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16th International Symposium on Solid Oxide Fuel Cells, SOFC 2019

作者： Qi, H. Yang, T. Li, W. Ma, L. Hu, S. Shi, W. Sabolsky, E.M. Zondlo, J. Hart, R. Hackett, G.A. Liu, X. Department of Mechanical and Aerospace Engineering West Virginia University MorgantownWV26506 United States National Energy Technology Laboratory MorgantownWV26505 United States Oak Ridge Institute for Science and Education P.O. Box 117 Oak RidgeTN37830 United States Department of Energy and Power Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing10083 China GE Global Research Centre NiskayunaNY12309 United States

ISBN: (纸本)9781607688747

In-situ exsolution is widely considered to be an efficient and cost-effective method to enhance the electrochemical performance of a ceramic anode in solid oxide fuel cells (SOFCs). In this study, by controlling the non-stoichiometry of Sr2Fe1.5Mo0.5O6-δ with A-site doping, evenly distributed Fe nano-particles (~100 nm) were obtained on surface of La0.5Sr1.5Fe1.5Mo0.5O6-δ (LSFM) when treated in hydrogen. In a redox environment, excellent exsolution-dissolution reversibility was also demonstrated. Electrical conductivity relaxation (ECR) and electrochemical impedance spectroscopy (EIS) were employed to evaluate the surface reaction kinetics change during exsolution. The surface exchange coefficient (kex) was increased by 1.5 to 2 times with Fe exsolution. Based on distribution of relaxation time (DRT) analysis, the polarization resistance (Rp) associating with surface process was reduced in the first few hours. Both results revealed an enhanced surface reaction kinetics which mainly benefits from the high catalytic activity of exsolved nano-particles to H2 adsorption and dissociation process. © The Electrochemical Society.

关键词： Electrochemical impedance spectroscopy

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Novel ZnO Varistors for Dramatically Improving Protective Effect of Surge Arresters

Novel ZnO Varistors for Dramatically Improving Protective Ef...

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International Conference on Lightning Protection (ICLP)

作者： Pengfei Meng Yao Zhou Jinbo Wu Jun Hu Jinliang He State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China

The insulation level of power apparatus is based on the protection level of overvoltage in power systems. Deeply suppressing the switching overvoltage of UHV systems will reduce the manufacturing cost and technical bottlenecks of UHV power apparatus. We studied the effects of multi-elements doping on the electrical properties of ZnO varistors co-doped with Al2O3, Ga2O3, and In2O3 Scanning electron microscopy, current-voltage testing, capacitance-voltage testing, and X-ray diffraction were performed. The results showed that the residual voltage ratio of sintered varistors decreased as the indium dopant concentration was increased. The samples with 0.03 mol % indium, 0.2 mol % aluminum, and 0.42 mol % gallium showed excellent overall performance, exhibiting a nonlinear coefficient of 61.2, a leakage current of 1.63 μA /cm2, a 1-mA residual voltage of 435 V/mm, and a residual voltage ratio of 1.52. These optimized properties will be of great utility in the manufacture of metal oxide arresters. The protective effects of this kind of novel surge arresters for lightning and switching overvoltage in UHV systems are analyzed. With the low residual voltage ZnO varistors applied to surge arresters will dramatically improving the protective effect of surge arresters, to realize the target to deeply suppress the lightning and switching overvoltages, and then reduce the insulation level and manufacturing bottleneck of UHV power apparatus.

关键词： Zinc oxide II-VI semiconductor materials Arresters Varistors Indium Surges

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A software and hardware design of intelligent measurement and control terminal of distribution network based on a communication adaptive approach

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IOP Conference Series: Earth and Environmental Science 2021年第2期651卷

作者： Yujie Ding Xiaobing Xiao Hao Tian Chang Liu Guangze Ouyang Ruifeng Zhang Anshun Power Supply Bureau of Guizhou Power Grid Co. Ltd. Anshun China Electric Power Research Institute of Guizhou Power Grid Co. Ltd. Guiyang China State Key Lab of Control and Simulation of Power Systems and Generation Equipments (Dept. of Electrical Engineering Tsinghua University) Beijing China Binjiang College of Nanjing University of Information Science and Technology Wuxi China

With the development of science and technology, the hardware and software design of transformer intelligent measurement and control terminal is very important. Based on the hardware and software appization of internet of things, the design scheme of hardware and software structure is given. Supported by high-performance operating system, the terminal device can be upgraded flexibly through APP application software. The intelligent terminal pair can realize full data collection, full control and full fusion, and real-time exchange of key operation data with the power distribution master station. The intelligent terminal can support 5G communication and realize full compatibility of communication conditions downward.

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Space Charge Behavior in AC Electrically Aged Low-Density Polyethylene Films 2

Space Charge Behavior in AC Electrically Aged Low-Density Po...

