{"title":"A strategy for accurate prediction of dielectric permittivity and dielectric strength in polyimide","authors":"Yu Wang, Changhai Zhang, Jiaqi Lin, Hongguo Sun, Ying Yang, Wenlong Yang","doi":"10.1049/hve2.12479","DOIUrl":"https://doi.org/10.1049/hve2.12479","url":null,"abstract":"<p>A strategy was proposed to predict accurately the dielectric permittivity and dielectric strength based on the Onsager local field theory. The molecular dynamic simulation was utilised to analyse the dipole moment fluctuation in polyimide (PI) to reflect the polarisation response of applied electric field. The simulation results revealed that the optical dielectric permittivity and static dielectric permittivity were 2.62 and 3.34, showing that the electronic displacement polarisation of the PI acted as a major contributor. The deviation between simulated and measured values of the frequency-dependent relative dielectric permittivity was no more than 5%, which exhibited high accuracy. As the polarisation response of the polar groups in the PI was at infrared frequencies, the conductive loss may be the dominant role in 10<sup>2</sup>–10<sup>6</sup> Hz at room temperature. Moreover, the effect of Joule heat on the structure, dielectric permittivity and Young modulus was considered to accurately predict the dielectric strength of the PI (359 kV/mm), which was in agreement with experimental values in the literature. These results establish a clear correlation between structural characteristics and dielectric properties of the PI, which would be the theoretical insights into the design and synthesis of the PI with tailored dielectric properties.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1393-1401"},"PeriodicalIF":4.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12479","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143252979","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":"High-strength, electrically insulated industrial meta-aramid paper reinforced with polyethylene terephthalate microfibre pulp in a sandwich structure","authors":"Meijun Chen, Songjun Yao, Guobin Zhu, Mengyun Wu, Zhiying Li, Siwei Xiong, Shiwen Yang, Hua Wang, Liangbo Zhu, Luoxin Wang","doi":"10.1049/hve2.12474","DOIUrl":"https://doi.org/10.1049/hve2.12474","url":null,"abstract":"<p>The weak interfacial strength and porous structure of the meso-aramid paper cause mechanical and insulating deficiencies. Enhancing density, regulating pore structure, and improving interfacial interactions of meso-aramid are crucial for promoting the performance of meso-aramid papers. A PMIA/polyethylene terephthalate (PET) composite paper was prepared using the wet method with meso-aramid short cut fibres (PMIA) and PET pulp as raw materials. The sandwich-structured PMIA/PET paper was achieved by covering PET microfiber non-wovens served as the surface layer while the PMIA/PET composite paper acted as the core layer. During the high-temperature hot pressing process, the PET pulp transformed into a viscous melt that coated on aramid fibres in between layers, forming a typical ‘reinforced concrete’ interface structure within the core layer of the PMIA/PET composite paper. The PET non-wovens on top and bottom surfaces were converted into a dense PET film that filled and covered the holes and defects in the PMIA/PET composite paper. This unique structure enabled the sandwich-structured PMIA/PET composite paper to exhibit excellent tensile strength (80.41 N/cm) and breakdown strength (56.35 kV/mm), surpassing most reported performances of meso-aramid papers in literature. This work not only provides novel insights for preparing high-performance meso-aramid papers, but also shows potential applications for other materials and structures.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1402-1413"},"PeriodicalIF":4.4,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12474","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143252782","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}
High VoltagePub Date : 2024-08-01DOI: 10.1049/hve2.12473
Shifang Yang, Zexuan Zhang, Qianpeng Hou, Yunpeng Liu, Chi Gong
{"title":"Preparation, characterisation and enhanced fungistatic properties of silicone rubber with different concentrations of CMIT/MIT","authors":"Shifang Yang, Zexuan Zhang, Qianpeng Hou, Yunpeng Liu, Chi Gong","doi":"10.1049/hve2.12473","DOIUrl":"https://doi.org/10.1049/hve2.12473","url":null,"abstract":"<p>The authors explore the limitations of silicone rubber (SR) in tropical environments due to its lack of antimicrobial activity. The use of a 2-methylisothiazol-3(2H)-one compound with 5-chloro-2-methylisothiazol-3(2H)-one is proposed as an efficient and environmentally friendly antimicrobial agent to enhance the fungistatic properties of SR. The fungicide added specimen was obtained by directly adding a quantitative amount of isothiazolinone to the polymer