Статті в журналах: "Silicone rubber insulators"

1

Yang, Haitao, Zhensheng Wu, Weinan Dong, Junpeng Dang, and Hao Ren. "Analysis of the Influence of Silicone Rubber Aging on the Transmission Parameters of Terahertz Waves." Energies 14, no. 14 (July 14, 2021): 4238. http://dx.doi.org/10.3390/en14144238.

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In this study, a method for testing the aging of silicone rubber insulators using terahertz waves in the 0.17–0.22 THz frequency band is proposed, aiming at the problem of online non-destructive testing of the aging degree of composite insulators. The relationship between the aging degree of silicone rubber composite insulators and the relative dielectric constant was studied through first-principles calculations and molecular chain scission models. In addition, the electromagnetic model of the terahertz signal incident on the silicon rubber sheet was simulated and the relationship between the aging degree of the silicon rubber and the terahertz input return loss was obtained. Eleven insulator samples with different degrees of aging were selected. In these samples, the degree of aging was calibrated according to the degree of surface deterioration and the average partial discharge voltage. The terahertz return loss measurement experiment was performed after that. Finally, the results of experiment and calculation simulation were compared and the reliability of the relationship between the aging degree of the silicone rubber insulator and the terahertz input return loss was verified.

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2

Mavrikakis, N., K. Siderakis, E. Koudoumas, E. Drakakis, and E. Kymakis. "Laboratory Investigation of the Hydrophobicity Transfer Mechanism on Composite Insulators Aged in Coastal Service." Engineering, Technology & Applied Science Research 6, no. 5 (October 23, 2016): 1124–29. http://dx.doi.org/10.48084/etasr.614.

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Silicone rubber (SIR) insulators are known to maintain their surface hydrophobicity even under severe pollution conditions in contrast to the other composite insulator materials used at the last decades. This critical advantage of silicone rubber insulators has made them dominant in high voltage power systems despite the fact that there are other composite materials with better static hydrophobicity. In service conditions, priority is given to the dynamic performance of hydrophobicity due to the unpredictable environmental pollution conditions. This dynamic performance of silicone rubber insulators is also known as hydrophobicity transfer mechanism. In literature, the hydrophobicity transfer mechanism of silicone rubber is related to the reorientation of methyl-groups and the existence of low molecular weight components. However there are many parameters which can change the effectiveness of this mechanism. Some of them referred to the ageing effects on the material structure. Thus it is of great importance to investigate the hydrophobicity transfer mechanism of field aged composite insulators. For this reason a new experimental procedure is introduced based on Cigre TB 442. The results of field aged insulators are compared to that of a new SIR insulator revealing the superiority of silicone rubber even after 17 years of field ageing.

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3

Wang, Xiaoqing, Haonan Fan, Wenrong Li, Yuyang Zhang, Ruiqi Shang, Fanghui Yin, and Liming Wang. "Effect of Ultraviolet—A Radiation on Alicyclic Epoxy Resin and Silicone Rubber Used for Insulators." Polymers 14, no. 22 (November 12, 2022): 4889. http://dx.doi.org/10.3390/polym14224889.

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Compared with the high-temperature vulcanized silicone rubber (HTVSR) insulator, the alicyclic epoxy resin insulator has higher hardness and better bonding between the core and the sheath. This makes the latter very promising in the coastal area of Southern China. Outdoor insulators are often subjected to high intensity of ultraviolet (UV)-A radiation. The influence of UV-A radiation is significant for alicyclic epoxy resin insulators. To help address the concern, the surface of two kinds of samples, namely the alicyclic epoxy resin insulator and HTVSR insulator, with UV-A aging time was characterized by tests of scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The operation properties (mechanical properties, hydrophobicity) for outdoor insulators were also analyzed. It was found that the appearance color of the alicyclic epoxy resin has changed greatly, and there is a certain degree of fading. The mechanical properties of the alicyclic epoxy resin are maintained well and, the hydrophobicity decreases gradually. For silicone rubber, the appearance color change of silicone rubber is smaller, and the mechanical properties of silicone rubber decreased greatly. In addition, although the hydrophobicity of silicone rubber decreased gradually, it is still better than that of alicyclic epoxy resin. Both materials have broken chemical bonds, but the degree is relatively light, which meets the requirements of insulators for outdoor operation.

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4

Li, B., H. Huang, L. Fan, G. X. Pan, Z. Tan, F. Li, X. W. Xie, and Z. J. Zhang. "Analysis of aging status of silicone rubber insulation material and research progress of its repair countermeasures." Journal of Physics: Conference Series 2045, no. 1 (October 1, 2021): 012016. http://dx.doi.org/10.1088/1742-6596/2045/1/012016.

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Abstract Due to its good hydrophobicity and hydrophobicity migration, silicone rubber can be used as umbrella sheath of insulators. With the continuous deterioration of environmental conditions, silicone rubber insulators in the process of power grid operation are vulnerable to a variety of environmental factors, such as humidity, partial discharge, ultraviolet radiation, icing and so on, which lead to a significant decline in hydrophobicity, mechanical properties and electrical properties, and bring serious threats to the safe operation of power grid. At present, the anti-pollution flashover mode of power grid power transmission and transformation equipment, which takes cleaning as the main method, can-not adapt to the current power grid operation environment and the impact of harsh environment, resulting in frequent power grid safety accidents. This paper summarizes the influencing factors, aging mechanism and evaluation methods of aging degree of silicone rubber insulators at present, and how to repair aging insulators and improve their anti-pollution flashover performance. Finally, the effective repair of aging silicone rubber insulator is summarized and prospected, the aging factors of insulator in specific environment are analysed, and corresponding countermeasures are taken to repair, which lays a good theoretical foundation for the future research of silicone rubber insulation materials.

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5

Liang, Pei Song, Ying Liang, and Yun Peng Liu. "Study of the Mechanical Properties of Ceramics Modified Composite Insulator Materials." Applied Mechanics and Materials 668-669 (October 2014): 70–73. http://dx.doi.org/10.4028/www.scientific.net/amm.668-669.70.

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A large number of ceramic insulators that are widely used in the power systems are returning shipment every year but there is no better processing method. Silicone rubber insulators have highly required the additive of the formulation. So this article combining the advantages of ceramic insulators and chemical composition, studies the mechanical properties of ceramics modified composite insulator materials. The measurements include the tensile strength, tear strength, hardness, SEM and Fourier transform infrared spectroscopy test of the new silicone rubber. The effects of adding different proportions of ceramic powder on the mechanical properties of silicone rubber are compared. And from the microscopic analysis the mechanism of the improved properties of the modified silicone rubber is analyzed. The results showed that a proportion of the ceramic part can replace aluminum hydroxide powder and the fumed silica powder can significantly improve the mechanical properties of the silicone rubber.