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2nd IEEE International Electrical and Energy Conference, CIEEC 2018

作者： Cheng, Zixia Shi, Jinxing Zhang, Ling Zhou, Yuanxiang Lu, Zekai Guo, Shaowei School of Electrical Engineering Zhengzhou University Zhengzhou450001 China State Key Lab of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing100084 China School of Electrical Engineering Xinjiang University Urumqi830047 China Electric Power Research Institute State Grid Jibei Electric Power Company Beijing100045 China

ISBN: (纸本)9781538653913

In order to study the effect of AC aging on space charge characteristics of low-density polyethylene (LDPE) films, an AC electric field of 50 kV/mm (peak value) was adopted for the accelerated aging test and space charge measurements of AC aged LDPE films were carried out subsequently. The results show that no significant space charge accumulation in the LDPE samples aged under a 50 kV/mm AC electric field. It can be seen that a significant positive space charge accumulation occurs inside the sample, when DC electric fields were applied to the AC aged LDPE samples. The long-term AC aging also causes more and deeper cracks on the surface of LDPE samples. Moreover, AC aging promotes the oxidation reaction of LDPE. The longer the aging time, the higher the degree of oxidation. On this basis, the probable relationship between space charge characteristics and material physicochemical properties of LDPE during AC electrical aging is clarified. © 2018 IEEE.

关键词： Electric space charge

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Statistical characteristics of transient enclosure voltage in ultra-high-voltage gas-insulated switchgear

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Plasma Science and Technology 2017年第6期19卷 74-81页

作者： Yuanji CAI Yonggang GUAN Weidong LIU State Key Lab of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 People＇s Republic of China

Transient enclosure voltage（TEV）,which is a phenomenon induced by the inner dielectric breakdown of SF_6 during disconnector operations in a gas-insulated switchgear（GIS）,may cause issues relating to shock hazard and electromagnetic interference to secondary *** is a critical factor regarding the electromagnetic compatibility of ultra-high-voltage（UHV）*** this paper,the statistical characteristics of TEV at UHV level are collected from field experiments,and are analyzed and compared to those from a repeated strike *** TEV waveforms during disconnector operations are recorded by a self-developed measurement system ***,statistical characteristics,such as the pulse number,duration of pulses,frequency components,magnitude and single pulse duration,are *** transmission line theory is introduced to analyze the TEV and is validated by the experimental ***,the relationship between the TEV and the repeated strike process is *** proves that the pulse voltage of the TEV is proportional to the corresponding breakdown *** results contribute to the definition of the standard testing waveform of the TEV,and can aid the protection of electronic devices in substations by minimizing the threat of this phenomenon.

关键词： transient enclosure voltage （TEV） gas-insulated switchgear （GIS） ultra-high-voltage （UHV） repeated strike process disconnector

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Effect of Vinyl Content on Mechanical Property and Electrical Tree Initiation in Silicone Rubber 2

Effect of Vinyl Content on Mechanical Property and Electrica...

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2nd IEEE International Electrical and Energy Conference, CIEEC 2018

作者： Sui, Jiangyuan Zhang, Ling Zhou, Yuanxiang Zhang, Xinyan Cheng, Zixia Guo, Shaowei School of Electrical Engineering Xinjiang University Urumqi830047 China State Key Lab of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing100084 China State Key Lab of Electrical Insulation and Power Equipment Xi'an Jiaotong University Xi'an710049 China School of Electrical Engineering Zhengzhou University Zhengzhou450001 China Electric Power Research Institute State Grid Jibei Electric Power Company Beijing100045 China

ISBN: (纸本)9781538653913

The vinyl content in methyl vinyl silicone oil has a significant impact on the mechanical and electrical properties of reinforced silicone rubber. In this study, mechanical property and electrical tree initiation of silicone rubber were studied by comparing different vinyl contents. The results show that shore hardness, tensile strength, elongation at break, and tear strength of insulating silicone rubber material increase first and then decrease with the of vinyl content increasing from 1% to 5%. The breakdown strength and the initiation voltage of electrical tree are basically consistent with the variation of tensile strength and tear strength. Detailed discussion are presented. This work could provide data support for the practical preparation of engineering silicone rubber. © 2018 IEEE.

关键词： Tensile strength

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An Improved Master-Slave control for Three-port Converter Based Distributed DC Grid-connected PV system 8

An Improved Master-Slave Control for Three-port Converter Ba...

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8th International power Electronics Conference, IPEC-Niigata - ECCE Asia 2018

作者： Jiang, Siyue Sun, Kai Wu, Hongfei Shi, Haixu Dong, Xiaofeng Raza Kazmi, Syed Muhammad State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China Jiangsu Key-Laboratory of New Energy Generation and Power Conversion Nanjing University of Aeronautics and Astronautics Nanjing Jiangsu Province China United States Pakistan Center for Advanced Studies in Energy National University of Sciences and Technology Islamabad Pakistan

ISBN: (纸本)9784886864055

With the development of DC grid technology, it has become a trend to introduce photovoltaic(PV) as a power source to the DC power distribution network. In this paper, an improved master-slave control strategy is proposed to realize power splitting and voltage sharing in a modular system with PV connected. Each module is a three-port converter: Input port connects distributed PV, output port connects to DC grid, and intermediate port is connected in parallel with other modules as a bus to realize the power splitting. For a single module, input voltage, intermediate bus voltage and output voltage should all be controlled to reference but only duty ratio and phase-shifting angel can be regulated hence it may occur the multi-objective variables control problem. While using the proposed strategy, this problem can be solved effectively and the system stability is ensured during the voltage sharing process. This control strategy is verified by simulation and experiment. © 2018 IEEJ Industry Application Society.

