scholarly journals Characteristics of Silicone Composites for High Voltage Insulations

2018 ◽  
Vol 56 (1) ◽  
pp. 91-123 ◽  
Author(s):  
Hidayatullah Khan ◽  
Muhammad Amin ◽  
Ayaz Ahmad
Keyword(s):  
High Voltage ◽  
Silicone Rubber ◽  
Water Immersion ◽  
Research Work ◽  
Volume Resistivity ◽  
Dielectric Strength ◽  
Review Article ◽  
Base Polymer ◽  
Comprehensive Survey ◽  
Term Performance

AbstractSilicone rubber (SiR) composites have been widely used for high voltage (HV) electrical and non-electrical applications for the last three decades. To increase the long-term performance of SiR composites under diverse environmental, mechanical and electrical stresses; detailed characterization and aging analysis is required. This review article presents a comprehensive survey on SiR composites that are used in HV applications. Particular emphasis is on silicon (Si) applications, chemistry, polymerization, silicone rubber properties enhancement by addition of fillers, composite materials, engineering requirements of polymer insulants, overview of high voltage (HV) electrical insulators and their aging. In addition, this review article includes appropriate discussions concerning the influence of fillers (micro/nano-sized) on the physical, thermal, mechanical and electrical properties of base polymer. Tensile strength, elongation at break, hardness, thermal degradation, dielectric strength, surface resistivity, volume resistivity, tracking/erosion resistance, partial discharge and water immersion resistance of SiR composites are analyzed. Finally, it was inferred that in order to diversify the SiR blends with micro/nano fillers and optimize their properties for particular applications further research work must be conducted.

Effect of hybrid-SiO2 particles on characterization of EPDM and silicone rubber composites for outdoor high-voltage insulations

2017 ◽  
Vol 37 (7) ◽  
pp. 671-680 ◽  
Author(s):  
Hidayatullah Khan ◽  
Muhammad Amin ◽  
Muhammad Yasin ◽  
Muhammad Ali ◽  
Ayaz Ahmad
Keyword(s):  
High Voltage ◽  
Silicone Rubber ◽  
Hybrid Composites ◽  
Standard Procedure ◽  
Research Work ◽  
Dielectric Strength ◽  
Hybrid Silica ◽  
Roll Mill ◽  
Thermal And Electrical Properties

Abstract Ethylene propylene diene monomer (EPDM) and silicone rubber (SiR) are well-known polymers for high-voltage (HV) outdoor applications. In this research work, the effect of hybrid SiO2 (a mixture of 15% microsized and 5% nanosized silica) has been investigated on the mechanical, thermal, and electrical properties of EPDM and SiR composites. Using the ASTM standard procedure, the EPDM and SiR composites filled with hybrid silica were compounded by two roll mill and simple blending techniques, respectively. It was observed that with the addition of hybrid SiO2, the composites exhibited improved tensile strength of ~2500 kPa, reduced elongation at break, and enhanced hardness. The samples filled with SiR hybrid silica showed higher thermal stability and volume/surface resistivities relative to EPDM hybrid composites. However, EPDM hybrid composites showed higher dielectric strength of ~23.4 kV/mm as compared with SiR composites. From these characterization results, it can be suggested that SiR hybrid composites are more suitable for outdoor HV insulation applications.

Linear low-density polyethylene/silicone rubber nanocomposites

2017 ◽  
Vol 50 (1) ◽  
pp. 36-57 ◽  
Author(s):  
Nurul Hidayah ◽  
Mariatti Mustapha ◽  
Hanafi Ismail ◽  
Mohamad Kamarol
Keyword(s):  
Silicone Rubber ◽  
Performance Optimization ◽  
Small Variation ◽  
Volume Resistivity ◽  
Dielectric Strength ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Content Type ◽  
The Relationship

This study determines the applicability of nanofillers (silica, boron nitride, and zinc oxide) in linear low-density polyethylene (LLDPE)/silicone rubber (SR) insulation compounds. Design of experiment is adopted to model the relationship between the properties (permittivity, loss tangent, dielectric strength, and volume resistivity) and factors (SR content, type of nanofiller, and nanofiller loading) for performance optimization. It is observed that SR content and type of nanofiller significantly influence the electrical properties of LLDPE/SR nanocomposites. Nanofiller loading, however, causes a small variation in the properties of the nanocomposites except for dielectric strength. From the optimization, it is found that the optimum formulation composition is 10 wt% of SR and 2 vol% of nanoboron nitride.

scholarly journals Fabrication, mechanical, thermal, and electrical characterization of epoxy/silica composites for high-voltage insulation

2018 ◽  
Vol 25 (4) ◽  
pp. 753-759 ◽  
Author(s):  
Muhammad Amin ◽  
Muhammad Ali ◽  
Abraiz Khattak
Keyword(s):  
Electrical Properties ◽  
High Voltage ◽  
Electrical Characterization ◽  
Volume Resistivity ◽  
Dielectric Strength ◽  
Ceramic Materials ◽  
Neat Epoxy ◽  
Hardness Tests ◽  
High Voltage Insulation ◽  
Improved Performance