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6

Jiang, Yuze, Yong Zhang, Diwen Jiang, Chao Wang, and Yimin Chen. "Resource utilization of composite insulator silicone rubber." E3S Web of Conferences 194 (2020): 05066. http://dx.doi.org/10.1051/e3sconf/202019405066.

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Composite insulators provide highly effective insulation support, and their application in power transmission lines has seen rapid growth in recent years. However, every year, a large quantity of composite insulators are scrapped on reaching the end of their service life. Due to the exceptional chemical inertness of the silicone rubber in the insulators, they have poor self-degradation characteristics, and end up filling landfills and occupying a lot of space, which inadvertently endangers the ecological environment. So far, there has not been any effective means to recycle composite insulators. This paper analyzes the material composition and characteristics of the silicone rubber in the core and housing of composite insulators, and proposes a resource utilization approach for the application of the pulverized silicone rubber powder from the insulators in the following three applications: use in producing silicone rubber asphalt at a blending ratio of 15%–18%—the corresponding market demand is large enough to meet the disposal needs of scrapped composite insulators; use in modification of waste rubber powder and blending with ethylene propylene diene monomer rubber (EPDM) at a blending ratio of 10%—as the annual production capacity of EPDM is more than 850,000 tons in China, thousands of tons of waste insulators can be thus disposed; and use as an aggregate for non-slip coatings, which accounts for more than 40% of the coatings material. Thus, there is tremendous scope for recycling waste insulator.

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7

Liu, Song Tao, Yong Chao Liu, Li Na Zhu, Hong Wei Cao, and Chuan Min Chen. "Analysis on Aging Characteristics of Composite Insulators." Applied Mechanics and Materials 768 (June 2015): 406–11. http://dx.doi.org/10.4028/www.scientific.net/amm.768.406.

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Composite insulator was widely used in the power grid because its excellent performance. Aging issue of composite insulators was appeared with the long-term operating. The internal structure of silicone rubber may be changed with the broken of macromolecular chains of silicone rubber, because long-term operating in the environments of surface discharge, ultraviolet, pollution and other harsh conditions. In order to study the aging characteristics of composite insulator at the different operating life, the components and thermal stability were analyzed using fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis (TGA) respectively. The results of FTIR showed that silicon rubber composition in composite insulator changed slightly with different operating life, especially in the internal surface. However, the absorption peaks of Si-CH3 and Si-O-Si on external surface of the insulator were decreased obviously with operating life longer. The thermal gravimetric analysis results showed that the thermostability of composite insulator was almost not changed with different operating life. The temperature of 5% weightlessness was between 320°C to 335°C. It illustrated that the composite insulator had a good thermostability at room temperature and qualitative change wouldn't occur for a long time laying aside. The study of the aging characteristics of composite insulators will provided the reference for performance evaluation of running composite insulators.

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8

Zhou, Chao, Ran Jia, Jiafeng Qin, Hui Liu, Na Li, and Hao Shen. "Study on aging index of mechanical and electrical properties of high temperature vulcanized silicone rubber." IOP Conference Series: Earth and Environmental Science 983, no. 1 (February 1, 2022): 012023. http://dx.doi.org/10.1088/1755-1315/983/1/012023.

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Abstract Composite insulators are affected by various factors in operation. With the increase of operation time, the shed of silicone rubber composite insulators will become hard and brittle. In this paper, it is found that the hardness of long-term silicone rubber shed meets the standard requirements. The tear strength, tensile strength, elongation at break, resistance to electric tracking and corrosion loss decrease significantly after 5-10 years of operation. The decline of silicone content on the micro surface and the escape of inorganic fillers are the reasons for the deterioration of macro performance. Finally, the evaluation system for aging performance of insulators is preliminarily established, according to the aging degree of insulator, operation and maintenance suggestions are proposed.

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9

Zhang, Zhijin, Jianjie Zhao, Xiaodong Wan, Xingliang Jiang, and Jianlin Hu. "Mechanical Properties of High Temperature Vulcanized Silicone Rubber Aged in the Natural Environment." Polymers 14, no. 20 (October 20, 2022): 4439. http://dx.doi.org/10.3390/polym14204439.

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Composite insulators operate in harsh field environments all year round. Their various properties and states of aging require attention. It is important to study the performance changes of composite insulator sheds after aging to evaluate the life of insulators operating on grids. For this reason, 22 composite insulator sheds from different factories, with different voltage levels and different ages years were selected to conduct mechanical properties testing. The mechanical properties include hardness, tensile strength, and elongation at break, and were investigated by thermogravimetric (TGA) testing, surface morphology, and nuclear magnetic resonance (NMR) characterization. The changes in mechanical properties of high temperature vulcanization (HTV) composite insulator silicone rubber aged in the natural environment were analyzed, including the reasons for these changes. The results showed that the transverse relaxation time T2 of the sample was closely related to its aging state. The more serious the silicone rubber’s aging, the smaller was the T2. The state of the composite insulator can be evaluated by using T2 and aging years simultaneously. With the actual degree of aging in the silicone rubber intensified, its tensile strength and elongation at break generally showed a downward trend.

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10

Xie, Pengkang, and Kai Ning. "Study on the aging characteristics of silicone rubber materials for composite insulators." E3S Web of Conferences 242 (2021): 02002. http://dx.doi.org/10.1051/e3sconf/202124202002.

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The electron beam radiation method is emitted by electronic accelerators, which can change the chemical physical properties of radiation. Silicone rubber samples after different irradiation intesities were carried out for the 1000h aging test, and the electronic scanning microscopy (SEM), mechanical tensile and hydrophhy angle of the silicone rubber sample were measured, the test results shows that: after 1000h aging test, the visual apperence of the sample did not changed, the SEM showed that the surface of the silicone rubber became rough and the porosity increased, and the mechanic tension decrease. For moderate Irradiation intensity(60KGy), the aging characteristics of silicon rubber can be improved.

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11

Wang, Sihua, Junjun Wang, Chen Long, and Zhao Lei. "Influence of Corona Discharge on CaSO4 Solubility of Silicone Rubber Insulator Surface." Electrotehnica, Electronica, Automatica 69, no. 1 (February 15, 2021): 74–79. http://dx.doi.org/10.46904/eea.21.69.1.1108010.

