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1
Utami, Agnes Manik Sari, Abdul Syakur i Hermawan Hermawan. "Analysis of Leakage Current and Insulator Resistivity for Quality Assurance of Medium Voltage Network Polymer Insulators Alumina - SiO2 in Tropical Climate Simulator Room". TEKNIK 42, nr 1 (6.04.2021): 10–19. http://dx.doi.org/10.14710/teknik.v42i1.36152.
Pełny tekst źródłaStreszczenie:
The tropical climate of Indonesia, which has moderately high rainfall, has an impact on the output of outdoor insulators. The presence of chemical particles, pollen, and salt in the air will bind to the insulating material's outer surface and settle, resulting in crystallization that allows the insulating material's surface roughness to increase. One of the insulators that are being produced is an insulator made of epoxy resin. The injection of fillers is used to further improve the durability of the outdoor epoxy resin insulators installed in tropical climatic conditions. Epoxy resin from bisphenol A-epichlorohydrin and polyaminoamide combined with silane, alumina, and SiO2 is used as research materials. The parameters examined were leakage current and resistance to insulation. The use of silane as a hardener will also improve the resistivity on the surface of the insulator, which makes it more difficult to flow or reduces the leakage current. Alumina is well-known for being a solid heat and voltage insulator. The addition of SiO2 to the epoxy resin insulating material increases the insulator's mechanical strength in the form of tensile and compressive strength. With fluctuations in temperature and humidity, the artificial tropical environment is replicated in a test chamber. The value of the leakage current increases with an increase in temperature and humidity. The correlation between air temperature and humidity and insulation resistance is inversely proportional, the higher the temperature applied to the insulator, the lower the insulator resistivity. The same refers to the relationship between air humidity and resistance to insulation. The higher the humidity applied to the insulator, the lower the insulator resistivity. At a test voltage of 11 kV, a humidity of 60%, and a temperature variation of 25oC, the leakage current of epoxy resin insulators is up to 9.2 uA lower than in a factory-made SiR insulator. The leakage current and insulator resistivity's number is already in the good and protected range such that the insulator can be used and reproduce.
2
Darwison, Darwison, Syukri Arief, Hairul Abral, Ariadi Hazmi, M. H. Ahmad, Eka Putra Waldi i Rudy Fernandez. "A leakage current estimation based on thermal image of polymer insulator". Indonesian Journal of Electrical Engineering and Computer Science 16, nr 3 (1.12.2019): 1096. http://dx.doi.org/10.11591/ijeecs.v16.i3.pp1096-1106.
Pełny tekst źródłaStreszczenie:
Polymer insulators tend to fail because of the climatic and environmental conditions. The failure occurs when the surface of insulator is contaminated by sea salt or cement dust which lead to partial discharge (PD). Leakage currents will increase by PD that causes deterioration of insulation. To predict the insulation failures, an adaptive neurofuzzy inference system (ANFIS) method using initial color detection processes are proposed to estimate the leakage currents based on the polymer insulator thermal images (infrared signature). In this study, the sodium chloride and kaolin are used as pollutants of the polymer insulator according to IEC 60507 standards. Then, the insulator is tested in the laboratory using AC high voltage applied at 18 kV where the temperature detection is controlled at 26° C and 70% RH (relative humidity). The percentage of colors (Red, Yellow, and Blue) from the thermal image is measured using the color detection method. Correspond to the color percentage, the ANFIS method predicts leakage currents from polymer insulators. Furthermore, this system interprets measured data from insulators that need to be categorized as Safe, Need Maintenance or Harmful. The final application of the system can be a non-contact tool to predict the polymer insulators used by technicians in the field.
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Luk’Yanov, A. M., Yu G. Chepelev i A. A. Luk’Yanova. "Reliability and durability of polymer insulators of the contact network". Vestnik of the Railway Research Institute 77, nr 2 (28.04.2018): 110–17. http://dx.doi.org/10.21780/2223-9731-2018-77-2-110-117.
Pełny tekst źródłaStreszczenie:
On the network of electrified railroads and power lines of advanced countries there is an intensive work undergoing on the conversion of traditional insulating structures made of porcelain and glass to new ones - polymeric. In order to minimize mechanical damage, it is necessary first of all to investigate the stress-strain state in the connection zone “end terminal - fiberglass rod”, and on the basis of the results obtained, to develop a number of design solutions that make it possible to provide the required reliability of such connection. The analysis of the stress-strain state and the strength of the joint between the fiberglass rod and the end terminal is of greatest interest, taking into account the viscoelastic properties of the glue (glue creeping). Authors present a method for calculating axis-symmetric glue joints of polymer insulators based on the finite element method. The stress state of the junction zone (“end terminal - fiberglass rod”) is analyzed. Optimum sizes of the glue-joint connection of the insulator are determined taking into account the viscoelastic properties of the glue. The results of testing the models of polymer insulators of the contact network in the temperature range -60 ... + 100 °C are given and the life of tension (suspension), fixation and console polymer insulators is estimated on the basis of the principle of temperature-time analogy. The proposed technique for assessing the stress-strain state of the glued joint of polymer insulators, taking into account the viscoelastic properties of the adhesive, allows to determine the optimal parameters of the end caps, taking into account the time of action of the load on the insulator. An analysis of the experimental curves of durability has made it possible to establish the norms governing the change in the durability of a polymer insulator, depending on the load acting on it. A load, that provides reliable operation of the polymer insulator for 30 years, can be accepted for tension insulators, which is not more than 40 % of the destructive insulator, and for fixative and console - not more than 45 and 50 % respectively.
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Darmadi, Agam Celvano, Kholistainingsih Kholistianingsih i Priyono Yulianto. "ANALISIS TAHANAN ISOLASI PADA ISOLATOR PORSELIN DAN POLIMER TERHADAP POLUTAN GARAM DI GISTET 500 KV ADIPALA CILACAP". Teodolita: Media Komunkasi Ilmiah di Bidang Teknik 23, nr 2 (8.01.2023): 42–55. http://dx.doi.org/10.53810/jt.v23i2.455.
Pełny tekst źródłaStreszczenie:
GISTET 500 kV Adipala is one of the locations that is in the spotlight in the Central Java Transmission
Main Unit (UIT JBT) because of frequent pollutant problems, especially during the dry season. This causes
the surrounding air to have a high salt content and also the flyash from the PLTU. This condition causes
the insulators on the tower and gantry to be exposed to pollutants and can result in flashover and
breakdown. This study discusses the effectiveness of polymer insulators by testing the insulation resistance
of clean porcelain insulators, polluted porcelain, clean polymers, and polluted polymers. To get the
condition of the insulator polluted with salt water, the method of raining on the insulator is carried out.
The result of the clean porcelain test was 2970 GOhm. in the experiment with polluted porcelain insulators,
the following results were obtained: the minimum 50ml experiment measured a resistance value of 2950
GOhm, which was reduced by 1% from the clean one and the maximum 500ml experiment measured the
resistance value to 390,3 GOhm, which was 87% reduced from the clean one. The net polymer insulator test
results are 3222.8 GOhm. In the experiment with polluted polymer insulators, the following results were
obtained: the minimum 50ml experiment measured a resistance value of 2982 GOhm, which was 7% less, the
maximum 500ml experiment was 2382.8 GOhm, 26% less. From the results of these experiments, it can be
seen that in the porcelain insulator experiment with salt water polluted, the insulation resistance value
decreased in each experiment until the maximum experiment was 500ml which obtained a resistance value
of 390.3 GOhm. The results of the clean polymer insulator test were 3222.8 GOhm, while the pollutant polymer
insulator experiment recorded a value that was not significantly decreased with the lowest value in the
500ml experiment of 2382.8 GOhm. When compared with the minimum standard of insulation resistance for
the 500 kV system used by PLN is 500 MOhm. Porcelain insulators that experience continuous exposure to
pollutants have the potential to experience flashover and faster breakdown compared to polymer insulators
when viewed from the trend of decreasing insulating resistance. It can be concluded that polymer insulators
are more effective for use in environments that have a high level of exposure to air pollution such as at
GISTET Adipala.
