bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress and Deformation Analysis of High Concrete Face Rockfill Dam Based on COMSOL Multiphysics
Authors: Wang Runying , Yu Keping
Published: February 2021

In order to study the stress and deformation characteristics of the high concrete face rockfill dam over 100 meters, in this paper, Duncan-Zhang E-B nonlinear elastic hyperbolic model is adopted, the finite element software COMSOL Multiphysics is used to establish the model and the MATLAB function is used for secondary development to analyze the stress and deformation of the concrete face rockfill dam of the Panshitou reservoir. The stress and deformation characteristics of the concrete face rockfill dam at the completion period, normal water storage condition, designed flood level condition and checked flood level condition are obtained through analysis, which provide theoretical guidance for the construction and operation of the high concrete face rockfill dam of more than 100 meters.
Study on mechanical properties of triaxial unloading of granite under pore pressure
Authors: Ren Jianxi , Yun Mengchen , Zhang Kun
Published: February 2021

This research analyzes the strength and deformation characteristics of rock samples under varying pore pressures during the unloading process. By using fine-grained granite from Western China as the research exemplar, laboratory tests of triaxial unloading under pore pressure are conducted by utilizing the unloading confining pressures method without changing the axial pressure. Pore pressure is tested with a design value of 5 MPa. When the confining pressures are released at 35, 25, 15, and 5 MPa, the pore pressures drainage valve are opened, and the mechanical properties of fine-grained granite under pore pressures are analyzed. The following results are obtained. After unloading at different confining pressures, pore pressure has an evident influence on the stress–strain curve of the rock sample. The bearing capacity of the rock sample decreases. The hole pressure has a significant effect on the ring and volume deformation in the unloading process. Consequently, the evident deformation and damage are generated immediately after unloading to 25 MPa. Under the condition of constant pore pressure for a long time, numerous tension fractures are distributed around the main shear fracture owing to the promotion of pore pressure on the fracture opening. Hence, an evident swelling phenomenon occurs in the rock sample.
Study on thermal fracture modeling by the Scaled boundary finite element polygons
Authors: Wen Zhou , Zhong Hong , Tu Jin , Liang Hui
Published: February 2021

Thermal load is an important cause of structural fracture. A model based on the Scaled boundary finite element method (SBFEM) is presented for the fracture modeling due to thermal load. The SBFEM is a semi-analytical method, which has the advantages of both the Finite element method (FEM) and the Boundary element method (BEM) while possessing its own special features. The structure is discretized only at the boundary, thus reducing the dimension of solution. In addition, the stress field and displacement field are obtained analytically in the radial direction, so the stress intensity factors can be obtained directly from its definition and this works for homogeneous material, bi-material and orthotropic material. In the presented model, the temperature load is transformed from the temperature field of the structure, which is included in the structural analysis to get the displacement field, stress field and therefore the stress intensity factors. By introducing the polygon technique, the remeshing process due to crack propagation can be modeled conveniently. Two numerical examples including a rectangular plate and a cross plate are employed for verification of the model.
A study on energy distribution law of frame structure across ground fissure
Authors: Zhongming XIONG , Yixin LIU , Xuan CHEN , Jianjian XU
Published: February 2021

In order to study the frame structure energy dissipation mechanism on the ground, a 3x3 span 5-story frame structure was used as the research background, and a shaking table test with a scale ratio of 1:15 was designed. Based on the prototype structure, a finite element model based on ABAQUS is established. The correctness of the finite element model is verified by experimental comparison. On this basis, the plastic energy dissipation and damping energy consumption of the structural beam and the plastic energy dissipation law of the column are analyzed. The weak part of the structure of the trans-ground fissure structure under energy conversion is found. This study provides a reference for the arrangement of energy-consuming devices in seismic design and disaster prevention and mitigation design for similar structural engineering.
Analysis of Influencing Factors on Durability of Sludge Flow Solidified Soil
Authors: Yue Shaolin , Feng Zhongmin , Wu Mingjiang , Ding Jihui , Gan Yu , Wang Guanghong
Published: February 2021

In order to transform a large amount of dredged sludge into sustainable development of land resources, this paper takes the submarine dredged sludge in Dalian Bay as the research object, and uses the composite solidified material composed of cement, fly ash and phosphogypsum to carry out flow solidification treatment. Through laboratory experiments, the influence of curing temperature, dry-wet cycle and freeze-thaw cycle on the sludge flow solidified soil was studied. The results showed that:(1) When the fly ash-cement mass ratio RFC=0.65 and the cement-sludge mass ratio RCS=0.09-0.16, the unconfined compressive strength of the 35°C sludge flow-solidified soil is the mud-solidified soil in the outdoor curing environment 1.04 times.(2) When RCS=0.11∼0.14 and RFC=0.65, the strength loss rate of silt-solidified soil after the first dry-wet cycle is the highest, respectively 43% and 50%.(3) When RCS=0.09∼0.16 and RFC=0.65, after the third freeze-thaw cycle, the strength loss rate of the sludge solidified soil is the smallest of the first five times.
Study on Tensile Stress-Strain Relationship of BFRC
Authors: He Jingjing , Shi Junping , Zhang Yong , Wang Haiting , Lu Haodan , Fan Lihao , Min Yongtao
Published: February 2021