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Some studies have shown that the operating state of silicone rubber insulators is not only affected by surface corona discharge, but also different due to the surface covered with different pollutants, but few studies have linked the two. In this paper, by designing the corona discharge test of silicone rubber insulator, the output of nitric acid from its surface product was calculated, and the concentration of nitric acid under different air humidity was obtained. The solubility test of slightly dissolved salt calcium sulfate in nitric acid solution at 293.15K and 333.15K was designed to obtain the solubility of calcium sulfate at different concentrations of nitric acid at two temperatures. Finally, a quantitative analysis of the solubility of calcium sulfate on the surface of insulator FXBW-10/70 in nitric acid solution shows that the surface contamination of insulator with good hydrophobicity may be completely dissolved by nitric acid solution, but the surface of insulator with loss of hydrophobicity cannot be completely dissolved by nitric acid. This study provides a theoretical basis for the dissolution characteristics of silicon rubber insulator corona discharge on its surface soluble salt composition and provides a new idea for the influence of insulator corona discharge on its electrical properties.

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12

Zhang, Zhijin, Guohui Pang, Ming Lu, Chao Gao, and Xingliang Jiang. "Research on Silicone Rubber Sheds of Decay-Like Fractured Composite Insulators Based on Hardness, Hydrophobicity, NMR, and FTIR." Polymers 14, no. 16 (August 22, 2022): 3424. http://dx.doi.org/10.3390/polym14163424.

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The safety and stability of power systems are seriously threatened by the decay-like fracture of composite insulators. This paper analyzes the aging characteristics (physical properties, NMR, and FTIR) of the silicone rubber sheds of the decay-like fractured insulator. The same V-string insulator and a new insulator are used for comparison. The study shows that the sheds’ degradation is concentrated on the side with heavy pollution. The physical properties (appearance, pollution, hardness, and hydrophobicity) of the high voltage end decrease significantly compared to other positions, but there is no direct connection between the physical properties of sheds and the decay-like fracture of the core rod. The severity of aging increases with a decrease in the equivalent transverse relaxation time T2. The main chain of the PDMS material was severely damaged at the location of the insulator fracture. NMR and FTIR can well judge the aging degree of silicone rubber housings. However, no definite characteristic quantity can characterize the decay-like fracture. It is challenging to evaluate the decay-like fracture of the silicone rubber shed only by its aging degree.

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13

Popescu, Daniel, and Corina Cernăianu. "The Influence of Alloy Elements on the Mechanical Features of Nanostructured Composite Materials with Recovered Silicone Rubber Matrices." Applied Mechanics and Materials 880 (March 2018): 262–66. http://dx.doi.org/10.4028/www.scientific.net/amm.880.262.

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The following paper indicates variants of new materials obtained with various organic alloy elements. Our research has used recoverable silicone rubber, obtained from used scrapped silicone rubber, used for the tyre of 24 kV composite electrical insulators as a basic matrix, under the form of silicone powder, liquid silicone rubber to various proportions, along with nanopowders obtained through recycling

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14

Zhang, Zhijin, Tian Liang, Zhenglong Jiang, Xingliang Jiang, Jianlin Hu, and Guohui Pang. "Application of Infrared Spectroscopy in Research on Aging of Silicone Rubber in Harsh Environment." Polymers 14, no. 21 (November 4, 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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15

Ramirez-Vazquez, Isaias, Fermin Pascual Espino-Cortes, and Carlos Gómez-Yáñez. "Direct Current Inclined Plane Testing on Silicone Rubber Composites Reinforced with Silica Nano Particles." Journal of Nano Research 71 (January 25, 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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16

Gao, Zi Wei, Xue Cheng Zhu, Sheng Jie Yang, and Hong Yan Nie. "The FTIR Analysis of Field Aged Composite Insulators." Advanced Materials Research 1008-1009 (August 2014): 620–23. http://dx.doi.org/10.4028/www.scientific.net/amr.1008-1009.620.

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With the increasing of the amount of composite insulators in power network, the transmission accidents caused by the fault of composite insulators are increased and the aging of composite insulators should be paying more attention. In the paper, fourier transform infrared spectroscopy (FTIR) is used to analysis the molecular structure of silicone rubber material of composite insulators. The results indicated that the higher the electric field of the insulator shed, the lower the peak of FTIR spectra. The heavier pollution the sample run, the lower the peak of FTIR spectra. So more attention should be pay to the samples which run in heavier pollution region or the high field part of the insulator.

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17

Tudose, I. V., M. Suchea, K. Siderakis, E. Thalassinakis, and E. Koudoumas. "Comparative study on field collected samples of aged silicon rubber composite coatings for high voltage insulators." Acta Chemica Iasi 21, no. 2 (December 1, 2013): 93–106. http://dx.doi.org/10.2478/achi-2013-0009.

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Abstract : Pollution of high voltage (HV) insulators is a phenomenon with a considerable impact to the performance of transmission and distribution electrical networks. The use of composite materials and especially Silicone Rubber proved to be an efficient improvement, capable of suppressing the problem and diminishing the flashover probability. As a result ceramic insulators in transmission lines are replaced by insulators with composite housing, either HTV Silicone Rubber or LSR. In the case of HV substations however, the replacement of insulators is rather difficult, due to the complexity of the equipment and the corresponding financial cost. In this case the application of RTV Silicone Rubber is an equivalent alternative. The ceramic insulators are covered with a 0.5 mm RTV SIR coating which provides the advantages of composite insulators on a ceramic substrate. After installation the possible material lifetime, which is determined by the service conditions and the material formulation, is of primary concern. In Crete, a large scale application exists and coatings that exceed a service period of 10 years are still in operation. The present study focuses on the structural and morphological characterization of field collected composite insulators of various ages so that the degradation degree can be correlated with their service.

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18

Zeng, Zhou, Pan Guo, Ruoshuang Zhang, Zhirui Zhao, Jiankang Bao, Qian Wang, and Zheng Xu. "Review of Aging Evaluation Methods for Silicone Rubber Composite Insulators." Polymers 15, no. 5 (February 24, 2023): 1141. http://dx.doi.org/10.3390/polym15051141.

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Silicone rubber insulation material is widely used for the external insulation of power systems. During the continuous service of a power grid, it will be seriously aged due to the influence of high voltage electric fields and harsh climate environments, which will reduce its insulation performance and service life and cause transmission line failure. How to evaluate the aging performance of silicone rubber insulation materials scientifically and accurately is a hot and difficult issue in the industry. Starting from the composite insulator, which is the most widely used insulating device of silicone rubber insulation materials, this paper expounds the aging mechanism of silicone rubber materials, analyzes the applicability and effectiveness of various existing aging tests and evaluation methods, especially discusses the magnetic resonance detection methods emerging in recent years, and finally summarizes the characterization and evaluation technology of the aging state of silicone rubber insulation materials.

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19

Satheesh, G., B. Basavaraja, and P. M. Nirgude. "Electric Field Simulation Around Contaminated SIR Insulators Using MATLAB." Engineering, Technology & Applied Science Research 8, no. 1 (February 20, 2018): 2542–45. http://dx.doi.org/10.48084/etasr.1742.