Keywords: Porcelain Insulator, Polymer Insulator, Pollutant, Flashover, Breakdown
GISTET 500 kV Adipala adalah salah satu lokasi yang menjadi sorotan di Unit Induk Transmisi Jawa
Bagian Tengah (UIT JBT) karena seringnya masalah polutan terutama pada musim kemarau. Hal ini
menyebabkan udara sekitar memiliki kandungan garam yang tinggi dan juga flyash dari PLTU. GISTET
Adipala. Hal ini menyebabkan isolator pada tower dan gantry menjadi terpapar polutan dan dapat
mengakibatkan terjadinya flashover dan breakdown. Oleh karena itu diperlukan analisis efektifitas isolator
polimer dengan cara melakukan pengujian tahanan isolasi terhadap isolator porselin bersih, porselin
berpolutan, polimer bersih, dan polimer berpolutan. Untuk mendapatkan kondisi isolator berpolutan air garam, dilakukan metode penghujanan ke arah isolator. Hasil pengujian porselin bersih tercatat 2970 GOhm.
pada percobaan isolator porselin berpolutan didapat hasil sebagai berikut: percobaan 50ml, terukur nilai
tahanan sebesar 2950 GOhm, yaitu berkurang 1% dan percobaan 500ml terukur nilai tahanan sebesar 390,3
GOhm, yaitu berkurang 87%. Untuk hasil pengujian isolator polimer bersih sebesar 3222,8 GOhm. 50ml terukur
nilai tahanan sebesar 2982 GOhm, yaitu berkurang 7%, 500ml yaitu sebesar 2382,8 GOhm, berkurang 26% dari
yang bersih. Dari hasil percobaan tersebut dapat dilihat pada percobaan isolator porselin berpolutan air
garam adalah nilai tahanan isolasi yang menurun pada tiap percobaan hingga percobaan paling banyak yaitu
500ml yang diperoleh nilai tahanan 390,3 GOhm. Hasil pengujian isolator polimer bersih sebesar 3222,8 GOhm,
sementara percobaan isolator polimer berpolutan tercatat nilai yang tidak begitu turun dengan nilai paling
rendah pada percobaan 500ml sebesar 2382,8 GOhm. Jika dibandingkan dengan Standar minimal tahanan
isolasi untuk sistem 500 kV yang digunakan PLN adalah 500 MOhm. Isolator porselin yang mengalami
paparan polutan secara terus menerus berpotensi mengalami flashover dan breakdown lebih cepat
dibandingkan dengan isolator polimer jika dilihat dari trend penurunan tahanan isolasinya. Dapat
disimpulkan bahwa Isolator polimer lebih efektif untuk digunakan pada lingkungan yang memiliki tingkat
paparan polusi udara yang tinggi seperti di GISTET Adipala.
Kata Kunci: Isolator porselin, Isolator Polimer, Polutan, Flashover, Breakdown
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Aziz, Esraa, Fatiha Aouabed, Hossam Abdellah i Adrienn Dineva. "Case Study: Optimizing Grading Ring Design for High Voltage Polymeric Insulators in Power Transmission Systems for Enhanced Electric Field and Voltage Distribution by Using a Finite Element Method". Energies 16, nr 13 (7.07.2023): 5235. http://dx.doi.org/10.3390/en16135235.
Pełny tekst źródłaStreszczenie:
This research paper aims to investigate the optimal design of grading rings for high-voltage polymeric insulators in an actual power transmission system, with a focus on improving the electrical representation of the insulator strings. One such subsidiary accessory commonly used with porcelain and polymer insulator strings is the grading ring, which is employed to improve the electric field and voltage distribution surrounding the insulator string. The efficiency of insulator strings can be enhanced by grading rings, as they facilitate a more linear potential division along the strings. The design parameters of grading rings significantly influence their performance on insulator strings. In this study, we examine the optimal design of the grading rings of high-voltage polymer insulators, since no uniform design methodology has been developed for high-voltage polymer insulators, and their optimization is currently the subject of many research studies. The electric field on an outdoor polymeric insulator is examined using finite element method (FEM) software and COMSOL Multi-Physics program. A 2D model is utilized to simulate a 220 kV polymeric insulator. The effectiveness of high-voltage polymeric insulators greatly depends on the dimensions and locations of the grading rings. Therefore, the impacts of the radius of the grading ring and that of its tube and the tube’s vertical position are thoroughly investigated, under dry and humid conditions. To achieve this objective, a search algorithm is employed to adjust the dimensions and locations of the grading ring. The optimization approach in this study is based on determining the maximum electric field across the insulator surface, while ensuring that it remains below the corona initiation level.
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Nesenyuk, Tatyana Anatolyevna, i Ekaterina Evgenyevna Poluyanova. "RFID-indicators for polymer stick insulators". Transport of the Urals, nr 3 (2020): 82–88. http://dx.doi.org/10.20291/1815-9400-2020-3-82-88.
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The paper is devoted to the use of RFID-technology in electrical power engineering, in particular, for controlling the condition of high-voltage equipment of feeding transmission lines. It also describes studies on development of RFID-tag designed to indicate dielectric condition of line polymer insulator. The authors present results of tests of pilot samples of LKi-70/110-4-GP-UKhL1 polymer stick insulators with built-in RFID-indicators. The tests have been executed in accordance with the GOST R 55189-2012 requirements. As a result, the authors have made a conclusion on the possibility of using RFID-technologies for technical control of insulators on overhead transmission lines, high-voltage equipment of traction and transformer substations.
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Dimitropoulou, M., D. Pylarinos, K. Siderakis, E. Thalassinakis i M. Danikas. "Comparative Investigation of Pollution Accumulation and Natural Cleaning for Different HV Insulators". Engineering, Technology & Applied Science Research 5, nr 2 (20.04.2015): 764–74. http://dx.doi.org/10.48084/etasr.545.
Pełny tekst źródłaStreszczenie:
High Voltage insulators are scattered throughout any HV network and a single insulator fault may cause an excessive outage. Reliability is a key issue for electric power systems and fault-free performance of insulators greatly reflects on the reliability of the system. Environmental influence is rather important for the optimum selection of outdoor insulators and, therefore, field measurements provide valuable information. Utilities perform such measurements in order to decide upon the location/route of new HV installations (substations, lines etc) and also to optimize the selection, maintenance and replacement of already installed insulators. A rather interesting case in Greek territory is the island of Crete, due to the coastal development of the network and the local weather conditions. The Greek utility has employed a variety of remedies to cope with the pollution problem. Following the positive feedback after the installation on certain tower in the past, a large project to replace all ceramic insulators with new polymer ones of hydrophobic surface is now in progress. Polymer coatings have also been extensively applied on substations and also on certain areas/towers of the transmission network in the past. In order to investigate the pollution accumulation and the impact of natural washing on different insulator types, a series of periodical ESDD and NSDD pollution measurements were conducted in HEDNO’s TALOS High Voltage Test Station for a 3-months period. Multiple measurements were performed on each insulator every month in order to collect additional data. Five different insulators were selected based on the types historically used in the Cretan Network. Along with the standard glass disc profile, two strings of glass fog profile (the one coated with RTV) and two long-rod composite insulators of different shed profile and material were used. Results are presented and discussed in this paper.
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Hawal, Abdallah O., Suliman A. Ben Rahma i Moayed M. Abdul Samed. "Electrical Performance Study of 11kV Coated Porcelain, Coated Glass, and Polymer Outdoor High Voltage Insulators". مجلة الجامعة الأسمرية: العلوم التطبيقية 8, nr 2 (5.06.2023): 31–45. http://dx.doi.org/10.59743/jauas.8.2.1.