system. Through an in-depth analysis of the material properties of MCMSR, the form in which 2-methyl-4-isothiazolin-3-one/5-chloro-2-methyl-4-isothiazolin-3-one (MIT/CMIT) exists in the molecular structure of the SR crosslink system was carefully explored. The accelerated hydrolysis process of polysiloxane, which caused fungi secretion, was proven to be suppressed due to the effects of MIT/CMIT. The antimicrobial mechanism of isothiazolinone in preventing microbial growth was interpreted as the apoptosis and necrosis procedures of <i>Aspergillus niger</i> cells, which were verified by flow cytometry results. By choosing the appropriate concentration of isothiazolinone, the original properties of the SR were successfully maintained while effectively preventing the aggregation of isothiazolinone. This opens up a new research direction and application prospect for the antimicrobial modification of SR.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1370-1382"},"PeriodicalIF":4.4,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12473","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143243213","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}
High VoltagePub Date : 2024-07-31DOI: 10.1049/hve2.12476
Manuel De La Hoz, Petrus Jacobus Pieterse, Agurtzane Etxegarai, Diego Gonzalez, Ángel Javier Mazon, Dirk Uhrlandt
{"title":"Comparison of corona effect prediction criteria on sphere-plane configuration","authors":"Manuel De La Hoz, Petrus Jacobus Pieterse, Agurtzane Etxegarai, Diego Gonzalez, Ángel Javier Mazon, Dirk Uhrlandt","doi":"10.1049/hve2.12476","DOIUrl":"https://doi.org/10.1049/hve2.12476","url":null,"abstract":"<p>When designing high-voltage elements, knowing if the corona effect will be present during their life cycle is relevant. Therefore, designers consider several prediction criteria based on physical features related to breakdown discharge principles to predict the corona effect. The introduced practical set-up consists of a concave cone electrode with a hemispheric tip above a plate to evaluate selected corona prediction criteria. The hemisphere has a fixed diameter of 7 mm, and the electrode separation ranges from 2.5 to 39 cm. Information about the corona mode inception under different voltage sources was extracted using an intensified charge-coupled device camera and a partial discharge metre. The prediction criteria were connected to a specific corona mode depending on the main discharge structure behind its development. The average deviation between these criteria and experimental results was around eight percent. Underlying assumptions in criteria are also discussed in light of the experimental results.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"957-969"},"PeriodicalIF":4.4,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12476","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007199","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}
High VoltagePub Date : 2024-07-30DOI: 10.1049/hve2.12475
Giovanni Gardan, Gian Carlo Montanari
{"title":"AC ripple on DC voltage: Experimental and theoretical investigation of the impact on accelerated ageing in electrical insulation","authors":"Giovanni Gardan, Gian Carlo Montanari","doi":"10.1049/hve2.12475","DOIUrl":"https://doi.org/10.1049/hve2.12475","url":null,"abstract":"<p>With the increasing penetration of DC systems into the high voltage and medium voltage power industry, DC voltage is becoming common for distribution/transmission and to supply different typologies of loads. The allowable extent of AC ripple superimposed to DC, and its effect on insulation ageing, is a long-term discussed topic. The most harmful phenomenon causing extrinsic ageing acceleration and insulation system premature failure is partial discharges (PD); thus, the risk of incepting PD due to AC ripple could become a primary issue for electrical asset equipment reliability. In this work, the impact of AC sinusoidal ripple on insulation system life and reliability is dealt with, considering both intrinsic and extrinsic ageing but focusing on the latter, that is, the PD aspect. Experiments are performed to assess how the jump voltage (due to AC ripple) and the DC component impact on PD activity in terms of amplitude and repetition rate. For the first time, the correlation between the magnitude of jump voltage associated with ripple and PD inception is established, shedding a light on the allowable ripple extent which does not impact significantly on ageing and premature insulation failure. This approach can provide straightforward tools for design specification and ageing inference of insulation systems.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"902-910"},"PeriodicalIF":4.4,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12475","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007198","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}
