High Voltage最新文献

{"title":"Intelligent identification method of insulation pull rod defects based on intactness-aware Mosaic data augmentation and fusion of YOLOv5s","authors":"Changyun Li,&nbsp;Yuze Hua,&nbsp;Yilin Liu,&nbsp;Kai Liu,&nbsp;Sanyi Zhang","doi":"10.1049/hve2.12447","DOIUrl":"10.1049/hve2.12447","url":null,"abstract":"<p>The authors introduce the intactness-aware Mosaic data augmentation strategy, designed to tackle challenges such as low accuracy in detecting defects in insulation pull rods, limited timeliness in intelligent analysis, and the absence of a comprehensive database for information on insulation pull rod defects. The proposed strategy incorporates the YOLOv5s algorithm for detecting defects in insulation pull rods. Initially, the YOLOv5s network was constructed, and a dataset containing photos of insulation pull rods with white spots, fractures, impurities, and bubble flaws was compiled to capture images of defects. The research presented a data enhancement approach to improve the images and establish a dataset for insulation pull rod defects. The YOLOv5s algorithm was applied for both training and testing purposes. A comparative analysis was conducted to assess the detection performance of YOLOv5s against a conventional target detector for identifying defects in insulation pull rods. Furthermore, the utility of Mosaic's data augmentation technique, which incorporates intactness awareness, was evaluated to enhance the accuracy of identifying insulation pull rod defects. The research findings indicate that the YOLOv5s algorithm is employed for intelligent detection and precise localisation of flaws. The intactness-aware Mosaic data augmentation strategy significantly improves the accuracy of detecting faults in insulation pull rods. The YOLOv5s model used achieves a performance index [email protected]:0.95 of 0.563 on the test set, distinct from the training set data. With a threshold of 0.5, the [email protected] score is 0.904, indicating a substantial improvement in both detection efficiency and accuracy compared to conventional target detection methods. Innovative approaches for identifying defects in insulation pull rods are introduced.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"1171-1182"},"PeriodicalIF":4.4,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12447","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141114825","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}

{"title":"Characteristics of perfluoromethyl vinyl ether: A new eco-friendly alternative gas for SF6","authors":"Song Xiao,&nbsp;Yijiang Chen,&nbsp;Mingjun Tang,&nbsp;Shuangshuang Tian,&nbsp;Haoran Xia,&nbsp;Yifan Wang,&nbsp;Ju Tang,&nbsp;Yi Li,&nbsp;Xiaoxing Zhang","doi":"10.1049/hve2.12454","DOIUrl":"10.1049/hve2.12454","url":null,"abstract":"<p>The exploration of eco-friendly insulating gas to substitute the most potent greenhouse gas sulphur hexafluoride (SF₆) has consistently garnered significant attention. Herein, the authors evaluated the feasibility of utilising perfluoromethyl vinyl ether (PMVE, C₃F₆O) as a new branch of eco-friendly insulating gas for the first time. The primary dielectric and stability characteristics of PMVE regarding AC breakdown, partial discharge, dielectric recovery, and decomposition properties were revealed under various gas pressure and electrical field conditions. It was found that PMVE demonstrated superior dielectric strength, with the AC breakdown and PD inception voltage (PDIV) 1.10 and 1.14 times that of pure SF₆. Furthermore, the dielectric strength of PMVE exhibits stability even after undergoing 100 cycles of AC breakdowns, and there is no observable formation of solid precipitation on the electrode surface. The discharge decomposition of PMVE mainly generates fluorocarbon (CF₄, C₂F₆, C₃F₆, C₃F₈, etc.) and CO. Overall, the exceptional insulation stability and no absence of solid precipitation features endow PMVE to be utilised as a new eco-friendly gas for SF₆-free gas-insulated equipment.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 3","pages":"509-517"},"PeriodicalIF":4.4,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12454","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127082","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}

