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High Voltage 2024年第3期9卷 566-580页

作者： Xu Dai Yuan Yuan Jiang Zhou Guoyong Liu Tao Zhu Huiying Xiang Qi Yu Xue Gao Ruijin Liao State Key Laboratory of Power Transmission equipment&system Security and New Technology Chongqing UniversityChongqingChina co.lege of Materials Science and Engineering Chongqing UniversityChongqingChina Dongfang Electric Machinery co. LtdDeyangChina

As a typical failure phenomenon in transformers,sulfur co.rosion has garnered significant attention in the field of high-voltage *** boundary character distribution(GBCD)co.per windings have been introduced to enhance sulfur co.rosion resistance by slowing down intergranular *** this study,the sulfur co.rosion behaviour and mechanisms of the GBCD co.per windings under various temperatures were experi-mentally and theoretically *** show that GBCD can enhance the co.rosion resistance of co.per in liquid *** the increase in temperatures,the insulating properties of oil and papers in traditional co.per windings experience notable degradation,while GBCD co.per windings show more stable insulating *** addition,modelling of grain boundary energy indicates that the grain boundary structure of GBCD co.per windings has a lower average interface energy of 0.170 eV/Å***-culations of reaction thermodynamics show that GBCD co.per windings possess a higher failure temperature(135.2℃)and inhibition degree(activation energy)of the sulfur co.rosion(32,557.62 J/mol),revealing the stability and enhanced sulfur co.rosion resis-tance at elevated temperatures.

关键词： co.rosion grain co.per

Transient Stability Analysis of co.verter-based Islanded Microgrids Based on Iterative Equal Area Criterion co.sidering Reactive Power Loop Dynamics and Varying Damping

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Journal of Modern Power systems and Clean Energy 2024年第4期12卷 1170-1182页

作者： Xilin Li Jingyi Zhang Zhen Tian Xiaoming Zha Wei Wang Meng Huang Chong Shao Hubei Key Laboratory of Power equipment&system Security for Integrated Energy School of Electrical Engineering and AutomationWuhan UniversityWuhanChina NARI Technology co. Ltd.NanjingChina State Grid Gansu Electric Power co.pany LanzhouChina

With the rapid increase in the installed capacity of renewable energy in modern power systems,the stable operation of power systems with co.siderable power electronic equipment requires further *** co.verter-based islanded mi-crogrid(CIM)systems equipped with grid-following(GFL)and grid-forming(GFM)voltage-source co.verters(VSCs),it is chal-lenging to maintain stability due to the mutual co.pling effects between different VSCs and the loss of voltage and frequency sup-port from the power *** previous studies,quantitative transient stability analysis was primarily used to assess the active power loop of ***,frequency and voltage dy-namics are found to be strongly co.pled,which strongly affects the estimation result of stability *** addition,the vary-ing damping terms have not been fully *** bridge these gaps,this paper investigates the transient stability of CIM co.sid-ering reactive power loop dynamics and varying ***,an accuracy-enhanced nonlinear model of the CIM is derived based on the effects of reactive power loop and post-disturbance frequency jump *** these effects will elimi-nates the risk of *** reactive power loop dynamics make the model co.fficients be no longer co.stant and thus vary with the power *** evaluate quantitatively the effects of re-active power loop and varying damping on the transient stability of CIM,an iterative criterion based on the equal area criterion theory is *** addition,the effects of parameters on the stable boundary of power system are analyzed,and the dynamic interaction mechanisms are *** and experiment results verify the merits of the proposed method.

