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Effect of Multiple Models of Closed-loop Transfer Functions on Inter-harmonic Oscillation Characteristics of Grid-connected PMSG

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 1955-1964页

作者： Jingyi Li Jianjun Yang Xiaorong Xie Haozhi Li Ke Wang Zhaohui Shi Key Laboratory of Far-shore Wind Power Technology of Zhejiang Province Huadong Engineering Corporation LimitedPower ChinaHangzhou 310014China. State Key Lab of Control and Simulation of Power Systems and Generation Equipment(dept.of electrical eng.neering Tsinghua University)Beijing 100084China.

Establishing a suitable closed-loop transfer function model for the grid-connected PMSG system is the key basis in performing inter-harmonic characteristics *** closed-loop transfer functions can be constructed when different components of the converter controller are taken into ***,the effect of different components of the converter controller on inter-harmonic stability analysis is not *** this paper,the complete transfer function,considering different loops,is first *** on the complete closed-loop transfer function,the DC-link,PLL and voltage forward-feed are removed step by step to derive different closed-loop transfer *** inter-harmonic related poles of different closed-loop transfer functions are further calculated to analyze the effect of closedloop transfer functions on inter-harmonic characteristics ***,by performing time domain simulation,the correctness of the theoretical analysis results is *** results show that under the conditions of a weak AC system,each loop of the converter control system will reduce the stability of the interharmonic in the sub-synchronous frequency range and influence the inter-harmonic oscillation *** transfer function needs to consider the influence of each loop to accurately calculate the inter-harmonic stability of the system.

关键词： Closed-loop transfer function converter controller inter-harmonic characteristics PMSG

A Multi-Channel CMOS Analog Front-End Interface IC with 157.8 d B Current Detection Dynamic Range

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Chinese Journal of electronics 2024年第2期33卷 393-402页

作者： Kunyu WANG Wenjing XU Cheng.in ZHANG Yanjun YANG Man-Kay LAW Li ZHOU Jie CHEN Ming CHEN Institute of Microelectronics of the Chinese Academy of Science University of Chinese Academy of Sciences Zunyi Normal University Institute of Microelectronics and dept.of ECE FST University of Macau

A high dynamic range and low-noise CMOS(complementary metal-oxide-semiconductor transistor)front-end interface integrated circuit(IC) with multi-channel detection is presented in this paper. Two different current detection channels, composed of a trans-impedance amplifier(TIA) and an integrator-differentiator TIA, are used to boost the current detection range. A capacitance-coupled instrument amplifier(CCIA) is also included to realize high precision voltage detection. A fourth-order sigma-delta modulator using a second-order loop filter and a second-order noise shaping integral quantizer is adopted to realize effective number of bits above 16 bits. The presented interface IC is implemented in 0.18-μm CMOS process with supply voltage of 3.3 V, and a proto-type electrochemical sensor platform with miniaturized sensor array is developed to verify the functionality of the interface IC. Measurement results indicate that the designed interface IC achieves 157.8 d B current detection dynamic range, and the measured input-referred current noise and voltage noise floor are 1.04 p A and 58.4 n V within 10 k Hz integration bandwidths,respectively.

关键词： Integrated circuits Sigma-delta modulation Semiconductor device measurement Voltage measurement Current measurement Noise Bandwidth

Analysis of travelling wave solutions of double dispersive sharma-Tasso-Olver equation

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Journal of Ocean eng.neering and Science 2024年第5期9卷 461-474页

作者： Kamruzzaman Khan Henk Koppelaar M.Ali Akbar Syed Tauseef Mohyud-Din Department of Mathematics Pabna University of Science and TechnologyPabna 6600Bangladesh Fac.of electrical eng. Mathematics and Comp.ScienceUniversity of DelftNetherlands Department of Applied Mathematics University of RajshahiRajshahi 6205Bangladesh Department of Mathematics HITEC University Taxila CanttPakistan School of Science and Technology University of New EnglandArmidaleNSW 2351Australia