Pełny tekst źródłaStreszczenie:
The study in this paper investigates how contaminations and different types of pollutants affect the electrical performance of outdoor coated porcelain, coated glass, and composite insulators when subjected to an 11 kV AC voltage. The ceramic insulators (porcelain and glass) coating layer is assumed to be RTV silicon rubber material with a 0.5 mm thickness. The effect of these three pollution cases on the electrical performance were investigated using a commercial software called COMSOL Multiphysics based on the finite element method (FEM). The three pollution cases were uniform, non-uniform pollution, and water droplets. In the uniform pollution condition, the pollution layer over the surface of the insulators was assumed to be 0.5 mm; however, in non-uniform pollution condition, water patches with a thickness varying from 0.5 to 1.5 mm was used. In water droplets condition, hemispherical shapes were used to model water droplets with a diameter of 1 mm. Voltage, electrical field distributions, and dissipated power were computed along the creepage distance of the three insulators models. The simulation results indicated that for the uniform case, the lowest electrical field appeared on the silicon rubber insulator. For the non-uniform case, the electrical field distribution became more non-uniform for the three models. In the water droplets case, more fluctuations appeared in the metal end fittings where the water droplets were located. The analysis indicated that the maximum dissipated power was found to be for the coated glass. The obtained results showed that the silicon rubber insulator offered better performance compared with coated porcelain and glass. Coated porcelain offered better performance compared with the coated glass insulator.
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Nesenyuk, Tatiana A., Viktor N. Sokolov, Inna N. Maksimova i Evgenia P. Nikitina. "Investigation of radio frequency characteristics of RFID indicators for linear polymer insulators of various voltage levels". Innotrans, nr 2 (2023): 51–56. http://dx.doi.org/10.20291/2311-164x-2023-2-51-56.
Pełny tekst źródłaStreszczenie:
The article describes the possibilities of using the digital method of non-destructive testing of polymer linear insulators using RFID technologies. The possibility of installing RFID indicators is being considered not only on specially designed insulators with built-in electrodes, but also on standard insulators currently produced by Russian manufacturers. The location of RFID indicators for installation on polymer linear insulators of the LC type is shown. A comparison of the radiation patterns of RFID indicators installed on polymer insulators with the voltage of 110 and 35 kV is provided, the results obtained are analyzed. Conclusions are drawn about the possibility of using RFID-indication for insulators at different voltage levels for both overhead power lines and contact network insulators.
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Andreenkov, Evgeniy S., Vaclav E. Skorubskiy i Sergey A. Shunaev. "On the issue of modeling a high-voltage insulator in the COMSOL Multiphysics 5.6 soft package". Journal Of Applied Informatics 16, nr 95 (29.10.2021): 126–35. http://dx.doi.org/10.37791/2687-0649-2021-16-5-126-135.
Pełny tekst źródłaStreszczenie:
The article discusses the main aspects of modeling suspended polymer high-voltage insulation of overhead power lines (PTL) in the COMSOL Multiphysics 5.6 software package. Analytical expressions of the mathematical model of the electromagnetic field around the insulator are given, on the basis of which a numerical solution is formed within the software package that allows you to build a model of the electric field in two-dimensional and three-dimensional space. There are three main stages of working with the program interface. At the first stage, the task of the geometric dimensions of the model and the surrounding area is considered, attention is paid to the formation of the design features of polymer insulators. In the second stage, the physical properties of the structural materials of the insulator, as well as the surrounding space, are described. The third stage is reduced to the determination of boundary conditions for solving the Poisson differential equation. Recommendations for finite element mesh density are given. A gradient picture of the distribution of the electric potential near the surface of the insulator is presented. The graphs of the distribution of the normal component of the electric field strength along the surface of the insulator are also plotted. On the basis of the obtained results, the influence of external factors on the properties of the polymer insulator is studied. A possible variant of modeling influencing factors, such as pollution and moisture, by making changes in the description of the physical properties of the insulator surface, namely by including a uniform and continuous layer with a given conductivity, is described. The distribution of the normal component of the electric field strength along the surface of the insulator with contamination is obtained. The results of modeling the electric field distribution with the presence of contamination on the surface of the insulator and its absence are summarized in the table where the electric field strength is indicated depending on the distance to the traverse. Based on the analysis of the results obtained, an assumption is made about the overestimated level of the maximum electric field on the insulators recommended by the manufacturers. The convergence of the considered models with the experimental data obtained in the course of long-term observation of the dynamics of the degradation and aging processes of the surface of polymer suspended insulators of overhead transmission lines is discussed.
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Negara, I. Made Yulistya, I. G. N. Satriyadi Hernanda, Dimas Anton Asfani, Mira Kusuma Wardani, Bonifacius Kevin Yegar i Reynaldi Syahril. "Effect of Seawater and Fly Ash Contaminants on Insulator Surfaces Made of Polymer Based on Finite Element Method". Energies 14, nr 24 (20.12.2021): 8581. http://dx.doi.org/10.3390/en14248581.
Pełny tekst źródłaStreszczenie:
Polymer is an insulating substance that has become increasingly popular in recent years due to its benefits. Light density, superior dielectric and thermal properties, and water-resistant or hydrophobic properties are only a few of the benefits. The presence of impurities or pollutants on the insulator’s surface lowers its dielectric capacity, which can lead to current leakage. The influence of seawater and fly ash pollutants on the distribution of the electric field and the current density of the insulator was simulated in this study. The finite element method was used to execute the simulation (FEM). Polymer insulators are subjected to testing in order to gather current leakage statistics. The tested insulator is exposed to seawater pollution, which varies depending on the equivalent salt density deposit value (ESDD). The pollutant insulator for fly ash varies depending on the value of non-soluble deposit density (NSDD). The existence of a layer of pollutants increased the value of the electric field and the value of the surface current density, according to the findings. Both in simulation and testing, the ESDD value of seawater pollutants and the NSDD value of fly ash contaminants influenced the value of the leakage current that flowed. The greater the ESDD and NSDD values are, the bigger the leakage current will be.
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Shevchenko, S. Y., D. A. Danylchenko, Y. A. Vyazovichenko, A. E. Potryvai i V. N. Tsyupa. "Simulation of the electric field of a polymeric insulator bushing to determine the field concentration points". Electrical Engineering and Power Engineering, nr 2 (30.06.2022): 49–57. http://dx.doi.org/10.15588/1607-6761-2022-2-5.
Pełny tekst źródłaStreszczenie:
Purpose. The use of modeling as a tool that allows you to identify design weaknesses in electrical equipment and, on their basis, perform its optimization in order to level weaknesses due to design imperfections. Designation of a real problem in the design of polymer bushings, which negatively affects their technical, economic and operational characteristics and makes them less competitive compared to other types of insulators.
Methodology. Analysis of experiments to detect partial discharges, simulation of electric field strength, synthesis of analyzed works and simulation results.
Findings. As a result of the performed scientific research, it was found that the process of partial discharges has a direct effect on the electrical strength of the polymer bushing insulator. This fact is taken as the basis for searching for methods of further influence on the design of the insulator in order to increase its service life. It was found in the work that the reason for the occurrence of partial discharges is the uneven distribution of the electric field strength. This was the reason for further study of the electric field strength of the pass-through insulator and its modeling. As a result of the simulation, points of concentration of the electric field strength in the bushing polymer insulator were found and designated as points of action to increase the electrical strength of the bushing polymer insulator.
Originality. The scientific novelty of the performed research work lies in the use of the simulation of the electric field of a polymer bushing as a tool for detecting weak points in its design, when exposed to which, a positive effect on its technical characteristics can be observed.
Practical value. The practical value of the research work done is that the results of the research serve as a solid foundation for further optimization of the design of polymer bushings, which will lead to a positive impact on their technical characteristics and make them competitive compared to other types of insulators.
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Kim, Jung Min, Hyun Jung Her, J. H. Yoon, Jae Wan Kim, Y. J. Choi, C. J. Kang, D. Jeon i Yong Sang Kim. "Characteristics of Pentacene with Different Polymer Gate Insulators for Organic Thin-Film Transistors". Solid State Phenomena 124-126 (czerwiec 2007): 451–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.451.
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We investigated the characteristics of pentacene thin films of different materials for gate insulators using atomic force microscope (AFM) and x-ray diffraction (XRD). The pentacene thin films are fabricated by evaporation on different polymer substrates. We used HMDS (Hexa Methyl Di Silazane), PVA (Poly Vinyl Alcohol) and PMMA (Poly Methyl Meth Acrylate) for the polymer substrates, on which pentacene is deposited at various substrate temperatures. The case of pentacene deposited on the PMMA has the largest grain size and least trap concentration. We also fabricated pentacene TFTs with the PMMA gate insulator. Pentacene TFTs with PMMA gate insulator, shows high field-effect mobility (ｕFET= 0.03 cm2/Vs) and large on/off current ratio (>105) and small threshold voltage (Vth= -6 V).
