High Voltage最新文献_第7页

Anisotropy in Dry-Type Valve-Side Bushings of Converter Transformer: Phenomena and Effects 干式换流变压器阀侧套管的各向异性：现象与影响

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-26 DOI: 10.1049/hve2.70166

Gaoyi Shang, Xueyang Bai, Wanhao Shi, Jinzhong Li, Shuqi Zhang, Hao Tang, Xuandong Liu

{"title":"Anisotropy in Dry-Type Valve-Side Bushings of Converter Transformer: Phenomena and Effects","authors":"Gaoyi Shang, Xueyang Bai, Wanhao Shi, Jinzhong Li, Shuqi Zhang, Hao Tang, Xuandong Liu","doi":"10.1049/hve2.70166","DOIUrl":"https://doi.org/10.1049/hve2.70166","url":null,"abstract":"The safe and stable working of dry-type valve-side bushings, important components of converter transformers, is essential. In recent years, poor design has led to several core breakdown, flashover and cracking failures. The bushing cores, composed of crepe paper and aluminium foil, exhibit significant anisotropic physical properties due to its arrangement. However, in previous designs and simulations, the epoxy resin impregnated paper (ERIP) material of the core is often treated as isotropic, and even combined with aluminium foil for the thermal and mechanical calculations. This simplification results in considerable deviations between simulated and actual performance. In this paper, radial and axial ERIP slices are prepared and their electrical, thermal and mechanical anisotropy parameters are measured. A new modelling method of bushing anisotropy is proposed. Based on COMSOL Multiphysics 6.2, the electrical–thermal–mechanical–fluid simulation model of ± 800 kV dry-type valve-side bushing is established. The results indicate that the anisotropic model exhibits a 19.1% higher temperature rise, a 15.2% higher maximum radial field strength, and an 85.7% lower damage stress margin than those of the isotropic model. These results show that bushing anisotropy cannot be ignored in modelling and design.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"3 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147523932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanism of Damage and Micro-Characterisation of Irradiation-Induced Free Radicals on the Epoxy Insulation of the Bridge Arm Reactors at High Altitude 高海拔条件下辐照自由基对桥臂式反应器环氧绝缘损伤机理及微观表征

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-22 DOI: 10.1049/hve2.70182

Liang Zou, Xinya Luo, Zhiyun Han, Zhen Li, Xiaofeng Ding, Kejie Huang

{"title":"Mechanism of Damage and Micro-Characterisation of Irradiation-Induced Free Radicals on the Epoxy Insulation of the Bridge Arm Reactors at High Altitude","authors":"Liang Zou, Xinya Luo, Zhiyun Han, Zhen Li, Xiaofeng Ding, Kejie Huang","doi":"10.1049/hve2.70182","DOIUrl":"https://doi.org/10.1049/hve2.70182","url":null,"abstract":"Damage degradation of epoxy resin insulating materials by free radicals triggered by the ultraviolet irradiation environment at high altitude has become a key issue that restricts the reliability of the bridge arm reactor at high altitude. The dynamic degradation mechanism of three types of distinctive free radicals, namely alkyl (CH2), alkoxyl (CH2O) and peroxyl (CH2OO), on the epoxy resin cross-linked network is systematically elucidated using the ReaxFF molecular dynamics simulation approach. The analysis of the study demonstrates that the radicals initiate main chain breaks by precipitating H ions or directly attacking the weak aliphatic bonds in the cross-linked network. The degradation product results show H2O and H2 small molecule products under all three radicals. Furthermore, it is also found that alkoxyl and peroxyl also induce CO generation, with the highest number of small molecule products under peroxyl. To quantitatively evaluate microscopic damage in ultraviolet (UV)-aged epoxy resins, this study introduced cross-linked structural integrity as an evaluation index. The integrity calculations indicate that peroxyl radicals, characterised by their dioxygen structure, induce the most severe degradation, ultimately reducing the cross-linked structural integrity to as low as 56%. This finding provides a profoundly detailed understanding of the mechanism of chemical bond cleavage and degradation product formation during UV ageing of epoxy resins at the molecular level and identifies peroxyl as the primary inhibitory target for material stabilisation. Consequently, this study establishes a theoretical basis for the rational design of irradiation-resistant epoxy resin modification, ultimately enhancing the operational stability of bridge-arm reactors at high altitude.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"16 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147523939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface Micro-Discharge Plasma for Multiple Teeth Bleaching: Efficacy, Mechanism and Safety 表面微放电等离子体多牙漂白：疗效、机制和安全性