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High voltage insulators are mainly used to support transmission lines. This paper focuses on simulating the electric field along the surface of contaminated Silicone Rubber (SIR) insulators. The electric field (EF) distribution is important to determine the EF stress occurring on the insulator surface. So, the EF distribution is analyzed using a FEM tool in MATLAB under various conditions. Two types of insulators, straight and alternate sheds, were considered. Results showed that higher EF stresses occurs on the trunk portions of both straight shed and alternate shed types. Also, the results showed higher EF magnitude on the straight shed compared to the alternate shed, under both clean and contamination conditions.

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Zhang, Zhijin, Zhiqin Zhang, Song Yue, Xingliang Jiang, and Jianlin Hu. "Performance Characteristics of Silicone Rubber for Use in Acidic Environments." Polymers 15, no. 17 (August 30, 2023): 3598. http://dx.doi.org/10.3390/polym15173598.

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Silicone rubber insulators are widely used in power grids because of their excellent performance, but aging has been an inevitable problem of silicone rubber, especially in extreme conditions, such as acidic conditions. In order to clarify the performance changes in silicone rubber in an acidic environment, this paper uses the developed acid-resistant silicone rubber sheet and common silicone rubber samples as the research objects, and conducts an aging comparison test on them in a natural acidic environment. The electrical properties, physical properties, and chemical properties of the two types of silicone rubber specimens with different aging times are analyzed to obtain the performance characteristics of silicone rubber under a natural acidic environment. The research results show that the dry flash voltage and pollution flashover voltage of the acid-resistant silicone rubber after one year of aging are greater than those of the common type; the water repellency of both types of silicone rubber remains in good condition. The silicone rubber produced by our team according to the self-developed acid-resistant silicone rubber formula has indeed played a role in delaying aging in an acidic environment compared with the common-type silicone rubber.

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21

Hai, Jing, Jin Xin Yang, Jiang Cheng, and Zhuo Ru Yang. "Preparation and Performance of RTV Coating for Anti-Pollution Flashover with Superhydrophobicity by Filling CaCO₃/SiO₂ Composite Particles into Silicone Rubber." Advanced Materials Research 328-330 (September 2011): 1263–67. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1263.

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Room temperature vulcanizing (RTV) silicone rubber coating with superhydrophobicity for anti-pollution flashover is prepared by filling silica-encapsulated calcium carbonate particles (CaCO3/SiO2 composite particles) into polydimethylsiloxane (PDMS) rubber. Two-step spraying technology is applied for fabricating the superhydrophobic RTV coating film on outdoor insulators. The primary spray coating provides basically the strong adhesion and certain hydrophobicity, and the second one produces the appropriate roughness structure and further enhances the superhydrophobicity. The water contact angle on the prepared RTV coating film is 165°and the sliding (rolling) angle of water droplet is about 5°, allowing water droplets to move easily on the coating surface and give self-cleaning function of the RTV coated insulator surface. The flashover voltage of insulators with superhydrophobic RTV coating is 29.95 kV, quite higher than that of insulators with common RTV coating (23.29) and that without RTV coating (11.34 kV).

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Nan, Jing, Hua Li, Xiaodong Wan, Feng Huo, and Fuchang Lin. "Pollution Flashover Characteristics of Composite Crossarm Insulator with a Large Diameter." Energies 14, no. 20 (October 11, 2021): 6491. http://dx.doi.org/10.3390/en14206491.

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The composite crossarm insulator differs greatly from the suspension insulator in structure and arrangement. This study aims to determine the pollution flashover characteristics of composite crossarm insulators under different voltage grades. Four types of AC composite crossarm insulators with diameters ranging from 100 mm to 450 mm are subjected to artificial pollution test, and then the effects of the surface hydrophobicity state of silicone rubber, core diameter, umbrella structure, arrangement, and insulation distance on the pollution flashover voltage of the composite crossarm insulators are analyzed. Under the pollution grade 0.2/1.0 mg/cm2 and voltage grade from 66 kV to 1000 kV, if the silicone rubber surface changes from HC5 to HC6, the pollution flashover voltage of the composite crossarm insulator will increase by 13.5% to 21.0% compared with the hydrophilic surface. If the core diameter changes from 100 mm to 300 mm, the pollution flashover voltage gradient decreases with the increase in core diameter; if the core diameter changes from 300 mm to 450 mm, the pollution flashover voltage gradient increases with core diameter. Under the same insulation height and core diameter, the umbrella structure will have a certain impact on pollution flashover voltage by up to 1.7% to 5.4%. Under the horizontal arrangement, the pollution flashover voltage can increase by 10.5% to 12.1% compared with that under the vertical arrangement. Under the hydrophilic surface and weak hydrophobicity state, the pollution flashover voltage has a linear relationship with the insulation distance. The above results can provide a reference for the structural design and optimization of the composite crossarm insulator.

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23

Albano, M., P. Charalampidis, R. Waters, H. Griffiths, and A. Haddad. "Silicone rubber insulators for polluted environments part 2: textured insulators." IEEE Transactions on Dielectrics and Electrical Insulation 21, no. 2 (April 2014): 749–57. http://dx.doi.org/10.1109/tdei.2013.004016.

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Cherney, E. A., and R. S. Gorur. "RTV silicone rubber coatings for outdoor insulators." IEEE Transactions on Dielectrics and Electrical Insulation 6, no. 5 (December 1999): 605–11. http://dx.doi.org/10.1109/tdei.1999.9286764.

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25

Cherney, E. A., and R. S. Gorur. "RTV silicone rubber coatings for outdoor insulators." IEEE Transactions on Dielectrics and Electrical Insulation 6, no. 5 (1999): 605–11. http://dx.doi.org/10.1109/94.798117.

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26

Rao, Allu Shanmukha. "Experimental Study on Optimization of Filler Concentration of Silicon Rubber Compound Used in High Voltage Insulators." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (December 31, 2021): 327–46. http://dx.doi.org/10.22214/ijraset.2021.39282.

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Abstract: In any power transmission system, insulators are essential for a reliable electrical power supply. The Efficiency of insulators will be decided by their electrical and mechanical properties. Recently in many of the power transmission systems, the conventional porcelain insulators are being replaced by polymeric insulators due to various advantages in their properties. Polymeric insulators have been increasingly popular in recent years as a result of their superior performance in contaminated environments due to their hydrophobic nature. However, research is still being carried out on Polymeric material with regards to ageing condition and feasibility for large scale utilization. Ageing of insulation is due to Environmental, Tracking and Erosion conditions. Ageing leads to immature failures and uncertainty in the performance of the insulators. The constituent materials and their properties have a significant impact on the performance of polymeric insulators. There is a strong need to look into newer filler materials which can be added to the existing polymeric base materials to constitute a composite. Keeping this in mind, in the proposed research uses Silicone rubber as base polymeric material and along with that additives are added to arrive at three different composites. A new filler material will be added to the base material forming a new composite. All these HTV Silicone rubber based composites are then tested the recovery of hydrophobicity, dielectric strength, hardness, specific gravity, tensile strength , ultimate elongation ,tear strength properties based on ASTM standards. Further, Inclined plane Tracking and Erosion studies are also conducted on the polymeric test samples for 6 hours to evaluate the SiR housing material suitability for outdoor insulator applications by subjecting them to AC high voltages under laboratory conditions as per IEC 60587 standards. Keywords: Recovery of hydrophobicity, dielectric strength, hardness, specific gravity, tensile strength, ultimate elongation, tear strength, inclined plane tracking and erosion, ageing, filler material.