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Kim, Minhee, Su-Hun Kim i Se-Hee Lee. "Finite Element Analysis of the Breakdown Prediction for LDPE Stressed by Various Ramp Rates of DC Voltage Based on Molecular Displacement Model". Energies 13, nr 6 (12.03.2020): 1320. http://dx.doi.org/10.3390/en13061320.
Pełny tekst źródłaStreszczenie:
Predicting the electrical breakdown of polymers is critical for certifying the endurance and lifetime of high voltage power equipment. Since various factors contribute nonlinearly to the breakdown phenomena of polymer insulators, it is difficult to assess the impact of each factor independently. In this study, we numerically analyzed the breakdown phenomenon because of the ramp rate of the DC voltage applied to a polymer insulator, low-density polyethylene (LDPE), using the finite element method (FEM). To predict the breakdown initiation, we analyzed the relaxation time of the conduction current through the insulator as a significant indicator. The bipolar charge transport (BCT) model was used to analyze the charge behavior within the LDPE, and the breakdown voltage was predicted by incorporating the molecular displacement model. This analysis was conducted for a wide range of ramp rates from 10 to 1500 V/s. The current density was calculated using two different methods, namely the energy and average methods, and the results were compared with each other. The results of the numerical model were further verified by comparing with those from experiments reported in the literature.
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Ameer Ali, Anis Akilah Binti, Hafisoh Ahmad, Hoon Yap i Hafizul Azizi Bin Ismail. "Investigation of Electrical Properties of TiO2 Nanocomposite Based Polymer". Journal of Physics: Conference Series 2120, nr 1 (1.12.2021): 012031. http://dx.doi.org/10.1088/1742-6596/2120/1/012031.
Pełny tekst źródłaStreszczenie:
Abstract Past research has reported the challenges regarding on degradation and aging due to high localization of electric field at triple point areas of polymeric insulator. The different materials and designs of polymeric insulator have initiated the partial discharge and arching activities which eventually lead to the insulation failures. The compounding of nanomaterials in the polymer shows a promising result to overcome this problem by redistributing the uniformity of electrical field lines on the insulator. In the present work, ethylene-propylene-diene rubber (EPDM) and titanium dioxide (TiO2) is introduced as nano composites that been embedded into insulator’s housing made of 1) silicone rubber (SiR) and 2) Ethylene Propylene Diene Monomer (EPDM) Rubber. Titanium dioxide (TiO2) is a semiconductor material that can be formed in different sizes either micron or nano-sized filler and has high relative permittivity that be able to reduce the high electrical stresses on high voltage equipment. Meanwhile EPDM shows good mechanical profile, excellent resistance properties and low cost. Therefore, it brings to the new opportunity to fabricate the nanocomposite based on both materials which exhibits an improved electrical properties and good distribution of electric field on polymeric outdoor insulators. In depth investigation was carried out to analyze the effect of different nano-filler loading in the compound and behavior of nanocomposites at different polymer base. An 11kV polymeric insulator is modelled to be simulated by using COMSOL Multiphysics software under dry-clean surface conditions to investigate the electric field distribution at terminal ends and along the insulator creepage path. The Electrostatics interface from the AC/DC Module is used in the evaluation of electric field distribution of insulator model correspondingly with the variations in filler percentage in the host matrix.
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Wintle, H. J., i R. Dörsam. "Phenomenological piezoelectricity of polymer insulators". Physical Review B 39, nr 6 (15.02.1989): 3862–70. http://dx.doi.org/10.1103/physrevb.39.3862.
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Din, A., M. A. M. Piah, A. R. Abdullah i N. F. Kasri. "Surface roughness condition of field-aged polymer insulators at different installation area". Indonesian Journal of Electrical Engineering and Computer Science 15, nr 2 (1.08.2019): 600. http://dx.doi.org/10.11591/ijeecs.v15.i2.pp600-608.
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<span>This paper presents surface degradation assessment based on surface roughness condition for various field-aged high voltage polymer insulators that were installed at different locations. The measurement of arithmetical mean surface roughness is done, and statistical analysis is implemented in this study. Three groups of insulators labeled as 6 years, 12 years, 18 years, and with their respective controlled samples are tested using a surface roughness tester. Data measurements from the testing are analyzed in conjunction with visual observation to investigate an indication of surface degradation within the groups. Further statistical analysis is applied for the comparison of the surface roughness conditions. In order to observe the environmental stress factors that will affect the roughness condition, within the installation area, the virtual three-dimensional mapping program represented the Earth based on satellite imagery is utilized. The correlation analysis on all that three groups has indicated the positive outcomes with the roughness increased with respect to the age of insulator that located in quite similar environmental stress conditions. Regardless of the age of an insulator, the degradation due to surface roughness condition can be used to indicate what levels of environmental stress around the installation area have.</span>
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Chang, J., s. Krause i R. Gorur. "Application of low-voltage Scanning Electron Microscopy to studies of polymer near-surface diffusion and hydrophobicity". Proceedings, annual meeting, Electron Microscopy Society of America 48, nr 4 (sierpień 1990): 1108–9. http://dx.doi.org/10.1017/s0424820100178677.
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The study of the surface characteristics of a polymeric insulator - such as silicone rubber (SR) and ethylene propylene diene monomer (EPDM) -- is necessary to understand the hydrophobicity recovery mechanism that governs the ability of insulators to withstand electrical stresses during high voltage service. It has been shown that hydrophobicity of a polymeric insulator surface could be reduced by electrical discharges during outdoor service, causing the surface to become wettable, and thus allow water films to form, and ultimately leading to power outages. It was also reported that the recovery process could be due to the diffusion of low molecular weight (LMW) polymer chains from the bulk of the material to the surface. Because the LMW chains are in fluidic form (oil), they are able to diffuse through the material due to the concentration gradient of these species between the bulk and the surface. The exact mechanism of hydrophobicity recovery in polymeric insulators is still not well understood. In this study, an investigation was conducted to examine the effects of near surface molecular diffusion in the hydrophobicity recovery process of SR and EPDM insulators. Different analytical techniques were used to examine the surface morphology and surface charging effects of these elastomeric materials. Low voltage scanning electron microscopy (LVSEM) was used to measure the second cross-over point (E2) of the material surfaces, and electron spectroscopy for chemical analysis (ESCA) was also used to identify the surface chemical composition.
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Hatta, Hideyuki, Yuhi Miyagawa, Takashi Nagase, Takashi Kobayashi, Takashi Hamada, Shuichi Murakami, Kimihiro Matsukawa i Hiroyoshi Naito. "Determination of Interface-State Distributions in Polymer-Based Metal-Insulator-Semiconductor Capacitors by Impedance Spectroscopy". Applied Sciences 8, nr 9 (29.08.2018): 1493. http://dx.doi.org/10.3390/app8091493.
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Information on localized states at the interfaces of solution-processed organic semiconductors and polymer gate insulators is critical to the development of printable organic field-effect transistors (OFETs) with good electrical performance. This paper reports on the use of impedance spectroscopy to determine the energy distribution of the density of interface states in organic metal-insulator-semiconductor (MIS) capacitors based on poly(3-hexylthiophene) (P3HT) with three different polymer gate insulators, including polyimide, poly(4-vinylphenol), and poly(methylsilsesquioxane). The findings of the study indicate that the impedance characteristics of the P3HT MIS capacitors are strongly affected by patterning and thermal annealing of the organic semiconductor films. To extract the interface-state distributions from the conductance of the P3HT MIS capacitors, an equivalent circuit model with continuum trap states is used, which also takes the band-bending fluctuations into consideration. In addition, the relationship between the determined interface states and the electrical characteristics of P3HT-based OFETs is investigated.
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Luk’yanov, A. M., i A. A. Luk’yanova. "About structural elements of polymer insulators of the contact network". VNIIZHT Scientific Journal 79, nr 5 (10.11.2020): 310–16. http://dx.doi.org/10.21780/2223-9731-2020-79-5-310-316.
