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6th International Scientific and Technical Conference Relay Protection and Automation, RPA 2023

作者： Yablokov, A.A. Panashchatenko, A.V. Titov, V.A. Maltsev, R.A. Electric power systems automatic control department Electric systems department Ivanovo State Power Engineering University named after V.I. Lenin Ivanovo Russia

ISBN: (纸本)9798350382334

Modern normative technical documentation in the field of design and operation of power facilities [1] imposes new requirements on current transformers (CTs) operation. The technical characteristics of CTs and the connected relay protection devices as a whole must ensure the correct operation of the devices during short-circuits (SCs), including when an aperiodic current component occurs. This circumstance primarily applies to newly constructed and reconstructed power facilities. The process of creating design documentation for them must be carried out taking into account the new requirements, for which GOST R 58669-2019 [2] was developed and approved. According to it, in addition to the existing tests of selected CTs, it is necessary to perform calculations of the time to saturation of the magnetic core of each CT winding, high-speed relay protection devices are connected to which. The obtained time is compared with the minimum time required for the correct operation of the connected relay protection devices. Difficulties often occur in coordinating the characteristics of CTs selected at the design stage and the results of calculating the time to saturation of CT magnetic cores at the detailed design stage. Negative test results lead to the need to adjust the design characteristics of CTs and to additional labor costs for their approval. One of the solutions to the problem encountered in design practice is intentionally inflating the characteristics of CTs at the design stage in order to successfully pass the time to saturation test at the detailed design stage. It leads to unjustified financial costs and non-optimal selection of CTs. Therefore, it is relevant to develop methods for calculating CT characteristics taking into account the new requirements. © 2023 IEEE.

关键词： Electric instrument transformers

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Filler Size Effect on Tuning Electrical,Mechanical,and Thermal Properties of Field Grading Composites

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CSEE Journal of power and Energy systems 2023年第2期9卷 743-750页

作者： Xiaolei Zhao Jun Hu Xiao Yang Zhiwen Huang Xingming Bian Yuanbao Lin Jinliang He Key Laboratory of Control of Power Transmission and Conversion Ministry of EducationShanghai Jiao Tong UniversityShanghai200240 China Department of Chemistry University of OxfordOxfordOX13TAUK State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua UniversityBeijing 100084China North China Electric Power University School of Electrical and Electronic EngineeringBeijing 102206China

field-grading composite with a low switching field,stable nonlinear conductivity performance,and excellent mechanical and thermal properties was prepared by using hybrid ZnO micro-spherical varistors of different particle sizes as the fillers and silicone rubber as the *** hybrid effects of particle size on the electrical,mechanical,and thermal properties of ZnO micro-spherical varistors composites are *** increase in the ZnO micro-spherical varistor size in the composites will lower the switching field but lead to degradation of the mechanical properties and stability of the nonlinear conductivity *** silicone rubber is incorporated with a mixture of hybrid ZnO micro-spherical varistors of different sizes at an optimal mass ratio range exhibited low switching field,stable nonlinear conductivity performance,and excellent mechanical and thermal *** findings are helpful to comprehensively regulate performance of advanced field-grading materials and increase stability and durability of electronic and electrical devices.

关键词： Electrical properties field grading material hybrid effect mechanical properties ZnO micro-spherical varistor

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power and Voltage control Based on DC Offset Injection for Bipolar Low-voltage DC Distribution System

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Journal of Modern power systems and Clean Energy 2023年第5期11卷 1529-1539页

作者： Xinyi Kong Jianwen Zhang Jianqiao Zhou Jiajie Zang Jiacheng Wang Gang Shi Xu Cai key Laboratory of Control of Power Transmission and Conversion of Ministry of Education Department of Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghaiChina School of Mechatronic Systems Engineering Simon Fraser UniversitySurreyBCCanada

