Enhanced breakdown strength and electrical tree resistance properties of MMT/SiO2 /LDPE multielement composites

2019 ◽  
Vol 136 (17) ◽  
pp. 47364 ◽  
Author(s):  
Xiaohong Zhang ◽  
Zexiang Shi ◽  
Lisha Ma ◽  
Junguo Gao ◽  
Ning Guo
Keyword(s):  
Breakdown Strength ◽  
Tree Resistance ◽  
Electrical Tree

scholarly journals Effect of Acetylated SEBS/PP for Potential HVAC Cable Insulation

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1811
Author(s):  
Peng Zhang ◽  
Xuan Wang ◽  
Jiaming Yang ◽  
Yongqi Zhang
Keyword(s):  
Breakdown Strength ◽  
Thermoplastic Elastomer ◽  
Alternating Current ◽  
High Energy ◽  
Voltage Stabilizer ◽  
Breakdown Field ◽  
Isomerization Reaction ◽  
Insulation Material ◽  
Tree Resistance ◽  
Electrical Tree

Blending polypropylene (PP) with thermoplastic elastomer SEBS can effectively improve the mechanical toughness of PP, thus leading to the promise of SEBS/PP as the primary insulation material for high voltage alternating current (HVAC) cables. However, the growth of electrical trees during cable operation limits the application of SEBS/PP. In this paper, acetylation reaction is used to construct acetophenone group at the end of the benzene ring on SEBS so that it has the effect of both a toughening agent and a voltage stabilizer. Then PP was melt blended with acetylated SEBS (Ac-SEBS), and the effects of Ac-SEBS on the mechanical properties, electrical tree resistance, alternating current (AC) breakdown strength, and dielectric spectrum of PP were mainly investigated with reference to PP and SEBS/PP. The results showed that Ac-SEBS with 30% content could enhance the mechanical toughness of PP and improve the electrical tree resistance and AC breakdown strength of SEBS/PP. The AC breakdown field strength of Ac-SEBS/PP reached the highest when the acetylation level was 4.6%, which was 9.2% higher than that of SEBS/PP. At this time, Ac-SEBS was also able to absorb high-energy electrons through the keto-enol interchange isomerization reaction, which inhibited the initiation and growth of electric trees and caused the development of electric dendrites in a jungle-like manner. Moreover, the dielectric loss factor of AC-SEBS/PP in power frequency is within the allowable range of industry. Therefore, Ac-SEBS/PP is expected to be applied to HVAC cables, thus further improving the efficiency of HVAC power transmission.

scholarly journals Use of Grafted Voltage Stabilizer to Enhance Dielectric Strength of Cross-Linked Polyethylene

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 176 ◽  
Author(s):  
Wei Dong ◽  
Xuan Wang ◽  
Bo Tian ◽  
Yuguang Liu ◽  
Zaixing Jiang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
Voltage Stabilizer ◽  
Cross Linking ◽  
Practical Application ◽  
Electrical Tree ◽  
Research Goal ◽  
The Stability ◽  
New Research

Aromatic voltage stabilizers can improve the dielectric properties of cross-linked polyethylene (XLPE); however, their poor compatibility with XLPE hinders their practical application. Improving the compatibility of aromatic voltage stabilizers with XLPE has, therefore, become a new research goal. Herein 1-(4-vinyloxy)phenylethenone (VPE) was prepared and characterized. It can be grafted onto polyethylene molecules during the cross-linking processes to promote stability of the aromatic voltage stabilizers in XLPE. Fourier transform infrared spectroscopy confirmed that VPE was successfully grafted onto XLPE, and effectively inhibited thermal migration. Thermogravimetric analysis showed that the grafted VPE/XLPE composite exhibits a better thermal stability than a VPE/PE blend composite. Evaluation of the electrical properties showed that the breakdown strength and electrical tree initiation voltage of the VPE/XLPE composite were increased by 15.5% and 39.6%, respectively, when compared to those of bare XLPE. After thermal aging, the breakdown strength and electrical tree initiation voltage of the VPE/XLPE composite were increased by 9.4% and 25.8%, respectively, in comparison to those of bare XLPE, which indicates that the grafted voltage stabilizer can effectively inhibit its migration and enhance the stability of the composite material.

scholarly journals Ameliorated Electrical-Tree Resistant Characteristics of UV-Initiated Cross-Linked Polyethylene Nanocomposites with Surface-Functionalized Nanosilica