In this paper, different types of basalt fiber concrete (BFRC) were been researched on the tensile properties. Moreover, analyzed the influence of fiber length and fiber volume fraction on the tensile properties of concrete. The results showed that the tensile strength of BFRC increased significantly with the increase of fiber volume fraction, and the strain increased significantly with the increase of fiber length. The BFRC tensile stress-strain curve shows obvious staged failure, and the function of stress-strain relationship based on the regression method has burning relevance with the test results.
The influence of materials parameters on chloride diffusion coefficient in concrete
Authors: Ding Ping-xiang
Published: February 2021

In order to investigate the influence of materials parameters on chloride diffusion coefficient in concrete, experiments were conducted by orthogonal design and factorial design, and 15 sets of concrete specimens with different mix proportion were prepared. RCM test for each concrete specimen was performed to determine the chloride diffusion coefficient. Results show that water-to-binder ratio, replacement of mineral admixtures and the ratio of replacement of fly ash to replacement of granulated blast furnace slag have a significant influence on chloride diffusion coefficient, but the water-to-binder ratio is the most important one.
Analysis on Risk Control of Civil Engineering Cost Based on BIM Technology
Authors: Yang Yaru
Published: February 2021

With the rapid development of my country’s construction industry, people’s requirements for construction quality and safety control are becoming more and more stringent. However, the results are often unsatisfactory, and the cost risk in civil engineering construction still cannot be effectively controlled. This article aims to study the risk control analysis of civil engineering costs based on BIM technology. This article analyzes the experiment from the perspective of quantification. The Experimental Integration Facility Engineering Center has conducted research on multiple BIM projects and learned about the actual operation status of these projects. Then summarize the actual effect of BIM technology. Experimental data shows that the use of BIM technology can improve the quality of design, quickly determine project cost, control design changes, avoid rework, and reduce costs. The experimental results show that the use of BIM can reduce the time used to estimate the cost to 35%, the accuracy of the estimate is controlled to <5%; the extra-budgetary changes are reduced to 70%; through the discovery and resolution of conflicts, the contract price is reduced by 13%; The project time has been reduced by 10%, and investment income can be obtained relatively quickly. Therefore, the research on construction hazard management and control based on BIM technology can not only promote the development of BIM information technology, but also make up for the inefficient and imperfect defects of hazard management and control, and greatly improve the cost risk of civil engineering.
Axial compressive behaviour of double steel-concrete shear wall constrained with ribs and bars
Authors: Xinzhi ZHENG , Shuang ZHENG , Yutao SUN
Published: February 2021

The double steel-concrete shear wall combines the advantages of steel and concrete effectively, with high bearing capacity, good plasticity, superior seismic and fire resistance performance, saving materials and simple construction, and has obvious advantages in the application of high-rise buildings, especially super high-rise buildings. Research on axial compressive behavior of double steel-concrete shear wall constrained with ribs and bars is less. In this paper, the constitutive relation of double steel-concrete column with ribs and bars is used to change the relevant parameters and program to analyze the influence of ribs and bars on the axial compression performance of double steel-concrete shear wall.
Viscoelasticity Evaluation of Regenerated Asphalt Containing Waste Engine Oil Based on Rheological Analysis
Authors: Xiao YAJUN , Wang WENTONG , Wang WENWEN , Yuan DONGDONG
Published: February 2021

In order to explore the viscoelastic properties of waste engine oil (WEO) on mixed asphalt, mixed asphalt was prepared by fusing base asphalt and aged asphalt. The effect of waste engine oil content on the physical and viscoelastic properties of asphalt mixtures was studied through experiments. The test results show that the viscosity and softening point of asphalt mixture is reduced by adding waste engine oil. The complex modulus (G*) of asphalt binder decreases with the addition of waste oil at different test frequencies. With the increase of waste oil content, the phase angle (ä) of asphalt mixtures increases at specific frequencies. When the content of waste oil exceeds 6%, G* and δ will not change significantly. The stiffness increase caused by ageing asphalt in mixed asphalt will be offset by adding 2-4% waste oil. This indicates that waste oil can be used as regenerant to provide elasticity and flexibility for asphalt binder.
Simulation of the anoxic effect of ecological regulation on Guanting Reservoir
Authors: Sun Xianren , Zhou Gang , Zhao Gaofeng , Huang Guoxian , Xiong Yongfeng , Lei Kun
Published: February 2021

