High Voltage最新文献_第3页

Hindered phenolic antioxidant grafting on tailoring the DC electrical characteristics of polypropylene cable insulation 受阻酚类抗氧化剂接枝对定制聚丙烯电缆绝缘直流电特性的影响

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-30 DOI: 10.1049/hve2.12450

Boxue Du, Guoning Sun, Heyu Wang, Zhonglei Li

{"title":"Hindered phenolic antioxidant grafting on tailoring the DC electrical characteristics of polypropylene cable insulation","authors":"Boxue Du, Guoning Sun, Heyu Wang, Zhonglei Li","doi":"10.1049/hve2.12450","DOIUrl":"https://doi.org/10.1049/hve2.12450","url":null,"abstract":"The authors focus on the impact of melt-free radical grafting with hindered phenolic antioxidants (AO3052) on the electrical properties of polypropylene (PP) for DC cable insulation. The DC conductivity, space charge distribution and breakdown characteristic tests of grafting-modified PP are performed by comparing unmodified PP. The results demonstrate that the grafting of antioxidants can effectively suppress space charge injection, owing to the deeper trap sites at the grafting molecule. The breakdown strength of the grafted PP is significantly enhanced from 30°C to 90°C and especially achieves a 5.3%–6.7% increase after the same DC-prestressed time at 90°C. The surface electrostatic potential and molecular orbitals of the grafted PP are calculated. Simulation shows that the antioxidant introduces multi-level local state traps that can effectively trap the injected space charge, thus decreasing the destruction of molecular chains by electrons and increasing the breakdown strength level. In conclusion, antioxidant grafting modification can improve the breakdown characteristics with or without DC prestress, and thus it appears to be promising in the application of PP-insulated cables.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"971-980"},"PeriodicalIF":4.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12450","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541027","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

Study on space charge accumulation characteristics of silicone elastomer under DC voltage 直流电压下硅树脂弹性体的空间电荷积累特性研究

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-30 DOI: 10.1049/hve2.12445

Jinqiang Zhang, Xuebao Li, Peng Sun, Zhibin Zhao, Xiang Cui, Xiaoguang Wei, Xinling Tang, Rui Jin

{"title":"Study on space charge accumulation characteristics of silicone elastomer under DC voltage","authors":"Jinqiang Zhang, Xuebao Li, Peng Sun, Zhibin Zhao, Xiang Cui, Xiaoguang Wei, Xinling Tang, Rui Jin","doi":"10.1049/hve2.12445","DOIUrl":"https://doi.org/10.1049/hve2.12445","url":null,"abstract":"The electric field distortion caused by the accumulation of space charge in the insulating dielectric is easy to lead to accelerated ageing and even breakdown. In this paper, the space charge characteristics and the interfacial electric field change with time of silicone elastomer under different polarity DC voltages are studied. The results show that the homopolar charge injection is dominant in the silicone elastomer, and the electric field threshold is less than 4 kV/mm. The accumulation of homopolar charge weakens the interfacial electric field, resulting in the reduction of charge injection, and the interfacial electric field and spatial charge distribution gradually stabilise over time. In addition, the electric field at the interface does not decrease to the charge injection field threshold when it reaches stability. A time-varying electric field model of the metal-dielectric interface under a direct current field is derived and a calculation method for the time of charge accumulation to stabilise is proposed, based on the Schottky injection model and the relation between current density and volume charge density. The accuracy of the model is verified by comparing it with the experimental results of the stability time of silicone elastomer. This model is used to estimate the time when space charge accumulation reaches stability by means of the electric field threshold and the interface barrier, which can provide reference for the experimental measurement of space charge.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"1001-1010"},"PeriodicalIF":4.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12445","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541026","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

Failure mechanism of metallized film capacitors under DC field superimposed AC harmonic: From equipment to material 直流电场叠加交流谐波下金属化薄膜电容器的失效机理：从设备到材料

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-28 DOI: 10.1049/hve2.12453

Zhiyuan Li, Yihan Zhou, Xuguang Wang, Hongbo Liu, Lu Cheng, Wenfeng Liu, Shengtao Li, Jiang Guo, Yang Xu

