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field PMU test and Calibration Method——PartⅡ:test Signal Identification Methods and field test Applications

Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 243-253页

作者： Sudi Xu Hao Liu Tianshu Bi State Key Lab of Alternate Electric Power System with Renewable Energy Sources(North China Electric Power University) Beijing 102206China State Grid Jangsu Electric Power CO. LTD Research InstituteNanjing 211103China

Synchrophasor measurement units(PMUs)provide synchronized measurement data for wide-area *** improve the effectiveness of synchrophasor-based applications,field PMUs must be tested to ensure their performance and data *** the companion paper(Part I),we proposed a field PMU test and calibration framework consisting of a PMU calibrator and analysis *** I presents the development and test of the PMU *** paper focuses on the analysis center and field test ***,the critical component of the analysis center is the signal identification module,for which the step and oscillation signal identification methods are ***,the performance evaluation criteria of PMU in these two cases are different from *** methods include a step signal detection method based on singular value decomposition(SVD),which has the capability of weak step detection to account for energy leakage of the signal during the step process,and an oscillation signal identification method based on SVD and fast Fourier transform,which can accurately extract oscillation components that benefit from the adaptive threshold setting ***,the analysis center software is implemented based on identification *** integrating the PMU calibrator in Part I with the analysis center in Part II,we can examine in depth the field PMU test applications in three test scenarios,including standard,playback,and field signal *** demonstrate the effectiveness and applicability of the proposed field PMU test methods from both Parts I and II.

关键词： Phasor measurement unit(PMU) field test signal identification oscillation

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Impact and explosion resistance of NPR anchor cable:field test and numerical simulation

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Underground Space 2023年第3期10卷 76-90页

作者： Manchao He Aipeng Guo Zhigang Meng Yuefeng Pan Zhigang Tao State Key Laboratory for Geomechanics and Deep Underground Engineering Beijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China Department of Civil and Mineral Engineering University of TorontoToronto M5S 1A4Canada NingboTech University Ningbo 315100China The PLA Rocket Force Engineering Design and Research Institute Beijing 100011China

With the reduction of shallow resources,the degree of damage and the frequency of dynamic hazards,such as deep rock bursts and impact ground pressure,are increasing ***,the existing support materials are incapable of meeting the safety require-ments of the refuges and roadways under a strong impact *** effectively solve these problems,a novel negative Poisson’s ratio(NPR)anchor cable with excellent properties,such as impact resistance and the ability to withstand large deformation,is *** the present study,a series of field tests and numerical simulations are conducted to investigate the mechanical and support charac-teristics of NPR anchor cables under blast *** mechanical tests show that NPR anchor cables can maintain constant resistance and produce large deformation under the action of multiple drop hammer *** to the results of field tests,the roadway supported by conventional anchor cables was unable to endure the blast impact,while the roadway supported by NPR anchor cables was able to withstand the severe impact equivalent to a Class 3 mine *** dynamic response of the NPR anchor cable that supports the roadway under explosion is investigated using the innovative coupled modeling approach that combines the finite element method and the discrete element method,and the support effect of the NPR anchor cable is *** study shows that the NPR anchor cable has a superior impact and blast resistance performance,and a broad application prospect in the support of chambers and roadways that are at high risk of rock bursts and impact ground pressure.

关键词： Negative Poisson’s ratio(NPR)anchor cable Rock burst Tunnel support field test Numerical simulation

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Study on Load Bearing Characteristics of Novel Expandable Deepwater Drilling Conductor Based on Laboratory Experiment and field test

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China Ocean Engineering 2023年第1期37卷 16-28页

作者： ZHANG Ming-he YANG Jin YANG Yu-xiang XU Dong-sheng ZHOU Yi-su College of Safety and Ocean Engineering China University of Petroleum-BeijingBeijing 102249China

A novel expandable conductor was designed and applied in deep-water drilling to improve the vertical and lateral bearing capacity with a significant reduction of conductor jetting depth and soaking time. The vertical and lateral bearing capability of expandable conductors was depicted based on the ultimate subgrade reaction method and pile foundation bearing theory. The load-bearing characteristics of a laboratory-scale expandable conductor were analyzed through laboratory experiments. The serial simulation experiments are accomplished to study the bearing characteristics(vertical ultimate bearing capacity, lateral soil pressure, and lateral displacement) during the conductor soaking process. The laboratory experimental results show that the larger the length and thickness of expandable materials are,the higher the bearing capacity of the wellhead will be. During the conductor soaking process, the soil pressure around the three expandable conductors increases faster, strings representing a stronger squeezing effect and resulting in higher vertical bearing capacity. Furthermore, the lateral displacement of novel expandable conductor is smaller than that of the conventional conductor. All the advantages mentioned above contributed to the reduction of conductor’s jetting depth and soaking time. Lastly, the application workflow of a novel expandable deep-water drilling conductor was established and the autonomous expandable conductor was successfully applied in the South China Sea with a significant reduction of conductor’s jetting depth and soaking time. According to the soil properties and designed installation depth of the surface conductor, the arrangement of expandable materials should be designed reasonably to meet the safety condition and reduce the construction cost of the subsea wellhead.