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 313 ◽  
Author(s):  
Yong-Qi Zhang ◽  
Ping-Lan Yu ◽  
Wei-Feng Sun ◽  
Xuan Wang
Keyword(s):  
Fractal Dimension ◽  
Electric Fields ◽  
Tree Growth ◽  
Electrical Resistance ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Sio2 Nanoparticles ◽  
Polyethylene Matrix ◽  
Electrical Tree ◽  
Electrical Trees

Given the high interest in promoting crosslinking efficiency of ultraviolet-initiated crosslinking technique and ameliorating electrical resistance of crosslinked polyethylene (XLPE) materials, we have developed the funcionalized-SiO2/XLPE nanocomposites by chemically grafting auxiliary crosslinkers onto nanosilica surfaces. Trimethylolpropane triacrylate (TMPTA) as an effective auxiliary crosslinker for polyethylene is grafted successfully on nanosilica surfaces through thiolene-click chemical reactions with coupling agents of sulfur silanes and 3-mercaptopropyl trimethoxy silane (MPTMS), as characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The functionalized SiO2 nanoparticles could be dispersively filled into polyethylene matrix even at a high filling content that would generally produce agglomerations of neat SiO2 nanofillers. Ultraviolet-initiated polyethylene crosslinking reactions are efficiently stimulated by TMPTA grafted onto surfaces of SiO2 nanofillers, averting thermal migrations out of polyethylene matrix. Electrical-tree pathways and growth mechanism are specifically investigated by elucidating the microscopic tree-morphology with fractal dimension and simulating electric field distributions with finite-element method. Near nano-interfaces where the shielded-out electric fluxlines concentrate, the highly enhanced electric fields will stimulate partial discharging and thus lead to the electrical-trees being able to propagate along the routes between nanofillers. Surface-modified SiO2 nanofillers evidently elongate the circuitous routes of electrical-tree growth to be restricted from directly developing toward ground electrode, which accounts for the larger fractal dimension and shorter length of electrical-trees in the functionlized-SiO2/XLPE nanocomposite compared with XLPE and neat-SiO2/XLPE nanocomposite. Polar-groups on the modified nanosilica surfaces inhibit electrical-tree growth and simultaneously introduce deep traps impeding charge injections, accounting for the significant improvements of electrical-tree resistance and dielectric breakdown strength. Combining surface functionalization and nanodielectric technology, we propose a strategy to develop XLPE materials with high electrical resistance.

Electrical Treeing Breakdown Properties for Polyimide Nanocomposite Film in Inverter-Fed Motors

2012 ◽  
Vol 455-456 ◽  
pp. 553-558
Author(s):  
Yi Cui ◽  
Guang Ning Wu ◽  
Yi Qiang Zhang ◽  
Zheng Liang Xin ◽  
Yang Luo
Keyword(s):  
Energy Spectrum ◽  
Spectrum Analysis ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Dielectric Strength ◽  
Main Body ◽  
Energy Spectrum Analysis ◽  
Electrical Tree ◽  
Magnet Wire ◽  
Turn Insulation

The failure of magnet wires used in inter-turn insulation of inverter-fed motor winding is the main cause which leads to the motor insulation breakdown. This paper conducted electrical tree breakdown experiments on magnet wire insulating film (FCR 100) used in the inter-turn insulation of JD117 inverter-fed motor and meanwhile combining with energy spectrum analysis and scanning electrical microscope (SEM), by which type and content of elements, breakdown main body and electrical tree channel could be clearly observed, the corresponding failure mechanisms were analyzed. The experiment results reveal that all the breakdown main bodies are located at the pointedness and insulation joint of magnet wires, of which dielectric strength is relatively lower; they are the insulation “weak point”, which should be paid enough attention and strengthened at the manufacturing period. The electrical tree breakdown time is quite long and the life span of magnet wire is 11 hours. The electrical breakdown strength of envelope is very low when containing metal impurity. It is also found that the aluminum occupies the highest content tested by energy spectrum analysis.

scholarly journals Effect of Doping Microcapsules on Typical Electrical Performances of Self-Healing Polyethylene Insulating Composite

2019 ◽  
Vol 9 (15) ◽  
pp. 3039 ◽  
Author(s):  
Youyuan Wang ◽  
Yudong Li ◽  
Zhanxi Zhang ◽  
Yanfang Zhang
Keyword(s):  
Space Charge ◽  
Structural Damage ◽  
Carrier Transport ◽  
Breakdown Strength ◽  
Mechanical Damage ◽  
Electrical Performance ◽  
Self Healing ◽  
Nucleation Effect ◽  
Electrical Tree ◽  
Effect Of Doping