关键词： Transient stability co.verter iterative criterion reactive power loop post-disturbance frequency jump

Seasonal thermal energy storage using natural structures:GIS-based potential assessment for northern China

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Building Simulation 2024年第4期17卷 561-574页

作者： Yichi Zhang Jianjun Xia Midea HVAC Heating&Ventilation equipment co. LtdFoshan528311China Building Energy Research Center Tsinghua UniversityBeijing100084China

Seasonal thermal energy storage(STES)allows storing heat for long-term and thus promotes the shifting of waste heat resources from summer to winter to decarbonize the district heating(DH)*** being a promising solution for sustainable energy system,large-scale STES for urban regions is lacking due to the relatively high initial investment and extensive land *** close the gap,this study assesses the potentials of using two naturally available structures for STES,namely valley and ground pit *** on geographical information system(GIS)methods,the available locations are searched from digital elevation model and selected co.sidering several criteria from land uses and co.struction *** co.ts of dams to impound the reservoir and the yielded storage capacities are then quantified to guide the choice of suitable *** assessment is co.ducted for the northern China where DH systems and significant seasonal differences of energy demand *** total,2,273 valley sites and 75 ground pit sites are finally identified with the energy storage capacity of 15.2 billion GJ,which is much larger than the existing DH demand in northern *** results also prove that 682 valley sites can be achieved with a dam co.t lower than 20 CNY/m^(3).By co.ducting sensitivity analysis on the design dam wall height and elevations,the choices of available natural structures are expanded but practical issues about water pressures and co.structions are also ***,the identified sites are geographically mapped with nearest urban regions to reveal their roles in the DH *** general,560 urban regions are found with potential STES units and most of them have STES storage capacities larger than their own DH *** novel planning methodology of this study and publicly available datasets create possibilities for the implementations of large-scale STES in urban DH systems.

关键词： seasonal thermal energy storage geographical information system district heating water reservoir

A Defense Planning Model for a Power system Against co.rdinated Cyber-physical Attack

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Protection and co.trol of Modern Power systems 2024年第5期9卷 84-95页

作者： Peiyun Li Jian Fu Kaigui Xie Bo Hu Yu Wang Changzheng Shao Yue Sun Wei Huang State Key Laboratory of Power Transmission equipment&system Secu-rity and New Technology Chongqing UniversityChongqing 400044China State Grid Chengdu Power Supply co.-pany State Grid Sichuan Electric Power Co.Ltd.Chengdu 610041China China Yangtze Power co. LtdYichang 443002China

This paper proposes a tri-level defense planning model to defend a power system against a co.r-dinated cyber-physical attack(CCPA).The defense plan co.siders not only the standalone physical attack or the cyber attack,but also co.rdinated *** defense strategy adopts co.rdinated generation and transmission expansion planning to defend against the *** the process of modeling,the upper-level plan represents the perspective of the planner,aiming to minimize the critical load shedding of the planning system after the *** load resources available to planners are extended to flex-ible loads and critical *** middle-level plan is from the viewpoint of the attacker,and aims at generating an optimal CCPA scheme in the light of the planning strategy determined by the upper-level plan to maximize the load shedding caused by the *** optimal operational behavior of the operator is described by the lower-level plan,which minimizes the load shedding by defending against the *** tri-level model is analyzed by the co.umn and co.straint generation algorithm,which de-co.poses the defense model into a master problem and *** studies on a modified IEEE RTS-79 system are performed to demonstrate the eco.omic effi-ciency of the proposed *** Terms—co.rdinated cyber-physical attack,flexible load,co.umn-and-co.straint generation,defense planning,robust optimization.

关键词： co.rdinated cyber-physical attack flexible load co.umn-and-co.straint generation defense planning robust optimization.

Nanosize-effect on the distribution of heavy metals in co.per smelting dust:Based on sophisticated dust sorting approach

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Nano Research 2024年第1期17卷 312-320页

作者： Ken Li Zuwu Liao Hengdi Ye Qingzhu Li Fenghua Shen Qian Li Hui Liu Qingwei Wang Xu Yan Zhang Lin Liyuan Chai School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for co.trol&Treatment of Heavy Metal Pollution Changsha 410083China National Engineering Research Center of Sintering and Pelletizing equipment system Zhongye Changtian International Engineering Co.LtdChangsha 410205China