Travelling wave solutions have been played a vital role in demonstrating the wave character of nonlinear problems arising in the field of ocean eng.neering and *** describe the propagation of the nonlinear wave phenomenon in the ocean(for example,wind waves,tsunami waves),a variety of evolution equations have been suggested and investigated in the existing *** paper studies the dynamic of travelling periodic and solitary wave behavior of a double-dispersive non-linear evolution equation,named the Sharma-Tasso-Olver(STO)*** evolution equations with double dispersion enable us to describe nonlinear wave propagation in the ocean,hyperplastic rods and other mediums in the field of science and *** analyze the wave solutions of this model using a combination of numerical simulations and Ansatz *** analysis shows that the travelling wave solutions involve a range of parameters that displays important and very interesting properties of the wave *** relevance of the parameters in the travelling wave solutions is also *** simulating numerically,we demonstrate how parameters in the solutions influence the phase speed as well as the travelling and solitary ***,we discuss instantaneous streamline patterns among the obtained solutions to explore the local direction of the components of the obtained solitary wave solutions at each point in the coordinate(x,t).

关键词： Travelling wave Solitary wave Streamline Enhanced(G'/G)-expansion method STO equation

Application of Extended Kalman Filter to the Modeling of Electric Arc Furnace for Power Quality Issues

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 257-262页

作者：金之俭王丰华朱子述 dept.of electrical eng. Shanghai Jiaotong Univ.

Electric arc furnaces(EAFs)represent one of the most disturbing loads in the subtransmission or transmission electric power ***,it is necessary to build a practical model to descript the behavior of EAF in the simulation of power system for power quality *** paper deals with the modeling of EAF based on the combination of extended Kalman filter to identify the parameter of arc current and the power balance equation to obtain the dynamic,multi-valued u-i characteristics of EAF *** whole EAF systems are simulated by means of power system blockset in Matlab to validate the proposed EAF *** model can also be used to assess the impact of the new plant or highly varying nonlinear loads that exhibit chaos in power systems.

关键词： electric arc furnace(EAF) extended Kalman filter power quality chaos

A Novel Practical Cooperative Diversity Method for the Power-Limited Wireless Sensor Network

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 458-463页

作者：周亮郑宝玉 dept.of electrical eng. Shanghai Jiaotong Univ.

A novel practical cooperative diversity method for power-limited wireless sensor network system was proposed. At first, the system model was presented and the cooperation problem is formulated under the minimum outage probability criterion, then the focus was put on the power efficiency of system, such as the relay selection, cooperation strategy and power allocation etc. At last the uniform procedure of the proposed method was given. The results of the simulation clearly demonstrate that our method not only has the properties of simple operation and wide applying scope, but also outperforms those of current classical methods on the aspect of outage probability under the basis of the same power limitation.

关键词： cooperative diversity wireless sensor network power-limited

Wind Generator Stabilization with Doubly-Fed Asynchronous Machine

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Journal of Shanghai Jiaotong university(Science) 2007年第2期12卷 271-282页

作者：武黎王志新 dept.of electrical eng. Shanghai Jiaotong Univ.

This paper investigates the function of doubly-fed asynchronous machine(DASM)with emphasis placed on its ability to the stabilization of the power system including wind generators.P(active power)and Q(reactive power)compensation from DASM can be regulated independently through secondary-excitation *** results by power system computer aided design(PSCAD)show that DASM can restore the wind-generator system to a normal operating condition rapidly even following severe transmission-line *** studies have also been performed between wind turbine pitch control and proposed method.

关键词： doubly-ted asynchronous mahine(DASM) wind generator wind turbine pitch control power system computer aided design(PSCAD)

The Structural eng.neering Challeng.s Following the Wenchuan Earthquake

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四川大学学报（工程科学版） 2009年第3期41卷 223-230页

作者： GRUNDY Paul dept.of Civil eng. Monash Univ.

The "5·12" Wenchuan Earthquake presents two challeng.s-reconstruction of the devastated areas and building adequate seismic resistance into the rest of *** stages in recovery include structural condition assessment,identification of seismic weaknesses,appreciation of the variable seismicity of PR China,the development of a seismic performance index to aid the decision to relocate,rebuild or retrofit,development and application of the principles of retrofitting which recycles rubble and waste from Wenchuan "5·12",with an emphasis on integrating masonry construction into seismic *** recovery and resilience achieved through structural eng.neering must be integrated into a broader community involvement in disaster risk reduction.