{"title":"Failure mechanism of metallized film capacitors under DC field superimposed AC harmonic: From equipment to material","authors":"Zhiyuan Li, Yihan Zhou, Xuguang Wang, Hongbo Liu, Lu Cheng, Wenfeng Liu, Shengtao Li, Jiang Guo, Yang Xu","doi":"10.1049/hve2.12453","DOIUrl":"https://doi.org/10.1049/hve2.12453","url":null,"abstract":"This study focuses on the degradation behaviour of metallised film capacitors, which are the essential components for the stability of converter valves in flexible ultra-high voltage direct current (HVDC) transmission systems. Through systematic experimentation, we investigated the failure mechanisms of MFCs under HVDC fields with superimposed harmonics, considering both equipment and material perspectives. The experiments subjected capacitors to 500 h of ageing under two conditions: a DC/AC-superimposed field with a constant DC component of 290 kV/mm and an AC ripple rate varying from 12% to 28%, and a control group aged solely under a DC field. Our findings indicate that capacitors aged under the DC/AC-superimposed field exhibited shorter lifespans and more significant capacitance loss than those aged under only the DC field. This difference in performance is primarily attributed to the distinct electrode loss behaviours observed under each ageing condition, which are key factors in the capacitors' capacitance decay. Moreover, the biaxially oriented polypropylene films in the DC-aged samples showed more severe deterioration, characterised by more noticeable molecular chain scission and reduced breakdown strength, compared to those aged under the DC/AC superimposed field. This difference is partly due to the moderate temperature increase caused by harmonics, which benefits the aggregation structure, and partly to the reduced molecular structure damage from the AC field.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"1081-1089"},"PeriodicalIF":4.4,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12453","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541073","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

Degradation of superhydrophobic aluminium overhead line conductor surfaces 超疏水性架空线路铝导体表面的降解

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-22 DOI: 10.1049/hve2.12455

Xu Zhang, Chorphaka Plaengpraphan, Chengxing Lian, Wenyuan Li, Qinghua Han, Simon M. Rowland, Ian Cotton, Qi Li

引用次数: 0

Effect of electric field on bubble generation and dissolution characteristics in oil–paper insulation 电场对油纸绝缘层中气泡生成和溶解特性的影响

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-22 DOI: 10.1049/hve2.12456

Chaojie Yang, Tao Zhao, Yunpeng Liu, Jiajun Yang, Jiaxue Xu, Yingcong Xu

{"title":"Effect of electric field on bubble generation and dissolution characteristics in oil–paper insulation","authors":"Chaojie Yang, Tao Zhao, Yunpeng Liu, Jiajun Yang, Jiaxue Xu, Yingcong Xu","doi":"10.1049/hve2.12456","DOIUrl":"https://doi.org/10.1049/hve2.12456","url":null,"abstract":"The interturn paper insulation of oil‐immersed power transformer windings, under the combined influence of electric fields, moisture, and conductor heating, will produce bubbles, which pose a significant threat to the insulation system. However, there is limited research on the characteristics of bubble evolution in oil–paper insulation under the influence of electric fields and the subsequent dissolution process. Based on the continuous observation of bubble size using electron microscopes, experimental and theoretical investigations into the formation and dissolution of bubbles under electric field conditions are presented. The effects of different field strengths on bubble evolution and dissolution characteristics were studied. The results showed that the electric field promoted both the generation and dissolution of bubbles, with a more pronounced effect observed at higher field strengths (below partial discharge (PD) inception electric field, hereafter referred to as PDIE). However, when the field strength exceeded PDIE, the bubbles tended to shrink and gradually increase in size. The changes in bubble volume were related to not only gas diffusion but also oxygen consumption and fault gases generation due to PD. A better understanding of the formation and dissolution characteristics of bubbles under varying field strengths is achieved. Furthermore, it also provides a reference for assessing the risk of bubble generation and conducting bubble‐related fault diagnosis during the overload operation of oil‐immersed power equipment.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"78 9","pages":""},"PeriodicalIF":4.4,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141111796","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

Experiment of electrothermal stress for different types of end turn grading in the inverter-fed form-wound windings 变频器馈电形式绕组中不同类型端部匝数分级的电热应力实验

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-22 DOI: 10.1049/hve2.12449

Wenhuan Zhao, Peng Wang, Yingwei Zhu, Yue Zhang, Shuai Yang, Yan Liu, Yang Shi, Chaofan Yu