Water transfer is an effective approach to improve water quality in reservoir area. However, the research focusing on optimum efficiency of water transfer is limited, especially the dissolved oxygen (DO) in reservoir area. As a case study of Guangting reservoir (GTR) in Beijing City, the three-dimensional DO model was built based on environment fluid dynamic code (EFDC). And the spatial and temporal distributions of DO concentration with and without ecological regulation were analysed. The results show that both water transfer and ecological discharge will disturb the "oxycline” of the water body, while the effect on the surface DO is not obvious, ranging from -4.65% to 7.28%, but it has a significant impact on increasing oxygen in the bottom layer. The DO concentration in the bottom water increased by 1.85-8.52 mg/L when the output ecological discharge was used in the reservoir, and the oxygen enrichment effect of bottom water was more obvious when considering water transfer and ecological discharge simultaneously, with an increase of 2.71-12.83 mg/L. this study has the guiding significance to improve the dissolved oxygen in the bottom water of GTR area, and can also provide a method reference in evaluating the DO variation driven by the upstream water transfer or ecological discharge similar reservoirs.
The Connotation, Characteristics, Main Contents and Evaluation Research System and Construction of Ecological Irrigation District
Authors: Wang Yingying , Zhang Hengjia
Published: February 2021

Due to the construction of irrigation districts always aims at maximizing project benefits, coupling with the impact of climate change and human activities, the ecological environment of the irrigation areas has faced severe challenges, so, the construction of ecological irrigation areas and the formation of a systemic ecological production view are essential for realizing the modernization of irrigation areas and sustainable agricultural development. This paper briefly introduced the connotation, characteristics, main contents and evaluation research system of ecological irrigation districts by consulting literatures, summarized the current research and construction of ecological irrigation districts facing problems, and the inevitability of ecological transformation of irrigation districts. Integrating the overall development of irrigation areas and the harmonious coexistence concept of human and nature, the construction of ecological irrigation areas in the future will continue to move forward, and the research on relevant theories and technical systems has broad prospects.
Progress and Prospects of Research on Ecological Impact of Channel Regulation Structure
Authors: Li ShengJie , Tong Sichen
Published: February 2021

Focusing on the aquatic ecological and environmental problems of waterway regulation structure, the research progress of waterway regulation structure on the physical and chemical properties of river water bodies, river benthic community structure and distribution and fish habitat was summarized, and the existing problems in current scientific research and engineering application were analyzed. Key researches were also put forward that should be carried out in the future for the protection of water ecological environment of waterway regulation structure including constructing and protecting the regional river ecological health index system in the waterway regulation building area and improving the construction of ecological waterway.
Effect of Different Irrigation Patterns and Covering Methods on Onion Yield in the Hexi Corridor
Authors: Deng Haoliang , Wang Peng , Xiao Rang , Zhang Hengjia , Zhang Yongling , Wang Jiaqi , Chen Tao , He Wenbo
Published: February 2021

In order to investigate the influence of the yield and water use efficiency of onions in the Hexi Corridor, this paper tested the yield and water use efficiency of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the dry matter accumulation process of onion was measured in each reproductive period, and the results showed that: The black mulch full irrigation treatment T1 yielded 120393.45 kg⋅ha−1 with an output value of 72236.07 yuan⋅ha−1, while the black mulch moderate loss adjustment irrigation treatment T3 yielded only 61697.39 kg⋅ha−1and 37018.43 yuan⋅ha−1. The yield per square meter, irrigation water use efficiency and water use efficiency decreased with the increase of regulated deficit irrigation degree, and there was no significant difference between black film mulching and transparent plastic film mulching, but they were significantly higher than that of fine sand mulching. The onion yield and water use efficiency indexes were combined, so that the best control of yield could be achieved by covering the onion with black mulch and irrigation throughout the growing season, which is of theoretical guidance and significance for onion cultivation in the Hexi Corridor.
ShiTouzhai hydropower station hub layout pattern comparison research of pre-feasibility study stage
Authors: Shaohong Pan , jiajia Ding , changjie Luo
Published: February 2021

The selection of the layout scheme is the key content of the pre-feasibility study of large and medium-sized hydropower stations. Based on the topographical and geological conditions, and considering the construction conditions, reservoir flooding, project investment and other factors, this paper makes an in-depth analysis of the layout comparison and design of the pre-feasibility stage of Shitouzhai Hydropower station, in order to provide beneficial inspiration for similar project design.
Experimental Study on the Physical Model of Breakwater at a LNG Wharf in Pakistan
Authors: Xiaochang Ni , Xu Zhao , Ning Guan
Published: February 2021

In this paper, a two-dimensional physical model was established in a laboratory sink, the stability of a breakwater structure at a LNG terminal in Pakistan was studied, and the wave propagation simulation of two designed cross-sections was studied. And make conclusions to evaluate the layout scheme and provide a reference for other similar structures.
Effect of organic content on compression properties of municipal sewage sludge
Authors: Ruimin YANG , Zhenning ZHANG , Zihao FAN , Lu SHEN , Jinhui LI , Bang ZHOU
Published: February 2021