Polyethylene cables, as important transmission equipment of modern power grid, would inevitably be slightly damaged, which seriously threatens the safety of the power supply. This paper has pioneered the preparation and typical performances of a self-healing polyethylene insulating composite. The self-healing performance to structural damage was verified by tests of electrical and mechanical damage. The effect mechanism of doping microcapsules on the electrical performance of polyethylene was emphatically analyzed. The results show that in appropriate conditions (such as 60 °C/30 min), the composite can not only repair the electrical tree and scratches, but also restore the insulation strength of damaged area. The effect of doping microcapsules on the electrical performances of polyethylene, such as breakdown strength, volumetric resistivity, dielectric properties, and space charge characteristics, are mainly related to impurity and the interface of microcapsule. Polarization and ionization of impurities can reduce the electrical performance of polyethylene. The interface not only improves the microstructure of polyethylene (such as how the heterogeneous nucleation effect increases the number of crystal regions, and the anchoring effect enhances the stability of amorphous regions), but also increases the charge traps. Moreover, the microstructure and charge trap can affect the characteristics of carrier transport, material polarization, and space charge accumulation, thus improving the electrical performance of polyethylene. In addition, the important electrical performance of the composite can meet the basic application requirements of polyethylene insulating material, which has good application prospects.

scholarly journals Repair Performance of Self-Healing Microcapsule/Epoxy Resin Insulating Composite to Physical Damage

2019 ◽  
Vol 9 (19) ◽  
pp. 4098 ◽  
Author(s):  
Youyuan Wang ◽  
Yudong Li ◽  
Zhanxi Zhang ◽  
Haisen Zhao ◽  
Yanfang Zhang
Keyword(s):  
Epoxy Resin ◽  
Molecular Diffusion ◽  
Breakdown Strength ◽  
Mechanical Damage ◽  
Electrical Equipment ◽  
Physical Structure ◽  
Self Healing ◽  
Physical Damage ◽  
Repair Rate ◽  
Electrical Tree

Minor physical damage can reduce the insulation performance of epoxy resin, which seriously threatens the reliability of electrical equipment. In this paper, the epoxy resin insulating composite was prepared by a microcapsule system to achieve its self-healing goal. The repair performance to physical damage was analyzed by the tests of scratch, cross-section damage, electric tree, and breakdown strength. The results show that compared with pure epoxy resin, the composite has the obvious self-healing performance. For mechanical damage, the maximum repair rate of physical structure is 100%, and the breakdown strength can be restored to 83% of the original state. For electrical damage, microcapsule can not only attract the electrical tree and inhibit its propagation process, but also repair the tubules of electrical tree effectively. Moreover, the repair rate is fast, which meets the application requirements of epoxy resin insulating material. In addition, the repair behavior is dominated by capillarity and molecular diffusion on the defect surface. Furthermore, the electrical properties of repaired part are greatly affected by the characteristics of damage interface and repair product. In a word, the composite shows better repair performance to physical damage, which is conducive to improving the reliability of electrical insulating materials.

Ultrahigh Energy Storage Performances of Polymer-based Nanocomposite via Interfaces Engneering

2020 ◽  
Author(s):  
Peng Wang ◽  
Zhongbin Pan ◽  
Weilin Wang ◽  
Jianxu Hu ◽  
Jinjun Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Energy Storage ◽  
High Performance ◽  
Breakdown Strength ◽  
Composite Films ◽  
Power Electronic ◽  
Ultrahigh Energy

High-performance electrostatic capacitors are in urgent demand owing to the rapidly development of advanced power electronic applications. However, polymer-based composite films with both high breakdown strength (Eb) and dielectric constant...

Radiated Electro-Magnetic Waves Caused by Electrical Tree Development in Epoxy Resin

2009 ◽  
Vol 129 (12) ◽  
pp. 915-921 ◽  
Author(s):  
Hideki Ueno ◽  
Takashi Nagamachi ◽  
Masaki Nakamura ◽  
Hiroshi Nakayama ◽  
Kunihiko Kakihana
Keyword(s):  
Epoxy Resin ◽  
Electrical Tree ◽  
Electro Magnetic ◽  
Tree Development ◽  
Magnetic Waves
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