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Air-gap magnetic field distribution and inductance characteristics in a long primary sectional powered variable pole pitch linear induction motor

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Qinghua Daxue Xuebao/Journal of Tsinghua University 2014年第9期54卷 1161-1165and1172页

作者： Mu, Shujun Chai, Jianyun Sun, Xudong Wang, Shanming State Key Lab. of Security Control and Simulation of Power Systems and Large Scale Generation Equipments Department of Electrical Engineering Tsinghua University Beijing100084 China

This study investigated the air-gap magnetic field distribution and inductance characteristics of a long primary sectional powered variable pole pitch linear induction motor (VPPLIM). A one-dimensional analytical model and a 2-D finite element model were used to analyze the air-gap magnetic field distribution in the VPPLIM with harmonic fields for uniformly accelerating the mover with a typical AC supply. The air-gap magnetic field distribution was used to develop analytical expressions for the self-and mutual-inductances of the motor and their characteristics. The analytical expressions are verified by the finite element simulations. ©, 2014, Press of Tsinghua University. All right reserved.

关键词： Inductance

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Technology and application of online partial discharge monitoring for power equipments 5

Technology and application of online partial discharge monit...

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5th International Conference on Reliability of Electrical Products and Electrical Contacts, ICREPEC 2014

作者： Gao, Shengyou Gui, Junfeng Dept. of Elec. Eng. Tsinghua University State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Beijing100084 China School of Electrical Engineering Beijing Jiaotong University Beijing100044 China

ISBN: (纸本)9789881532329

Online partial discharge monitoring for power equipments is useful to improve the capacity of the power supply. Main technology for PD testing is introduced in this paper. Advantages and disadvantages of pulse current, UHF, ultrasonic and TEV method are present. The status quo of online PD monitoring is analyzed, and the detection effect of online PD monitoring is not good. Opinions to improve the effect are given. They include built-in sensors, increasing sensitivity and sample rate. Analysis of the state quo indicates that the relevant technical standards and specifications must be revised to improve the normalization and standardization.

关键词： Partial discharges

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Summary of health index theory and application of state maintenance equipment 5

Summary of health index theory and application of state main...

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5th International Conference on Reliability of Electrical Products and Electrical Contacts, ICREPEC 2014

作者： Cheng, Lin Manjun, L.I.U. Peng, Feijin Dept. of Elec. Eng. Tsinghua University State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Beijing100084 China Guangdong Power Grid Company Foshan Power Supply Bureau Foshan528010 China

ISBN: (纸本)9789881532329

This paper describes several methods for condition-based maintenance, introduced CBM, RCM development process, the main theoretical logic, techniques and practices. Focuses on the health index based on equipment maintenance strategies, namely CBRM. Focused on the development of narrative context, theoretical foundation, model healthy index. And for its application in power transformers were introduced.

关键词： Condition based maintenance

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Modeling and control of a Linear Fresnel Reflector for an Integrated Solar Combined Cycle

Modeling and control of a Linear Fresnel Reflector for an In...

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European control Conference (ECC)

作者： Jessica Leo Chady Kharrat Alina Voda Gildas Besançon Frans Davelaar Control Systems Department Gipsa-lab. St Martin d'Heres BP France department EDF-R&D Simulation and Information Technologies for Power generation systems (STEP) Chatou France Institut Universitaire de France

ISBN: (纸本)9781479947287

This paper presents a dynamic model of a Linear Fresnel Reflector (LFR) used to describe the evolution of the output steam enthalpy and the control strategy that was developed to allow coupling with Combined Cycle Power Plants (CCPP) while respecting operational constraints. The modeling approach uses the principle of a moving boundary formulation of a two-phase flow region and results in a nonlinear finite dimensional state space description. In order to circumvent the problem of nonlinearities, a simple linearization-based approach is proposed, providing accurate simulation results. simulations illustrating tracking performances compatible with the CCPP coupling, as well as good (solar) disturbance rejection are shown.