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The high load on electrified lines makes tougher the requirements for the reliability and maintainability of power supply devices. Insulators are a critical element of the overhead contact network, and great attention is paid to improving their characteristics — electrical and mechanical strength. Advantages of polymer insulators in comparison with traditional ones made of porcelain and glass are generally recognized: manufacturability, low weight, compactness, ease of installation and transportation, high mechanical strength and shock resistance.The article presents the results of comprehensive studies of the electrophysical characteristics of fiberglass rods and bars made of AG-4S carried out by the University of Railway Engineers (MIIT), which were used in the developed polymer structures of the contact network. Recommendations are given on the maintenance of fiberglass rods and bars from AG-4S and their engineering support. The issues of the mechanical strength of polymer insulators of the overhead contact network are covered quite fully, therefore, this article offers the basic principles for calculating their electrical strength. The main requirements for modern polymer insulators and design features are briefly presented for each type: suspended, tension, cantilever, fixing and supporting.
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Lukyanov, A. M., i Y. G. Chepelev. "POLYMER INSULATORS FOR CONTACT NETWORK DEVICES". World of Transport and Transportation 14, nr 5 (28.10.2016): 56–70. http://dx.doi.org/10.30932/1992-3252-2016-14-5-6.
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For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT The results of studies of the developed designs of polymer suspension, tension, console, fixation and support insulators of the contact network are given. Recommendations for their maintenance and engineering support are suggested. Keywords: railway, contact network, polymer insulators, types of structures, reliability, maintenance REFERENCES 1.Lukyanov, A.M., Chepelev, Yu.G., Bardin, A. N.Development of Polymer Consoles.World of Transport and Transportation, Vol.14, 2016, Iss.3, pp.60-71. 2.Goroshkov, Yu.I., Ilyin, V.N., Lukyanov, A.M., Chepelev, Yu.G. Application of polymer insulators in devices of the contact network of electrified railways [Primenenie polimernih izolyatorov v ustroistvah kontaktnoi seti eletricirovannih zheleznih dorog].Moscow, Transport publ., 1987, 48 p. 3.Goroshkov, Yu.I., Bondarev, N. A. Contact network [Kontaktnaya set’].Moscow, Transport publ., 1981, 400 p. 4.Janick, J. Elektrischer Zugbetrieb.Der Eisenbahningenieur, 2015, Iss.1, pp.17-20. 5.Oberleitung Sicat SX - Zulassung und Betriebserfahrung in Ungarn.Kökėnyesi Miklŏs, Kunz Dietmar.Elek. Bahnen, 2013, 111, Iss.6-7, pp.440-444. 6.Chen Shaokuan, Wang Xiu-dan, Bai Yun, Liu Hai-dong, Mao Bao-huo.Tiedao xuebao=J. China Railway Soe, 2013, 35, Iss.12, pp.37-42. 7.Wienerwaldtunnel - Montage der Oberleitung.Hofbauer Gerhard.Elek. Bahnen, 2013, 111, Iss.6-7, pp.425-429.
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Ali, Muhammad, i Muhammad Ahmad Choudhry. "Preparation and characterization of EPDM-silica nano/micro composites for high voltage insulation applications". Materials Science-Poland 33, nr 1 (1.03.2015): 213–19. http://dx.doi.org/10.1515/msp-2015-0002.
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AbstractThe rising market for substitute materials in high voltage insulation components is stimulated largely by the need to reduce overall costs. In this respect, polymer insulators offer significant advantages over old traditional materials. In the present research, efforts have been made to quantify the effect of silica (having different particle size nano, micro and hybrid) loading on the mechanical and thermal behaviors of Ethylene-Propylene-Diene Monomer (EPDM) based high voltage electrical insulations. The fabricated composites were subjected to mechanical, thermal and electrical properties measurements. The results of dielectric strength, surface and volume resistivities showed that all composites had insulator properties, while their mechanical and thermal properties improved considerably. EPDM was compounded with different types of silica in a two roll mill using sulphur cure system. The outcome achieved from the comparative study revealed that the EPDM nanocomposites had enhanced mechanical, thermal and electrical properties even at 5 % loadings.
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Zhang, Zhijin, Tian Liang, Zhenglong Jiang, Xingliang Jiang, Jianlin Hu i Guohui Pang. "Application of Infrared Spectroscopy in Research on Aging of Silicone Rubber in Harsh Environment". Polymers 14, nr 21 (4.11.2022): 4728. http://dx.doi.org/10.3390/polym14214728.
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Polymer insulators using silicone rubber materials as sheds and sheaths are widely used in power systems to replace traditional porcelain and glass insulators which are heavy, inconvenient to install, and prone to pollution flashover. However, in recent years, polymer insulators that have been operating in harsh outdoor environments for many years have experienced different degrees of aging. The aging degree and aging products of silicone rubber are the focus of research. Fourier transform infrared spectroscopy (FTIR) is a technical method to analyze the internal molecular bonds and functional groups of materials, and it is often used to study the aging degree and aging products of silicone rubber. In this paper, the aging characteristics of silicone rubber samples in a high altitude area, salt fog environment, and acid environment were studied by FTIR. The results showed that the silicone rubber in a harsh environment, such as strong radiation, salt fog, and acid fog was degraded to some extent, and its main chain was cut off, the degree of polymerization was reduced, and the content of hydrophobic functional groups was reduced. Infrared spectroscopy can be used to analyze the aging phenomenon of polymers.
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Thomazini, Daniel, Raphael Ulisses Costa De Resende de Resende, Daniel Henrique Gueratto i Maria Virginia Gelfuso. "Artificial Neural Network Assisted Digital Image Processing to Determine the Hydrophobicity of Polymeric Materials". Materials Science Forum 775-776 (styczeń 2014): 743–48. http://dx.doi.org/10.4028/www.scientific.net/msf.775-776.743.
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Hydrophobicity of polymeric insulators of high power transmission line is an important property because it is a good monitor of aging of polymeric outdoor insulator. An employee on the high-voltage transmission line makes this procedure during operation, which can lead to injuries and incorrect estimation of the insulator integrity. In this way, digital image processing is a promising and objective tool to analyze the polymer surface. In this study, two thousand pictures were taken from the wetted insulator surface and analyzed by artificial neural network assisted digital image processing. The neural network used is based on back-propagation method, and Haralicks descriptors were used to quantify the hydrophobic aspect of various polymeric aged surfaces.
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Ramirez-Vazquez, Isaias, Fermin Pascual Espino-Cortes i Carlos Gómez-Yáñez. "Direct Current Inclined Plane Testing on Silicone Rubber Composites Reinforced with Silica Nano Particles". Journal of Nano Research 71 (25.01.2022): 135–49. http://dx.doi.org/10.4028/www.scientific.net/jnanor.71.135.
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Polymer insulators traditionally used in HVAC (High Voltage Alternating Current) are used in HVDC (High Voltage Direct Current) transmission lines. For these polymer insulators, silicone insulating rubber, based on Polydimethylsiloxane (PDMS), is used in industry to manufacture high voltage insulators for power lines. Silicone rubber material ages due to pollution and environmental factors such as UV (ultraviolet light), rain, and temperature. Moreover, no international standard is available to standardize its functional characteristics to ensure its best performance in HVDC regime. Standards usually define the testing procedures to measure the resistance of the materials to these conditions. One of the tests used to evaluate the performance in AC (alternating current) of the housing material of polymeric insulators is the inclined plane test (IPT). This test has the purpose of assessing the tracking and erosion resistance of housing materials. However, for the IPT, no consensus is reached yet for this testing in Direct Current (DC) voltage. In addition, there are no indications whether the formulations that have been successfully used for HVAC work fine; also, in HVDC regime, or not. In this paper, an investigation of the tracking and erosion resistance under positive DC IPT is presented. In this way, the study was carried out on skirts of an HVAC commercial insulator and samples of a new outstanding composite silicone rubber formulation filled with micro and nano particles. The results show that HVAC silicone rubber formulations could not be suitable for HVDC applications under highly polluted conditions. In the case of the new enhanced composite, it is shown how nano particles used in this material significantly enhance the performance during DC tracking and erosion testing well above other materials tested in previous works. Also, thermogravimetric analysis (TGA) of the composites is used to correlate thermal stability with the DC IPT performance.