Urban sewage sludge is rich in a large amount of organic matter, which has a significant impact on the compression characteristics of sludge, and ultimately affects the landfill disposal and resource utilization of sludge. Quartz sand was mixed into the sewage sludge to prepare sludge samples with an organic content of 8%, 16% and 26% (raw sludge) respectively, and then a standard consolidation test was carried out to explore the influence of the organic content on the compression properties of the sludge and mechanism of action. The results show that the compressibility of urban sludge increases with the increase of organic content. The compression coefficient and index of sewage sludge both increase exponentially with the increase of organic content. The ln(1+e)∼lgp curve of urban sludge has a significant "inflection point" and a certain consolidation yield stress. With the increase of organic content, the consolidation yield stress decays exponentially. Organic matter in the sludge has a flocculent structure and a large specific surface area. It is easily adsorbed on the surface of the clay particles, hindering the cementation of the clay particles and reducing the permeability of the sludge. At the same time, organic matter has water-retaining property, hinders the consolidation and drainage of sludge, and ultimately affects the compression properties of sludge.
Study on anti-seepage treatment and seepage control effect of core dam foundation curtain of the fault fracture zone in Xinjiang province
Authors: Cui Hao dong , Chen Liang , Wang Jin long , Zhang Wei
Published: February 2021

The treatment effect of dam foundation fracture zone is related to dam safety, A case is provided base on the fault-fracture zone with large permeability in a core dam foundation in Xinjiang province, The dam foundation seepage model is established with the seepage finite element method base on The test results of post-grouting in the fault-fracture zone, simulation working conditions of different curtain depth and permeability indicate that significant impervious effects of compound grouting and depth-curtain at fault zone, leakage is less in the dam foundation and seepage stability meet the requirement on the riverbed overburden in the downstream, The results are high reference value for similar projects.
Comparison and investigation on tidal levels designed for the coastal embankments in Guangdong-Hong Kong-Macao Greater Bay Area
Authors: Fang Shenguang , Cui Liqin , Lv Wenbin
Published: February 2021

Tidal levels designed for coastal levee in Pearl River estuary have been provided by Department of water resources of Guangdong Province in 2002 and played important role in ensuring the security of coastal cities in recent decades. However, big changes have taken place in the hydrological regime of the estuary as the sea water level rise and Frequent storm surges in recent years. The proportions of the coastal levee lengths in Guangzhou and Zhuhai city occupied a large part of the portion in the Bay Area, about 30% and 23% respectively, while the shortest in Shenzhen city, accounting for only 5%. The designed tidal levels used for coastal levees in the past were compared with those proposed by PRWRC in the year 2011, showing lower about 0.2∼0.5m totally in the mouths and open waters including Shiziyang of the estuary. It would reach to about 0.6∼0.7m lower in the waters around Nansha district after considering the influence of the typhoon Mangkhut and Hato, while there was little variation in the net river area upstream in any case. The controlled tidal levels designed for coastal levees were analyzed for its applicability and it showed that those used in Guangzhou, Shenzhen and Jiangmen city meet the requirements and were somewhat lower in Dongguan, Zhuhai and Zhongshan city under variation of hydrological regime recently.
Seepage improvement test and analysis of granite residual soil
Authors: Hu Hua , Wu Xuan
Published: February 2021

The influence of slag powder, cement and bentonite on the permeability coefficient of granite residual soil at different incorporation ratios was analyzed by means of seepage test with variable head. Meanwhile, the permeability coefficient was compared with that of the original granite residual soil. It is found that the effect of slag powder on reducing the permeability coefficient of granite residual soil under non-alkaline environment is limited. The effect of cement on decreasing permeability coefficient of granite residual soil is obvious. Bentonite has the best effect on reducing permeability coefficient of granite residual soil.
Comprehensive Evaluation of Water Environment Under “Zero direct discharge of sewage” Project
Authors: Zhangbin Fang
Published: February 2021

This paper takes Yuhuan City as the research object, based on the single factor evaluation method, Nemero index method and gray relevance analysis method, selects three indexes of ammonia nitrogen, total phosphorus and permanganate index. By analyzing the main pollutants, the reduction of each pollutant and the differences between different evaluation methods, the effectiveness of water environment governance is evaluated, and then targeted regulatory measures are proposed to further improve water environment. The results show that the main pollutants in Lupu Town, Yuhuan City are NH3-N and TP. The single factor evaluation method and the Nemero pollution index method showed that the water quality categories are mostly type III and type IV. The evaluation results of the gray correlation analysis method are mostly Class II water, and all three methods indicate that most of the sites before the construction meet the Class IV water standard. During the construction process, the single factor evaluation method and the Nemero pollution index method show improvement in water quality, while the grey correlation analysis method showed little change in water quality categories. According to the various indicators and water quality changes, it can be seen that the effect of the zero-drainage project is significant for the improvement of river water quality.
Analysis of navigation flow conditions in the entrance area of the Babao ship lock of Hangzhou section of Jinghang Grand Canal
Authors: Yang Yuanping , Zhang Zhiyong , Cheng Wenlong , Wang Reifeng
Published: February 2021