Dust particles emitted from smelters can be hazardous to eco.0}s and humans,as they are often enriched in metallic ***,we co.bined multi-method mineralogical analysis with a sophisticated size sorting approach for co.per smelting dust to study the nanosize-effect on heavy metal distribution,which has hitherto been *** types of dust were co.lected from a co.per flash smelter and then size-sorted using a Dekati low-pressure *** showed that all three samples co.ld easily sort out nanoscale dust particles(co.ld reach 10.71%.The presence of heavy metals(Pb,Zn,Cu,and As)and their mineral species in dust was examined at various particle *** was disco.ered that different heavy metals are enriched on nanoparticles in specific *** micron-sized particles,heavy metals are generally found in discrete phases(e.g.,CuSO_(4),PbSO_(4),and As_(2)O_(3)).In nanoscale particles,the dominant phase is Fe_(3)O_(4),while heavy metals are mostly found in lattice substitution(e.g.,CuFe_(2)O_(4)and ZnFe_(2)O_(4)).Two distinct nano-dust morphologies were found:One with irregular mesh or chain structures co.sisting of particles of a few nanometers,and the other with polygonal crystals in larger sizes of hundreds of *** enrichment of heavy metals in the latter morphology is more pronounced,possibly because lattice substitution of heavy metals is more likely to occur when polycrystalline particles are formed.

关键词： co.per flue dust size-sorted heavy metal distribution morphology nano-sized effects

Numerical Simulations of Snow Accumulation in the Bogie Region of a Train co.sidering Snow Particle Rotation

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2337-2352页

作者： Hong Lan Jiye Zhang Yao Zhang Lu Cai State Key Laboratory of Rail Transit Vehicle system Southwest Jiaotong UniversityChengdu610031China co.lege of Railway Transportation Hunan University of TechnologyZhuzhou412000China GD Midea Air-co.ditioning equipment co. Ltd.Foshan528311China

To investigate the influence of snow particle rotational motion on the accumulation of snow in the bogie region of high-speed trains,an Euler‒Lagrange numerical approach is *** study examines the effects of snow particle diameter and train speed on the ensuing *** is shown that co.sidering snow particle rotational motion causes significant deviation in the particle trajectories with respect to non-rotating *** a deviation increases with larger snow particle diameters and higher train *** snow accumulation on the overall surface of the bogie increases,and the amount of snow on the vibration reduction device varies *** certain co.ditions,the amount of accumulated snow can increase by several orders of magnitudes.

关键词： High-speed train bogie snow particle rotation discrete phase model snow accumulation

co.mand filtered integrated estimation guidance and co.trol for strapdown missiles with circular field of view

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Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei Wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China China Research and Development Academy of Machinery equipment Beijing 100089China Northwest Industries Group co. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and co.trol(IEGC)system is designed based on the co.mand filtered backstepping approach for circular field-of-view(FOV)strapdown *** threedimensional integrated estimation guidance and co.trol nonlinear model with limited actuator deflection angle is established co.sidering the seeker's FOV *** boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to co.strain the body line-of-sight(BLOS)in IEGC system to fit a circular ***,the nonlinear adaptive co.troller is designed to estimate the changing aerodynamic *** generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking ***,the co.mand filters are used to solve the"differential expansion"problem during the backstepping *** Lyapunov theory is used to prove the stability of the overall closed-loop IEGC ***,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： Integrated estimation guidance and co.trol Circular field-of-view Time-varying integral barrier Lyapunov function co.mand filtered backstepping co.trol Nonlinear adaptive co.trol Extended state observer

Machine learning for fault diagnosis of high-speed train traction systems: A review

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Frontiers of Engineering Management 2024年第1期11卷 62-78页

作者： Huan WANG Yan-Fu LI Jianliang REN Department of Industrial Engineering Tsinghua UniversityBeijing 100084China Zhibo Lucchini Railway equipment co. Ltd.Taiyuan 030032China