关键词： system stability

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Preventive control for combined heat and power system: A day-ahead security constrained economic dispatch model 11

Preventive control for combined heat and power system: A day...

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11th IET International Conference on Advances in power system control, Operation and Management, APSCOM 2018

作者： Lin, Qunli Shen, Xinwei Xu, Yinliang Sun, Yong Li, Zhenyuan Guo, Qinglai Sun, Hongbin Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen Institute Tsinghua University Shenzhen China Jilin Power Grid Company State Grid Corp. of China Jilin China State Key Lab of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781839530043

Integrated Energy system (IES), which plays a vital role in the development of Energy Internet (EI), can improve the efficiency of energy utilization and integration of renewable energy. However, the coupling between multiple energy systems will bring new challenges to the security control of the IES, such as combined heat and power (CHP) system. For IES, the preventive control is the first line of defense to ensure that the system can keep stable operation when contingencies such as the transmission outage or generator outage happen. This paper proposes a preventive control approach for CHP system, in which a day-ahead security constrained economic dispatch (SCED) model of CHP system considering the coupling of heat and electric is formulated. The model aims to minimize the cost of the whole system, while the preventive control of the system can be achieved with the constraints considering the normal states and contingencies states. Case studies based on the IEEE 9-bus system with CHPs are presented to illustrate the approach. The case result shows that the combined electric and heat optimal dispatch is more economical than when two systems are independently optimized and operated. And the proposed preventive control approach of the CHP system can satisfy both the electric and heat demand, and system security is ensured when the N-1 contingencies happened. © 2018 Institution of Engineering and Technology. All rights reserved.

关键词： Internet of Energy

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Wind farm active voltage regulation strategy of transient support improvement

Wind farm active voltage regulation strategy of transient su...

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8th Renewable power generation Conference (RPG 2019)

作者： Cui Yang Song Peng Cheng Xuekun Qiao Ying Wang Xiaosheng Liu Jingbo State Grid Jibei Electric Power Co. Ltd. Research Institute North China Electric Power Research Institute Co. Ltd. Xicheng District Beijing China Grid-connected Operation Technology For Wind-Solar-Storage Hybrid System State Grid Corporation Key Laboratory Xicheng District Beijing China State Key Lab of Control and Simulation of Power Systems and Generation Equipment Dept. of Electrical Engineering Tsinghua University Haidian District Beijing China

ISBN: (数字)9781839531248

ISBN: (纸本)9781839531255

The cumulative installed capacity of wind power worldwide has grown rapidly in recent years. Fixed reactive power control is adopted by wind turbines (WTs) to receive cycle instruction of wind farm (WF) automatic voltage control system (AVCS). It does not have active voltage regulation (AVR) capability, which reduces the reliability of power system operation. Firstly, two ways of WTs AVR which QV droop control and Vac control mode are introduced in this paper. On the basis, the problems of reactive power circulation and control points inconsistency during multi-WTs voltage regulation are discussed. The problems are solved by coordination of WTs of WF AVR strategy. WF voltage transient support capability is promoted by the strategy. Effectiveness is verified by simulation case of the proposed method.

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Non-communication Protection for Single-Phase-to-Ground Fault Feeder in Neutral Non-Effectively Grounded Distribution system

Non-communication Protection for Single-Phase-to-Ground Faul...

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IEEE General Meeting power& Energy Society

作者： Qi Jia Xinzhou Dong Shenxing Shi Xin He State Key Lab. of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing China Power Dispatching Control Center Guizhou Power Grid Co. Ltd Guiyang China

ISBN: (纸本)9781538677049

The traditional non-communication protection for distribution system is only applicable to fault feeders in neutral effectively grounded distribution system or the phase-to-phase fault feeders in neutral non-effectively grounded distribution system. For single-phase-to-ground fault feeders in the latter system, the protection will fail to operate because the magnitude of the current flow in the fault-to-ground connection is too small. To solve this problem, this paper presents a new non-communication protection compatible with the fault detection principle based on comparing the polarities of the initial voltage and current traveling waves. In this technique, when a single-phase-to-ground fault occurs, the relays which detect the fault is in the forward direction will operate based on the conventional time grading coordination at first, after one relay makes tripping decision which has the fastest time setting, the relay on the opposite side will detect the sound phase current changes in a time window to accelerate the operation. Extensive Electromagnetic Transients Program (EMTP) simulation studies with respect to a typical double end feeder system whose neutral is non-effectively grounded show that the proposed technique is able to fast and accurately remove a single-phase-to-ground fault line section from both ends.

关键词： Circuit faults Relays Acceleration Circuit breakers Wavelet transforms EMTP

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