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Liu, Yu-Rui, i Yan-Fei Xu. "Research progress of polymers with high thermal conductivity". Acta Physica Sinica 71, nr 2 (2022): 023601. http://dx.doi.org/10.7498/aps.71.20211876.
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<sec>Developing thermally conductive polymers is of fundamental interest and technological importance. Common polymers have low thermal conductivities on the order of 0.1 W·m<sup>–1</sup>·K<sup>–1</sup> and thus are regarded as thermal insulators. Compared with the traditional heat conductors (metals and ceramics), polymers have unparalleled combined properties such as light weight, corrosion resistance, electrical insulation and low cost. Turning polymer insulators into heat conductors will provide new opportunities for future thermal management applications. Polymers may replace many metals and ceramics, serving as lightweight heat dissipators in electronics, refrigerators, and electrical vehicles.</sec><sec>In this review and perspectives, we discuss the research progress of thermal transport mechanisms in polymers and reveal the relations between thermal conductivity and polymer structural parameters such as bond strength, crystallinity, crystallite size, chain orientation, radius of gyration, and molecular weight. We discuss the advanced strategies for developing thermally conductive polymers by both bottom-up and top-down approaches. We highlight how thermally conductive polymers provide new opportunities for thermal management applications. Finally, we emphasize the future challenges to and opportunities for designing and synthesizing polymers with metal-like thermal conductivity and exploring the thermal transport physics in polymers. We believe that the thermally conductive polymers with their unparalleled combination of characteristics (light weight, electrical insulation, easy processability, corrosion resistance, etc.) promise to possess many existing and unforeseen thermal management applications.</sec>
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Din, A., M. A. M. Piah, A. R. Abdullah, N. Norddin i F. S. Abdullah. "Leakage current signal parameter of various surface roughness conditions of field-aged polymer insulators". Indonesian Journal of Electrical Engineering and Computer Science 20, nr 2 (1.11.2020): 638. http://dx.doi.org/10.11591/ijeecs.v20.i2.pp638-645.
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This paper presents the signal parameter of leakage current based on various surface roughness degradation conditions for field-aged high voltage polymer insulators. The arithmetical mean of surface roughness is measured accordingly, and also the surface leakage current signal is captured effectively using data acquisition device via the electrical stress test. With the variation of field-aged insulators ages which include 6-year, 12-year and 18-year, they have been mechanically tested using a surface roughness tester along with electrical testing by using the standard method of inclined plane test. The surface roughness data are recorded meanwhile the leakage current signals are further analyzed using Spectrogram to extract the signal parameter. These include the instantaneous root mean squared current, the instantaneous total harmonic distortion, the instantaneous total non- harmonic distortion and the instantaneous total waveform distortion. From the results of the comparative study, it has shown that the statistical quantity of leakage current signal parameters is responding in an increasing trend with respect to the incremental of the surface roughness. Thus, the signal parameters of the leakage current are able to indicate the degradation conditions of insulator surface.
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Ahmed, Rizwan, Rahisham Abd Rahman, Arshad Jamal, Ali Ahmed Salem, Bander Saman, Kwan Yiew Lau i Sherif S. M. Ghoneim. "Field-Dependent Pollution Model under Polluted Environments for Outdoor Polymeric Insulators". Polymers 14, nr 3 (27.01.2022): 516. http://dx.doi.org/10.3390/polym14030516.
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In-depth understanding of the pollution problems such as dry bands and the polymeric aging process requires better determination of electric field strength and its distribution over the polymeric surface. To determine the electric field distribution over the insulator surface, this research proposes utilizing a novel approach model based on nonlinear electrical characteristics derived from experimental results for polluted polymer insulators. A case study was carried out for a typical 11 kV polymeric insulator to underline the merits of this new modeling approach. The developments of the proposed pollution model and the subsequent computational works are described in detail. The study is divided into two main stages; laboratory measurements and computer simulations. In the first stage, layer conductance tests were carried out to develop nonlinear field-dependent conductivity for the pollution modeling. In the second part, equipotential and electric field distributions along the leakage were computed using the finite element method (FEM). Comparative field studies showed that the simulation using the proposed dynamic pollution model results in more detailed and realistic field profiles around insulators. This may be useful to predict the formation of dry bands and the initiation of electrical discharges on the polymeric surface.
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Nagase, Takashi, Takeshi Hirose, Takashi Kobayashi, Rieko Ueda, Akira Otomo i Hiroyoshi Naito. "Influence of Substrate Modification with Dipole Monolayers on the Electrical Characteristics of Short-Channel Polymer Field-Effect Transistors". Applied Sciences 8, nr 8 (1.08.2018): 1274. http://dx.doi.org/10.3390/app8081274.
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This study investigates the influence of self-assembled monolayer treatment of gate insulators on the electrical characteristics of bottom-gate/bottom-contact organic field-effect transistors (OFETs) with short channel lengths of 5 μm to 30 nm. The treatment of 3-chloropropyltrichlorosilane (CPTS) with large dipoles produces a high built-in electric field perpendicular to the SiO2 gate insulator surface, which results in a threshold voltage shift and enhanced hole injection compared to the treatment of phenethyltrichlorosilane (PETS) with small dipoles. Pronounced parabolic drain current‒voltage (ID‒VD) characteristics due to a space-charge limited current are observed in short-channel OFETs based on poly(3-hexylthiophene) with CPTS-treated gate insulators. CPTS treatment on short-channel OFETs based on poly(9,9-dioctylfluorene-co-bithiophene) (F8T2) suppresses the nonlinear ID increase in the low VD region caused by the voltage drop at the Au/F8T2 contact. The influence of the increase in the net source-drain electric field associated with the reduced voltage drops on the channel-length dependence of the field-effect mobility of short-channel F8T2 FETs is also discussed.
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Nesenyuk, T. A. "TESTING OF PROTOTYPE SIGNALING DEVICES FOR INSULATOR CONTROL". World of Transport and Transportation 16, nr 3 (28.06.2018): 36–49. http://dx.doi.org/10.30932/1992-3252-2018-16-3-4.
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For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT The article introduces laboratory studies of RFID tags used for radio frequency identification and control of the dielectric state of linear polymer insulators LK-70, which are used in the overhead power lines, including the contact network. The effect of electrical discharges on RFID technology performance capability, the effect of climatic factors, the angular distance dependence and the speed of registration of RFID tags for signal reception by a terminal for data collection are measured, the breakdown current is determined. The results of tests that confirm the possibility of radio-frequency identification monitoring of the state of insulators are analyzed. Keywords: overhead power line, contact network, polymer insulators, RFID technology, tests, prototypes, built-in signaling device, RFID tags.
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Al-Shawabkeh, Ali F. "Optoelectronic investigation and spectroscopic characteristics of polyamide-66 polymer". e-Polymers 22, nr 1 (1.01.2022): 858–69. http://dx.doi.org/10.1515/epoly-2022-0078.
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Abstract A semi-crystalline designated nylon 66 polymer is a crucial, high-performance engineering material that is used in wide variety of industrial applications including sensors, electrical insulators, electronic devices, and automotive sector. Using modules based on density functional theory and finite-field approaches, this work explores the optoelectronic and spectroscopic characteristics of this polymer. Absorption, dielectric function, refractive index, and optical conductivity are the principle topics of this study. The effects indicated that nylon 66 is a first-rate insulator and the degree of crystallinity estimated is 46.44%. The simulated bandgap vs. the Tauc relation value is greater than 7.0 eV and has a proportional inaccuracy of 2.36%. Absorption coefficient value, however, suggests that while the refractive index and dielectric function remain stable, the optical conductivity is elevated. In order to determine the advantages appropriate for many applications, this research develops a strong basis and perception of the linear and nonlinear optical properties of nylon 66.
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Gunasekaran, Muthian. "Needed Research for Further Enhancing the Dielectric Properties of Polymer Concrete". Advanced Materials Research 687 (kwiecień 2013): 430–32. http://dx.doi.org/10.4028/www.scientific.net/amr.687.430.
