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Transmission and Distribution Conference and Exposition - Asia and Pacific

作者： Wang, Bin Dong, Xinzhou Bo, Zhiqian Klimek, Andrew Tsinghua Univ Dept Elect Engn State Key Lab Control & Simulat Power Syst & Gene Beijing 100084 Peoples R China AREVA T&D UK Ltd Stafford ST1 4LX England

ISBN: (纸本)9781424452293

The performance of the Negative Sequence Pilot Protection (NSPP) is less deteriorated by the phase-ground shunt capacitance since the negative sequence current loops in phase-phase lines. Hence NSPP is a good candidate for the main protection in UHV lines with the special characteristic of larger charging current. But as we all known, NSPP is not suit to the open-phase operations in transmission line, which limited its wide applications in HV/EHV lines in history. In response to this question, the performance of NSPP in transmission line with open-phase operation is analyzed, and the mal-operation reason of the NSPP relay is discovered. Then an improved algorithm for faults detection is proposed in open-phase line, and the simulation results verified its validity. The work in this paper is only the basic steps, the more research, such as the sensitivity and transient characteristics of ground fault detections in open-phase line should be discussed further.

关键词： UHV Negative sequence pilot protection Shunt capacitance distributed parameter

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Temperature Modeling and Simulation of the Asphaltic Emulsion in an Industrial Tank

Temperature Modeling and Simulation of the Asphaltic Emulsio...

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9th IEEE International Symposium on Applied Computational Intelligence and Informatics (SACI)

作者： Muresan, Vlad Abrudean, Mihail Colosi, Tiberiu Tech Univ Cluj Napoca Automat Dept Cluj Napoca Romania

ISBN: (纸本)9781479946945

In this paper, a solution for the modeling-simulation of the temperature propagation phenomenon in the asphaltic emulsion from an industrial tank is presented. The heating process of the asphaltic emulsion is a distributed parameter one, its model being expressed using a partial differential equation. The modeling-simulation procedure is based on the matrix of partial derivatives of the state vector (Mpdx) associated with Taylor series. Some suggestive 2D and 3D graphical representations are presented in order to show the temperature distribution inside the tank. Also, a solution for the designing of the emulsion's temperature control system is proposed in the end of the paper.

关键词： Tanks Graphic methods modeling and simulation PROCESS HEAT Temperature distribution Taylor series Industrial distributed parameter

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Relative Stability Assessment for Wideband Harmonic Resonances in distributed Generation Power Plants 45

Relative Stability Assessment for Wideband Harmonic Resonanc...

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45th Annual Conference of the IEEE Industrial Electronics Society (IECON)

作者： Chen, Zhiyong Luo, An Huang, Xucheng Xiangtan Univ Coll Informat Engn Xiangtan Peoples R China Hunan Univ Coll Elect & Informat Enineering Changsha Peoples R China

ISBN: (纸本)9781728148786

For assessing the influence of feeder's distributed parameter on the grid-connected current which is emitted by distributed generation power plants (DGPP), hyperbolic function should be introduced in the process of feeder modeling. However, the Taylor approximation of the hyperbolic function makes the Norton equivalent of the DGPP possess a certain number of poles in the right-half s plane. This pole configuration violates the impedance-based stability criterion to be applied. To this end, we proposed equivalently transforming the hyperbolic function via Euler's formula. The advantage of this transformation includes the following two aspects: 1) it could establish the direct correlation between time-domain eigenvalues and system frequencies;2) it enables us to assess the relative stability of systems in terms of pole-zero method. By using the proposed Euler's formula-based stability-analysis approach, we found that: 1) the underlying causes of the wideband harmonic resonances correlated with the motion patterns of the eigenvalues on the s plane;2) with the system frequencies increasing, the frequencies of the arc resonance peaks exactly corresponded to the frequencies which made the dominant pole traverse the negative real axis in the s plane from top to bottom.

关键词： distributed parameter pole-zero cancellation power quality relative stability renewable energy generation

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A Signal Model for Forensic DNA Mixtures 48

A Signal Model for Forensic DNA Mixtures

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48h Asilomar Conference on Signals, Systems and Computers

作者： Moenich, Ullrich J. Grgicak, Catherine Cadambe, Viveck Wu, Jason Yonglin Wellner, Genevieve Duffy, Ken Medard, Muriel MIT Elect Res Lab Cambridge MA 02139 USA Boston Univ Sch Med Biomed Forens Sci Boston MA 02215 USA Penn State Univ Dept Elect Engn University Pk PA 16802 USA Natl Univ Ireland Maynooth Hamilton Inst Maynooth Kildare Ireland

ISBN: (纸本)9781479982974

For forensic purposes, short tandem repeat allele signals are used as DNA fingerprints. The interpretation of signals measured from samples has traditionally been conducted by applying thresholding. More quantitative approaches have recently been developed, but not for the purposes of identifying an appropriate signal model. By analyzing data from 643 single person samples, we develop such a signal model. Three standard classes of two-parameter distributions, one symmetric (normal) and two right-skewed (gamma and log-normal), were investigated for their ability to adequately describe the data. Our analysis suggests that additive noise is well modeled via the log-normal distribution class and that variability in peak heights is well described by the gamma distribution class. This is a crucial step towards the development of principled techniques for mixed sample signal deconvolution.

