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Protection and Control of Modern Power Systems 2023年第2期8卷 244-259页

作者： Yaojian Wang Jie Gu Lyuzerui Yuan department of electrical engineering School of ElectronicsInformation and Electrical EngineeringShanghai Jiao Tong University209 of Smart Grid Building800 Dong Chuan RdShanghai 200240China

Because there is insufficient measurement data when implementing state estimation in distribution networks,this paper proposes an attention-enhanced recurrent neural network(A-RNN)-based pseudo-measurement modeling metho.First,based on analyzing the power series at the source and load end in the time and frequency domains,a period-dependent extrapolation model is established to characterize the power series in those domains.The complex mapping functions in the model are automatically represented by A-RNNs to obtain an A-RNNs-based period-dependent pseudo-measurement generation model.The distributed dynamic state estimation model of the distribution network is established,and the pseudo-measurement data generated by the model in real time is used as the input of the state estimation model together with the measurement data.The experimental results show that the method proposed can explore in depth the complex sequence characteristics of the measurement data such that the accuracy of the pseudo-measurement data is further improved.The results also show that the state estimation accuracy of a distribution network is very poor when there is a lack of measurement data,but is greatly improved by adding the pseudo-measurement data generated by the model proposed.

关键词： State estimation Pseudo measurement Recurrent neural network Attention mechanism Time-frequency domain analysis Distribution network

Geometric Probability on a Lattice with the 15th Type of Convex Pentagon as a Fundamental Region

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Acta Mathematica Sinica,English Series 2024年

作者： Jiang Fu ZHAO Jun JIANG Hai LIU National engineering Research Center for E-learning Central China Normal University College of Science Wuhan University of Science and TechnologyHubei Province Key Laboratory of Systems Science in Metallurgical Process department of Mathematics and Physics Fujian Jiangxia University

In 2015, a group of mathematicians at the University of Washington, Bothell, discovered the15th pentagon that can cover a plane, with no gaps and overlaps. However, research on its containment measure theory or geometric probability is limited. In this study, the Laplace extension of Buffon’s problem is generalized to the case of the 15th pentagon. In the solving process, the explicit expressions for the generalized support function and containment function of this irregular pentagon are derived.In addition, the chord length distribution function and density function of random distance of this pentagon are obtained in terms of the containment function.

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Using Interim Recommitment to Reduce the Operational-cost Impacts of Wind Uncertainty

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Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 839-849页

作者： Mahan A.Mansouri Ramteen Sioshansi department of Integrated Systems engineering The Ohio State UniversityColumbusOH 43210USA department of Integrated Systems engineering Department of Electrical and Computer Engineeringand Center for Automotive ResearchThe Ohio State UniversityColumbusOH 43210USA

Using wind-availability forecasts in day-ahead unit commitment can require expensive real-time operational adjustments.We examine the benefit of conducting interim recommitment between day-ahead unit commitment and real-time dispatch.Using a simple stylized example and a case study that is based on ISO New England,we compare system-operation costs with and without interim recommitment.We find an important tradeoff—later recommitment provides better wind-availability forecasts,but the system has less flexibility due to operating constraints.Of the time windows that we examine,hour-20 recommitment provides the greatest operational-cost reduction.

关键词： Power-system operation power-system economics unit commitment economic dispatch wind generation.

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Mixed convectional and chemical reactive flow of nanofluid with slanted MHD on moving permeable stretching/shrinking sheet through nonlinear radiation,energy omission

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Chinese Physics B 2024年第5期33卷 193-202页

作者： Saleem Nasir Sekson Sirisubtawee Pongpol Juntharee Taza Gul department of Mathematics Faculty of Applied ScienceKing Mongkut's University of Technology North BangkokBangkok 10800Thailand department of Mathematics City University of Science and Information TechnologyPeshawarPakistan