In this paper, we used typical riverbed topography and hydrodynamic conditions, combined with the arrangement of the Babao ship lock exit guiding wall and three tidal gate construction schemes, to calculate the planar flow regime for the exit channel area. In addition, the variation of the planar flow field at typical moments in local outside the entrance area, the size of the recirculation region, the lateral flow velocity, and the longitudinal flow velocity in the outlet channel are used to analyze and compare the navigational flow conditions of different schemes. The calculation shows that the magnitude and direction of the mainstream flow outside the guiding wall are basically unchanged after the construction of tidal gates. Out-of-port flow patterns are not related to whether or not tide gates are built, and the impact of building gates is primarily in the waters inside the head of the guiding wall. Compared with and without a tidal gate, the time required for transverse velocity to meet navigational requirements is less for each scheme.
Application of Digital Monitoring System of Stone Column Piles in Airport Construction
Authors: Zou Tingnian , Wang Jin , Dong Li , Chen Fengchen
Published: February 2021

On the background of airfield engineering of Chengdu Tianfu International Airport, firstly, the paper introduces the construction method of vibrated stone column piles and explains its importance in foundation treatment. Secondly, it describes the basic concept of vibrated stone column piles and the digital monitoring system, and mainly describes the system function of the digital monitoring system. Thirdly, it shows that the system is fully installed and used in the construction of the airport. Finally, we analyzed the collected real data to testify our opinion that the system can optimize management level, ensure and improve the quality of the airport construction.
Indoor Property Flood damage Assessment and Insurance for Residential Buildings based on HAZUS -- A case study of Mayangxi River Basin
Authors: Deng Nan , Wang Xiao , Yang Ying
Published: February 2021

The flood disaster is one of the most common natural disasters in China, and the indoor property loss of residents is huge every year due to the flood. Therefore, it is of great significance to study the evaluation of the indoor property flood loss of residential buildings. Based on HAZUS flood loss assessment method, this paper reclassifies the residential buildings in China according to the number of households. The post-disaster loss data and household income level were used to establish the depth-loss percentage function. It provides an important method for the rapid evaluation of the loss after disaster in this area. In order to transfer the risk of flood loss of indoor property of residents in Mayangxi River Basin, an insurance scheme is designed, which provides an important idea for disaster prevention and mitigation in similar areas.
Statistical Analysis and Risk control of Civil Engineering Safety Management Accidents
Authors: Chen Yijiao
Published: February 2021

The management of civil construction safety must start from understanding the causes of construction safety accidents. For this reason, experts and scholars at home and abroad have conducted a lot of investigation and research, and have come up with a series of good analysis theories of the causes of construction safety accidents. This article aims to study the statistical analysis and risk control of civil construction safety management accidents. This paper is based on the safety risk assessment model of construction projects, and uses it to discover potential construction risk factors. The experiment in this paper mainly USES statistical analysis method to estimate the probability of each possible event by observing the occurrence times of each potential construction safety risk. Experimental data shows that construction safety risks are mainly caused by certain uncertain reasons during the construction process, and then the future state of the construction of the project can be accurately judged based on historical data or statistical data. The results show that after the classification of 400 accidents occurred in the investigation area, 150 of them fell from high places and 140 people died. 87 electric shocks, 75 deaths; 73 collapses, 65 deaths; Objects struck 38 times, killing 22 people; 43 mechanical injuries, 36 persons. It is the government’s responsibility to reduce construction safety and quality accidents, and it is also the minimum requirement of construction enterprises. The safety issues of civil construction must be strictly managed.
Numerical Simulation of the flow Past a Passenger Cable Car
Authors: Ma Zhe , Zhang Hongfu , Xin Dabo
Published: February 2021

In this paper, a numerical calculation method based on CFD is proposed to calculate the force and analyze the flow field of the cable car in static state. When the wind attack angle and the wind deflection angle are both 0°and the wind speed is 10m/s, the drag coefficient of the cable car is calculated by numerical simulation to be 0.77, which is consistent with the experimental results. Vortices with different sizes and intensities were observed on the lateral, upper and lower sides, and behind the cable car. The positions of the vortices correspond to the positions of the negative pressure zone.
Safety risk Assessment for Construction of Highway on Plateau Mountainous
Authors: Tian Jian , Li Zhiqiang , Xi Jianfeng
Published: February 2021