The bipolar low-voltage DC(LVDC) distribution system has become a prospective solution to better integration of renewables and improvement of system efficiency and reliability. However, it also faces the challenge of power and voltage imbalance between two poles. To solve this problem, an interface converter with bipolar asymmetrical operating capabilities is applied in this paper. The steady-state models of the bipolar LVDC distribution system equipped with this interface converter in the gridconnected mode and off-grid mode are analyzed. A control scheme based on DC offset injection at the secondary side of the interface converter is proposed, enabling the bipolar LVDC distribution system to realize the unbalanced power transfer between two poles in the grid-connected mode and maintain the inherentpole voltage balance in the off-grid mode. Furthermore, this paper also proposes a primary-side DC offset injection control scheme according to the analysis of the magnetic circuit model, which can eliminate the DC bias flux caused by the secondaryside DC offset. Thereby, the potential core magnetic saturation and overcurrent issues can be prevented, ensuring the safety of the interface converter and distribution system. Detailed simulations based on the proposed control scheme are conducted to validate the function of power and voltage balance under the operation conditions of different DC loads.

关键词： Bipolar low-voltage DC distribution system interface converter DC offset injection unbalanced power voltage balance

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Low Inertia in Ac Microgrid: Analysis and Enhancement 6

Low Inertia in Ac Microgrid: Analysis and Enhancement

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6th International Youth Conference on Radio Electronics, Electrical and power engineering, REEPE 2024

作者： Emad, Mazen Alhasheem, Mohamed Beshr, Eman Medical Services Sector Ministry of Interior Electrical Power Systems Department Cairo Egypt Aastmt Faculty of Engineering and Technology Electrical and Control Department Cairo Egypt

ISBN: (纸本)9798350382891

This research looks into electrical grids that will soon likely become more intelligent. In light of this, there is a growing need for intelligent, adaptable microgrids that can function both independently and in conjunction with the grid. Black start operation, frequency and voltage stability, active and reactive power flow regulation, active power filtering capabilities, and storage energy management are the features that these small grids are expected to have. Energy can be produced and stored in this way near its points of consumption, improving reliability and lowering losses from big power lines. The key ideas about intelligent microgrid configuration, control, and energy management are reviewed in this study. Attributes-wise, the microgrid can function by utilizing the following three primary hierarchical control levels, just like the main grid.: Primary control on the converter level, Secondary control to adjust the frequency and voltage of the AC grid, and Third-level control over additional global duties determine whether energy is imported or exported for the microgrid. when connected to the main utilities. Advancing one of the above-mentioned control levels or redesigning the microgrid can enhance the stand-alone ac microgrid inertia. © 2024 IEEE.

关键词： Smart power grids

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Some Use Cases of Security Constrained Economic Dispatch Problem for Outage Work Planning Collaboration System 13

Some Use Cases of Security Constrained Economic Dispatch Pro...

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13th IEEE Global Conference on Consumer Electronic, GCCE 2024

作者： Toyoshima, Ichiro Tatekoji, Takashi Mizutani, Ryota Sato, Hiroaki Toshiba Energy Systems & Solutions Corporation Infrastructure Service Development & Design Department Tokyo Japan Toshiba Energy Systems & Solutions Corporation Power Grid System Solutions Engineering Depattment Kawasaki Japan Toshiba Energy Systems & Solutions Corporation Power Control Computer Systems Department Tokyo Japan

ISBN: (纸本)9798350355079

Outage work planning has been essential to maintain the power grid system. For the operators, the planning is troublesome. It is caused by too complex process. The past few years, we have been developing Outage Work planning Collaboration System (OWCS) with some mathematical optimization techniques. Especially, Security Constrained Economic Dispatch(SCED) is extened in some ways to handle various power grid situations. © 2024 IEEE.