High-speed trains(HSTs)have the advantages of co.fort,efficiency,and co.venience and have gradually beco.e the mainstream means of *** the operating scale of HSTs co.tinues to increase,ensuring their safety and reliability has beco.e more *** the co.e co.ponent of HST,the reliability of the traction system has a substantially influence on the *** the long-term operation of HSTs,the co.e co.ponents of the traction system will inevitably experience different degrees of performance degradation and cause various failures,thus threatening the running safety of the ***,performing fault monitoring and diagnosis on the traction system of the HST is *** recent years,machine learning has been widely used in various pattern reco.nition tasks and has demonstrated an excellent performance in traction system fault *** learning has made co.siderably advancements in traction system fault diagnosis;however,a co.prehensive systematic review is still lacking in this *** paper primarily aims to review the research and application of machine learning in the field of traction system fault diagnosis and assumes the future development ***,the structure and function of the HST traction system are briefly ***,the research and application of machine learning in traction system fault diagnosis are co.prehensively and systematically ***,the challenges for accurate fault diagnosis under actual operating co.ditions are revealed,and the future research trends of machine learning in traction systems are discussed.

关键词： high-speed train traction systems machine learning fault diagnosis

Algorithm for Solving Traveling Salesman Problem Based on Self-Organizing Mapping Network

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Journal of Shanghai Jiaotong university(Science) 2024年第3期29卷 463-470页

作者：朱江辉叶航航姚莉秀蔡云泽 Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of system co.trol and Information Processing Ministry of EducationShanghai 200240China Shanghai Engineering Research Center of Intelligent co.trol and Management Shanghai 200240China Key Laboratory of Marine Intelligent equipment and system Ministry of EducationShanghai 200240China Huawei Technologies co. Ltd.Shanghai 201206China

Traveling salesman problem(TSP)is a classic non-deterministic polynomial-hard optimization *** on the characteristics of self-organizing mapping(SOM)network,this paper proposes an improved SOM network from the perspectives of network update strategy,initialization method,and parameter *** paper co.pares the performance of the proposed algorithms with the performance of existing SOM network algorithms on the TSP and co.pares them with several heuristic *** show that co.pared with existing SOM networks,the improved SOM network proposed in this paper improves the co.vergence rate and algorithm *** with iterated local search and heuristic algorithms,the improved SOM net-work algorithms proposed in this paper have the advantage of fast calculation speed on medium-scale TSP.

关键词： traveling salesman problem(TSP) self-organizing mapping(SOM) co.binatorial optimization neu-ral network

Lead-free(Ba,Sr)TiO_(3)-based ceramics with superior tunable properties by the semi-solution method

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Journal of Advanced Ceramics 2024年第6期13卷 746-756页

作者： Yi Zhao Wenfeng Liu Dongsheng Ran Yihang Jin Zhiyuan Li Chengzhi Zhong Fanyi Kong Shengtao Li State Key Laboratory of Electrical Insulation and Power equipment Xi’an Jiaotong UniversityXi’an 710049China Jiaxing Electric Power co.pany State Grid Zhejiang Electric Power co. Ltd.Jiaxing 314000China

High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable *** the present study,a new system,(Ba_(0.675)Sr_(0.325))_(1−x)La_(x)Ti_(1−x)MnxO_(3)(x=0.25%,0.5%,0.75%,and 1.0%),was *** acceptor dopant Mn was added to lower dielectric loss,while the donor dopant La was introduced to enhance dielectric *** samples were prepared using the co.ventional solid-state(CS)reaction method and the semi-solution(SS)*** experimental results showed that the morphology of the ceramics was optimized by further improving the processing *** microstructures,homogeneous grains,and uniform dopant distributions co.ld be achieved successfully by the semi-solution ***,a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned *** optimum tunable properties occurred in the samples prepared by the semi-solution method at x=0.75%,with a high dielectric tunability of 85.0%,a low dielectric loss of 0.0011,and an excellent figure of merit(FOM)of *** tunable properties of(Ba,Sr)TiO_(3)(BST)ceramics were even superior to those of lead-based materials,with an FOM of approximately *** the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices.

关键词： microstructure tunable properties (Ba,Sr)TiO_(3)(BST)ceramics semi-solution(SS)method