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27

Bezerra, Daniella Cibele, Ignat Pérez Almirall, Edson Guedes da Costa, Ana Cristina Figueiredo de Melo Costa, and Edcleide Maria Araújo. "Evaluation of the Hydrophobicity on Silicon Rubber Coating with Loads of Alumina Trihydrate and Nanosilica for Use in Electrical Insulation Coatings." Materials Science Forum 820 (June 2015): 405–10. http://dx.doi.org/10.4028/www.scientific.net/msf.820.405.

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This study aims to evaluate the hydrophobicity of vulcanized silicone rubber coatings at room temperature (RTV SR) with loads of alumina trihydrate (ATH) and nanosilica (NS) in the polymeric silicone rubber matrix, in order to obtain coatings ATH/NS/RTV SR to cover the surface of glass electrical insulators. The coatings were characterized by scanning electron microscopy (SEM), testing in salt spray chamber, loss test and recovery of hydrophobicity. These coatings showed varying sizes of agglomerates and heterogeneous distribution of particles within the matrix RTV SR. In the test in salt spray chamber smaller leakage current values was observed for the insulator coating with the ATH/NS loads. In the loss and recovery of the hydrophobicity test the best result was observed for insulating load RTV SR / 20: 1 (ATH: NS).

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28

Gao, Song, Yunpeng Liu, and Le Li. "A Comparative Study of Abnormal Heating Composite Insulators." Polymers 15, no. 13 (June 21, 2023): 2772. http://dx.doi.org/10.3390/polym15132772.

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The abnormal heating of composite insulators on transmission lines frequently occurs, seriously threatening the power grid’s safe and stable operation. For different types of abnormal heating composite insulators, undifferentiated replacement wastes a lot of labor and material resources. This study explores the abnormal heating composite insulators under different environmental humidity and wind speed conditions. The heating and discharge of composite insulators are observed, and the heating range, heating shape, and temperature rise (ΔT) are analyzed. The abnormal heating of the sheath-aging composite insulator is related to the aging of the silicone rubber and the environmental humidity. The partial discharge caused by the core rod’s defect is the primary source of the temperature rise in the decay-like insulator. The heating range of the contaminated insulator is connected to the environmental humidity, and the ΔT increases with the salt density. The ΔT and heating range of the three types of abnormal heating increase with the ambient humidity. The heating phenomenon under low humidity is an important characteristic that distinguishes decay-like and contaminated insulators from sheath-aging insulators. Therefore, the on-site infrared inspection should be carried out in sunny and windless weather to prevent the impact of high humidity and wind speed on infrared temperature measurement.

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29

Zhuang, Aoyun, Chao Li, Jianping Yu, and Yao Lu. "The Glaze Icing Performance of a Robust Superhydrophobic Film Composed of Epoxy Resin and Polydimethylsiloxane." Coatings 13, no. 7 (July 20, 2023): 1271. http://dx.doi.org/10.3390/coatings13071271.

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Ice accretion on transmission lines can cause operational difficulties and disastrous events. In this study, a micro/nano-structured epoxy resin/polydimethylsiloxane (EP/PDMS) film on glass, with water droplet contact angles (CA) observed as high as 160° and the water droplet sliding angle (SA) < 1° was fabricated by aerosol-assisted chemical vapor deposition (AACVD). The glaze icing performance of the superhydrophobic EP/PDMS films have been investigated by comparing the bare glass and room temperature vulcanized (RTV) silicon rubber-coated glass substrate representing the glass insulators and silicone rubber insulators, respectively. Compared with the bare glass and the RTV silicon rubber coating, the EP/PDMS superhydrophobic coating showed excellent performance in delaying glaze icing, especially in the early stages of icing. After 20 min of glaze icing with tilting angle of 90° at −5 and −10 °C, 38.9% and 85.7% of the RTV silicon rubber coating were covered, respectively, and less than 3% of the EP/PDMS coating was covered by ice when the blank glass sheet was completely covered. The EP/PDMS films also showed good mechanical robustness and long-term stability, which are important considerations in their widespread real-world adoption.

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30

Kamand, Fadi Z., Basharat Mehmood, Refat Ghunem, Mohammad K. Hassan, Ayman El-Hag, Leena Al-Sulaiti, and Ahmed Abdala. "Self-Healing Silicones for Outdoor High Voltage Insulation: Mechanism, Applications and Measurements." Energies 15, no. 5 (February 24, 2022): 1677. http://dx.doi.org/10.3390/en15051677.

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This paper discusses the state of the art in the application of self-healing silicone-based materials for outdoor high-voltage insulation. Both the dynamic behavior of the dimethyl side groups of silicone rubber and the diffusion of a bulk siloxane to maintain low surface energy are respectively reported as intrinsic mechanisms responsible for the self-healing of silicone rubber. Localization, temporality, mobility, and the type of synthesis are the aspects defining the efficiency of the self-healing ability of silicone rubber. In addition, the deterioration of the self-healing ability with filler loaded into silicone rubber insulation housing composites is discussed. Taking the self-healing property into consideration among the other properties of silicone rubber insulators, such as tracking and erosion resistance, can be a useful design practice at the material development stage. Hydrophobicity retention, recovery, and transfer measurements are discussed as useful indicators of the self-healing ability of silicone rubber. Nevertheless, there remains a need to standardize them as design tests at the material development stage. The paper is intended to shed the light on the hydrophobicity recovery, a key material design parameter in the development of silicone rubber outdoor insulating composites, similar to the tracking and erosion resistance.

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CHRZAN, Krystian. "Anomalous Leakage Currents on Silicone Rubber Hollow Insulators." PRZEGLĄD ELEKTROTECHNICZNY 1, no. 10 (October 1, 2020): 93–95. http://dx.doi.org/10.15199/48.2020.10.15.

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32

Kokalis, Christos-Christodoulos A., Vassiliki T. Kontargyri, and Ioannis F. Gonos. "A Proposal for the Evaluation of HTV Silicone Rubber Composite Insulators." Polymers 13, no. 21 (October 20, 2021): 3610. http://dx.doi.org/10.3390/polym13213610.