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During the past four decades, starting with the pioneering R&D work at Westinghouse in the 1970s, considerable work has been done, especially in the USA, on the dielectric properties and long-term performance of specialized polymer concrete composites for applications in the electric power industry. Polymer concrete is now well-established as a viable technical alternative to standard electrical porcelain. Its energy efficiency, its low cost, its universal processability at ambient temperature, and its design versatility have now spawned a wide variety of successful applications world-wide. Post insulators up to and including 138 kV, pin insulators, integrally cast instrument and potential transformers, various kinds and sizes of bushings, surge arresters, bus ducts, third-rail insulators in transportation, etc, are just some of the products operating successfully in the field to-day.The full potential of polymer concrete as a dielectric material has not yet been reached. With some thoughtful and functionally directed research on the properties and processing of polymer concrete, it is felt that significant advances can be made in the capabilities of dielectric polymer concrete.These advances can revolutionize the design and operation of electric power systems in the 21st century when the demands of the environment and the constraints of cost of new Ultra High Voltage power systems will be important factors governing the choice of materials. This paper gives a brief over-view of the state-of-the-art of polymer concrete dielectrics and discusses some of the needed research to meet the new challenges facing the electric power industry.
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Kuroda, Shin-ichi, Hisaaki Tanaka i Yukihiro Shimoi. "Microscopic observation of efficient intergrain charge transport processes in organic transistors of semicrystalline poly(3-hexylthiophene)". Applied Physics Express 15, nr 4 (24.03.2022): 041004. http://dx.doi.org/10.35848/1882-0786/ac5d79.
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Abstract Carrier dynamics in polymer transistors were investigated microscopically using electron spin resonance (ESR) spectroscopy for poly(3-hexylthiophene), a typical semicrystalline conjugated polymer. Charge transport processes across crystalline grains, indispensable for enhancing macroscopic mobility, are highlighted. For this purpose, we used high-molecular-weight (∼500 000) polymers to connect the grains by tie chains. Motional narrowing effects in ESR spectra demonstrated that efficient intergrain charge transport takes place for transistors with self-assembled monolayer (SAM) treatment on SiO2 gate insulators. Meanwhile, transistors without SAMs showed un-narrowed signals, indicating that the surface treatment possibly controls molecular orientations of tie chains more favorable for intergrain charge transport.
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Aryal, Anil, Adelaide Bradicich, Ethan T. Iverson, Carolyn T. Long, Hsu-Cheng Chiang, Jaime C. Grunlan i Patrick J. Shamberger. "Thermal conductivity of multilayer polymer-nanocomposite thin films". Journal of Applied Physics 132, nr 19 (21.11.2022): 195104. http://dx.doi.org/10.1063/5.0102203.
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The development of electrical insulators that are thermally conducting is critical for thermal management applications in many advanced electronics and electrical devices. Here, we synthesized polymer nanocomposite (PNC) films composed of polymers [polyethylenimine, poly(vinylamine), poly(acrylic acid), and poly(ethylene oxide)] and dielectric fillers (montmorillonite clay and hexagonal boron nitride) by layer-by-layer technique. The cross-plane thermal conductivity [Formula: see text] of the film was measured by the 3ω method. The effect of various factors such as film growth, filler type, filler volume fraction, polymer chemical structures, and temperature on the thermal conductivity is reported. The [Formula: see text] of PNCs with thickness from 37 nm to 1.34 μm was found to be in the range of 0.11 to 0.21 ± 0.02 W m−1 K−1. The [Formula: see text] values were found to be lower than the constituent polymer matrix. The experimental result is compared with existing theoretical models of nanocomposite systems to get insight into heat transfer behavior in such layered films composed of dielectrics and polymers.
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Wanasinghe, Dimuthu, Farhad Aslani, Guowei Ma i Daryoush Habibi. "Review of Polymer Composites with Diverse Nanofillers for Electromagnetic Interference Shielding". Nanomaterials 10, nr 3 (17.03.2020): 541. http://dx.doi.org/10.3390/nano10030541.
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Polymer matrix composites have generated a great deal of attention in recent decades in various fields due to numerous advantages polymer offer. The advancement of technology has led to stringent requirements in shielding materials as more and more electronic devices are known to cause electromagnetic interference (EMI) in other devices. The drive to fabricate alternative materials is generated by the shortcomings of the existing metallic panels. While polymers are more economical, easy to fabricate, and corrosion resistant, they are known to be inherent electrical insulators. Since high electrical conductivity is a sought after property of EMI shielding materials, polymers with fillers to increase their electrical conductivity are commonly investigated for EMI shielding. Recently, composites with nanofillers also have attracted attention due to the superior properties they provide compared to their micro counterparts. In this review polymer composites with various types of fillers have been analysed to assess the EMI shielding properties generated by each. Apart from the properties, the manufacturing processes and morphological properties of composites have been analysed in this review to find the best polymer matrix composites for EMI shielding.
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YOSHIMURA, Noboru, i Seiji KUMAGAI. "Hydrophobicity and Multiple Aging Phenomena of Polymer Insulators". NIPPON GOMU KYOKAISHI 76, nr 4 (2003): 119–24. http://dx.doi.org/10.2324/gomu.76.119.
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Meunier, M., i N. Quirke. "Molecular modeling of electron trapping in polymer insulators". Journal of Chemical Physics 113, nr 1 (lipiec 2000): 369–76. http://dx.doi.org/10.1063/1.481802.
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Zaheer, Muhammad, Yichen Cai, Abu Bakar Waqas, Saadullah Farooq Abbasi, Guodong Zhu, Chunxiao Cong, Zhi-Jun Qiu i in. "Liquid‐Metal‐Induced Memristor Behavior in Polymer Insulators". physica status solidi (RRL) – Rapid Research Letters 14, nr 5 (12.03.2020): 2000050. http://dx.doi.org/10.1002/pssr.202000050.
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Zaheer, Muhammad, Yichen Cai, Abu Bakar Waqas, Saadullah Farooq Abbasi, Guodong Zhu, Chunxiao Cong, Zhi-Jun Qiu i in. "Liquid‐Metal‐Induced Memristor Behavior in Polymer Insulators". physica status solidi (RRL) – Rapid Research Letters 14, nr 5 (maj 2020): 2070023. http://dx.doi.org/10.1002/pssr.202070023.
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Ratner, Mark A., i D. F. Shriver. "Polymer Ionics". MRS Bulletin 14, nr 9 (wrzesień 1989): 39–51. http://dx.doi.org/10.1557/s0883769400061728.
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The preparation, utilization, and understanding of high polymers represents one of the great triumphs of chemistry and materials science in the 20th century. Synthetic polymers have traditionally been used as structural materials and electrical insulators. Biopolymers often exhibit interesting electrical response phenomena. A recent article in the MRS BULLETIN, for example, discussed piezoelectric properties of both synthetic and biopolymer systems. The newer, synthetic electroactive polymeric materials, however, represent one of the most exciting current areas of polymer materials science.Many synthetic ionic polymer materials are known; perhaps the first were the polyelectrolytes and crosslinked ion exchange materials. These are materials whose backbone contains charges of one sign, balanced by small counter ions of the opposite sign. Such polyelectrolytes have found very important applications in analytical chemistry, water purification, and chemical processing.Complexes, in which salts are dissolved in neutral polymer hosts, have until recently received less attention. The area of polymer/salt complexes became extremely active following the work of P.V. Wright, who first clearly showed that polyethylene oxide (PEO) is an excellent polymer host for a number of salts, and that the resulting solid polymer/salt complexes are electrical conductors. M. Armand broadened the investigation of electrical properties of polymer/salt complexes and pointed out that these materials might be useful in electrochemical devices, especially batteries.This article will discuss the formation, properties, behavior, and applications of polymer electrolytes and mixed conductors—that is, polymeric materials in which charge is transported either by ions or by ionic and electronic charge motion. Our concentration will be on solvent-free materials—materials in which no small molecule solvents are present. There is substantial interest, and substantial progress, in the area of solvent-swollen polymer electrolytes.
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Suri, K. R., A. Gupta, Y. Anand i S. Anand. "Porcelain versus Polymer Insulator- A Changing Era in Transmission Lines". International Journal of Advance Research and Innovation 3, nr 2 (2015): 76–82. http://dx.doi.org/10.51976/ijari.321518.
