High Voltage最新文献_第6页

Fast prediction of temperature distributions in oil natural air natural transformers using proper orthogonal decomposition reduced-order data-driven modelling

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-30 DOI: 10.1049/hve2.12446

Haijuan Lan, Wenhu Tang, Jiahao Gong, Zeyi Zhang, Xiongwen Xu

{"title":"Fast prediction of temperature distributions in oil natural air natural transformers using proper orthogonal decomposition reduced-order data-driven modelling","authors":"Haijuan Lan, Wenhu Tang, Jiahao Gong, Zeyi Zhang, Xiongwen Xu","doi":"10.1049/hve2.12446","DOIUrl":"https://doi.org/10.1049/hve2.12446","url":null,"abstract":"In response to the time-consuming computational fluid dynamics simulations faced in naturally convective oil-immersed transformers, which result from complex models and a high degree of freedom, an innovative reduced-order digital twin prediction model for transformer temperature fields is proposed. This model facilitates fast predictions of transient temperature distributions. Initially, a comprehensive full-order finite element model of transformer temperature distributions is established. Subsequently, a hybrid approach, combining proper orthogonal decomposition (POD)-Galerkin and data-driven techniques, is proposed to create a reduced-order model (ROM). In this model, a Fourier number is utilised as a criterion to select POD training snapshot sets. Subsequently, the dynamic predictive capability of the proposed model under changing operational conditions is validated. Finally, the ROM is employed for fast predictions of temperature field, and its computational errors and time efficiency are compared across diverse operating conditions with full-order models. The research findings confirm the precision, timeliness, and dynamic nature of the reduced-order prediction model, offering a substantial improvement in prediction efficiency and capabilities, all while preserving the accuracy of the digital twin model.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1246-1259"},"PeriodicalIF":4.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12446","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253712","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

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

An analysis of parameters affecting ampacity in aircraft bipolar MVDC power cables via coupled electrical, thermal, and computational fluid dynamic modelling

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-28 DOI: 10.1049/hve2.12452

Arian Azizi, Mona Ghassemi

{"title":"An analysis of parameters affecting ampacity in aircraft bipolar MVDC power cables via coupled electrical, thermal, and computational fluid dynamic modelling","authors":"Arian Azizi, Mona Ghassemi","doi":"10.1049/hve2.12452","DOIUrl":"https://doi.org/10.1049/hve2.12452","url":null,"abstract":"The next generation of aircraft, including more electric aircraft and all-electric aircraft (AEA), requires electric power systems with high power density and low system mass specifications. Increasing the voltage of the system to the range of a few kV, medium voltage (MV), is a reasonable approach to achieving high-power-density and low-system-mass EPSs for aircraft applications. Higher voltages, however, pose many challenges for aviation MV power cables such as arcs and arc tracking, partial discharges (PDs), and thermal management. In this regard, thermal management is more challenging since heat transfer by convection is greatly reduced at wide-body aircraft's cruising altitudes due to the reduced air pressure. In this paper, a finite element method (FEM) model is developed in COMSOL Multiphysics for an aircraft bipolar MVDC (±5 kV) power cable. Using the model, the maximum permissible cable current at a low pressure of 18.8 kPa (at an altitude of 12.2 km from sea level, the usual cruising altitude for wide-body aircraft) is calculated. Also, an analytical model is developed based on analytical and proven empirical correlations governing conductive, radiative, and convective heat transfers at the steady state to estimate the ampacity of the bipolar cable system at reduced pressure. It was shown that the proposed analytical model can be used for atmospheric pressure and systems with a larger number of poles, expanding its range of applications. The results of the FEM and analytical models correlate at wide ranges of parameters such as ambient temperature, duct size, distance between the positive and negative pole cables, and the overall diameter of the cables. The influence of horizontal and vertical arrangement of poles is included in the analytical model. The results of this study can be used to design bipolar MVDC power cable systems for the envisaged wide-body AEA.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1208-1220"},"PeriodicalIF":4.4,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12452","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253734","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

Accumulation characteristics of precipitation static on rotating wind turbine blades and its influence on the lightning attachment characteristics

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-24 DOI: 10.1049/hve2.12458

Lingfeng Jiang, Zhenglong Jiang, Jiazheng Lu, Dexiong Hu, Pengkang Xie, Xiaoqi Huang

{"title":"Accumulation characteristics of precipitation static on rotating wind turbine blades and its influence on the lightning attachment characteristics","authors":"Lingfeng Jiang, Zhenglong Jiang, Jiazheng Lu, Dexiong Hu, Pengkang Xie, Xiaoqi Huang","doi":"10.1049/hve2.12458","DOIUrl":"https://doi.org/10.1049/hve2.12458","url":null,"abstract":"The linear velocity at the tip of large wind turbine blades can reach 100 m/s, generating static electricity through friction with airborne particles. However, the accumulation characteristics of precipitation static on the blade surface and its impact on the lightning attachment characteristics are rarely reported. The authors constructed a platform for measuring charges on rotating wind turbine blades and employed the electrostatic probe method to obtain the accumulation characteristics of surface charges under different environmental conditions. The experimental results show that positive charges accumulate on the blade surfaces, peaking at 0.69 μC/m2 under experimental conditions. The charge density is positively correlated with airborne particle concentration and blade rotation speed, while it is negatively correlated with relative air humidity. Additionally, the authors developed a model of the electric field distribution on wind turbine blades considering the effects of precipitation static. Simulation results indicate that the electrostatic field induced by precipitation static weakens the field strength in the vicinity of receptors, reaching a minimum of only 38% of the original strength, thereby increasing the probability of lightning protection failure. The findings provide an effective supplement to the lightning attachment mechanism of rotating wind turbine blades.","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1270-1279"},"PeriodicalIF":4.4,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12458","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143253185","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

Theoretical and experimental studies on the self-healing properties of metallised capacitor films under multiple stresses

IF 4.4 2区工程技术

High Voltage Pub Date : 2024-05-24 DOI: 10.1049/hve2.12459

Zhiyuan Wu, Shangshu Liu, Tong Tong, Shaolong Zhong, Jiantao Wang, Hongbin Qi, Zhimin Dang, Wei Wang

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