Under the condition of high altitude and complicated geological environment, lots of risks existing in the process of highway construction, how to control effectively safety risk has become the serious problem. Taking the construction project of Sichuan-Tibet highway as an example, combining with regional environment, safety risk indicators of construction project for plateau mountain highway is constructed. Method of construction safety risk assessment for plateau mountain highway is established. The feasibility of the evaluation method is verified by a case, and corresponding risk control measures are put forward.
Integrated energy system planning of distribution network considering load timing coupling characteristics
Authors: Hu Zhiyun , Cao Qian , Zhang Ruilong , Zhou Honglian , Wang Wei , Du Zunsheng
Published: February 2021

The integrated energy system can effectively improve energy utilization and reduce environmental pollution. Existing research mainly focuses on the equipment type, capacity and optimal configuration of the pipeline network of the integrated energy system in the microgrid. However, there are few studies on the planning of integrated energy systems at the distribution network level. Therefore, under the condition of fully considering the time-series coupling characteristics of the cooling and heating load, a mathematical model of the integrated energy system planning of the distribution network is established in this article. A method of planning and solving the integrated energy system of the distribution network based on the K-means clustering algorithm is proposed to realize the coordinated planning of multiple integrated energy stations in the distribution network. An example of distribution network in Xinjiang region verifies the rationality and effectiveness of the proposed method.
Research on Suppression Method of Power Noise in the Stability Test Device
Authors: Huang Junhao , Fang Fang , Wang Zhihua , Hang Mingxuan , Wang Yibo , Chen Yong
Published: February 2021

The static tester has simultaneous output of multiple voltage and current sources, and supports multiple communication interfaces such as GPS (Global Positioning System),the functional characteristics of the statility test device determine its high demands for power supply noise and radiation. Aiming at the specific requirements for power supply system in the main functional modules of statility test device, the operating principle of switching power supply is analyzed, the generation and transmission mode of power supply noise are studied. Under the condition of ensuring the analog output accuracy and communication statility of the test device, the noise of the switch and the rectifier circuit is reduced, and the influence of the distributed capacitance is minimized to achieve the purpose of suppressing the noise of the switching power supply.
Probabilistic Energy Flow Analysis for Integrated Energy Systems Considering Correlated Uncertainties
Authors: Yuan Xu , Haifeng Cen , Tao Li , Wu C.Q. , Zheng J. H.
Published: February 2021

The integrated energy systems (IES) contain various energy sub-systems, thus uncertainties of one sub-system will not only threaten its own safety operation but also be likely to have a significant impact on the operation of other sub-systems. Therefore, it is of great significance to study the variation of state variables when random fluctuations emerge in the IES. This paper proposes a unified steady state probabilistic energy flow (PEF) analysis for the IES considering the correlated uncertainties. Firstly, a Latin hypercube sampling with inverse Nataf transformation is developed to deal with correlated uncertainties of the IES. Furthermore, in order to solve the PEF problem, a unified method, Newton-Raphson embedded with Newton Downhill technique, is proposed to accelerate the iteration and improve the computation efficiency. The effectiveness of the proposed PEF analysis method is verified by a set of test results conducted on an IES composed of the IEEE 118-bus system coupled with 15-natural gas system and 32-district heating system.
Research on energy autonomy system design of field patrol car based on solar energy
Authors: Wenlan Wang , Xionghuai Bai , Xiuling Wang
Published: February 2021

The Inner Mongolia Autonomous Region has abundant solar energy and electric power resources. Due to the long distance between cities, the transmission lines are too long, which leads to difficulties in line inspection. To overcome the problem of line inspection, a field patrol car using solar energy is studied in this paper, the energy system of which can complete the charge and discharge independently and then realize the inspection task.Revolving around the energy autonomy of solar-energy field inspection vehicle, this paper first selects the appropriate components and builds the energy-autonomy inspection system of the patrol car, according to its design requirements. Then the solar tracking algorithm and MPPT control algorithm are used to improve the conversion rate of solar panels, so that the fast charging can be realized. Finally, the hardware and software of the solar controller are designed, and the corresponding functions are debugged.
Research and Design of Aviation Active Power Filter Based on DSP
Authors: Shuang Wang Xiao , Fu Wang Ji , Yan Zhao Hai , Jing Zhao
Published: February 2021

As the application of power electronic devices in aviation power system become more and more widely, the harmonic and reactive power problems are becoming more and more serious. Active power filter has become an important research direction of power electronics technology. In this paper, the harmonic harm and harmonic suppression methods are briefly described. Then the software and hardware of APF are designed. Finally, the system is simulated by Simulink, which proves the rapidity and accuracy of harmonic and reactive current detection and compensation.
A vulnerability scanning scheme based on attack graph for smart grid industrial control system
Authors: Xu Kai , Wang Xiangqun , Xu Hao , Dong Ning , Han Meng , Zhou Xianfei
Published: February 2021