Hybrid nanofluids are remarkable functioning liquids that are intended to reduce the energy loss while maximizing the heat transmission.In the involvement of suction and nonlinear thermal radiation effects,this study attempted to explore the energy transmission features of the inclined magnetohydrodynamic(MHD)stagnation flow of CNTs-hybrid nanofluid across the nonlinear permeable stretching or shrinking sheet.This work also included some noteworthy features like chemical reactions,variable molecular diffusivity,quadratic convection,viscous dissipation,velocity slip and heat omission assessment.Employing appropriate similarity components,the model equations were modified to ODEs and computed by using the HAM technique.The impact of various relevant flow characteristics on movement,heat and concentration profiles was investigated and plotted on a graph.Considering various model factors,the significance of drag friction,heat and mass transfer rate were also computed in tabular and graphical form.This leads to the conclusion that such factors have a considerable impact on the dynamics of fluid as well as other engineering measurements of interest.Furthermore,viscous forces are dominated by increasing the values ofλ_(p),δ_(m)andδ_(q),and as a result,F(ξ)accelerates while the opposite trend is observed for M andφ.The drag friction is boosted by the augmentation M,λ_(p)andφ,but the rate of heat transfer declined.According to our findings,hybrid nanoliquid effects dominate that of ordinary nanofluid in terms of F(ξ),Θ(ξ)andφ(ξ)profiles.The HAM and the numerical technique(shooting method)were found to be in good agreement.

关键词： hybrid nanofluid(SWCNT+MWCNT/H_(2)O) velocity slip conditions nonlinear thermal radiation exponential stretching/shrinking sheet inclined magnetohydrodynamic(MHD)stagnation flow

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Generative Multi-Modal Mutual Enhancement Video Semantic Communications

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2985-3009页

作者： Yuanle Chen Haobo Wang Chunyu Liu Linyi Wang Jiaxin Liu Wei Wu The College of Communication and Information engineering Nanjing University of Posts and TelecommunicationsNanjing210023China The College of Science Nanjing University of Posts and TelecommunicationsNanjing210023China

Recently,there have been significant advancements in the study of semantic communication in single-modal scenarios.However,the ability to process information in multi-modal environments remains limited.Inspired by the research and applications of natural language processing across different modalities,our goal is to accurately extract frame-level semantic information from videos and ultimately transmit high-quality videos.Specifically,we propose a deep learning-basedMulti-ModalMutual Enhancement Video Semantic Communication system,called M3E-VSC.Built upon a VectorQuantized Generative AdversarialNetwork(VQGAN),our systemaims to leverage mutual enhancement among different modalities by using text as the main carrier of transmission.With it,the semantic information can be extracted fromkey-frame images and audio of the video and performdifferential value to ensure that the extracted text conveys accurate semantic information with fewer bits,thus improving the capacity of the system.Furthermore,a multi-frame semantic detection module is designed to facilitate semantic transitions during video generation.Simulation results demonstrate that our proposed model maintains high robustness in complex noise environments,particularly in low signal-to-noise ratio conditions,significantly improving the accuracy and speed of semantic transmission in video communication by approximately 50 percent.

关键词： Generative adversarial networks multi-modal mutual enhancement video semantic transmission deep learning

Solution to Coordination of Transmission and Distribution for Renewable Energy Integration into Power Grids:An Integrated Flexibility Market

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CSEE Journal of Power and Energy Systems 2023年第2期9卷 444-458页

作者： Tao Jiang Zhongwei Shen Xiaolong Jin Rufeng Zhang Alessandra Parisio Xue Li Xiao Kou department of electrical engineering Northeast Electric Power UniversityJilin 132012China Key Laboratory of Smart Grid of Ministry of Education Key Laboratory of Smart Energy&Information Technology of Tianjin MunicipalityTianjin UniversityTianjin 300072China department of electrical and Electronic engineering The University of ManchesterManchesterUK department of electrical engineering and Computer Science University of TennesseeKnoxvilleTN37996USA.