{"title":"How do the non-linear I–V curves of ZnO-based adaptive composites behave with electrodes placed on the opposite sides with a series of horizontal distances?","authors":"Ya Sun,&nbsp;Zhikang Yuan,&nbsp;Zhiwen Huang,&nbsp;Jun Hu,&nbsp;Jinliang He,&nbsp;Qi Li","doi":"10.1049/hve2.12444","DOIUrl":"10.1049/hve2.12444","url":null,"abstract":"<p>Recently, ZnO-based composites have been widely applied in the field of electric power. To meet the diverse application requirements, it is necessary to figure out the <i>I–V</i> characteristics of ZnO composites whose high-voltage and ground-voltage electrodes are arranged on the opposite sides with a certain horizontal distance. 30 vol%, 40 vol% and 50 vol% ZnO-based silicone rubber composites were prepared. The horizontal distance between their electrodes was set as 50, 100, 500 μm, 1 and 2 mm, respectively. Results showed that with the increase of ZnO fillers volume fraction under a fixed horizontal distance of 100 μm, from 30 vol% to 50 vol%, the <i>I–V</i> curves shifted left, the leakage current increased and the switching voltage decreased. When the horizontal distance between electrodes increased from 50 μm to 1 mm under a fixed doping concentration of 40%, the <i>I–V</i> curves shifted to the right, the leakage current dropped and the switching voltage rose. The mathematical and physical models were established to explain the results. This work provides a referential significance for the practical application of ZnO composites, such as 5G folding mobile phones and power electronic modules.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"981-988"},"PeriodicalIF":4.4,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12444","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140987136","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}

{"title":"Relationship between radar reflectivity thresholds and very low frequency/low frequency total lightning for thunderstorm identification","authors":"Yijun Huang,&nbsp;Jianguo Wang,&nbsp;Li Cai,&nbsp;Yadong Fan,&nbsp;Hongbin Wang,&nbsp;Tao Zhang","doi":"10.1049/hve2.12441","DOIUrl":"10.1049/hve2.12441","url":null,"abstract":"<p>To improve our knowledge of the spatio-temporal correspondence between radar reflectivity and VLF/LF total lightning data, this paper proposes indexes to quantify the horizontal distribution and temporal evolution characteristics between radar composite reflectivity images and total lightning density map, lightning clusters and radar cells with different radar reflectivity thresholds (30, 35, 40, 45 and 50 dBZ), respectively. It is found that the number of radar grid cells with radar reflectivity over 30 dBZ is ten times the number of lightning grid cells. At the identification stage, the lightning activity regions in a radar cell account for less than 30% using thresholds of 30, 35 and 40 dBZ, respectively, and the radar cell has more than one lightning cluster, which means that the mesoscale convective systems typically have more than one draft, and drafts are only small part of the convection. The majority of the centroid deviations is less than 10 km, indicating that there are some shifts between electrically active regions and convective regions. Results suggest that VLF/LF total lightning data are consistent with radar data and total lightning data can be used individually on a smaller spatio-temporal scale than radar data.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"1068-1080"},"PeriodicalIF":4.4,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12441","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140990099","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}

{"title":"Predicting transformer temperature field based on physics-informed neural networks","authors":"Pengfei Tang,&nbsp;Zhonghao Zhang,&nbsp;Jie Tong,&nbsp;Tianhang Long,&nbsp;Can Huang,&nbsp;Zihao Qi","doi":"10.1049/hve2.12435","DOIUrl":"10.1049/hve2.12435","url":null,"abstract":"<p>The safe operation of oil-immersed transformers is critical to the safety and stability of the power grid. As the operating time increases, the failure rate of oil-immersed transformers shows an increasing trend, posing serious challenges to safe operation. It is necessary to investigate the internal state of the oil-immersed transformer to improve the digital degree and achieve digitalisation and intelligent operation and maintenance. A physics-informed neural network (PINN) for oil-immersed transformers was introduced to reconstruct the temperature distribution inside the transformer. According to the approach, the loss function of the network would be optimised by incorporating physical constraint loss terms including heat transfer equations, initial conditions and boundary conditions. The results show that the method proposed can be used to reconstruct and predict the temperature field of transformers in a few seconds with satisfactory accuracy. In conclusion, the PINN proposed outperforms deep neural networks in terms of accuracy, reliability and interpretability, especially in data-poor cases.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"839-852"},"PeriodicalIF":4.4,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12435","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140996455","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}