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-22 DOI: 10.1049/hve2.70149

Ruike Chen, Haoran Feng, Yinglong Li, Hong Pan, Hangbo Xu, Zhen Jiao, Dongjie Cui, Ruonan Ma

{"title":"Surface Micro-Discharge Plasma for Multiple Teeth Bleaching: Efficacy, Mechanism and Safety","authors":"Ruike Chen, Haoran Feng, Yinglong Li, Hong Pan, Hangbo Xu, Zhen Jiao, Dongjie Cui, Ruonan Ma","doi":"10.1049/hve2.70149","DOIUrl":"https://doi.org/10.1049/hve2.70149","url":null,"abstract":"Hydrogen peroxide (H2O2) is the commonly-used bleaching chemical in clinical practice, but its excessive concentrations can cause tooth damage. Atmospheric pressure cold plasma is considered a promising new technique for tooth bleaching. Surface micro-discharge (SMD) devices can generate large-scale plasma, which holds potential for treating multiple teeth simultaneously. However, research in this area remains limited. This study systematically evaluated the bleaching efficacy, mechanism and safety of SMD plasma treatment of multiple human tooth stain models. The results demonstrated that SMD plasma effectively whitens multiple teeth simultaneously, achieving a ΔE00 value of 5.65 within 10 min. Its whitening efficacy surpasses that of the 10% H2O2 group. SMD plasma generates substantial reactive oxygen species, and the degradation efficiency of theaflavin can reach 99.59% within 5 min. Hydroxyl radicals and ozone serve as primary agents reacting with coloured molecules, cleaving chemical bonds and facilitating tooth whitening. Following SMD plasma treatment, the tooth surface temperature increased but remained within the acceptable range for the oral cavity. Meanwhile, the surface hydrophilicity declined, whereas surface roughness, microhardness and morphology remained largely unchanged. This study provides a crucial theoretical foundation for the application of SMD plasma in tooth whitening.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"92 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Time to Breakdown for Type I Motor Winding Insulation Under High-Frequency High-Slew-Rate Square Wave Voltages 高频高转速方波电压下I型电机绕组绝缘的击穿时间

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-19 DOI: 10.1049/hve2.70174

Easir Arafat, Md Asifur Rahman, Farzana Islam, Mona Ghassemi

{"title":"Time to Breakdown for Type I Motor Winding Insulation Under High-Frequency High-Slew-Rate Square Wave Voltages","authors":"Easir Arafat, Md Asifur Rahman, Farzana Islam, Mona Ghassemi","doi":"10.1049/hve2.70174","DOIUrl":"https://doi.org/10.1049/hve2.70174","url":null,"abstract":"The emergence of (ultra)wide bandgap ((U)WBG)-based devices has significantly enhanced performance in high-frequency switching applications, enabling breakthroughs in electric transportation, aerospace, and renewable energy systems. However, it also presents considerable challenges to insulation systems, such as electric motor winding insulation, which are subjected to these high-frequency high-slew-rate voltage pulses. This paper explores the impact of high-frequency, high-slew-rate square wave voltages on degradation and the time required for breakdown of Type I electric motor winding insulation. Although past studies reported in the literature were conducted at frequencies of a few kHz and low slew rates. The question remains unanswered: what occurs at higher frequencies, up to a few hundred kHz and at elevated slew rates? This paper addresses this technical gap. Utilising a state-of-the-art custom-built high-voltage, high-frequency high-slew-rate square wave generator, this study reports and analyses experimental results up to 200 kHz and short rise times down to 50 ns, which have not been reported to date. Two types of specimens, twisted and perpendicular pairs, are considered to simulate the motor winding configuration, and the test results are analysed using the Weibull model and multi-factor lifetime modelling. This paper corrects the common misconception that the higher the frequency of the applied voltage, the shorter the insulation lifetime. We found that this is incorrect when operating at frequencies above a few 100 kHz (> 100 kHz), where saturation or critical frequency exists, and beyond that point, the lifetime may even increase.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"27 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147523943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regional Infrared and Visible Image Registration for Distribution Substation Areas With Wide Depth of Field 大景深配电变电所区域红外与可见光图像配准

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-19 DOI: 10.1049/hve2.70152

Yingchen Zhang, Bo Wang, Fei Tang

引用次数: 0

Recognition of Spatiotemporal Feature Images of Zero-Sequence Voltage for Single-Phase High-Impedance Ground Faults Under Complex Conditions 复杂条件下单相高阻抗接地故障零序电压时空特征图像识别