关键词： signals distributed parameter ANALYTICAL DATA Additive noise Single Person DNA log normal distribution Gamma Distribution DNA Fingerprinting mixtures Microsatellite Repeats

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Frequency Effect on Calculation for Voltage Distribution of Winding

Frequency Effect on Calculation for Voltage Distribution of ...

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General Meeting of the IEEE-Power-and-Energy-Society

作者： Zhao, Chun Ruan, Jiangjun Ruan, Ling Du, Zhiye Chen, Liang Yu, Shifeng Wuhan Univ Sch Elect Engn Wuhan 430072 Hubei Peoples R China Hubei Elect Power Testing & Res Inst Wuhan Hubei Peoples R China

ISBN: (纸本)9781424442409

This paper models simplified transformer winding model by multi-conductor transmission line (MTL) model. Because inductance and resistance of transformer winding are frequency-dependent parameters, frequency effect on parameters should be considered when calculating distributed parameter matrices. Then, when solving for voltage distribution of winding model, the distributed parameter matrices should be selected according to the frequency of signal source. Because of frequency change, voltage distribution of winding model changes very significantly. This phenomenon can he verified by accurate experiment.

关键词： distributed parameter Experiment Frequency Effect Finite Element Method Inductance Multi-Conductor Transmission Line Partial Discharge Resistance Voltage Distribution and Winding

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Short-circuit current calculation on DC side of MMC-HVDC system with long distance transmission lines 3

Short-circuit current calculation on DC side of MMC-HVDC sys...

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3rd International Conference on Electrical Engineering and Control Science, IC2ECS 2023

作者： Wang, Zhuoya Hao, Liangliang He, Jinghan College of Electrical Engineering Beijing Jiaotong University Beijing China

ISBN: (纸本)9798350382426

The development of DC side faults in flexible DC transmission systems is rapid, and the short-circuit current rises very quickly. With the gradual expansion of flexible DC transmission technology to long-distance and long transmission line scenarios, the calculation of short-circuit current considering distributed parameter lines urgently needs attention. This article is based on the MMC DC side short-circuit current calculation universal model, studies the transmission line structure, establishes a long-distance transmission line mathematical model considering the distribution parameter characteristics and line frequency variation characteristics, and proposes a DC side short-circuit current calculation method for flexible DC transmission systems containing long-distance transmission lines. The comparison between simulation and calculation results verified the correctness of the theoretical model and the effectiveness of the calculation method. © 2023 IEEE.

关键词： distributed parameter modular multilevel converter short-circuit current calculation transmission lines model

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Study on multi scattering point modeling for target in fuze RF simulation and its application 3

Study on multi scattering point modeling for target in fuze ...

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3rd Asia-Pacific Conference on Antennas and Propagation, APCAP 2014

作者： Qian, Chen Jun, Gu ChunHua, Zhou XiaoBing, Wang Beijing Institute of Technology Beijing100094 China Science and Technology on Electromagnetic Scattering Laboratory Shanghai200438 China Shanghai Radio Equipment Reaearch Institute Shanghai200438 China

ISBN: (纸本)9781479943548

This article acquires the microwave imagery of target through simulation, bases on ISAR imagery of complex target, and adopts the CLEAN method to extract the strong scattering point of target imagery;meanwhile, combine the non-uniform illumination under missile-target encounter conditions, respectively obtain the distribution parameters of target scattering points at various miss distance, providing input data source for fuse RF simulation. © 2014 IEEE.

关键词： Atmospheric modeling Data models Electromagnetic scattering Fuses Radio frequency Vectors multi scattering point radio frequency simuation research of application Fuses radiofrequency Atmospheric models data models Electromagnetic scattering microwave images Targets distributed parameter broadcasting Scattering simulating Cloning Vectors

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Optimal configuration of microstructure in ferroelectric materials by stochastic optimization

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JOURNAL OF APPLIED PHYSICS 2010年第2期108卷 024101-024101页

作者： Jayachandran, K. P. Guedes, J. M. Rodrigues, H. C. Univ Tecn Lisboa IDMEC Inst Super Tecn P-1049001 Lisbon Portugal