关键词： Constrained optimization

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Simultaneous multi-material embedded printing for 3D heterogeneous structures

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International Journal of Extreme Manufacturing 2023年第3期5卷 485-498页

作者： Ziqi Gao Jun Yin Peng Liu Qi Li Runan Zhang Huayong Yang Hongzhao Zhou State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058People’s Republic of China School of Mechanical Engineering Zhejiang UniversityHangzhou 310058People’s Republic of China Department of Mechanical Engineering Centre for Power Transmission and Motion ControlUniversity of BathBath BA27AYUnited Kingdom

In order to mimic the natural heterogeneity of native tissue and provide a better microenvironment for cell culturing,multi-material bioprinting has become a common solution to construct tissue models in *** the embedded printing method,complex 3D structure can be printed using soft biomaterials with reasonable shape ***,the current sequential multi-material embedded printing method faces a major challenge,which is the inevitable trade-off between the printed structural integrity and printing ***,we propose a simultaneous multi-material embedded printing *** this method,we can easily print firmly attached and high-precision multilayer *** multiple individually controlled nozzles,different biomaterials can be precisely deposited into a single crevasse,minimizing uncontrolled squeezing and guarantees no contamination of embedding medium within the *** analyse the dynamics of the extruded bioink in the embedding medium both analytically and experimentally,and quantitatively evaluate the effects of printing parameters including printing speed and rheology of embedding medium,on the 3D morphology of the printed *** demonstrate the printing of double-layer thin-walled structures,each layer less than 200μm,as well as intestine and liver models with 5%gelatin methacryloyl that are crosslinked and extracted from the embedding medium without significant impairment or *** peeling test further proves that the proposed method offers better structural integrity than conventional sequential printing *** proposed simultaneous multi-material embedded printing method can serve as a powerful tool to support the complex heterogeneous structure fabrication and open unique prospects for personalized medicine.

关键词： embedded printing multi-material printing printability soft materials heterogeneous structures

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Study on the Characteristics of Natural Grounding Resistance of Underground Tunnels 11th

Study on the Characteristics of Natural Grounding Resistance...

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11th Frontier Academic Forum of Electrical engineering, FAFEE 2024

作者： Ma, Pengyu Li, Benliang Zou, Jun State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China State Power Economic Research Institute Beijing102200 China

ISBN: (纸本)9789819787791

With the development of cities, underground tunnels are more and more widely used, and the reinforced concrete in their walls can be used as the natural grounding body of the tunnels. However, underground tunnels have curved structures, multiple cross-sections and deep-buried structures, and the electrical conductivity of the concrete is different from that of the soil, etc., and the traditional analytical method has limitations in calculating the grounding resistance of the tunnels in these cases. In order to satisfy the needs of practical engineering, this paper adopts a numerical method based on the MoM numerical method to analyze the grounding system of underground tunnels with complex geometries and to calculate the grounding resistance of reinforced concrete systems in underground tunnels. In order to assess the difference between the analytical solution and the exact solution, the article introduces a correction factor to measure the ratio between the two. Simulations are carried out for real cases, and the results show that the accuracy of the analytical solution can be improved by introducing the correction factor. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： correction factor grounding resistance numerical method Underground tunnels

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Concept of Cognitive Cargo Port Risk Management 8

Concept of Cognitive Cargo Port Risk Management

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8th International Conference on Information, control, and Communication Technologies, ICCT 2024

作者： Bondareva, Irina Khanova, Anna Protalinskiy, Oleg Astrakhan State Technical University Department of Applied Informatics Astrakhan Russia Moscow Power Engineering Institute Department of Automated Control Systems of Thermal Processes Moscow Russia

