high successful reclose rates. Moroever, rate of emergency shut-down is considerablly low. The wide use of RTV silicon with rubber coating, composite insulators is resulted in the considerable reduction of accidents caused by the pollution flashover. However, people needs t pay considerable attention as the pollution flashover accidents caused by the weather conditions do happned periodically. Moreover, the accidents that are cause by the short circuit and illegal constructions are the mian resaon behind the accidents of transmission lines. In this regard, the effective methods must be addopted by the people to strengthen the management as well as prevention of such accidents. Moreover, the glass, composite and porcelain insulators have their won specific characterists along with the range of applications. These insulators have considerablly high potential for development. Moroever, the need fo quality monitoringa nd on-line monitring is required as the rapidly developing composite insulators [15].

        Three different types of silicone rubber and the already existing standard of ac developed the dc test. This test does not specify erosion test IEC-60587 neither does  it specify plane tracking. Then the former aforementioned things were given different voltages that acted with both directions of ac,  we found that when dc test was positive, the extent of damage to surface and current leakage was more. Therefore, deformation of surface depends upon poles. If we see this test in terms of erosion, we find that erosion is directed from the bottom electrode towards the top one. Erosion also was more in positive dc tests. When tests were positive on 2.7 kV as well as 3.2 kV, about half the distance that was between the electrodes was eroded. Different techniques have been used in analyzing the results.In this test, the fact that leakage current gave lower frequencies was checked by a recorder which checked 15 samples in a second. This is a normal result. When we changed the directions of ac, the leakage current is found to be independent of the pattern of demortation of surface, even though for the first three hours deep erosion might be dependant on this. [16].

        One way to improve the efficientcy of outdoor polymeric SR insulators that find applications in high volateg transmission, is to add some kind of inorganic substances in them in extremely small quantities. Another way to to alter their design to make should their creepage distance is increased so the problems related to erosion chould be cushioned, at least to some extent. ASTM D2303 is a standard which facilitates us in conjuring a procedure which can be used to find and track the resistance to erosion of outdoor polymeric samples when they are given the laboratory conditions and applied ac voltages. This paper is aimed to record tests of inclined plane and similar erosion tests under conditions of both positive and negative voltages of ac on silicon rubber samples that had extremely small sized particles. The particles added to the silicon matrix include Alumina Trihydrate and fillers of alumina. The reason for that is to improve the efficiency. Moreover, monitoring of the leakage current and the mass that was eaten away was also done. The dispersion of filler and changes in structure of surface are done by SEM and EDX methods. Nano particles, it was found, were more efficient than micro particles even if they were in a lesser percentage. It was also recorded that negative dc was better for reducing erosion. EDX  has proved that different ions move on the surface under positive current causes bad performance then negative dc. [17].

        Insulators may have pollution flashovers that can cause accidents. It is important to research on the extent of the effect of pollution of insulators.  In this aspect, we can get better outdoor coordinations.Given below are some details of a research that dealt with possible effects of pollution of non-uniform kind distributed on an insulator ring that had a standard x-70 ceramic insulator as well as 14 rings in a transmission line of 220kV. It is found that rest, T/B, and N have some impact on polluted insulator’s ability of bearing voltage, but none of the impacts depend on each other. It decreases when the T/B is decreased. This test is instrumental in learning about the relation in 14-unit XP-70 and those impacting things. They effect the insulation of transmission lines. , We also need to understand the whole process that is applied here. At the surface of the insulator, we find that the pollution is not equally distributed, this causes the conductivity to be lessened and hydroscopic is deceased as well. These factors cause the voltage to be increased and runs of leakage current to increased.

        14-unit XP-70 insulator combined with the regulating factors was taken and it was a model that could be conducted in outdoor insulation. As there is a difference between the surface hygroscopicity and pollution distribution to be anomalous, conductivity is decreased as well as withstand voltage is increased and leakage current’s rms value is decreased. We believe that more research should be done to make correction in all factors. [18].

        G., Vermeulen, & Holtzhausen,( 2010) they gave a review after doing research about a practical study  during the research method used is called inclined plane Test Method to wathc the type of work performed by classic power line insulator materials, that were HTV (High Temperature Vulcanized) silicone rubber RTV (Room Temperature Vulcanized) Silicone rubbber coated porcelain, EPDM rubber. Constant voltage method was used to check the performance for these smaples that were given under stipulation where both ac and dc voltage that was polarities was there. The main theme of this research was to find out the action of different materials. And the effect of type of voltage in accordance to each other. RTV silicone rubber coating showed the great level of erosion for dc voltage that was negative while it showed minimum erosion for ac voltage when the results were drawn. The HTV silicone rubber coating displays least erosion for ac test voltage and most erosion for positive dc voltage, which led to sample failure. EPDM, on the other hand, shows the slightest erosion for negative dc voltage, but shows maximum erosion harshness for the ac voltage. Important information was produced by the Inclined Plane Tests examination about the activity of normally used insulator materials when charged by both the polarities of ac and dc voltages. The important and crucial information gained through this experiment was that EPDM rubber performs well when subjected to dc voltage rather than silicone rubber based materials. It was also concluded that dc test is more severe in contrast to the ac test for all the materials in spite of the fact that 40% of ac voltage is exceeding the constant dc voltage. It is envisioned to perform various other ac and dc tests at an outdoor pollution test environment so as to  gauge all the importance of this experiment hypothetically (Sima, Yuan, Yang, Xu, & Sun, 2010)