关键词： novel expandable surface conductor deep water subsea wellhead laboratory experiment field test

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field test of Concrete Impermeability of Side Wall of Lakeside Highway Tunnel

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Journal of Architectural Research and Development 2022年第4期6卷 1-9页

作者： Yueyue Kong China Railway 14th Bureau Group Co.Ltd. Jinan 250101China

The impermeability of concrete of the exterior wall of the underground tunnel in water-rich stratum is a key concern of *** the Aixihu highway tunnel in Nanchang city as an example,the impermeability of the concrete in the side wall of the highway tunnel is tested,through multiple tests,such as the embedded steel pipe,water injection,and field *** results show that,under the action of 2mpa of water pressure,no water flow permeates from the side wall of the concrete tunnel,indicating that the impermeable performance of concrete tunnel in this section meets the engineering requirements,and hoping that this research can be used as a reference for other similar projects.

关键词： Water-rich layer Concrete impermeability field test Aixihu highway tunnel

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A field test DATA RESEARCH BASED ON A NEW HYDRAULIC PARAMETERS QUICK test TECHNOLOGY

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Journal of Hydrodynamics 2010年第4期22卷 562-571页

作者： ZHAO Yan-rong ZHOU Zhi-fang School of Earth Sciences and Engineering Hohai University Nanjing 210098 China

The hydraulic parameter quick test system in accordance with the oscillation principle can overcome the shortcomings of traditional methods in determining hydraulic parameters which,besides having complex hydrogeological restrictions and needing complex equipment in the field,are often both time and energy consuming,and high *** on the hydrogeological conditions in the north anchorage of Taizhou Yangtze River Highway Bridge,a quick hierarchical test is carried out for different depths of single-hole drilling to verify the function of the system in this ***,with a purification of the raw data gathered in the test by wavelet denoising,the hydraulic parameters are worked out by adopting the Kipp model.A comparison between the Kipp model results and stratigraphic data as well as pumping test results justifies the reliability and accuracy of the new *** study finds other advantages of the method like high efficiency in operation,flexibility in stratified test,as well as ***,the technology is of significant practical value and application prospect.

关键词： hydraulic parameters oscillation principle slug test field test wavelet denoising

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field test and evaluation on crop dividers of sugarcane chopper harvester

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International Journal of Agricultural and Biological Engineering 2021年第1期14卷 118-122页

作者： Jing Bai Shaochun Ma Fenglei Wang Haonan Xing Jinzhi Ma Jiwei Hu Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment College of EngineeringChina Agricultural UniversityBeijing 100083China

In South China,the tropical weather and climate result in severe sugarcane lodging problems which greatly hinders sugarcane mechanical *** main function of the crop divider is to lift lodged canes and facilitate base-cut cane *** this study,a series of field tests were conducted on crop dividers of Liugong 4GQ-180 sugarcane chopper *** tests were designed to identify the relationships of the performance index(maximum lifting height of sugarcane)and the main influencing factors(machine forward speed,rotational speed of inside scrolls,and ground clearance of crop divider toes).The single factor test was conducted to determine optimum range of these test factors:the forward speed(FS)was 2.0-4.0 km/h,the rotational speed of inside scrolls(RS)was 100-140 r/min,and the toe ground clearance(GC)was 0-5 *** orthogonal test(three factors and three levels)was carried out to determine the optimal combination of operating parameters:FS was 2.0 km/h,RS was 115 r/min,and GC was 0 *** addition,the range analysis of orthogonal test results revealed that the order of each test factor affecting crop divider performance was RS,FS,*** study was expected to provide valuable references for the optimal operation of sugarcane harvester crop dividers.

关键词： sugarcane chopper harvester parameter optimization machine forward speed rotational speed of scrolls ground clearance maximum lifting height field test evaluation crop divider

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Analysis and field test on reactive capability of photovoltaic power plants based on clusters of inverters

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Journal of Modern Power Systems and Clean Energy 2017年第2期5卷 283-289页

作者： Jingsheng HUANG Meiying LIU Junjun ZHANG Wei DONG Zhilei CHEN China Electric Power Research Institute Beijing China

With the increasing capacity of photovoltaic(PV)power plants connected to power systems, PV plants are often required to have some reactive power control capabilities to participate in reactive power regulation. Reactive power regulation of grid-connected PV inverters can be achieved using different control strategies. In this paper, the reactive power capability of inverters and the technical requirement of PV plants are analyzed. The reactive power capability of a 30 MW PV plant is evaluated against relevant technical standards using a new testing method proposed in this paper.