High VoltagePub Date : 2024-07-30DOI: 10.1049/hve2.12477
Abdul Samad, W. H. Siew, Martin Given, John Liggat, Igor Timoshkin
{"title":"Effects of polyurethane hardness on the propagation of acoustic signals from partial discharge","authors":"Abdul Samad, W. H. Siew, Martin Given, John Liggat, Igor Timoshkin","doi":"10.1049/hve2.12477","DOIUrl":"https://doi.org/10.1049/hve2.12477","url":null,"abstract":"<p>Polymeric insulation is a critical component of high voltage systems. However, exposure to high electric stress can cause partial discharges (PDs) to occur and may result in the deterioration of insulation and lead to dielectric failure. These PD events are accompanied by the production of acoustic pressure impulses in the polymer. Detection of these acoustic pressure impulses can reveal the presence of PDs and locate their source. However, analysing the detected acoustic emission (AE) signal is challenging. The acoustic pressure source's nature and the propagating medium's properties, such as density, viscosity, and elasticity, significantly affect the propagating AE signal. The effects of the hardness of the polyurethane (PU) on the propagating AE signal are reported by the authors based on results obtained from laboratory experiments. It was observed that the decay rate in the magnitude of the acoustic impulse was high in PU at all hardness levels following an exponential behaviour. The analysis of the frequency spectra indicates that the higher frequency components attenuate more strongly with distance. These laboratory results can be valuable for engineers and industries as they provide valuable insight into how the physical characteristics of a material affect the propagation characteristics of AE signals during the detection and location of PD source using the AE detection technique.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 5","pages":"1125-1135"},"PeriodicalIF":4.4,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12477","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142541060","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":"Ultrasonic localization method based on Chan-WLS algorithm for detecting power transformer partial discharge faults by fibre optic F-P sensing array","authors":"Hong Liu, Tianhe Yang, Zhixian Zhang, Haoyuan Tian, Yuxuan Song, Qiuxia Sun, Wei Wang, Yunjun Geng, Weigen Chen","doi":"10.1049/hve2.12472","DOIUrl":"10.1049/hve2.12472","url":null,"abstract":"<p>Fibre optic F-P sensor has become one of the mainstream detection methods for partial discharge faults due to their advantages of good insulation, high sensitivity, resistance to electromagnetic interference, simple structure and inexpensive pricing. The first-order resonant frequency of the acoustically sensitive diaphragm of the F-P sensor is given based on the theory of plate and shell vibration, and the fibre optic F-P sensing array is designed based on the Fabry–Perot interference principle. A sensor installation method is also proposed for introducing a fibre optic F-P probe into the power transformer interior using a fibre optic penetrator through flange at the power transformer oil change valve. A system of non-linear equations is developed by utilising the time difference of arrival (TDOA) of the partial discharge ultrasound signal propagation to the F-P sensing array. The Chan-WLS algorithm is used to convert the non-linear equations in the TDOA localisation method into a non-linear optimisation problem to be solved and experimentally verified on the 220 kV real power transformer. The experimental results show that the error in the partial discharge fault localisation is solved based on the Chan-WLS algorithm and the actual location is 20.27 cm, which is within the acceptable error.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1234-1245"},"PeriodicalIF":4.4,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141822932","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}
High VoltagePub Date : 2024-07-15DOI: 10.1049/hve2.12465
Shijie Huang, Haiqing Niu
{"title":"Modular digital twin modelling method for 10 kV cable lines based on real-time temperature field inversion","authors":"Shijie Huang, Haiqing Niu","doi":"10.1049/hve2.12465","DOIUrl":"10.1049/hve2.12465","url":null,"abstract":"<p>State perception of long-span 10 kV cable lines is one of the critical issues in building intelligent distribution networks. Digital twin (DT), which can map the physical status of equipment in real-time, has received extensive attention. However, traditional modelling methods cannot meet the requirement of long-span complex DT's real-time computation and scalability. In order to reduce the modelling cost and improve the calculation speed, a modular DT modelling method for cable lines based on real-time temperature field inversion is proposed. The authors develop a modular reduced-order modelling method that applies to long-span 10 kV cable lines. Combined with the temperature field inversion, a DT inversion algorithm is proposed to evaluate the transient temperature field and contact resistance inside cable lines, which has been used to evaluate the emergency load capacity. Finally, temperature rise tests verified the DT inversion algorithm's correctness. The operating status of cable lines was evaluated through the modular DT, and the emergency time and emergency ampacity were calculated. The result shows that the new method meets the real-time and high-precision requirements of DT calculation in actual operation scenarios. It can be easily extended to cable lines of different voltage levels.