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For the past few years with an increase in the globalization, the environmental challenges and an increase in pollution levels have become a global phenomenon as well as matter of discussion. The power transmission lines passing through transverse areas within the country as well as worldwide are facing various problems related to environment and pollution. Such an exponential increase in the pollution levels lead to frequent faults in transmission lines which finally lands to permanent breakdown of transmission lines. These breakdowns sometimes may leads to collapse of grid and are also inconvenient to everyone besides interrupting the growth of nation as well as society breakdown. Over the years engineers and scientists have made efforts to meet such threats and to overcome situations rising form the failure of transmission lines the environmental challenges and an increase in pollution levels. The scientific community proposes a solution to resolve transmission failure by adopting polymer insulators instead of conventional porcelain insulators because the demand is on increase by virtue of its proven inactive use. In this article, an effort has been made to understand difference between the two and agency would decide the type of insulators to be deployed for ensuring long life of transmission line with respect to rate of rise of pollution in country.
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Abdihamzehkolaei, Alireza, Md Tanvir Ahad i Zahed Siddique. "Volume Resistivity of Viton Polymer under Thermal Aging". Polymers 13, nr 5 (3.03.2021): 773. http://dx.doi.org/10.3390/polym13050773.
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This study examines the influence of various electrical parameters on the volume resistivity of the Viton fluoroelastomer. The transient current, the temperature dependence of volume resistivity, the voltage dependence of resistivity, and the surface morphology of Viton insulators are investigated for new and aged specimens. An accelerated aging process has been employed in order to simulate the natural aging of insulators in service. A detailed comparison between the new and aged samples is presented. The transient effect, which is a challenge to the resistivity measurement of insulators, has been investigated. The first 60 s of the resistivity measurement test showed a significant influence from the transient effect and should be excluded from the data. The volume resistivity of both new and aged samples decreased when the temperature increased. However, the resistivity of the aged sample was lower than the new one at all tested temperatures. When the temperature increased from 35 to 190 °C, resistivity decreased from 4.77 × 1010 to 6.99 × 108 Ω-cm for the new sample and from 2.6 × 1010 to 6.68 × 108 Ω-cm for the aged sample under 500 V. Additionally, the results from this study showed that the volume resistivity is inversely proportional to the applied voltage. Finally, scanning electron microscope (SEM) micrographs/images allowed us to closely examine the surface morphology of new and aged Viton samples. The surface of aged samples has been recognized with higher surface roughness and more significant surface cracks leading to poor performance under high voltage applications.
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Kumosa, Maciej S. "Damage Mechanisms in Polymer Matrix Composites in Extreme Environments". Key Engineering Materials 324-325 (listopad 2006): 663–66. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.663.
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In this work, potential problems with the application of polymer matrix composites (PMC) in extreme environments [1] is discussed. Then, two specific examples of the applications of PMCs in high voltage [2-7] and high temperature [8-15] situations are evaluated. The first example deals with damage evolution in high voltage composite insulators [2-7] with PMC rods subjected to a combined action of extreme mechanical, electrical and environmental stresses. These insulators are widely used in transmission line and substation applications around the world. Subsequently, advanced high temperature graphite/polyimide composites [8-15] are evaluated for aerospace applications. The composite investigated in this project were used to manufacture and successfully test a Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket engine, which is one possible engine for a future single-stage-to-orbit vehicle [8].
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Zarifian, A., R. A. Izadi fard i A. Khalighi. "Experimental study on the behavior of thermally insulated RC beams strengthened with CFRP after their exposure to high temperatures compared to non- insulated ones". Canadian Journal of Civil Engineering 47, nr 7 (lipiec 2020): 875–83. http://dx.doi.org/10.1139/cjce-2019-0001.
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With regard to the expansion of the use of carbon fiber reinforced polymer (CFRP) in strengthening civil engineering structures due to its high positive points (like high tensile strength and low thickness) as well as its weaknesses in high temperatures especially in buildings and weak points of existing thermal insulators, the experiments mentioned in this article have been carried out to investigate the post-fire conditions of CFRP retrofitting systems using the externally bonded reinforcement technique which resulted from the need to use insulation for this type of reinforcement system to improve its heat performance, as well as the weak points of common insulations. In the first phase, 12 samples of reinforced concrete (RC) beams strengthened with externally bonded carbon fiber reinforced polymer (UD200) were heated at 400 °C, 500 °C, 600 °C, and 800 °C and loaded after cooling, then they were compared with the results of the second phase of the tests which have been explained completely, consisting of 11 RC beams strengthened with CFRP having exactly the same properties as those in the first phase. They were also thermally insulated with intumescent paint that had some advantages like low thickness (1.1 mm) and the speed and ease of implementation and restoration. These results have clearly shown that the new insulating layer not only can maintain the positive feature of common insulations, but also unlike other common insulators, does not add to the thickness of the specimens. Moreover, the application of the intumescent paint both increased the performance of the specimens at high temperatures and covered the weaknesses of CFRP reinforcement system against heat so that the CFRP sheets unlike the ones on the non-insulated specimens did not completely disappear at the highest temperature.
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Awsiuk, Kamil, Paweł Dąbczyński, Mateusz M. Marzec, Jakub Rysz, Ellen Moons i Andrzej Budkowski. "Electrically Switchable Film Structure of Conjugated Polymer Composites". Materials 15, nr 6 (17.03.2022): 2219. http://dx.doi.org/10.3390/ma15062219.
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Domains rich in different blend components phase-separate during deposition, creating a film morphology that determines the performance of active layers in organic electronics. However, morphological control either relies on additional fabrication steps or is limited to a small region where an external interaction is applied. Here, we show that different semiconductor-insulator polymer composites can be rapidly dip-coated with the film structure electrically switched between distinct morphologies during deposition guided by the meniscus formed between the stationary barrier and horizontally drawn solid substrate. Reversible and repeatable changes between the morphologies used in devices, e.g., lateral morphologies and stratified layers of semiconductors and insulators, or between phase-inverted droplet-like structures are manifested only for one polarity of the voltage applied across the meniscus as a rectangular pulse. This phenomenon points to a novel mechanism, related to voltage-induced doping and the doping-dependent solubility of the conjugated polymer, equivalent to an increased semiconductor content that controls the composite morphologies. This is effective only for the positively polarized substrate rather than the barrier, as the former entrains the nearby lower part of the coating solution that forms the final composite film. The mechanism, applied to the pristine semiconductor solution, results in an increased semiconductor deposition and 40-times higher film conductance.
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Kim, Jae-Kyoung, Jung-Min Kim, Tae-Sik Yoon, Hyun-Ho Lee, D. Jeon i Yong-Sang Kim. "Pentacene Thin Film Transistors with Various Polymer Gate Insulators". Journal of Electrical Engineering and Technology 4, nr 1 (1.03.2009): 118–22. http://dx.doi.org/10.5370/jeet.2009.4.1.118.
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Gataullin, A. M., V. L. Matukhin i NI Nizamov. "Nondestructive testing method of polymer 35 kV composite insulators". St. Petersburg State Polytechnical University Journal 219, nr 2 (czerwiec 2015): 119–25. http://dx.doi.org/10.5862/jest.219.13.
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Sandberg, Henrik G. O., Tomas G. Bäcklund, Ronald Österbacka, Maxim Shkunov, David Sparrowe, Iain McCulloch i Henrik Stubb. "Insulators and device geometry in polymer field effect transistors". Organic Electronics 6, nr 3 (czerwiec 2005): 142–46. http://dx.doi.org/10.1016/j.orgel.2005.04.001.
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Cherney, E. A. "Partial discharge. V. PD in polymer-type line insulators". IEEE Electrical Insulation Magazine 7, nr 2 (marzec 1991): 28–32. http://dx.doi.org/10.1109/57.75766.
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Bezerra, J. M. B., S. H. M. S. Rodrigues, B. R. F. Lopes, D. S. Lopes i V. A. L. Ferreira. "Evaluating failures of polymer insulators in Brazilian distribution networks". IEEE Electrical Insulation Magazine 35, nr 1 (styczeń 2019): 38–44. http://dx.doi.org/10.1109/mei.2019.8575685.
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