关键词：建筑工程抗振结构建筑结构建筑物

Output only modal identification and structural damage detection using time frequency & wavelet techniques

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Earthquake eng.neering and eng.neering Vibration 2009年第4期8卷 583-605页

作者： S.Nagarajaiah B.Basu dept.of Civil & Environmental eng.and dept.of Mechanical eng.& Material Sc. Rice University dept.of Civil Structural& Environmental Eng.Trinity College Dublin

The primary objective of this paper is to develop output only modal identification and structural damage detection. Identification of multi-degree of freedom （MDOF） linear time invariant （LTI） and linear time variant （LTV--due to damage） systems based on Time-frequency （TF） techniques--such as short-time Fourier transform （STFT）, empirical mode decomposition （EMD）, and wavelets--is proposed. STFT, EMD, and wavelet methods developed to date are reviewed in detail. In addition a Hilbert transform （HT） approach to determine frequency and damping is also presented. In this paper, STFT, EMD, HT and wavelet techniques are developed for decomposition of free vibration response of MDOF systems into their modal components. Once the modal components are obtained, each one is processed using Hilbert transform to obtain the modal frequency and damping ratios. In addition, the ratio of modal components at different degrees of freedom facilitate determination of mode shape. In cases with output only modal identification using ambient/random response, the random decrement technique is used to obtain free vibration response. The advantage of TF techniques is that they arc signal based; hence, can be used for output only modal identification. A three degree of freedom 1：10 scale model test structure is used to validate the proposed output only modal identification techniques based on STFT, EMD, HT, wavelets. Both measured free vibration and forced vibration （white noise） response are considered. The secondary objective of this paper is to show the relative ease with which the TF techniques can be used for modal identification and their potential for real world applications where output only identification is essential. Recorded ambient vibration data processed using techniques such as the random decrement technique can be used to obtain the free vibration response, so that further processing using TF based modal identification can be performed.

关键词： Time-frequency methods short time Fourier transform Hilbert transform wavelets modal identification:output only structural health monitoring damage detection

Slope Stability Analyses of Outang Landslide Based on the Peak and Residual Shear Streng.h Behavior

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工程科学与技术 2019年第4期51卷 55-68页

作者： YANG Xiuhan VANAPALLI Sai dept.of Civil eng. Univ.of Ottawa

Most of the natural and compacted fine-grained soil slopes that are in saturated or unsaturated condition undergo a large deformation prior to reaching failure *** slopes should be designed taking account of their strain-softening behavior using the residual shear streng.h (RSS) *** this paper,the slope stability of a recently reactivated Outang landslide near the Three Gorges Dam in China is analyzed based on the RSS parameters of unsaturated *** addition,comparisons are provided in the FOS values of slope using both the peak shear streng.h (PSS) and RSS ***,a series of site investigations of the hydrologic and geologic conditions,ground surface displacements and cracks were *** PSS and RSS behaviors of the sliding soils derived from a series of direct shear test results performed on saturated and unsaturated soil specimens are ***,a series of slope stability analysis were conducted considering the precipitation and Yangtze River water level variation within a representative period of 7 months,based on the PSS and the RSS *** this study,three different scenarios were considered,which include: i) considering only the precipitation with a constant water level;ii) considering only the decrease in water level without rainfall;iii) considering the combination of precipitation and decrease in water *** each scenario,four steps were included to calculate the values of factor of safety (FOS) at different times.1) A steady-state seepage analysis was conducted with a constant total head at 525 m on the left boundary and 175 m on the slope surface below the Yangtze River water *** initial pore water pressures were simulated in the slope under no precipitation and variation of water level.2) A specific boundary condition was applied on the slope surface to model the precipitation and Yangtze River water level variation.A transient seepage analysis was conducted to calculate pore water pres

关键词： unsaturated soil landslide reactivation residual shear streng.h slope stability analysis