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This paper describes in detail a step-by-step methodology for obtaining specimens from the housing material (high temperature vulcanized (HTV) silicone rubber with aluminum trihydrate (ATH) filler) of composite insulators (finished products), for five well known and commonly used tests. The aim of the paper is to render practical clarifications and additions to the instructions for five tests on composite insulators provided by international standards. Additionally, the ranges of the results of these tests are presented. More specifically, shore A hardness measurement, tensile strength and elongation at break test, tear strength test, density measurement and inclined plane test were conducted on the housing material of ten, new, unaged medium voltage composite insulators made by six different manufacturers. The results of these tests are presented as a contribution to the existing knowledge and a comparative study of corresponding results of previous investigations is performed. The presented procedures for specimens’ preparation, as well as the results (arithmetical ranges), could be used as guidelines for future testing on the housing material (HTV silicone rubber with ATH filler) of composite insulators, either by researchers and manufacturers, during laboratory testing and material development processes, or by customers (distribution and transmission networks owners), during batch acceptance tests.

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33

A. Salem, Ali, R. Abd-Rahman, M. S. Kamarudin, H. Ahmed, N. A. M. Jamail, N. A. Othman, M. F. M. Yousof, M. T. Ishak, and S. Al-Ameri. "The effect of insulator geometrical profile on electric field distributions." Indonesian Journal of Electrical Engineering and Computer Science 14, no. 2 (May 1, 2019): 618. http://dx.doi.org/10.11591/ijeecs.v14.i2.pp618-627.

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<span>In recent years, silicone rubber (SIR) insulators are use widely on high voltage transmission lines, particularly in heavy polluted environment. The performance of SIR in highly dependent on electric field profile that may lead to other serious problem such as ageing and flashover phenomenon. In this paper, electric field and potential distribution around insulator profile were computed using finite element method approach. Insulator geometrical profile i.e. shed radius, inclination angle, width and length has been varied and analyzed. Simulation results reveal that electric field is greatest at area near to the ground and high voltage terminal. Several recommendations have been proposed on insulator profile in achieving optimized electrical performance of the insulator.</span>

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34

Abrukov, Viktor S., Konstantin V. Efimov, Nikolai A. Tarasov, and Nikolay I. Kol'tsov. "STUDY OF INFLUENCE OF STABILIZERS ON BURNING OF SILICONE RUBBER WITH HELP ARTIFICIAL NEURAL NETWORKS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 1 (December 21, 2017): 84. http://dx.doi.org/10.6060/tcct.20186101.5559.

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Silicone rubbers are used for manufacturing fireproof insulating sheaths for cables and high voltage insulators. Highly oil-resistant silicone rubber of brand IRP 1338 of JSC “Kazan plant of synthetic caoutchouc” production should be singled out among silicone rubbers. This rubber is made from synthetic caoutchouc SKTV and contains Aerosil A-300, titanium oxide, fumed silica U-333 curing agent Perkadox BC-FF and anti-structuring agent ND-8 - α,ω-polydimethyl-siloxanediol. Previously we investigated the kinetics of combustion process of this rubber containing anti-structuring agent ND-8 as well as Ca/Zn-stabilizer Kompanoks (2,6-bis((3,5-di-tert-butyl-4-hydroxyphenyl)methyl)cyclohexane-1-one) and their combination which are used to enhance the thermal stability of the rubbers on the basis of carbon-chain caoutchoucs. In given paper using artificial neural networks (ANN) the computational multifactor model of combustion of rubber IRP 1338 has been obtained. The influence of selected stabilizers on the combustion rate of silicone rubber IRP 1338 has been studied. The combustion process was investigated by measuring at different points in time the relative height of the unburned portion of the rubber samples in the form of standard rectangular bars with a size of 10x2x2 mm. Combustion occurred under the action of the infrared beam (wavelength 10.6 μm) of laser LG-25 at three temperatures radiation (800, 900, 1000°C). As the main factors influencing the combustion of rubber, the laser radiation temperature was chosen, under which the forced combustion of rubber occurred. The nature of the stabilizers introduced into the rubber and the combustion temperature of the rubber was measured by a thermocouple placed on the surface of combustion rubber. The objective function of ANN-model was the relative height of the unburned portion of the rubber samples. Moreover, it was believed, the greater the relative height of the unburned portion of the rubber samples, the lower the burning rate and the higher the efficiency of the stabilizer. The received ANN-model has allowed to reveal three stages of combustion of rubber and to investigate features of influence of stabilizers on process of combustion. It was established that from the three stabilizers studied, the Ca/Zn stabilizer most effectively slows down the combustion of rubber due to the interaction of calcium oleates and zinc of this stabilizer with caoutchouc molecules. Thus, the possibility of increasing the fire resistance of rubber based on the silicone rubber SKTV by replacing the anti-structuring agent ND-8 on the Ca/Zn stabilizer has been established.Forcitation:Abrukov V.S., Efimov K.V., Tarasov N.A., Koltsov N.I. Study of influence of stabilizers on burning of silicone rubber with help artificial neural networks. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 1. P. 84-88

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35

Komatsu, Kazuki, Hao Liu, Mitsuki Shimada, and Yukio Mizuno. "Assessment of Surface Degradation of Silicone Rubber Caused by Partial Discharge." Energies 12, no. 14 (July 18, 2019): 2756. http://dx.doi.org/10.3390/en12142756.

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This paper reports experimental and analytical results of partial discharge degradation of silicone rubber sheets in accordance with proposed procedures. Considering the actual usage condition of silicone rubber as an insulating material of polymer insulators, an experimental procedure is established to evaluate long-term surface erosion caused only by partial discharge. Silicone rubber is subjected to partial discharge for 8 h using an electrode system with air gap. Voltage application is stopped for subsequent 16 h for recovery of hydrophobicity. The 24 h cycle is repeated 50 or 100 times. Deterioration of sample surface is evaluated in terms of contact angle and surface roughness. It is confirmed the proposed experimental procedure has advantage of no arc discharge occurrence, good repeatability of results, and possible acceleration of erosion. Surface erosion of silicone rubber progresses gradually and finally breakdown of silicone rubber occurs. Alumina trihydrate (ATH), an additive to avoid tracking and erosion by discharge, is not necessarily effective to prevent breakdown caused by partial discharge when localized electric field in air is enhanced by adding ATH. In such a situation, lower permittivity and higher resistance of silicone rubber seem dominant factors to prevent partial discharge breakdown and a careful insulation design should be required.

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36

Abou-Kandil, Ahmed I., Loai Nasrat, and EmanL Fareed. "High temperature vulcanized ethylene propylene diene rubber nanocomposites as high voltage insulators: Dielectric breakdown measurements and evaluation." Polymers and Polymer Composites 30 (January 2022): 096739112211325. http://dx.doi.org/10.1177/09673911221132593.