As the core of national development, smart grid industrial control system has extremely high security requirements. However, due to the existence of many security vulnerabilities and lack of effective security protection measures, it is vulnerable to attacks from the Internet. Therefore, the vulnerability scanning of smart grid ICS has important research significance. Aiming at the problem that the smart grid ICS cannot bear the heavy system overhead, a safe and low system overhead vulnerability scanning scheme for smart grid ICS is innovatively proposed. This scheme introduces attack graph technology into vulnerability scanning, proposes vulnerability risk assessment indicators, and flexibly designs the scanning cycle according to the generated attack graph. Simulation results show that this scheme effectively reduces scanning costs while ensuring system security, and is better adapted to smart grid ICS.
A new high-precision Fourier frequency measurement algorithm based on modified sampling sequence
Authors: Ju Jingjing , Han Guozheng
Published: February 2021

Aiming at the accuracy of frequency measurement algorithms in power systems, this paper proposes a new high-precision Fourier frequency measurement algorithm based on modified sampling sequence. Through the improvement of the traditional Fourier algorithm, the theoretical error of the traditional algorithm is eliminated and the speed of the algorithm is improved. By modifying the sampling sequence and iterative methods, the original sampling sequence is as close to the ideal sequence as possible, so that the sampling frequency and the fundamental frequency of the system tend to be synchronized, thereby reducing the problem of spectrum leakage and the fence effect. Through simulation analysis, the algorithm effectively improves the frequency measurement accuracy.
Fast Calculation of Steady-state Voltage in Power System Based on Monte Carlo and Deep Learning
Authors: Zhou Ting , Xu Xiaochun , Li Jianyi , Xu Xian , Li Peng , Shi Wen , Wang Jiahao
Published: February 2021

It is of great significance to calculate the steady-state voltage of the power grid including the access of complex distributed power sources. To solve the problems of strong intermittent and high volatility of existing wind turbines, photovoltaics and other new energy sources, this paper generates a large number of section data in different scenarios according to the integrated probability model, and uses large data sets to train deep learning models. The steady-state voltage of each node is calculated for the distribution network under different scenarios in the IEEE 39-node system. The results of the calculation example show that the deep learning model trained by the proposed method can achieve 98% accuracy with less time of calculation. It is suitable for calculating the steady-state voltage of the large-scale complex power system.
Approximate Dynamic Programming of Long Term Power Generation Schedule
Authors: Liang Zhencheng , Li Yiming , Zhuo Yixin , Su YinSheng
Published: February 2021

With respect to the features in optimal scheduling of long-term power generation such as long cycle, large scale and strong randomness, the paper proposed a multi-stage optimized decision model based on approximate dynamic programming. In this model, the influence of random variables including load, fuel price, and water was tested by means of stochastic simulations. Staged solution was used to reduce the size and difficulty of solving the problem. The proposed value function approximation strategy of pondage and coal inventory solved the "curse of dimensionality" in staged recursion and maintained the overall optimization characteristics after staged decomposition. Through the iterative update between the decision and the approximation function, the approximate optimal decision sequence was solved to obtain the optimization scheme of power generation scheduling. The calculation and analysis results in a real system in some province showed that the modeling by approximate dynamic programming is an effective way to solve such large-scale optimization and has a promising future by virtue of its conciseness, effectiveness, convenience in dealing with random factors, high calculation accuracy and rapidity of solution.
A Golden Section-based Double Population Genetic Algorithm Applied to Reactive Power Optimization
Authors: Wang Zhongyong , Xu Yingjing
Published: February 2021

In this paper, a more effective method-the improved double population genetic algorithm is applied to reactive power optimization. The proposed algorithm is aimed at optimization strategy which makes the population exploit in new space successively. Premature convergence and weak local optimization are two key problems existing in the conventional genetic algorithm. Based on the golden section, the double population genetic algorithm (DPGA) is optimized and applied to the reactive power optimization in power system. Numerical simulation results demonstrate the validity of the proposed design algorithm.
Equivalent Model of Active Distribution Network Considering Uncertainties of Wind Turbines, Photovoltaics and Loads
Authors: Wei Qianlong , Zheng Jiehui , Tang Wenhu , Wu Q. H.
Published: February 2021

With the integration of large-scale distributed renewable energy, the model of active distribution network (ADN) becomes more complicated. This paper proposes an equivalent ADN model considering the uncertainties of wind turbines, photovoltaic (PV) systems and loads. The model output is composed of deterministic and uncertain components. First, the model of wind turbines, PV systems and loads are developed to describe the deterministic components and the Gaussian probability density model is used to describe the uncertain components. Then, model parameters are optimized using a reinforcement learning algorithm to track the time-varying equivalent wind turbines, PV systems and loads. Finally, case studies are carried out on a 63-bus distribution network. Simulation results demonstrate that errors of power flow calculation of the equivalent ADN model are reduced in the case that the uncertainties of wind turbines, PV systems and loads are considered.
Thoughts on the Development of Molybdenum Beneficiation Technology
Authors: Kang Jian Xiong , Li Xin Kuan
Published: February 2021