{"title":"Experiment of electrothermal stress for different types of end turn grading in the inverter-fed form-wound windings","authors":"Wenhuan Zhao, Peng Wang, Yingwei Zhu, Yue Zhang, Shuai Yang, Yan Liu, Yang Shi, Chaofan Yu","doi":"10.1049/hve2.12449","DOIUrl":"10.1049/hve2.12449","url":null,"abstract":"End turn grading with resistive–capacitive coupling experiences severe electrothermal stress when subjected to pulse width modulation (PWM) voltage. In this paper, several experiments and simulations were carried conducted for four types of end turn grading. First of all, the temperature rise in the end turn grading increased with a decrease in rise time. When the rise time was less than 500 ns, the temperature rise at the terminal was higher owing to the increased capacitive current coupled from the main wall insulation. Further, the current in the linear region exhibited minimal variation at different fundamental frequencies resulting in synchronized the temperature rise at the terminal and overlap. Furthermore, the jump voltage was the key factor influencing temperature rise in end turn grading, confirmed by comparing different voltage magnitudes. Finally, the transient behaviour of the maximum field in the stress grading material was determined at rise time. The experimental and simulation results indicate that balancing and interdependently addressing the electrical and thermal stress protection in end turn grading is crucial. The study aims to provide an experimental and theoretical foundation for an insulation system of inverter-fed rotating machinery operating under PWM voltage.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"853-861"},"PeriodicalIF":4.4,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12449","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141112654","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

Intelligent identification method of insulation pull rod defects based on intactness-aware Mosaic data augmentation and fusion of YOLOv5s 基于完好性感知 Mosaic 数据增强和 YOLOv5s 融合的绝缘拉杆缺陷智能识别方法

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-21 DOI: 10.1049/hve2.12447

Changyun Li, Yuze Hua, Yilin Liu, Kai Liu, Sanyi Zhang

{"title":"Intelligent identification method of insulation pull rod defects based on intactness-aware Mosaic data augmentation and fusion of YOLOv5s","authors":"Changyun Li, Yuze Hua, Yilin Liu, Kai Liu, Sanyi Zhang","doi":"10.1049/hve2.12447","DOIUrl":"10.1049/hve2.12447","url":null,"abstract":"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.","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}

引用次数: 0

Characteristics of perfluoromethyl vinyl ether: A new eco-friendly alternative gas for SF6 全氟甲基乙烯基醚的特性：替代 SF6 的新型环保气体

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-17 DOI: 10.1049/hve2.12454

Song Xiao, Yijiang Chen, Mingjun Tang, Shuangshuang Tian, Haoran Xia, Yifan Wang, Ju Tang, Yi Li, Xiaoxing Zhang

{"title":"Characteristics of perfluoromethyl vinyl ether: A new eco-friendly alternative gas for SF6","authors":"Song Xiao, Yijiang Chen, Mingjun Tang, Shuangshuang Tian, Haoran Xia, Yifan Wang, Ju Tang, Yi Li, Xiaoxing Zhang","doi":"10.1049/hve2.12454","DOIUrl":"10.1049/hve2.12454","url":null,"abstract":"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.","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}

引用次数: 0

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? 氧化锌基自适应复合材料的非线性 I-V 曲线在电极相对放置并保持一系列水平距离的情况下表现如何？

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-12 DOI: 10.1049/hve2.12444

Ya Sun, Zhikang Yuan, Zhiwen Huang, Jun Hu, Jinliang He, Qi Li

{"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, Zhikang Yuan, Zhiwen Huang, Jun Hu, Jinliang He, Qi Li","doi":"10.1049/hve2.12444","DOIUrl":"10.1049/hve2.12444","url":null,"abstract":"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–V 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–V 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–V 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.","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}

引用次数: 0

Relationship between radar reflectivity thresholds and very low frequency/low frequency total lightning for thunderstorm identification 用于识别雷暴的雷达反射率阈值与极低频/低频总闪电之间的关系

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-10 DOI: 10.1049/hve2.12441

Yijun Huang, Jianguo Wang, Li Cai, Yadong Fan, Hongbin Wang, Tao Zhang

{"title":"Relationship between radar reflectivity thresholds and very low frequency/low frequency total lightning for thunderstorm identification","authors":"Yijun Huang, Jianguo Wang, Li Cai, Yadong Fan, Hongbin Wang, Tao Zhang","doi":"10.1049/hve2.12441","DOIUrl":"10.1049/hve2.12441","url":null,"abstract":"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.","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}

引用次数: 0