{"title":"Adsorption and sensing characteristics of insulating gas C4F7N on 3d late transition metal-phthalocyanine: Theoretical and experimental study","authors":"Dachang Chen,&nbsp;Ziang Zheng,&nbsp;Cong Zhang,&nbsp;Yi Luo,&nbsp;Song Xiao,&nbsp;Qing Miao,&nbsp;Ke Liu,&nbsp;Beibei Xiao","doi":"10.1049/hve2.12437","DOIUrl":"10.1049/hve2.12437","url":null,"abstract":"<p>Heptafluoroisobutyronitrile (C₄F₇N) is being considered as a promising alternative to the greenhouse gas SF₆ in the electrical industry. However, its biotoxicity necessitates the development of gas sensing technology to detect leaked C₄F₇N. A combination of density functional theory and experiments was employed to evaluate the adsorption and sensing performance of different metal-phthalocyanines as potential sensing materials for C₄F₇N detection. The study included exploring adsorption configurations with adsorption energies, electron transfer, and adsorption distance, as well as comparisons of electronic properties, electron distribution, and density of states (DOS) among the MPcs. Furthermore, gas sensing experiments were conducted using different MPcs to detect 25–100 ppm C₄F₇N. The results revealed that Mn-Pc, Fe-Pc, Co-Pc, and Zn-Pc exhibited considerable chemical interactions, while Ni-Pc and Cu-Pc showed weaker adsorption strength. These findings were further elucidated based on the electron density and DOS of atomic orbitals. Moreover, gas sensing experiments indicated that Co-Pc demonstrated a higher response compared to Fe-Pc at the same concentration of C₄F₇N. Overall, the theoretical and experimental insights offer valuable guidance for C₄F₇N detection and provide a systematic approach to screen and explore organometallic polymer-based gas sensors applicable in various fields.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"870-878"},"PeriodicalIF":4.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004606","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}

{"title":"Photodetector array for measuring the spatial–temporal distribution characteristics of electric field in oil–pressboard insulation based on the Kerr electro-optic effect","authors":"Chunjia Gao,&nbsp;Bo Qi,&nbsp;Chengrong Li,&nbsp;Yukung Zheng","doi":"10.1049/hve2.12442","DOIUrl":"10.1049/hve2.12442","url":null,"abstract":"<p>Accurate measurement and effective analysis of the space electric field and charge characteristics within the oil–pressboard insulation structure of converter transformer are essential for achieving precise insulation structure design. Presently, most electric field measurement methods relying on the Kerr electro-optical effect are limited to single-point measurements. Given the complexity of converter transformer insulation structures, including their large scale and the use of various materials, existing technologies and findings struggle to provide comprehensive electric field observations within the oil–pressboard region. After leveraging the Kerr electro-optic effect, a high-precision 32-unit photodetector array has been developed to achieve regional measurements of spatial-temporal electric field in oil–pressboard insulation. The array boasts a measurement spatial resolution of 1.4 mm² and a sensitivity of 0.15 kV/mm, ensuring measurement accuracy exceeding 96.50%. Through practical measurements of the spatial electric field distribution within the oil–pressboard insulation under direct current voltage, the non-uniform distribution of the electric field is effectively captured in oil. Notably, the maximum deviation in field strength at different positions within the transformer oil can reach 18.5%. Moreover, as the applied voltage increases, the unevenness coefficient of the field strength gradually rises, peaking at 1.19, which signifies a progressive expansion in the area affected by electric field distortion. By conducting tests to assess the dispersion of volume resistivity in samples from various positions within large sheets of pressboard, the variation in volume resistivity of materials is posited as one of the contributing factors to the non-uniform distribution of electric field within the oil. The detailed accomplishments aim to provide essential technical and theoretical support for optimising insulation structure design of converter transformers.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"10 1","pages":"95-105"},"PeriodicalIF":4.4,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12442","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140658093","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}