An optimization procedure determining the ideal configuration at the microstructural level of ferroelectric (FE) materials is applied to maximize piezoelectricity. Piezoelectricity in ceramic FEs differs significantly from that of single crystals because of the presence of crystallites (grains) possessing crystallographic axes aligned imperfectly. The piezoelectric properties of a polycrystalline (ceramic) FE is inextricably related to the grain orientation distribution (texture). The set of combination of variables, known as solution space, which dictates the texture of a ceramic is unlimited and hence the choice of the optimal solution which maximizes the piezoelectricity is complicated. Thus, a stochastic global optimization combined with homogenization is employed for the identification of the optimal granular configuration of the FE ceramic microstructure with optimum piezoelectric properties. The macroscopic equilibrium piezoelectric properties of polycrystalline FE is calculated using mathematical homogenization at each iteration step. The configuration of grains characterized by its orientations at each iteration is generated using a randomly selected set of orientation distribution parameters. The optimization procedure applied to the single crystalline phase compares well with the experimental data. Apparent enhancement of piezoelectric coefficient d(33) is observed in an optimally oriented BaTiO3 single crystal. Based on the good agreement of results with the published data in single crystals, we proceed to,apply the methodology in polycrystals. A configuration of crystallites, simultaneously constraining the orientation distribution of the c-axis (polar axis) while incorporating ab-plane randomness, which would multiply the overall piezoelectricity in ceramic BaTiO3 is also identified. The orientation distribution of the c-axes is found to be a narrow Gaussian distribution centered around 45 degrees. The piezoelectric coefficient in such a ceramic is fou

关键词： Optimization Procedure crystalline phase Solution space homogenization iterative methods Piezoelectricity GTF2E1 gene Iron distributed parameter single crystals self-potential methods

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NMR investigation of mechanically milled nanostructured GaF₃ powders

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JOURNAL OF PHYSICS-CONDENSED MATTER 1999年第40期11卷 L423-L431页

作者： Bureau, B Guérault, H Silly, G Buzaré, JY Grenèche, JM Univ Maine UPRESA CNRS 6087 Lab Phys Etat Condensee F-72085 Le Mans 9 France

High-energy ball milling is suitable for the preparation of nanostructured powders. First, high-resolution, solid-state nuclear magnetic resonance (NMR) investigations of F-19, Ga-69 and Ga-71 in ball-milled ionic GaF3 are presented. The quadrupolar parameter and the isotropic chemical shift distributions are determined for the three nuclei. The quadrupolar parameter distributions give clear evidence of two main structurally different phases in mechanically milled GaF3. A discussion based upon molecular dynamics simulations allows us to distinguish these two phases according to the size of the distortion of the GaF6 octahedral units: the lowest distortion is related to crystalline grains and the highest one to grain boundaries. It is thus concluded that NMR is a technique well adapted to the quantification and characterization of these two phases.

关键词： abnormal shapes TWO-PHASE Ball milling Nuclear Magnetic Resonance High energy milling distortion Cereal Grain Molecular Dynamics Simulation distributed parameter Grain boundaries

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Fault location for general AC/DC transmission lines: Multi-phase, non-homogeneous, partially mutually coupled and multi-terminal lines

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ELECTRIC POWER SYSTEMS RESEARCH 2023年第1期222卷

作者： Lu, Dayou Liu, Yu ShanghaiTech Univ Sch Informat Sci & Technol Shanghai 201210 Peoples R China Minist Educ Key Lab Control Power Transmiss & Convers SJTU Shanghai 200240 Peoples R China

The complexity of a general AC/DC transmission line is mainly caused by the components such as multi-phase line, non-homogeneous line, partially mutually coupled line and multi-terminal line. This paper proposes a systematic methodology to accurately locate faults in a general complex AC/DC transmission line. Instantaneous measurements only at line terminals are required. First, the modeling methodologies of symmetrical/asym-metrical multi-phase line, non-homogeneous (including partially mutually coupled) line and multi-terminal line are proposed. The distributed parameter line model is fully considered with partial differential equations (PDEs) in time domain. Second, the voltage distribution along the entire line is obtained via numerical solutions. Third, the faulted segment and fault location is determined based on the calculated voltage distribution. The proposed method is carefully designed to ensure applicability for a general AC/DC transmission line, independent of the numbers of phases/poles, non-homogeneous (including partially mutually coupled) sections, terminals, and joint points. Numerical experiments in two example complex transmission lines prove that the proposed method can accurately identify faulted segments and locate faults under different fault conditions. The method works with a relatively low sampling rate of 20k samples/sec and a data window of 5 ms after the fault occurs.

关键词： Fault location Multi-phase line Non-homogeneous line Partially mutually coupled line Multi-terminal line Time domain distributed parameter Partial differential equations (PDEs)

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