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-14 DOI: 10.1049/hve2.70172

Zhengyang Li, Yijia Cao, Chun Chen, Weiyu Wang, Yansha Li, Jinglu Li

{"title":"Recognition of Spatiotemporal Feature Images of Zero-Sequence Voltage for Single-Phase High-Impedance Ground Faults Under Complex Conditions","authors":"Zhengyang Li, Yijia Cao, Chun Chen, Weiyu Wang, Yansha Li, Jinglu Li","doi":"10.1049/hve2.70172","DOIUrl":"https://doi.org/10.1049/hve2.70172","url":null,"abstract":"Diagnosing high-impedance ground faults (HIGFs) in distribution networks is extremely challenging because high transition resistance significantly reduces electrical signal strength and unpredictable initial fault phase angles coupled with asymmetric voltage disturbances often lead to misclassification. This paper proposes a novel method for identifying single-phase HIGFs based on spatiotemporal feature imaging of zero-sequence voltage. By analysing and characterising the transient characteristics and phase-space trajectories of zero-sequence voltage in the complex frequency domain under both HIGFs and asymmetric disturbance conditions, a fault identification scheme is developed that integrates high- and low-frequency information into spatiotemporal feature images. Leveraging a target recognition algorithm, the proposed method utilises low-frequency image features for direct HIGF identification and high-frequency image features to distinguish asymmetric disturbances from HIGFs in ambiguous cases, enabling automatic fault classification with enhanced accuracy. Experimental results demonstrate that the proposed method achieves superior performance, with classification accuracies exceeding 97% for HIGFs and 96% for asymmetric disturbances. Notably, it significantly outperforms conventional methods in distinguishing between asymmetric disturbances with specific initial fault phase angles and high-impedance ground faults.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"10 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147454708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on Ultra-Wideband Pulse Current Method for DC Partial Discharge Measurement 超宽带脉冲电流法测量直流局部放电的研究

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-12 DOI: 10.1049/hve2.70175

Kaining Hou, Zhaoyang Kang, Dongxin He, Hongshun Liu, Qingquan Li

{"title":"Research on Ultra-Wideband Pulse Current Method for DC Partial Discharge Measurement","authors":"Kaining Hou, Zhaoyang Kang, Dongxin He, Hongshun Liu, Qingquan Li","doi":"10.1049/hve2.70175","DOIUrl":"https://doi.org/10.1049/hve2.70175","url":null,"abstract":"The conventional pulse current method is commonly used in AC or DC withstand voltage tests with partial discharge (PD) monitoring. Because of its relatively narrow measurement bandwidth, this method tends to ignore critical information in PD waveforms, making it difficult to eliminate pulse-type interference under DC voltage conditions, where phase information is absent. To enhance interference rejection and achieve effective separation of multiple PD sources under DC voltage, an ultra-wideband pulse current method was proposed. A detection impedance was developed to extend the upper limit of the measurement bandwidth to 50 MHz to retain PD waveform information. PD waveforms measured from three defect models using both the conventional pulse current method and the ultra-wideband method were analysed in both time and frequency domains. The criterion function was employed to evaluate the difficulty level of classification of the PD waveforms obtained by the two measurement methods, and the results were validated using equivalent time–frequency (T–F) spectra. Field interference waveforms were introduced, and the density-based spatial clustering of applications with noise (DBSCAN) clustering method was applied for unsupervised clustering of the PD waveforms and interference waveforms. The results demonstrate that the ultra-wideband method can effectively separate multiple PD sources and eliminate interference sources under DC voltage conditions.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"19 1","pages":""},"PeriodicalIF":4.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of Positive Corona Discharge of Needle Plate Electrodes in Airflow 针板电极在气流中的正电晕放电研究

IF 4.4 2区工程技术

High Voltage Pub Date : 2026-03-10 DOI: 10.1049/hve2.70176

Lei Lan, Zhengxian Du, Qiang Wu, Yeqiang Deng, Yu Wang, Zeliang Wu, Xiankang Wang

引用次数: 0

Investigation of Dielectric and Thermal Properties of Mineral Oil-Based Fe3O4-Coated SiO2 Core-Shell Nanofluids 矿物油基fe3o4包覆SiO2核壳纳米流体介电和热性能研究