Currently, the speed of national economic development is accelerating, and the level of science and technology has also been significantly improved, and the demand for molybdenum in modern industrial production has increased accordingly. With the large-scale extraction of molybdenum resources, the amount of molybdenum resources stored is constantly decreasing. For this reason, the optimization and innovation of molybdenum ore beneficiation technology is very important to improve the utilization of molybdenum ore resources and provide necessary assistance for the sustainable development of the modern mineral industry. Based on this, the paper takes molybdenum ore as the main research topic with focus on the development of the beneficiation process in hope of helping related communities.
Fault Characteristic Analysis of Pole-to-Ground Fault in DC Side of Energy Router in Interacted and Interconnected Micro Grid
Authors: Sang Zi-xia , Zhang Dong-yin , Fang Reng-cun , Yan Jiong , Huang Jia-qi , Lei He
Published: February 2021

This paper takes the AC / DC interconnected system based on DAB energy router as the research object, analyzes the fault characteristics of AC side and DC side in detail, compares and analyzes the influence of DAB energy router on fault characteristics in the system with different grounding methods of DC capacitor midpoint in converter station, and explores the mechanism of interaction between AC and DC sides. The effect of dab on the interaction of AC and DC side faults under different fault types and capacitor neutral grounding modes is analyzed. Finally, the method of post fault system partition and fault analysis is proposed, which lays a theoretical foundation for fault detection and rapid location of AC / DC hybrid distribution system, and provides theoretical support for system equipment selection.
Research on Feature Extraction Method of Converter Transformer Vibration Signal Based on Markov Transition Field
Authors: Wang Pengfei , Yu Gang , Wu Huafeng , Zhang Zhanlong , Xiao Rui
Published: February 2021

In view of the high complexity of the vibration signal of the converter transformer and the large amount of data, the construction of the feature extraction model of the converter transformer based on the vibration signal is difficult and the accuracy is not high. This paper proposes a feature extraction model of commutation vibratiob signals based on Markov transition field and residual convolutional neural network. This paper first divides the interval according to the signal amplitude and calculates its Markov transition field matrix, and then obtains the two-dimensional representation of the one-dimensional vibration signal by calculating the Markov transition field matrix through the transition matrix. Finally, the feature extraction of the vibration map is performed through the residual convolutional neural network. Analysis of the actual measured data at the converter station shows that the average working condition recognition accuracy of the model in this paper reaches 93.1%. It is better than classic time series processing networks such as long and short-term memory networks and one-dimensional convolutional neural networks. It solves the problem of difficulty in building and training long vector deep learning networks by constructing two-dimensional representations of one-dimensional vectors. It is based on commutation The research on fault detection methods of variable vibration signals provides the basis.
Fault Zone Location Based on Transient Phase Current and Zero Mode Current
Authors: Wang Xiaowei , Ji Xingquan , Zhang Yumin , Song Qiang
Published: February 2021

To solve the problems of inaccurate location caused by unsynchronized measurement signals, high impedance grounding, and strong noise interference, in this paper, a novel fault location method based on the relationship between transient zero-mode current and transient phase current is proposed. Through analysis, the zero phenomenon is the main cause of misjudgment. The three-phase current of fault feeder detection point is obtained, the similarity between fault phase current and fault transient zero-mode current is calculated, and the segment location is conducted by using dichotomy method. Numerical simulation results demonstrate the effectiveness of the proposed method. This method can greatly reduce the probability of misjudgment and measurement difficulties, and improve detection efficiency.
Analysis and Research on the Comprehensive New Index of Bursting Liabilitys in Yima Coalfield
Authors: Yi Enbing
Published: February 2021

Aiming at the phenomenon that the impact energy index, the elastic energy index and the dynamic failure time are contradictory in the process of the impact tendency identification experiment, it is impossible to accurately distinguish the strength of impact tendency. This paper adopts the method of principal components analysis to confirm indexes weight and makes full use of experimental data, and a preliminary judgement is made that the value of the samples more than 0 is strong bump proneness, the other is weak bump proneness. The result agrees with the coal seam bump proneness of practical situation in Yima coalfield, namely strong bump proneness in Yima coalfield. The method of comprehensive new principal components analysis will judge the bump proneness very well and provides a new method to judge the bump proneness.
Research on Vibration of Ship Coupling Beam
Authors: Shuo Chen , Heng Zhang
Published: February 2021

With the continuous progress and development of the military strength of various countries, the concealment performance of submarines has received more and more attention from various countries. It has gradually become an effective way to reduce vibration and noise by studying the vibration and sound radiation characteristics of the propeller-shaft-boat coupling structure. The previous research methods for the vibration and sound radiation characteristics of simple and uniform structures are insufficient in meeting current actual engineering needs. Therefore, it is necessary to explore a more accurate and efficient method for modeling and calculating the complex non-uniform structure of the propeller-shaft-boat.