关键词： Electron tubes Equations Mathematical model Observers Power generation simulation Solar system

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Two-stage heuristic-correction for dynamic reactive power optimization based on relaxation-MPEC and MIQP

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2014年第13期34卷 2100-2107页

作者： Ding, Tao Guo, Qinglai Bo, Rui Sun, Hongbin Wu, Wenchuan Zhang, Boming Yao, Zhengyi State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Midwest ISO St. Paul 55108 United States Baoji Power Supply Bureau Baoji 721004 Shannxi Province China

To achieve a fast approach to the dynamic reactive power optimization model, a mixed integer nonlinear programming model was set up, with consideration of the discrete reactive power equipment operation limit and power grid security constraints, to minimize the transmission losses. Furthermore, a method called heuristic search and variable correction was proposed that for the first stage, the discrete variables are relaxed into continuous ones, which leads to an optimization model with equilibrium constraints. According to the optimal value of relaxed model, a mixed integer quadratic programming model is formulated to minimize the objective of approximation variance, satisfied the discrete switching operation constraints in primary model. For the second stage, the continuous variables are redressed with respect to the determined discrete variables. The impact of adjustment step and operation limit on the optimal solution was fully studied in IEEE 14-bus test system. Besides, the result of IEEE 30, 57, 118 test systems show that an optimal solution can fast be obtained by proposed method, and the precision satisfies the actual engineering, which can also employ the parallel technology. © 2014 Chinese Society for Electrical Engineering.

关键词： Integer programming

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26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 Antwerp, Belgium. 15-20 July 2017 Abstracts

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BMC NEUROSCIENCE 2017年第SUPPL 1期18卷 95-176页

作者： [Anonymous] Department of Neuroscience Yale University New Haven CT 06520 USA Department Physiology & Pharmacology SUNY Downstate Brooklyn NY 11203 USA NYU School of Engineering 6 MetroTech Center Brooklyn NY 11201 USA Departament de Matemàtica Aplicada Universitat Politècnica de Catalunya Barcelona 08028 Spain Institut de Neurobiologie de la Méditerrannée (INMED) INSERM UMR901 Aix-Marseille Univ Marseille France Center of Neural Science New York University New York NY USA Aix-Marseille Univ INSERM INS Inst Neurosci Syst Marseille France Laboratoire de Physique Théorique et Modélisation CNRS UMR 8089 Université de Cergy-Pontoise 95300 Cergy-Pontoise Cedex France Department of Mathematics and Computer Science ENSAT Abdelmalek Essaadi’s University Tangier Morocco Laboratory of Natural Computation Department of Information and Electrical Engineering and Applied Mathematics University of Salerno 84084 Fisciano SA Italy Department of Medicine University of Salerno 84083 Lancusi SA Italy Dipartimento di Fisica Università degli Studi Aldo Moro Bari and INFN Sezione Di Bari Italy Data Analysis Department Ghent University Ghent Belgium Coma Science Group University of Liège Liège Belgium Cruces Hospital and Ikerbasque Research Center Bilbao Spain BIOtech Department of Industrial Engineering University of Trento and IRCS-PAT FBK 38010 Trento Italy Department of Data Analysis Ghent University Ghent 9000 Belgium The Wellcome Trust Centre for Neuroimaging University College London London WC1N 3BG UK Department of Electronic Engineering NED University of Engineering and Technology Karachi Pakistan Blue Brain Project École Polytechnique Fédérale de Lausanne Lausanne Switzerland Departement of Mathematics Swansea University Swansea Wales UK Laboratory for Topology and Neuroscience at the Brain Mind Institute École polytechnique fédérale de Lausanne Lausanne Switzerland Institute of Mathematics University of Aberdeen Aberdeen Scotland UK Department of Integrativ

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Comparison of two basic structures in magnetically-coupled resonant wireless power transfer

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Diangong Jishu Xuebao/Transactions of China Electrotechnical Society 2013年第SUPPL.2期28卷 18-22页

作者： Zhang, Yiming Zhao, Zhengming Yuan, Liqiang Lu, Ting State Key Lab. of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing 100084 China

Wireless power transfer (WPT) has been a research focus in recent decades. Based on magnetically-coupled resonant WPT (MCR-WPT), this paper made a comparison of two basic structures in MCR-WPT: the two-coil structure and the four-coil structure. Their equivalent circuits were built. To illuminate the difference between these two structures, the input impedance, the transfer efficiency, and the load matching were studied and tested by experimental results. The conclusion is drawn that without reducing the transfer efficiency, the addition of the source coil and the load coil in the four-coil structure makes it easier to match the source and the load than the two-coil structure.