        In a research carried out by Nekeb, (2014) following recommendations were made: Silicone rubber (SiR) insulators can perform better under wet polluted conditions as compared to conservative porcelain and glass that is why Silicone rubber (SiR) insulators are used progressively more.though, in environments like high moisture level, pollution, the electrical discharges will develop on the surfaces of insulators. Electrical discharges ruin Silicone rubber (SiR) insulators in the form of tracking and erosion because of dry-band arcing when leakage current (LC) is developes. This happens in a long term time. Both of the traking and erosion are dangerous to life of the insulatoion. This proposition presents an experimental study on the electric activity of high voltage outdoor silicone rubber insulators. As explained in the literature review, when silicone rubber insulators are subjected to different environmental conditions they lose their unique property named as “hydrophobicity”, in review of this the research is focused on three areas: learning about the effect of ultraviolet (UV) radiation on the performance of silicone rubber insulation system.TS4 Textured Shank insulator of 4mm which is a newly designed insulator utilized for the intersection of 4mm square texture pattern on the shank regions of the insulator along with 11 kV non- textured were  set in vaccum casting machine. The exposed insulators were tested under different conditions. The doseage of UV is responsible for the electric charges and dry band formation on their surfaces. UV exposion to silicone rubber insulators result in the loss of the surface hydrophobicity through degradation in a form of tracking and erosion thus decreasing the anticipated life of the insulators. It was observed that the performance of silicone rubber insulators is greatly affected by the experimental conditions.

        Its was observed that Leakage Current exist on hydrophobic surfaces, increasing the insulation with an increase in the UV irradiation exposure, by maximizing the number of UV cycles. (ii) developing of a new test setuo to identify the efficiency of orientation angle on the performance of silicone rubber insulators subjected to different situations for example: wet and pollutic conditions: leakage current of silicone rubber insulators were maximized with the alteration of the orientation angle from vertical to horizontal, whereas the TS4 presented supreme performance under fog conditions in the orientation which is vertical.

    (iii) a new test is proposes, “high voltage rain ramp test” which is based on the high voltage ramp test method and the standard method of wet test. This test is suggested to assess the  activity of the TS4 silicone rubber insulators under the stimulated rain conditions at different orientations of angle.then the performance was compared to non-textured insulators. The resuklts concluded that, TS4 silicone rubber insulators are not much suitable for the wet weather conditions in any kind of orientation of angle because of the following reasons:a very low flashover voltage was observed in vertical orientation for the reason of productions of high magnitude electric fields in the shank region of insulator, (b) the non-textured insulators display a better flashover activity rather than their texrtured equivalents because of the inclined and horizontal orientation. Henceforth, little improvement is attained because of the use of expensive and complicated insulator design (Nekeb,2004).

        Another research laid down by Hammons & at.al, (2012) suggested that: this paper debates abouth the UHV ultra high voltage DC as an workable solution for substance transmitting power especially of the renewable energy. Following points are explained with the help of European policy and legal framework: how the technology is helpful in the corodinated international planning, international electricity market integration, and the distribution of wind and solar natural resources are a way towards the continent-wide internationally coordinated network planning with a view on long-term greenhouse gas reduction. Firstly, descriptions of UHV transmission in aspects of technical and economical are necessary. It includes conversion of configurations internally and externally. Onwards, the UHV transmission is questioned in reference to the context of power system development: AC and DC, micro grids, smart grids, power electronics, overhead lines, cables, and gas-insulated lines. Then the final discussion is about the climate protection and transmission system operator TSO in reference to European legal framework, for the coordination in the innovative legally mandated European transmission system operator association ENTSO-E, for joint European grid planning and for R&D. it shows the integration, economic and environmental goals for the whole continent-wide and internationally coordinated transmission developed by the UHV technology as an only option in the international long period of researches.

        UHVDC is very parsimoniously comprehensive key towards the transmission of power over very long distances.  The environmental influence is extremely great because its use helps in the reduction of CO2 by the replacement of fossil fuels. This technology is fully established now and running two projects to date. Its aspects are well known and under control. UHVDC provides different possible solutions to different needs and submissions. In planning and extending of power grids the utmost priority is the security of power supply in terms of dependability and blackout prevention. the important requirement in modern society is the availability of electric power. The aspect of gaining sustainability in this society is holding its root with global challenges of electricity power and climate conditions. (Hammons & at.al, 2012).

References of High Voltage Transmission Line Outdoor Insulations