Nowadays,transmission system operators(TSOs)encounter the challenges of securely operating power grids with high penetration of renewables.In this context,more flexibility is needed than ever to maintain system reliability.With rapid development of coordinated transmission and distribution technology recently,active distribution networks(ADNs)which have abundant flexible resources,have the potential to provide flexibility to the TSO.Hence,an integrated transmission-distribution flexibility market is proposed in this paper.In the proposed framework,the energy market is first cleared to obtain baseline generation schedules.Then the baseline generation schedules are treated as inputs to the flexibility market.Furthermore,the integrated flexibility market is cleared to facilitate flexibility trading between transmission and distribution networks.To preserve the data privacy of different market participants,an alternating direction method of multipliers(ADMM)based method is utilized to clear the markets in a distributed manner.In the energy market and flexibility market-clearing model,transmission network market clearing models are linear programming(LP)models,and distribution network market clearing models are second order cone programming(SOCP)models.Through the proposed method,only limited information is exchanged between TSO and DSOs.Case studies are conducted on a revised IEEE 30-bus transmission network with two 33-node ADNs.Numerical results demonstrate the proposed flexibility market framework can enhance competitiveness of generation companies in the transmission network and distributed generators(DGs)in the ADNs.Moreover,flexibility purchasing cost is reduced by 17.7%compared to traditional flexibility supplied by generators according to the case study results,and ADNs can gain additional flexibility profit by providing flexibility.

关键词： ADMM ADN energy market flexibility market TSO-DSO coordination

CdS/LaFeO_(3) heterojunctions with improved optical properties for visible-light catalytic applications

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Journal of Rare Earths 2024年第5期42卷 879-888,I0003页

作者： Jiaqi Wei Wen Zhu Xuelian Xu Xiao Xu Junjiang Zhu Hubei Key Laboratory of Biomass Fibers and Eco-dyeing&Finishing College of Chemistry and Chemical EngineeringWuhan Textile University ChemistryWuhan430200China

Construction of heterojunctions is a normal and effective strategy to improve the photocatalytic performances of semiconductors,through which both the lifetime and the redox ability of electrons/holes can be improved,as co mpared to the respective component.On this basis,we constructed Z-scheme CdS/LaFeO_(3) heterojunctions(CdS/LFO),by in-situ growing different amounts of CdS on the surface of LaFeO_(3),for photocatalytic degradation of tetracycline hydrochloride(TC)in aqueous solution at room temperature.The crystal structure,surface morphology and optoelectronic properties of the COS/LFO heterojunctions were systemically characterized to correlate the reaction activity.Photocatalytic tests indicate that the CdS/LFO heterojunctions exhibit promising activity for TC degradation under visible light irradiation(λ≥420 nm),with 85%TC conversion obtained at reaction time of 45 min,which is 3.4 and 1.9 times higher than that of CdS and LaFeO_(3).The CdS/LFO heterojunctions are also stable in the reaction and can be reused for four cycles with no appreciable activity loss.The applicability of CdS/LFO to photocatalytic degradation of organic dyes,as well as the reaction mechanism,was also explored.

关键词： LaFeO_(3) CdS Photocatalytic degradation Tetracycline hydrochloride Reaction mechanism Rare earths

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Fast SHEPWM Solution Method for Wind Power Converter Based on State Equations

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CSEE Journal of Power and Energy Systems 2023年第4期9卷 1383-1393页

作者： Ning Li Shiqian Zhang Xiaokang Liu Yan Zhang Lin Jiang School of electrical engineering Xi'an University of TechnologyXi'an 710048China. the department of Electron-University of Technology Xi'an 710048China Xi'an Jiaotong University Xi'anShaanxi 710049China department of electrical engineering and Electronics The University of LiverpoolUK.

Selective harmonic elimination pulse width modula-tion(SHEPWM)is a modulation strategy widely used for three-level wind power grid-connected converters.Its purpose is to eliminate specified sub-low frequency harmonics by controlling switching angle.Furthermore,it can reduce fluctuation of the microgrid system and improve system stability.Intelligent al-gorithms have been applied to the SHEPWM solution process to mitigate calculation complexity associated with the algebraic method,as well as the need to set the initial value.However,disorder of the optimization result causes difficulty in satisfying incremental constraint of the three-level NPC switching angles,and affects the success rate of the algorithm.To overcome this limitation,this paper proposes a fast SHEPWM strategy to optimize the result obtained by the intelligent algorithm.The SHEPWM can be realized by solving switching angles through a state equations-based mathematical model,which is constructed by using the initial variables randomly generated by the intelligent algorithm as the disturbance.This mathematical model improves the success rate of calculation by simplifying constraint representation of switching angles and solving the disorder problem of the optimization result.At the same time,a method based on the circle equation and the trigonometric function is applied to the initial variable assignment of the state equation,which further improves the speed and accuracy of the solution,realizes a more thorough filtering effect,and further reduces the impact of sub-low frequency harmonics on a wind power integrated system.Finally,simulation and experiment results have been used to prove the effectiveness of the proposed SHEPWM strategy when combined with intelligent algorithms.Index Terms-Wind power converter,adaptive genetic algorithm,selective harmonic elimination pulse-width modulation(SHEPWM),state equation,success rate.

