IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
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2024
·
IF 2.9
Qi Li,Boxue Du,WenBo Zhu,Xiaoxiao Kong
In this article, a simulation model of 110 kV cable termination based on COMSOL is established, and electro thermal coupling characteristics at different temperatures are simulated. Obvious uneven thermal stress distribution inside the termination is found at temperatures below −20 ∘ C, due to the difference in thermal expansion coefficients between different materials. Stress concentration at the interface between the metal insert and epoxy resin occurs. Tensile stress along the direction of the electric field in the epoxy increases as the temperature decreases, with a maximum value of 66.7 MPa at −40 ∘ C. The electrical treeing and partial discharge (PD) characteristics are investigated in epoxy resin under various thermal stress conditions. It is found that the electrical tree growth is accelerated under low temperatures, which is attributed to the increase in thermal stress and decrease in the toughness of the epoxy bushing. In such circumstances, the electrical tree growth rate is greatly increased, frequently accompanied by a sudden enhancement in PDs and expansion of deterioration channels, which is proved by a phase field model considering the induced thermal stress.
研究领域:
电气工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·Vol. 26
·期 7
·6429-6435
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IF 2.9
Yaru Zhang,Wenjia Zhang,Shixun Hu,Juan Li,Mingti Wang,Qi Zhang,Hao Yuan,Changlong Yang,Qi Li,Jinliang He
The electrical tree in grafted polypropylene (PP) is inhibited compared with that of pure PP. To understand the free radicals that are generated during the treeing process, we study the electron paramagnetic resonance (EPR) spectra. Additionally, to provide a clearer explanation of the suppression of electrical trees, this research uses electroluminescence (EL) and excitation computation. These methods help us to observe the movement of electrons and to understand the geometric and electronic structures involved. In pure PP, the energy required to excite the electrons is approximately the same as the band gap of PP while electrons are easier to be excited in grafted PP than in pure PP, because the band gap is narrower. As a result, though the electrical tree length is shorter in PP-g-MMA, the EPR signal is more intense because of the uneven distribution of electrons.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2023
·
IF 5.9
Xiaoxing Zhang,Hui Lin,Yiran Hu,Dalin Ding,Fujin Cai,Yunjian Wu
Epoxy resin is one of the most commonly used insulating materials for electricians. Nevertheless, the emergence of localized damage or subtle microcracks within the material poses a formidable challenge in terms of detection and subsequent repair. The safe operation of power equipment is seriously jeopardized. In this study, driven by the need for self-healing insulating materials in power equipment applications, the successful synthesis of high-performance epoxy insulating materials featuring varying disulfide bond contents was achieved. Mechanical properties such as tensile strength and elongation at the break of epoxy insulations are enhanced by small amounts of disulfide bond. While an elevated content of disulfide bond diminishes the heat resistance and electrical characteristics of epoxy insulating materials, it is noteworthy that the prerequisites of epoxy resins for electrical applications remain adequately fulfilled. The results of the mechanical damage Self-healing test showed that the optimal repair efficiency reached 81.23 %. Simultaneously, the differentiation of electric tree branches can be inhibited by a disulfide bond. The diminishment of electric tree damage extent within epoxy resin is optimized, and the impairments of electric trees are repaired. Grounded in a disulfide bond, the viability of utilizing self-healing epoxy resins as insulating materials for electrical equipment is substantiated in this paper.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 18
·6025-6033
·
IF 7.059
Jiaye Xie,Lei Gao,Jun Hu,Qi Li,Jinliang He
Electrical treeing is regarded as the major factor that results in electrical damage of polymer insulation and thus shortens the lifetime and compromises the reliability of electrical power systems and power electronics. In bulk thermoset polymers, which are widely used as electrical insulation, self-healing of the electrical damage caused by treeing has rarely been reported. In this work, self-healing of electrical damage in a thermoset polymer, i.e., epoxy, is achieved through an anionic polymerization-based microcapsule approach. The epoxy matrix is modified with 2-ethyl-4-methylimidazole that initiates anionic polymerization of the healing agents and thereby repairs the electrical tree channels. The anionic polymerization is designed to be favoured in a moderate temperature range that matches with the working condition of many polymer insulation materials in electrical power systems, eliminating the need of additional stimuli that are usually required to trigger the healing reaction. It is substantialized that the electrical tree channels in the self-healing epoxy are re-built once they encounter and rupture the microcapsules, and the dielectric properties are completely recovered. This design of a self-healing material offers new possibilities for smart dielectrics that are needed in future electrical power systems and power electronics with a longer service lifetime and improved reliability.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2021
·Vol. 14
·期 8
·1811
·
IF 3.623
Peng Zhang,Xuan Wang,Jiaming Yang,Yongqi Zhang
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.