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The use of porcelain and thermoplastic based materials as High voltage insulators has always been dominant in the industry. Several elastomers were also investigated, mainly Ethylene Propylene Rubber and Silicone rubbers were used as replacement of the traditional Porcelain high Voltage insulators. In this study we experiment with new elastomer, Ethylene propylene diene rubber (EPDM), that is capable of withstanding high voltage as well as being resistant to severe weathering conditions. In addition to having excellent mechanical properties that we discussed elsewhere. Detailed dielectric breakdown measurements were carried out for room temperature vulcanized and high temperature vulcanized samples. The effects of exposure to UV radiation on the dielectric breakdown strength was also studied. Different fillers were used to improve the dielectric breakdown strength of different polymer matrices. Both carbon black based fillers and inorganic fillers were experimented in order to reach optimum mix properties that provide the best dielectric breakdown strength. Resistance to thermal aging and UV radiation was also carried out on EPDM samples.

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37

Slama, Mohammed El Amine, Adnan Krzma, Maurizio Albano, and Abderrahmane Manu Haddad. "Experimental Study and Modeling of the Effect of ESDD/NSDD on AC Flashover of SiR Outdoor Insulators." Energies 15, no. 10 (May 20, 2022): 3782. http://dx.doi.org/10.3390/en15103782.

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Pollution flashover occurs when soluble and nonsoluble materials cover the surface of an insulator, and this may ultimately cause a reduction in its performance. In this paper, the common type of sodium chloride (NaCl) was used as a soluble pollutant (ESDD) and kaolin as a nonsoluble pollutant (NSDD). Samples of silicone rubber (SiR) insulators were selected for this study and fabricated at the Advanced High Voltage Engineering Research Centre (AHIVEC) at Cardiff University. The samples were preconditioned and polluted according to standard specifications. Additionally, the AC voltage ramp technique was used to achieve flashover (FOV) voltage with different pollution levels. The aim of this work was to investigate the effect of nonsoluble materials on flashover characteristics to understand their interaction with dry-band arcs by using FOV electrical equations and experimental data. The test results show that the FOV voltage of the silicone rubber insulator substantially decreased with the increase in both ESDD and NSDD values. It was also identified from these results that the dry-band arcs were considerably influenced by both ESDD and NSDD levels. This impact can be quantified by determining the variation of discharge parameters (N, n). Based on the FOV equations and experimental data, a mathematical model was suggested, taking into account the effect of both ESDD and NSDD.

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38

Venkatesulu, B., and M. J. Thomas. "Long-term accelerated weathering of outdoor silicone rubber insulators." IEEE Transactions on Dielectrics and Electrical Insulation 18, no. 2 (April 2011): 418–24. http://dx.doi.org/10.1109/tdei.2011.5739445.

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39

Kim, S. H., E. A. Cherney, and R. Hackam. "Hydrophobic behavior of insulators coated with RTV silicone rubber." IEEE Transactions on Electrical Insulation 27, no. 3 (June 1992): 610–22. http://dx.doi.org/10.1109/14.142726.

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40

Khaloo, Alireza, and Yaser Parvin darabad. "Investigation of Mechanical Properties of Concrete Containing Liquid Silicone Rubber Under Axial Loads." Shock and Vibration 2021 (February 8, 2021): 1–13. http://dx.doi.org/10.1155/2021/6637625.

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As the experts who have taken for granted the merits of utilizing the concrete as the most common material in the structural industry, there is a need to take affirmative steps to enhance the concrete’s weaknesses such as the low ductility and energy absorption capacity. One possible way to improve the mechanical properties of concrete is to add liquid silicone rubber to the concrete. Silicone rubber is an elastomer (rubber-like material) composed of liquid rubber polymer and its hardener which is widely used in voltage line insulators, automotive applications, and medical devices. In order to increase the ductility and energy absorption of concrete, the liquid silicone rubber replaced a portion of mineral aggregates in concrete. HSRC (hybrid silicone rubber concrete) is a mixture of liquid silicone rubber with fresh concrete that liquid silicone rubber after 24 hours becomes a flexible solid rubber with low strength. In this paper, liquid silicone rubber was used to replace 0%, 2%, 4%, 8%, 12.5%, 25%, and 50% of the total mineral aggregate’s volume in concrete. Standard specimens were fabricated and tested. The fresh HSRC exhibited acceptable workability and lower unit weight compared to ordinary plain concrete. The uniaxial compressive strain-control test was conducted on the hardened HSRC specimens to obtain the complete stress-strain curve. The results showed that, with the increase of liquid silicone rubber in concrete, the amount of compressive strength, splitting tensile stress, and elastic modulus decreased. It was also observed that the percentage of reduction in compressive strength was greater than the percentage of reduction in tensile strength. Increasing silicone rubber concentration in HSRC changes the brittle mode of failure to ductile that demonstrated using nonlinearity indices. Unlike plain concrete, the failure state in HSRC occurs gently and uniformly and does not cause so much separation in the specimens. Larger deformation and higher toughness indices were obtained, when the silicone rubber concentration was increased.

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41

Chen, Jigang, Kai Liu, Xiaoqing Zhang, Yujun Guo, Xueqin Zhang, and Guangning Wu. "Influence of AC corona discharge on the hydrophobicity of silicone rubber surface in high-speed airflow environment." AIP Advances 12, no. 10 (October 1, 2022): 105015. http://dx.doi.org/10.1063/5.0106452.

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Corona discharge is one of the key factors that lead to the hydrophobicity loss of silicone rubber insulators used on the roof of high-speed trains. Based on the artificial experimental wind-tunnel platform, influences of AC corona intensity and airflow velocity on the hydrophobicity distribution of the silicone rubber surface were studied. According to the corona discharge phenomena and measured discharge current, influences of airflow velocity and voltage on the characteristics of corona discharge in a high-speed airflow environment were discussed. Results reveal that the hydrophobicity distribution on the silicone rubber surface shifts along the airflow direction in the high-speed airflow environment when the voltage is relatively high. When ionization zone develops to the needle-plate gap, the discharge path is deflected to the direction of airflow, which is responsible for the change of the hydrophobicity distribution. It is notable that the deflection distance decreases with the increase of airflow velocity. This is attributed to the fact that the electrons with variable horizontal distance from the electron to the plate electrode center are subjected to different electric field forces, resulting in different influences of high-speed airflow on them. These results are of engineering and theoretical significance for insulators used in high-speed railways.

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42

Liang, Ying, Ting Gao, Xiangnian Wang, Mengting Sun, and Lijuan Gao. "Electric Field Intensity Effects on the Microstructural Characteristics Evolution of Methyl Vinyl Silicone Rubber via Molecular Simulation." Molecules 23, no. 8 (July 26, 2018): 1861. http://dx.doi.org/10.3390/molecules23081861.