IF 4.9 2区工程技术

High Voltage Pub Date : 2026-02-28 Epub Date: 2025-11-06 DOI: 10.1049/hve2.70115

Mohamed H. Abdo, El-Sayed M. El-Refaie, Abd Elrahman S. Tawfic, Diaa-Eldin A. Mansour

{"title":"Investigation of Dielectric and Thermal Properties of Mineral Oil-Based Fe3O4-Coated SiO2 Core-Shell Nanofluids","authors":"Mohamed H. Abdo, El-Sayed M. El-Refaie, Abd Elrahman S. Tawfic, Diaa-Eldin A. Mansour","doi":"10.1049/hve2.70115","DOIUrl":"10.1049/hve2.70115","url":null,"abstract":"This study investigates the dielectric and thermal properties of transformer oil-based nanofluids incorporating Fe3O4-coated SiO2 core–shell nanoparticles as nanofillers. The nanoparticles were synthesised with varying shell thicknesses, and two samples underwent surface treatment. Fourier transform infrared spectroscopy was used to characterise the nanoparticles. The spectra for unmodified and modified nanoparticles detected Fe-O bond, Si-O-Si bond and oleic acid existence. The nanofluids were prepared using a two-step method: nanoparticles were first prepared at concentrations of 0.04, 0.07 and 0.10 g/L, and then mixed with the base oil and dispersed using ultrasonication. AC breakdown strength was measured for samples at these concentrations to determine the optimum concentration for each type of nanoparticle. The optimum concentration, which provided the best performance for AC breakdown voltage across all nanoparticle types, was found to be 0.07 g/L. Thermal conductivity testing was then conducted at this optimum concentration. The addition of nanofillers resulted in increased AC breakdown strength and thermal conductivity. Particle size and zeta size measurements were carried out to assess the dispersion behaviour of the nanofluid samples. The physical discussion examined potential reasons for improvements in AC breakdown voltage and thermal conductivity. Trapping and de-trapping processes, shell thickness and surface modifications were analysed in relation to improved dielectric performance. Ballistic phonon transport and Brownian motion mechanisms were employed to explain the observed enhancements in thermal conductivity. These findings indicate the potential for developing a new class of liquid dielectrics suitable for use in power transformers.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"11 1","pages":"243-254"},"PeriodicalIF":4.9,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.70115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145454706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved DC Properties of Polypropylene HVDC Cable Insulation by Grafting and Blending Combined Modification 接枝共混复合改性改善聚丙烯高压直流电缆绝缘直流性能

IF 4.9 2区工程技术

High Voltage Pub Date : 2026-02-28 Epub Date: 2026-01-11 DOI: 10.1049/hve2.70129

Xindong Zhao, Jiaqi Wang, Xu Yang, Kai Wang, Ling Weng, Jiaming Yang, Hong Zhao, Yunpeng Zhan, Shuai Hou, Mingli Fu

{"title":"Improved DC Properties of Polypropylene HVDC Cable Insulation by Grafting and Blending Combined Modification","authors":"Xindong Zhao, Jiaqi Wang, Xu Yang, Kai Wang, Ling Weng, Jiaming Yang, Hong Zhao, Yunpeng Zhan, Shuai Hou, Mingli Fu","doi":"10.1049/hve2.70129","DOIUrl":"10.1049/hve2.70129","url":null,"abstract":"In order to meet the needs of mechanical properties of cable insulation, polypropylene (PP) needs to be blended with low modulus materials to achieve toughening and softening. However, the compatibility between two or more resins can significantly affect the electrical properties of the composites. To solve this problem, the styrene–ethylene/butylene–styrene block copolymer (SEBS) with high heat resistance is selected as the blending elastomer, and grafted polypropylene (GPP) is prepared to be as basic resin. The morphological structure, thermal properties, mechanical properties and high temperature DC electrical properties of PP, GPP, PP/SEBS and GPP/SEBS are studied. The results demonstrate that compared with PP/SEBS, GPP/SEBS has significantly refined ‘island phase’ structure, further reduced storage modulus and slightly increased tensile strength and elongation at break and higher viscosity at low shear frequency. Electrical properties test results show that the grafted composite exhibits obvious suppression effect on space charge and conductance current, and enhances the DC breakdown strength. The introduction of the grafted material not only effectively improves the compatibility of the composites but also significantly improves the electrical properties of the material. This result can provide a reference for the development of eco-friendly high voltage cable materials.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"11 1","pages":"73-82"},"PeriodicalIF":4.9,"publicationDate":"2026-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.70129","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145968635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0