研究领域:
材料科学
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电气工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2022
·Vol. 29
·期 11
·1-11
·
IF 3.061
Li Mingyue,Chen Yidong,Xu Qingwen,Chen Yilin,Ren Xiancheng,Zhou Kai
Underground power cables are prone to electrical tree aging and additives loss due to the harsh working environment. In this work, the thermal aged cross-linked polyethylene (XLPE) cables were restored by injecting a newly synthesized voltage stabilizer containing hydrolyzable siloxane groups. The voltage stabilizer functionalized siloxane groups greatly enhanced the electrical tree initiation voltage, significantly reduced the direct current (DC) conductivity and dielectric loss factor. The results of scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) indicated that the voltage stabilizer molecules were distributed in the electrical tree channels of the restored cables. After secondary thermal aging at 150 °C for 360 h, the characteristic electrical tree initiation voltage of the restored cable reached 12.10 kV, which was 66.90% higher than that of the unrestored cable. This indicated that the migration of voltage stabilizers could be inhibited by introducing hydrolyzable groups. This investigation provided a new approach to improve the migration resistance of the voltage stabilizer and the inhibitory effect of the rejuvenation liquid on the electrical tree.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 1
·176
·
IF 3.164
Wei Dong,Xuan Wang,Bo Tian,Yuguang Liu,Zaixing Jiang,Zhigang Li,Wei Zhou
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.Keywords:cross-linked polyethylene;grafted voltage stabilizer;breakdown strength;electrical tree initiation voltage
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 41
·14217-14225
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IF 6.4
Potao Sun,Zeyan Shi,Wenxia Sima,Xinyu Tang,Tao Yuan,Ming Yang,Hang Xu,Zhaoping Li
Microscale damage, including cracks and electrical trees, is inevitably generated in the polymer insulation materials used in the packaging of power equipment and power electronic devices during long-term operation, which leads to premature insulation failure or even widespread power outages. Self-healing insulation materials are the most promising way to solve this problem. However, the mechanical/electrical strength or the dimensional stability of the materials could be sacrificed during the repair process, which has limited their application as insulation materials. In this study, we report an intrinsic self-healing epoxy resin based on reversible anthracene photodimerization (ISEP-RAP) that remains mechanically robust while ensuring efficient healing via a reversible reaction. The damaged area is decrosslinked by 254 nm UV and thermal excitation, which accelerates the molecular chain diffusion to the damaged area to fill and repair the damaged channels. The ISEP-RAP is recrosslinked by 365 nm UV to restore the mechanical and electrical properties after self-healing. Due to the combined action of the epoxy-amine permanent crosslinking sites and the anthracene reversible crosslinking sites, high crosslinked ISEP-RAP possesses excellent tensile and dielectric strength similar to that of standard epoxy resin and a lower permittivity constant. Importantly, the decrosslinked ISEP-RAP still possesses sufficiently high strength to keep the macrostructure unchanged. ISEP-RAP achieves high-efficiency, repeatable, non-contact intrinsic self-healing of scratches and electrical trees with whole-process dimensional stability. This work provides a new method for intrinsic self-healing in mechanically robust insulation materials to eliminate microdamage with repeatability, high reliability, and high efficiency.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
·
2024
·
IF 2.9
Yongqiang Wang,Fengxiao Zhang,Yaqi Deng,Jing Shang