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Анотація:

During ultra high voltage (UHV) transmission, the discharge caused by high intensity electric fields aggravates the aging process of external insulation materials used for composite insulators. The microstructural characteristics of its base material polymer—methyl vinyl silicone rubber—are the key basis for the performance of insulation materials under electric field exposure. Based on molecular dynamics simulations, a molecular model of methyl vinyl silicone rubber was established. Mechanisms influencing the microstructure evolution under electric fields had been studied at the atomic level. The results showed that the initial reaction characteristics of silicone rubber molecules involve the violent vibrated of all the methyl and vinyl atoms, and shortening of the chemical bonds. The neighboring groups were close to each other and generated different amounts of -Si-Si- bonds. This promoted the helical shrinkage of the molecule, and protrusion of the middle of the molecule which presented an inverted U shape. The high electric field greatly reduced the total energy of molecules, and the potential energy in particular was more severely destroyed, resulting in degradation of its structure. Besides, as the electric field intensity increased, the elastic modulus of the molecule gradually increased. It was shown that high electric fields would make the stiffness of silicone rubber become larger, and the brittleness to become stronger, which reduced the mechanical properties of materials, accelerating its aging. The results provide a theoretical basis for establishing the connection between the micro appearance and macro characteristics of materials, as well as reference values for the optimization of base materials used for making composite insulators.

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43

Shaik, Mohamed Ghouse, and Vijayarekha Karuppaiyan. "Investigation of Surface Degradation of Aged High Temperature Vulcanized (HTV) Silicone Rubber Insulators." Energies 12, no. 19 (October 3, 2019): 3769. http://dx.doi.org/10.3390/en12193769.

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Polymeric composite insulators are subjected to varying work conditions like rain and heat, which create an impact on degradation during their long service period. Electrical tracking under the Alternating Current (AC) field plays a predominant role in surface degradation, which can be different for fresh and aged insulations. The tracking studies on the fresh and aged polymeric insulation therefore become significant. Motivated by this, an indigenous low-cost electrical tracking setup was developed, and the tracking studies were carried out as per International Electro technical Commission standard (IEC) 60587 on fresh, thermal-aged and water-aged silicone rubber samples. Contact angles of samples were measured to analyse the effect of ageing on hydrophobicity. Further, to analyse the influence of ageing on insulation integrity, tracking tests were conducted and parameters like leakage current pattern and magnitudes, tracking length and loss of weight in the material due to tracking were examined. The physicochemical impacts of ageing on the surface degradation of the samples were also analysed using X-ray diffraction analysis and Fourier Transform Infrared Spectroscopy analysis. The investigations added insight into the degradation mechanism of polymeric insulators in terms of their electrical performance and physicochemical changes in the material. Comparison of these changes showed that ageing could influence surface degradation of samples.

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44

Ameer Ali, Anis Akilah Binti, Hafisoh Ahmad, Hoon Yap, and Hafizul Azizi Bin Ismail. "Investigation of Electrical Properties of TiO₂ Nanocomposite Based Polymer." Journal of Physics: Conference Series 2120, no. 1 (December 1, 2021): 012031. http://dx.doi.org/10.1088/1742-6596/2120/1/012031.

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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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45

Abd El-Khalek, Mohamed, Loai Saad Nasrat, Mahmoud Abd El-Hamed, and Soliman El-Debeiky. "Electrical Characteristics of Silicone Rubber as Insulation Materials." Advanced Materials Research 1119 (July 2015): 317–23. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.317.

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This paper presents the results of a study carried out to examine electrical characteristics of high voltage Silicone Rubber (SIR) insulators under weather pollution conditions. The specimens of SIR with and without Alumina tri-hydrate (ATH) filler have been chemically prepared. The AC (50 Hz) surface aging of SIR specimens have been evaluated under salt fog chamber. Furthermore, the relationship between the leakage current and time to failure for SIR specimens with various concentrations of ATH filler under different weather pollution conditions has been measured in this work.

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46

El-hag, Ayman, Shesha Jayaram, and Edward Cherney. "Effect of insulator profile on aging performance of silicone rubber insulators in salt-fog." IEEE Transactions on Dielectrics and Electrical Insulation 14, no. 2 (April 2007): 352–59. http://dx.doi.org/10.1109/tdei.2007.344615.

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47

Hussain, Chaudhary, and Razaq. "Mechanism of Saline Deposition and Surface Flashover on High-Voltage Insulators near Shoreline: Mathematical Models and Experimental Validations." Energies 12, no. 19 (September 26, 2019): 3685. http://dx.doi.org/10.3390/en12193685.

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This paper deals with sea salt transportation and deposition mechanisms and discusses the serious issue of degradation of outdoor insulators resulting from various environmental stresses and severe saline contaminant accumulation near the shoreline. The deterioration rate of outdoor insulators near the shoreline depends on the concentration of saline in the atmosphere, the influence of wind speed on the production of saline water droplets, moisture diffusion and saline penetration on the insulator surface. This paper consists of three parts: first a model of saline transportation and deposition, as well as saline penetration and moisture diffusion on outdoor insulators, is presented; second, dry-band initiation and formation modelling and characterization under various types of contamination distribution are proposed; finally, modelling of dry-band arcing validated by experimental investigation was carried out. The tests were performed on a rectangular surface of silicone rubber specimens (12 cm × 4 cm × 8 cm). The visualization of the dry-band formation and arcing was performed by an infrared camera. The experimental results show that the surface strength and arc length mainly depend upon the leakage distance and contamination distribution. Therefore, the model can be used to investigate insulator flashover near coastal areas and for mitigating saline flashover incidents.

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48

Linjie Zhao, Chengrong Li, Jun Xiong, Shuqi Zhang, Jisha Yao, and Xiujuan Chen. "Online Hydrophobicity Measurement for Silicone Rubber Insulators on Transmission Lines." IEEE Transactions on Power Delivery 24, no. 2 (April 2009): 806–13. http://dx.doi.org/10.1109/tpwrd.2008.2005654.

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49

Albano, M., R. T. Waters, P. Charalampidis, H. Griffiths, and A. Haddad. "Infrared analysis of dry-band flashover of silicone rubber insulators." IEEE Transactions on Dielectrics and Electrical Insulation 23, no. 1 (February 2016): 304–10. http://dx.doi.org/10.1109/tdei.2015.005026.

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50

Chakraborty, Rahul, and Subba Reddy B. "Performance of Silicone Rubber Insulators Under Thermal and Electrical Stress." IEEE Transactions on Industry Applications 53, no. 3 (May 2017): 2446–54. http://dx.doi.org/10.1109/tia.2017.2672667.

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