AbstractFor improved performance of epoxy, its composites were studied for high-voltage insulation. Epoxy composites may offer several advantages over neat epoxy and ceramic materials. We fabricated nano- and microepoxy/silica composites with 5 wt% nanosilica and 20 wt% microsilica, respectively. The composites and neat epoxy were studied for thermal, mechanical, and electrical properties. A thermogravimetric analyzer was used for analyzing wt% loss with temperature. Tensile and hardness tests were performed according to DIN 53504/ASTM D412 and DIN 53505/ASTM D2240 standards, respectively. Electrical properties such as dielectric strength and resistivity were tested according to IEC-60243-1 and ASTM D257/IEC 60093 standards, respectively. Neat epoxy, microcomposite, and nanocomposite showed 50% weight loss at 392°C, 410°C, and 421°C, respectively. At 550°C, nanocomposite remained at 20% of its initial weight whereas neat epoxy and microcomposite remained at 10% of their initial weights. Microcomposite and nanocomposite showed tensile strengths of 65.7 Mpa and 69.3 Mpa, respectively. Enhancements of 8% and 19% in dielectric strength were recorded for microcomposites and nanocomposites, respectively. Nanosilica greatly improved surface and volume resistivity whereas microsilica showed negligible effect on resistivity.

Investigation of electrical, tracking/erosion, and water absorption resistance properties of ATH-SiO2-reinforced RTV-SiR composites for high-voltage insulations

2017 ◽  
Vol 50 (6) ◽  
pp. 501-519 ◽  
Author(s):  
Hidayatullah Khan ◽  
Muhammad Amin ◽  
Ayaz Ahmad ◽  
Muhammad Yasin
Keyword(s):  
Water Absorption ◽  
High Voltage ◽  
Erosion Resistance ◽  
Water Immersion ◽  
Dielectric Strength ◽  
Weight Percent ◽  
Surface Resistivity ◽  
High Voltage Insulation ◽  
Micro Silica ◽  
The Impact

In this work, we have investigated the impact of micro-silica (SiO2), micro-alumina-tri-hydrate (ATH), and mixture of micro/nano-sized particles (ATH + SiO2) on electrical, tracking and erosion, and water absorption characteristics of silicone rubber (SiR)-based novel composites. SiR-blends with varying concentrations by weight percent (wt%) of ATH and SiO2 were prepared by simple blending in a two-roll mixing mill. Tracking/erosion and water absorption resistance properties of SiR-blends were analyzed using the inclined plane test and water immersion tests, respectively, according to ASTM standards. Dielectric strength, volume and surface resistivity, tracking/erosion resistance, and water penetration resistance properties of SiR composites were determined and discussed. SiR composites with ATH showed enhanced dielectric strength, volume and surface resistivity, erosion resistance, and initial tracking voltage compared to SiO2-filled composites. Further, the ATH and SiO2 co-filled specimens showed better water immersion resistance compared to samples only filled with ATH or SiO2. We presume characterization results presented in this work will help researchers to optimize the performance of SiR for outdoor high-voltage insulation applications.

High voltage applications of low temperature co-fired ceramics

2018 ◽  
Vol 35 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Arkadiusz Dabrowski ◽  
Przemyslaw Rydygier ◽  
Mateusz Czok ◽  
Leszek Golonka
Keyword(s):  
Low Temperature ◽  
Field Intensity ◽  
High Voltage ◽  
Volume Resistivity ◽  
Dielectric Strength ◽  
Breakdown Field ◽  
Content Type ◽  
Suitable Material ◽  
Long Term Stability ◽  
High Voltage Generator

Purpose The purpose of this study was to design, fabricate and test devices based on transformers integrated with low-temperature co-fired ceramic (LTCC) modules with isolation between primary and secondary windings at the level between 6 and 12 kV. Design/methodology/approach Insulating properties of the LTCC were examined. Dielectric strength and volume resistivity were determined for common LTCC tapes: 951 (DuPont), 41020, 41060 (ESL), A6M (Ferro) and SK47 (KEKO). According to the determined properties, three different devices were designed, fabricated and tested: a compact DC/DC converter, a galvanic separator for serial digital bus and a transformer for high-voltage generator. Findings Breakdown field intensity higher than 40 kV/mm was obtained for the test samples set, whereas the best breakdown field intensity of about 90 kV/mm was obtained for 951 tape. The materials 41020 and 951 exhibited the highest volume resistivity. Fabricated devices exhibited safe operation up to a potential difference of 10 kV, limited by minimum clearance. Long-term stability was assured by over 20 kV strength of inner dielectric. Practical implications This paper contains description of three devices made in the LTCC technology for application in systems with high-voltage isolation requirement, for example, for power or railway power networks. Originality/value The results show that LTCC is a suitable material for fabrication of high-voltage devices with integrated passives. Technology and properties of three examples of such devices are described, demonstrating the ability of the LTCC technology for application in reliable high-voltage devices and systems.

Fractal analysis in biology and medicine

2020 ◽  
pp. 85-92
Keyword(s):  
Fractal Analysis ◽  
A Priori ◽  
Research Work ◽  
Structure And Function ◽  
Review Article ◽  
Living Systems ◽  
Modern Biology ◽  
Additional Information ◽  
Important Additional Information ◽  
And Function

The review article discusses the possibilities of using fractal mathematical analysis to solve scientific and applied problems of modern biology and medicine. The authors show that only such an approach, related to the section of nonlinear mechanics, allows quantifying the chaotic component of the structure and function of living systems, that is a priori important additional information and expands, in particular, the possibilities of diagnostics, differential diagnosis and prediction of the course of physiological and pathological processes. A number of examples demonstrate the specific advantages of using fractal analysis for these purposes. The conclusion can be made that the expanded use of fractal analysis methods in the research work of medical and biological specialists is promising.

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