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"10 1","pages":"56-68"},"PeriodicalIF":4.4,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12465","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141832819","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}
High VoltagePub Date : 2024-07-11DOI: 10.1049/hve2.12463
Mengqi Wang, Shihang Wang, Xinyu Li, Yang Feng, Jingran Wang, Shengtao Li
{"title":"Study on the terahertz domain dielectric relaxation response and mechanism of thermal-oxidative aged cross-linked polyethylene","authors":"Mengqi Wang, Shihang Wang, Xinyu Li, Yang Feng, Jingran Wang, Shengtao Li","doi":"10.1049/hve2.12463","DOIUrl":"10.1049/hve2.12463","url":null,"abstract":"<p>To further study the thermal-oxidative ageing mechanism of crosslinked polyethylene (XLPE), the terahertz frequency domain dielectric parameters and relaxation phenomena of thermal-oxidative aged XLPE are analysed using terahertz time domain spectroscopy. It is found that the real part of the terahertz dielectric constant increases with the increase of thermal-oxidative ageing duration, and the imaginary part shows an overall upward trend. Relaxation of the complex dielectric constant of the aged XLPE samples is obvious. Through the second-order Cole–Cole equation fitting, it is found that there are two relaxation processes around 0.15 and 1.5 THz, and the relaxation strength gradually increases with the ageing time. To explain this phenomena, microstructure changes and crystallisation behaviours are characterised using Fourier transform infrared spectrum and differential scanning calorimetry, respectively. It is suggested that the two relaxations may be caused by elastic dipole polarisation originating from the angular deflection of polar groups and stretching rotation of hydrogen bond. In addition, by comparing the relaxation strength in different temperatures, the source of the relaxation process is further confirmed.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 6","pages":"1311-1321"},"PeriodicalIF":4.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12463","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656601","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":"Safety monitoring method for powerline corridors based on single-stage detector and visual matching","authors":"Jinheng Li, Hanbo Zheng, Peng Liu, Yanshen Liang, Feng Shuang, Junjie Huang","doi":"10.1049/hve2.12464","DOIUrl":"10.1049/hve2.12464","url":null,"abstract":"<p>Effective monitoring and early warning of overhead power lines are critical for ensuring power supply stability and personnel safety. However, existing methods that rely solely on single vision or light detection and ranging (LiDAR) have limitations such as numerous invalid alarms, hardware equipment constraints, and lack of real-time monitoring capabilities. This article proposes an intelligent monitoring method for safety distance of the powerline corridor based on heterogeneous sensor information. Firstly, an optimised single-stage detector is designed to detect safety hazard objects. In the detector, the backbone network and the sample matching strategy are improved; in addition, the learning strategy is adjusted. Next, the pose transformation relationship is obtained through the visual matching of prior LiDAR information and images. The back projection transformation of 2D–3D is achieved according to the relationship. Finally, a monocular camera-based end-to-end distance measurement scheme is proposed by combining 2D object information with coordinate transformation relationships. The scheme is applied to the distance measurements from hazard objects to powerlines. The experimental results show that the optimisation method improves the detection accuracy and reduces the computational complexity of the model. Also, case experiments with continuous frame data verify the effectiveness of the safety distance monitoring scheme.</p>","PeriodicalId":48649,"journal":{"name":"High Voltage","volume":"9 4","pages":"805-815"},"PeriodicalIF":4.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/hve2.12464","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657744","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}