关键词： Wind power converter adaptive genetic algorithm selective harmonic elimination pulse-width modulation(SHEPWM) state equation success rate.

Emerging interactively stretchable electronics with optical and electrical dual-signal feedbacks based on structural color materials

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Nano Research 2024年第3期17卷 1837-1855页

作者： Jialin Wang Kai Zhao Changqing Ye Yanlin Song School of Materials Science and engineering Suzhou University of Science and TechnologySuzhou 215009China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of SciencesBeijing 100190China

The booming development of wearable devices has aroused increasing interests in flexible and stretchable devices.With mechanosensory functionality,these devices are highly desirable on account of their wide range of applications in electronic skin,personal healthcare,human–machine interfaces and beyond.However,they are mostly limited by single electrical signal feedback,restricting their diverse applications in visualized mechanical sensing.Inspired by the mechanochromism of structural color materials,interactively stretchable electronics with optical and electrical dual-signal feedbacks are recently emerged as novel sensory platforms,by combining both of their sensing mechanisms and characteristics.Herein,recent studies on interactively stretchable electronics based on structural color materials are reviewed.Following a brief introduction of their basic components(i.e.,stretchable electronics and mechanochromic structural color materials),two types of interactively stretchable electronics with respect to the nanostructures of mechanochromic materials are outlined,focusing primarily on their design considerations and fabrication strategies.Finally,the main challenges and future perspectives of these emerging devices are discussed.

关键词： stretchable electronics structural color materials interactive sensing mechanochromism dual-signal feedbacks

Controlled growth of vertically stacked In_(2)Se_(3)/WSe_(2) heterostructures for ultrahigh responsivity photodetector

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Nano Research 2024年第3期17卷 1856-1863页

作者： Cheng Zhang Biyuan Zheng Guangcheng Wu Xueying Liu Jiaxin Wu Chengdong Yao Yizhe Wang Zilan Tang Ying Chen Lizhen Fang Luying Huang Dong Li Shengman Li Anlian Pan Key Laboratory for Micro-Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Materials Science and EngineeringHunan UniversityChangsha 410082China

Transition metal dichalcogenides(TMDCs)are promising candidates for future optoelectronic devices accounting for their high carrier mobility and excellent quantum efficiency.However,the limited light absorption efficiency in atomically thin layers significantly hinders photocarrier generation,thereby impairing the optoelectronic performance and hindering practical applications.Herein,we successfully synthesized In_(2)Se_(3)/WSe_(2) heterostructures through a typical two-step chemical vapor deposition(CVD)method.The In_(2)Se_(3) nanosheet with strong light absorption capability,serving as the light absorption layer,was integrated with the monolayer WSe_(2),enhancing the photosensitivity of WSe_(2) significantly.Upon laser irradiation with a wavelength of 520 nm,the In_(2)Se_(3)/WSe_(2) heterostructure device shows an ultrahigh photoresponsivity with a value as high as 2333.5 A/W and a remarkable detectivity reaching up to 6.7×10^(12) Jones,which is the highest among almost the reported TMDCs-based heterostructures grown via CVD even some fabricated by mechanical exfoliation(ME).Combing the advantages of CVD method such as large scale,high yield,and clean interface,the In_(2)Se_(3)/WSe_(2) heterostructures would provide a novel path for future high-performance optoelectronic device.

关键词： transition metal dichalcogenides(TMDCs) In_(2)Se_(3) heterostructure photodetector ultrahigh responsivity