关键词： Magnetic resonance

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Fast evaluation of the lightning electromagnetic field in the time domain with an adaptive piecewise approximation of channel base current

Fast evaluation of the lightning electromagnetic field in th...

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作者： Lee, Jae-Bok Zou, Jun Li, Mo Chang, Sughun Electrical Environment Research Center Korea Electrotechnology Research Institute Changwon Korea Republic of State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing China

Purpose - A fast algorithm is proposed to calculate the lightning electromagnetic field over a perfectly conducting earth surface. Design/methodology/approach - The channel base current is approximated by a number of sub-domain quadratic functions using the proposed adaptive sampling technique, and the derivative and integral of the channel base current with respect to time can be analytically expressed. With the help of these approximations, the ideal electromagnetic field of the lightning channel can be evaluated along the lightning channel with respect to the height. Findings - The computational time can be greatly reduced using the proposed approach to evaluate the electromagnetic field of a lightning channel in the time domain. Originality/value - The adaptive sampling technique is a general-purposed approach, which can be potentially used in other applications to fit a function with the minimal number of intervals. © Emerald Group Publishing Limited.

关键词： Electromagnetic fields

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Design and implementation of automatic voltage control system applied to a power grid in Northeast US

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Dianwang Jishu/Power System Technology 2013年第2期37卷 349-355页

作者： Zhang, Mingye Guo, Qinglai Sun, Hongbin Tong, Jianzhong Zhang, Boming Wu, Wenchuan Wang, Bin State Key Lab. of Control and Simulation of Power Systems and Generation Equipments Dept. of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China PJM Interconnection PA 19403 United States

With the raising of requirement of power grid operation to voltage control and reactive power management level, automatic voltage control (AVC) becomes a hot spot in the research. Due to the constraints in the management mode, the applied research of AVC is hitherto a blank in North America power grids. An AVC system, which is suitable to special management modes of a certain interconnected power grid in Northeast U. S. and can meet the demand of on-line operation, is designed and implemented. In the designed system, phase shifter models are added into power flow modules and during the computation of control strategy by optimal power flow (OPF) the static security constraints after the assumed faults are considered. Both the data and assessment results of long-term on-line trail-operation show that the reactive power and voltage level of the interconnected power grid can be improved by applying the designed AVC system, and both security and economy of the interconnected power grid can be enhanced.

关键词： Electric power system control

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A non-iterative affine arithmetic methodology for interval power flow analysis of transmission network

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering 2013年第19期33卷 76-83页

作者： Ding, Tao Bo, Rui Guo, Qinglai Sun, Hongbin Wu, Wenchuan Zhang, Boming State Key Lab. of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Haidian District Beijing 100084 China Midwest ISO St. Paul 55108 United States

Power flow exhibits uncertainty when power injections randomly fluctuate. The variables of power flow problem are correlated through the constraints set forth by power flow equations. Affine arithmetic can effectively overcome the correlation and therefore is adopted in this paper. In order to improve the computational efficiency, non-iterative method was proposed, which can transform the interval power flow problem into optimization problems. Linear programming, nonlinear programming and quadratic programming optimization models were established to obtain intervals of nodal voltage magnitude, phase angle, branch active power and reactive power, respectively. simulation results of 9-bus and 57-bus test system show that the power flow interval obtained by the proposed algorithm is nearly the same as that by iterative algorithms, whereas the branch power flow results are better. The interval power flow problem can be solved quickly and efficiently with time complexity approximately O(m3). As well, parallel computing can be implemented to achieve promising improvement in computation time. © 2013 Chinese Society for Electrical Engineering.

关键词： Quadratic programming

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