{"title":"Effects of electrothermal ageing on dielectric performance of metallised biaxial orientation polypropylene film capacitors in strong magnetic fields","authors":"Haoliang Liu,&nbsp;Boxue Du,&nbsp;Meng Xiao,&nbsp;Ke Chen,&nbsp;Yanwei Ma","doi":"10.1049/hve2.12439","DOIUrl":"10.1049/hve2.12439","url":null,"abstract":"<p>The dielectric performance of the pristine and the electrothermal-aged metallised polypropylene capacitors are investigated under different magnetic fields. The energy storage capacity decreases under the magnetic field. At 12 T, the capacitance value of the pristine capacitors decreases by 8.4%–17% and that of the aged capacitors declines by 15%–20%. The dielectric loss is reduced by 2.6%–6.3%, but the equivalent series resistance shows an 8.3%–23.1% growth. The leakage conductivity increases to 202%–354%, which leads to a weakened voltage holding capacity. In addition to the effects of the magnetic fields, the impacts of ageing have also been investigated. The effects of the magnetic field and ageing on the electrical parameters of the capacitors are discussed separately. The molecular chains of the dielectric are oxidised and decomposed during the ageing process, which reduces the insulating properties of the dielectric. The magnetic field inhibits polarisation by changing the polarisation behaviour through Lorentz force and excites the electrons to enhance charge transmission.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"911-919"},"PeriodicalIF":4.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12439","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140690998","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}

{"title":"Experimental qualification and sensitivity study of antipodal patch antenna structures for orientation independent detection of partial discharges","authors":"Kerstin Friebe,&nbsp;Frank Jenau","doi":"10.1049/hve2.12434","DOIUrl":"10.1049/hve2.12434","url":null,"abstract":"<p>Partial discharge diagnosis is an important part of monitoring and diagnosing components of the power transmission system. Four different patch antenna structures for the detection of partial discharges are investigated. These patch antennas, which are realisable in a variety of geometric structures, are already the subject of research. They offer the advantage of contactless detection without intervention in the test object or the measuring circuit, and also offer the possibility of alignment independent detection compared to directional antennas. However, it is important and required to examine different structures extensively at the same measurement setup and to compare their performance. To achieve this, four different configurations of patch antenna structures based on basic geometries all in antipodal design are realised: a logarithmic periodic structure, a Hilbert fractal structure and two tapered slot antennas. They are exposed to the same conditions on a special and unique measurement setup. As the main aspect, the performance of orientation independent detection of partial discharges patch antennas with varying distance and rotation in relation to the partial discharge source as well as the operating bandwidth is examined. To rate the structures, an evaluation scheme is created and a sensitivity matrix is generated.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 3","pages":"674-684"},"PeriodicalIF":4.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12434","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140690516","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}

{"title":"Enhancing dielectric properties and energy storage performance of polyvinylidene fluoride composite by surface-modified AgNbO3 nanoparticles","authors":"Zhuo Wang,&nbsp;Ting Zhao,&nbsp;Dan Wu,&nbsp;Ying Xue,&nbsp;Zhihui Yi,&nbsp;Jinteng Kang,&nbsp;Ronghui Ye,&nbsp;Ning Guo","doi":"10.1049/hve2.12438","DOIUrl":"10.1049/hve2.12438","url":null,"abstract":"<p>The introduction of antiferroelectric filler AgNbO₃ into the polyvinylidene fluoride (PVDF) polymer matrix enhances its energy storage properties of PVDF. However, AgNbO₃ and PVDF matrix are incompatible due to their distinct physical and chemical properties, resulting in poor compatibility between the two phases. Surface modification enhances the large difference in physical and chemical properties between the filler and the polymer matrix, and improves the compatibility between the two phases. Silane coupling agents (KH550, KH560), dopamine (DA), and grafted poly(methyl methacrylate) (PMMA) were used to modify the surface of AgNbO₃ particles, and the effects of different surface modification methods on the energy storage performance of the composites were studied. The PVDF matrix was introduced with 0.3 wt% AgNbO₃ particle filler. The results showed that the amino group in KH550 had the strongest binding with PVDF. The ester group in PMMA has a strong binding with PVDF. The epoxy group in KH560 has a weak binding with PVDF, while the amino group in DA has the worst binding with PVDF. The compatibility of the two phases in AgNbO₃@KH550/PVDF composites is the best, and the charge distribution on the surface of the filler is uniform. Under an electric field of 350 kV/mm, the energy storage density is 8.48 J/cm³.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"939-947"},"PeriodicalIF":4.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12438","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140692066","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}