scholarly journals Kraft-Pulp Based Material for Electrical Insulation

2017 ◽  
Author(s):  
Rebecca Hollertz ◽  
Lars Wågberg ◽  
Claire Pitois
Keyword(s):  
Dielectric Properties ◽  
Kraft Pulp ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Electrical Equipment ◽  
Electrical Insulation ◽  
Insulation Material ◽  
High Frequency Response ◽  
Static Electrification ◽  
Electrical Breakdown Strength

<p>The dielectric properties of the electrical insulation material have a significant influence on the performance and reliability of components in electrical equipment. The influence of the chemistry and electronic structure of the different constituents of the kraft pulp (used in electrical insulation) on some dielectric properties is discussed in this paper. The studies and mechanisms discussed indicate that the presence of different wood polymers (cellulose, hemicellulose and lignin), have different effects on dielectric properties (static electrification and high frequency response). Our results show that the dielectric response of lignin is different compared with the response of hemicellulose and cellulose and this is also expected from the chemical structure of the different components. The lignin molecule has a higher polarizability at frequencies of significance for streamer inception and propagation. With spectroscopic ellipsometry measurements it has also been shown that the energy for electronic transitions in this spectral region is lower for lignin. The results also clearly indicate that the role of cellulose, lignin and hemicellulose should be further investigated for improving electrical breakdown strength of paper based insulation materials.</p>

scholarly journals The investigation of electrical properties and microstructure of ZnO-doped Ba0.9Sr0.1TiO3 ceramics

2017 ◽  
Vol 07 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Gang Liu ◽  
Wentao Jiang ◽  
Jingyong Jiao ◽  
Li Liu ◽  
Ziyang Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Electrical Breakdown Strength

Ba[Formula: see text]Sr[Formula: see text]TiO3 ceramics with or without ZnO have been prepared by traditional solid state reaction method. The XRD analysis showed that the doped Zn[Formula: see text] ions diffused into the BST crystal lattice, resulting in the variation of dielectric properties. Especially the dielectric constant at Curie point decreased with doping ZnO content when it is lower than 0.5[Formula: see text]mol%. Due to the promotion of sintering, doping ZnO can enhance the density of ceramics but increase grain size. However, ZnO is a kind of semiconductor and can lead to the decrease in electrical breakdown strength value.

Theoretical study on the radical reaction mechanism in the cross-linking process of polyethylene

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90343-90353 ◽  
Author(s):  
Hui Zhang ◽  
Yan Shang ◽  
Mingxia Li ◽  
Hong Zhao ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
High Voltage ◽  
Theoretical Study ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Radical Reaction ◽  
Voltage Stabilizer ◽  
Cross Linking ◽  
Insulation Material ◽  
Electrical Breakdown Strength

The mechanism of the valerophenone voltage stabilizer for increasing the electrical breakdown strength of cross-linked polyethylene is expected to provide reliable information to prepare insulation material for high voltage cables up to 500 kV.

Electrical breakdown strength enhancement in aluminum scandium nitride through a compositionally modulated periodic multilayer structure

2021 ◽  
Vol 130 (14) ◽  
pp. 144101
Author(s):  
Jeffrey X. Zheng ◽  
Dixiong Wang ◽  
Pariasadat Musavigharavi ◽  
Merrilyn Mercy Adzo Fiagbenu ◽  
Deep Jariwala ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Scandium Nitride ◽  
Strength Enhancement ◽  
Electrical Breakdown Strength

scholarly journals The Effects of Aluminum-Nitride Nano-Fillers on the Mechanical, Electrical, and Thermal Properties of High Temperature Vulcanized Silicon Rubber for High-Voltage Outdoor Insulator Applications

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3562 ◽  
Author(s):  
Chang Liu ◽  
Yiwen Xu ◽  
Daoguang Bi ◽  
Bing Luo ◽  
Fuzeng Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Thermal Properties ◽  
High Temperature ◽  
High Voltage ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Theoretical Models ◽  
Dielectric Constants ◽  
Silicon Rubber ◽  
Electrical Breakdown Strength

AlN nanoparticles were added into commercial high-temperature-vulcanized silicon rubber composites, which were designed for high-voltage outdoor insulator applications. The composites were systematically studied with respect to their mechanical, electrical, and thermal properties. The thermal conductivity was found to increase greatly (>100%) even at low fractions of the AlN fillers. The electrical breakdown strength of the composites was not considerably affected by the AlN filler, while the dielectric constants and dielectric loss were found to be increased with AlN filler ratios. At higher doping levels above 5 wt% (~2.5 vol%), electrical tracking performance was improved. The AlN filler increased the tensile strength as well as the hardness of the composites, and decreased their flexibility. The hydrophobic properties of the composites were also studied through the measurements of temperature-dependent contact angle. It was shown that at a doping level of 1 wt%, a maximum contact angle was observed around 108°. Theoretical models were used to explain and understand the measurement results. Our results show that the AlN nanofillers are helpful in improving the overall performances of silicon rubber composite insulators.

scholarly journals Characterization of Polypropylene Modified by Blending Elastomer and Nano-Silica

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1321 ◽  
Author(s):  
Xiaohong Chi ◽  
Lu Cheng ◽  
Wenfeng Liu ◽  
Xiaohong Zhang ◽  
Shengtao Li
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Power Transmission ◽  
Breakdown Strength ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Insulation Material ◽  
Nano Silica ◽  
Scanning Calorimetry ◽  
High Voltage Direct Current

Polypropylene (PP) contains promising application prospects in thermoplastic cables for high voltage direct current (HVDC) power transmission because of its outstanding thermal and dielectric properties. However, the problem of poor toughness and space charge has restricted the application of pure PP in HVDC cables. In this paper, polyolefin elastomer (POE) and nano-silica were blended thoroughly and added into a PP mixture by a melting method. Scanning electron microscopy (SEM) was employed to observe the dispersion of POE and nanoparticles. Thermal properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Mechanical properties were evaluated by tensile tests. The elastomeric properties of composites were improved as the dispersed POE could transfer and homogenize external mechanical forces. DC breakdown results showed that the fail strength of composite with 10 phr POE and 1 phr nano-silica was obviously enhanced. The pulsed electro-acoustic (PEA) results showed that the injection and accumulation of space charge was increased by the introduction of POE, while it was restrained by the collective effect caused by nano-silica filling. X-ray diffraction (XRD) spectrograms showed that secondary ordered structures existed in the composites of PP, POE, and nano-silica, and that the ordered structure around the nanoparticles contributed to the enhancement of breakdown strength. The mechanical and dielectric properties were modified synergistically, which made the modified PP a propitious insulation material for HVDC cables.

Carbon - silicon heterojunction diodes formed by CH4/ Ar rf plasma thin film deposition on Si substrates

1989 ◽  
Vol 162 ◽  
Author(s):  
G. A. J. Amaratunga ◽  
W. I. Milne ◽  
A. Putnis ◽  
K. K. Chan ◽  
K. J. Clay ◽  
...  
Keyword(s):  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Rf Plasma ◽  
Type I ◽  
Si Substrates ◽  
Semiconducting Properties ◽  
Electrical Breakdown Strength ◽  
Poly Crystalline Diamond

ABSTRACTThin C films deposited from a CH4/Ar plasma on Si substrates kept at 20C are shown to be semiconducting. The semiconducting properties are associated with the poly-crystalline diamond grains present within the films. Diode type I-V characteristics observed from AVC/Si verticle structures are explained by the action of a C-Si heterojunction. A band gap of 2eV, a resistivity of 106Ω.cm and an electrical breakdown strength of 5.106 V/cm are estimated for the C.

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