The introduction of micro- and nanoparticles is an important means to improve the electrical dendritic properties of epoxy resin (EP) composites. Aiming at the problem that the waste aramid powder generated during the production process of aramid fiber products is difficult to be effectively utilized, the paper adopts both dopamine modification and co-modification with dopamine and 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane in the treatment of micrometer-sized aramid fiber powders. The untreated powder(AP), dopamine-modified powder(DAP), and co-modified powder(SDAP) were prepared into composite specimens with EP, and the trap properties, electrical trees initiation, and growth characteristics of the three specimens with different doping concentrations were investigated for the first time. Tests and analyses show that the powder inside AP/EP is mostly agglomerated and entangled, the shallow phenomenon of deep traps is serious, electrical trees properties have declined. With the increase of doping concentration, the energy level and density of deep traps of DAP/EP and SDAP/EP specimens increased, which helped to improve the initiation and growth characteristics of the electrical trees. The results of the study expanded the application forms of aramid products and provided new ideas and choices for the search of high quality fillers to improve the electrical dendrite properties of epoxy resins.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2025
·
IF 4.7
Bo Zhu,Bo Yang,Xu Sun,Xinyu Tao,Xinlao Wei
Polymer insulation materials are affected by electromagnetic fields, mechanical stress, long-term illumination, ambient temperature, and other operating conditions. These conditions can cause water trees and electrical trees damage, resulting in insulation failure. Self-healing technology is the fundamental way to solve this problem. However, the effective self-healing of water trees and electrical tree damage in insulating materials is extremely challenging. To solve this problem, a dual-responsive self-healing insulating material was prepared by doping 1% modified silicon dioxide, which made a breakthrough in the self-healing and suppression of electrical trees and water trees, and doping modified silicon dioxide particles enhanced intermolecular interaction and improved material mechanics and insulation performance. When electrical and water-mixed tree branches aging occurs, oligomers generated by grafted siloxane groups and acrylate groups can effectively fill the pores of the electrical and water trees on top of the physical filling of the pores by silicon dioxide particles. The performance of the cured material is close to that of the pure sample. This method realizes the dual-response self-healing of the insulation material after the aging of the electro-hydro mixed tree, which provides a new way to repair polyethylene cable insulation and has great potential in practical applications.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2025
·
IF 6
Ke Li,Lu-Ming Zhou,Yun-Xiao Zhang,Yuan-Xiang Zhou
Electrical treeing is a primary degradation pathway in cross-linked polyethylene (XLPE) cable insulation, making enhancement of the tree-initiation voltage (TIV) critical for reliable high-voltage operation. We report a peroxide-assisted grafting strategy that covalently incorporates 2-vinylanthraquinone (VAQ) into XLPE during standard crosslinking, thereby addressing the migration and durability limitations of physically blended stabilizers. The grafted VAQ introduces deep electronic traps and mitigates defect-driven degradation, increasing the characteristic TIV by more than 160 % and markedly suppressing tree growth under AC voltage. This migration-resistant, trap-engineered stabilization provides a practical route to improve long-term insulation reliability and is directly relevant to the design of ultra-high-voltage polymeric cables.
研究领域:
高分子材料科学
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电气工程
·
绝缘技术
·
功能材料
·
电力系统可靠性
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2025
·
IF 2.7
Ze Yin,Wenxu Tang,Ke Zhao,Binghao Chen,Jinggang Yang,Lei Sun,Shan Gao,Potao Sun
Microcracks and electrical treeing within polymer insulating materials are the primary causes of insulation failure. Early detection and repair of such damages are crucial. In this study, we leveraged the aggregation-induced emission (AIE) effect and a microcapsule self-healing system to design a UV-triggered smart insulating material capable of autonomous damage repair and self-reporting. The composite material demonstrated effective healing of both mechanical damage and electrical treeing channels, achieving damage-recovery rates of 91.67 % and 93.26 % for tensile strength and electrical strength, respectively. As the released healing agent was solidified within the damage path, it triggered intense AIE fluorescence, precisely indicating the location of damage.
研究领域:
材料科学
·
高分子科学
·
电气工程
·
自修复材料
·
荧光传感器
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）