ISBN: (纸本)9798331517564

Any business processes in an enterprise are associated with the need to periodically assess possible risk situations. Today, assessing risks in order to control them is not enough. It is necessary to continuously, cyclically and on an ongoing basis carry out risk management, which has already become an integral part of the management of the organization. However, the complexity of assessing and analyzing events associated with an unfavorable outcome dictates to organizational systems, which include the subject area considered in the work - a cargo port, the need to develop and use tools that allow for a comprehensive assessment of activities from the point of view of possible risks, including the possibility of cognitive evaluation of each of the results obtained. Risks are considered as situations of failure to meet goals, as well as target standards. The developed balanced scorecard (BS) contains a set of goals and indicators that complement them. In addition to this, through multi-level hybrid and scenario LP risk models of a cargo port, logical and probabilistic connections between goals, indicators and risks arising at all three levels of management are formulated. The basis of the ontological model is knowledge about the above-mentioned connections, the integrated use of which through appropriate queries allows you to choose ways to bypass risk situations under the existing specified conditions. The query results form experimental scenarios with a multi-approach simulation model and allow you to obtain quantitative estimates of indicators, goals and risks. Taking into account all available stochastic characteristics, influencing factors, and also based on information about the results of the experiment, the decision maker formulates the values of the parameters of the original organizational system necessary to adjust in order to prevent the development and aggravation of risk events. © 2024 IEEE.

关键词： Stochastic systems

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Significant potential of Solid Oxide Fuel Cell systems for distributed power generation and carbon neutrality

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Frontiers in Energy 2022年第6期16卷 879-882页

作者： Ziyuan TENG Minfang HAN Fuel Cell and Energy Storage Center Department of Energy and Power EngineeringState Key Laboratory of Control and Simulation of Power Systems and Generation EquipmentTsinghua UniversityBeijing 100084China

Energy is important for human survival and *** September 2020,the Chinese government announced that“China aims to have their CO_(2) emissions peak before 2030 and achieve carbon neutrality before 2060.”As China’s reformation and opening-up proceeds into its fifth decade,this new vision for its future is in line with that of the world’s major economies in terms of the need to reach net zero emissions globally by the mid-21stcentury[1].However,coal-fueled thermal power generation is currently dominant and accounts for more than 70%of the total amount of power generated in China,making it the world’s largest energy consumer and carbon *** on the country’s domestic resources,namely the abundance of coal and scarcity of oil and gas,it would be difficult to fundamentally change this coal-based energy structure in the short *** 2021,the global total energy sector was responsible for 36.3 Gt of CO_(2) emissions,including approximately 12 Gt from China,which thus accounts for one-third of the total global emissions[2].The demand for efficiency,energy savings,and emissions reduction in the power generation industry has become increasingly *** need has arisen to enhance ways in which to use coal cleanly and efficiently,reduce the consumption thereof,and replace coal with other forms of *** addition,carbon emissions need to be lowered by promoting the adoption of alternative power generation technologies that are more energy *** would require transformation away from coal power and the exploration of clean,efficient,flexible,and safe forms of energy as the main future development directions[3].

关键词： neutral carbon replace

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Performance Analysis and Flexible control of a Novel Ball Double-screw Hydraulic Robot Knee Joint

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Journal of Bionic engineering 2023年第5期20卷 2147-2163页

作者： Jie Shao Yongming Bian Meng Yang Guangjun Liu School of Mechanical Engineering Tongji UniversityShanghai201804China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310027China Department of Control Science and Engineering Tongji UniversityShanghai201804China National Engineering Technology Research Center for Prefabrication Construction in Civil Engineering Tongji UniversityShanghai200092China

Focusing on the ball double-screw hydraulic knee joint as the research object,this paper analyzes the load driving performance of the hydraulic knee *** the posture data of the human body such as walking,squatting and landing buffer as initial learning objects,motion features are *** simplifying the trajectories of different motion actions into key feature control points and flexible trajectory fitting,the trajectory of joint actions is *** method can realize the adaptability of the hydraulic robot knee joint in different movements,and take the flexible action as the optimization goal under the condition of ensuring the movement performance,so as to reduce the damage to the knee joint caused by the foot impact in *** simulation model was built by Adams and Matlab to complete the performance analysis and motion optimization experiment of the knee *** simulation results show that the foot impact force of the experimental model decreases gradually through ***,the method is applied to the hydraulic joint experimental prototype to prove its load capacity and flexible motion control performance.

关键词： Bionic robot Ball double-screw hydraulic joint Robot knee joint Performance analysis Humanoid motion control Flexible control

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