关键词： Photovoltaic(PV)power plant Reactive power field test Inverter

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field test on temperature field and thermal stress for prestressed concrete box-girder bridge

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Frontiers of Structural and Civil Engineering 2009年第2期3卷 158-164页

作者： Baoguo CHEN Rui DING Junjie ZHENG Shibiao ZHANG School of Civil Engineering and Mechanics Huazhong University of Science and TechnologyWuhan 430074China Shi-man Expressway Construction Headquarters of Hubei Province Shiyan 432000China

A field test was conducted to investigate the distribution of temperature field and the variation of thermal stress for a prestressed concrete(PC)box-girder *** change of hydration heat temperature consists of four periods:temperature rising period,constant temperature period,rapid temperature fall period and stow temperature fall *** peak value of hydration heat temperature increases with the increasing casting temperature of concrete;the relation between them is approximately *** to field tests,the thermal stress incurred by hydration heat may induce temperature cracks on the PC ***,the nonlinear distribution of temperature gradient and the fluctuation of thermal stress induced by exposure to sunlight were also obtained based on continuous in-situ *** results show that the prevailing Chinese Code(2004)is insufficient since it does not take into account the temperature gradient of the bottom ***,some preventive measures against temperature cracks were proposed based on related *** conclusions can provide valuable reference for the design and construction of PC box-girder bridges.

关键词： box-girder bridge field test hydration heat temperature field temperature gradient thermal stress

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Design and field test of crosswise belt type whole plastic-film ridging-mulching corn seeder on double ridges

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International Journal of Agricultural and Biological Engineering 2019年第4期12卷 88-96页

作者： Fei Dai Wenjuan Guo Xuefeng Song Ruijie Shi Wuyun Zhao Fengwei Zhang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China

In order to realize seedbed mechanization of whole plastic-film mulching on double ridges and to overcome the difficulty in crosswise belt type soil covering by whole plastic-film,a kind of crosswise belt type whole plastic-film ridging-mulching corn seeder on double ridges was designed in this *** key components of the sample machine was designed and its working parameters of seedbed soil covering device,crosswise-belt soil covering mechanism and profiling sowing depth adjustment device were *** numerical simulation on the film edge and crosswise soil covering by whole plastic-film on double ridges by discrete element method,the velocity and displacement of the oscillating plate,and the variation rule of amount of covered soil with time were *** test results show that,when the advancing velocity of the machine was 0.50 m/s,the qualified rate of soil width covered on film edge of the seedbed reached 96.1%,qualified rate of crosswise soil belt width was 94.5%,qualified rate of soil thickness on seedbed was 95.3%,qualified rate of sowing depth was 89.3%,qualified rate of spacing between crosswise soil belts reached 93.6%,which all met related standards in China and satisfied design requirements,and could realize seedbed mechanization of whole plastic-film mulching on double *** tests on working performances of practical soil covering show a basic consistence with the seedbed soil covering simulation,and verified the effectiveness of the soil covering model built by using discrete element method.

关键词： whole plastic-film on double ridges crosswise belt soil covering combined machine discrete element numerical simulation field test

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Rapid monitoring of indoor airborne influenza and coronavirus with high air flowrate electrostatic sampling and PCR analysis

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 73-85页

作者： Sanggwon An Sangsoo Choi Hyeong Rae Kim Jungho Hwang School of Mechanical Engineering Yonsei UniversitySeoul 02876Republic of Korea Gas Metrology Group Korea Research Institute of Standards and Science(KRISS)Daejeon 34113Republic of Korea

The World Health Organization has raised concerns about the possibility of airborne transmission in enclosed and poorly ventilated ***,rapid monitoring of airborne viruses is necessary in multi-use facilities with dense ***,an electrostatic air sampler(250 L/min)was developed in this work to obtain indoor viral aerosol samples for analysis via the Polymerase Chain Reaction(PCR).Aerosol tests with H1N1 and HCoV-229E were performed to evaluate the sample collection *** analysis,along with another aerosol test,was conducted to evaluate the recovery of the virus particles collected by the *** laboratory tests,our electrostatic sampler obtained viral samples that were detectable by PCR under the simulated viral pandemic scenario(3000 RNA copies per cubic meter of air)within 40 *** resulting cycle threshold(C)values were 35.07 and 37.1 for H1N1 and HCoV-229E,*** the performance evaluation in the laboratory,field tests were conducted in a university classroom from October 28 to December 2,*** A and HCoV-229E were detected in two air samples,and the corresponding C,values were 35.3 and *** PCR results are similar to those obtained from laboratory tests,considering the simulatedviralpandemic scenario.

关键词： Airborne virus Electrostatic sampler Rapid monitoring Indoor environment field test

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