bluuebunny/crossref_metadata_2025 huggingface dataset:
The Observer Pattern Research Based on rCOS
Authors: Xiang Yan , Yang Jing , Zhu Hao , Dong Ding Xiang
Published: February 2014

Design patterns is a good method to solve software crisis and realize the software reuse. It is usually combined with the Unified Modeling Language (UML) to establish the system framework. And Observer pattern is high frequently used in actual modeling. So this paper presents formalization of the Observer pattern based on refinement Calculus of Object Systems (rCOS), this research describes formal semantics of the patterns UML class diagram and sequence diagram and guarantee the characteristics and properties of the pattern at the same time in order to use system model accurately which involved Observer pattern.
Cap Detection Algorithm Based on Pixel Measurement
Authors: Zhang Wei Guo , Zhang Chao , Li Li Feng
Published: February 2014

In order to improve the cap detection efficiency, reduce cost, this paper puts forward a kind of beverage bottle cap detection algorithm based on pixel, the algorithm according to find out the edge line on midperpendicular, left and right edges, and highlight the bottleneck to judge the cap of the four kinds of four steps. In practice, the system monitoring accuracy above 99%, experiments prove that algorithm has a good practicability.
Preparation and Properties of Biodegradable Polyurethane Scaffolds for Tissue Engineering
Authors: He Xian Yun , Xu Yong Jun , Wang Ying Jun , Wu Gang , Yuan Bo
Published: February 2014

3D porous scaffolds were produced by a combined salt leaching-phase inverse technique. Results showed that micorpores and macropores distributed in the produced scaffolds with high porosity (more than 75%). The interconnectivity can be influenced by the use of methanol and water as a nonsolvent to induce liquidliquid phase separation. The addition of the nonsolvent and NaCl had influence on compression property of the scaffolds.
Application of Multi-Computer Communication among Single-Chip Microcomputers on Distributed Data Acquisition
Authors: Zhang Chao , Zhao Jian , Wei Qiang
Published: February 2014

A distributed data acquisition system based on multi-computer communication among Single-chip Microcomputers is proposed in this paper. The AT89S52 is used as the control core, and multi-computer communication is realized by bus RS485. The hardware construction of the system is introduced. Circuits of each module including the microcomputer, temperature sensor, communication interface and voice alarming are designed. Process of multi-computer communication is described. Programs of master serial transmission and slave serial receiving are written and compiled. Experiments are conducted on temperature measure and acquisition. The results show that a satisfied effectiveness is obtained. A reliable performance can be achieved.
Design of Tunnel Personnel Positioning System Based on Android
Authors: Li Hao , Lai Hua , Cui Lin Lin
Published: February 2014

To eliminate hidden trouble of personnel positioning system, making services more accurate, timely and comprehensive for tunnel workers and managers on the ground, on the basis of original personnel positioning system, "secondary development" was applied on mobile terminal based on Android. Client and server software of tunnel personnel positioning system was designed as well as video, photo uploading and other functions were perfected. The original passive positioning was replaced by active positioning. Experiments in this paper have shown that this system has the advantages of safe, friendly interface and fully functional.
The Research of the Web Service Test Model
Authors: Ding Xiang Dong , Yang Jing , Xiang Yan , Zhu Hao
Published: February 2014

Web Service involves many participants including service developers, providers, UDDI, and clients, and provides a kind of distributed architecture model. Different participants of the web service own different resource related to the service, so, the test method they use will be also different. From the perspective of service users, the paper proposes a service test model. The model is mainly consist of three sub-models including the user requirements model, the WSDL model, and the generation model of the test cases. Users can make a function test by using the model only with the WSDL document. According to the test model, a prototype tool is implemented. In the last, an example is given to simulate the process of service test and validate the feasibility of the model.
Dynamic Experimental Study on Highly Weathered Granite
Authors: Niu Lei , Song Quan Jie , Xu Shuang , Guo Xiao Ming
Published: February 2014

The shear modulus and damping ratio are two important index in equivalent nonlinear model which is widely used in seismic response analysis. GDS resonant-column is used to study the shear modulus and damping ratio of highly weathered granite by controlling the consolidation confining pressure and pore water pressure. Variation of resonant frequency, shear modulus and damping ratio can be observed when different effective stress which is changed with confining pressure and pore water pressure applied on the sample. Hadin-Drnevich fitting curves are given on the basis of experimental data, and damping mechanism of highly weathered granite is discussed by making use of frictional theory. We can conclude from the results that there is a positive correlation between resonance frequency and shear strain, while there is a negative correlation between samples damping ratio and shear strain. The effective stress impact both samples shear modulus and damping ratio. However, pore water pressure can only act on damping ratio.
Residual Stress Study of Autofrettaged Barrel under Impulsive Loading
Authors: Qu Pu , Li Qiang , Yang Shu Fang
Published: February 2014

An analysis model of barrel was established for rapid-firing gun by using the thermal structure direct coupling analysis method. As a solving tactics, finite element method was employed to analyze the influence of degree of autofrettage on the residual stress of the tube under impact load caused by high temperature and high pressure powder gases during continuous shots process. The results indicated that there is a significant effect of degree of autofrettage on the residual stress distribution of barrel. As the autofrettage level increases, the radius of the compressive tangential plastic strain zone on the inner wall and the maximal residual stress of the base near chromium-steel interface become larger. This is the cause that the tensile tangential plastic strain in the self-reinforced barrel easily occurred in the process of continuous shots after cooling. This goes against stability of the stress condition of the gun tube.
Experiment Study on Influence of Initial Stress in Concrete Filled Steel Tubular Latticed Columns under Axial Load
Authors: Huang Fu Yun , Yu Guan , Chen Bao Chun , Li Jian Zhong
Published: February 2014

The testing of concrete filled steel tubular (CFST) latticed columns with initial stress had been conducted under axial load. The set-ups subjected to initial stress, the curves of load to deformation as well as the hooping effect were analyzed. The trial results indicate that the CFST columns with initial stress have smaller of combined stiffness and ultimate load-carrying capacity as compared with CFST columns without initial stress. Furthermore, the presence of initial stress will advance the coming of plastic phase, and contemporary, put off the appearances of hooping effect so that it cannot be sufficient exerted, which decrease the ultimate load-carrying capacity at all. Nevertheless, the mechanical behaviour of lacing tubes does not vary with the initial stress and all the lace tubes are stayed in the elastic phase during the testing.
Three-Dimensional Finite Element Analysis of Implants with Different Crown-to-Root Ratio and Different High Thread
Authors: Duan Ying Jie , Chen Ling , Xiong Tao , Niu Xing Hua
Published: February 2014

To compare the strain and stress distribution on jaw bone around the implant with different crown-root and different teeth high in teeth repairing, three-dimensional geometric model of the implant was created and analyzed through UG and finite element analysis software. Model came to workbench software after it was drawn and assembly by 3D mapping software of UG. Given material properties of the model, meshing, boundary conditions and forces applied for analysis. It was Obtained that the size and distribution of stress and strain about jaw bone and implant under different conditions. The influence of jaw bone and implant in different conditions was discussed. The main results of the study are as follows: different implant and crown-root, maximum stress with the crown-root increases, but the maximum stress is placid. Factor in the high thread where the maximum stress with high thread show an inverted "U" shape, the maximum strain with high thread becomes flat.
Disturbance Sampling Analysis in Sediment of the Yellow River Reservoir by Finite Element Method
Authors: Zhang Lei , Yang Yong , Zhang Bin , Zheng Jun
Published: February 2014

Based on the nonlinear finite element theory, the disturbance conditions of deep water reservoir sediment in the process of sampling with sampler are researched by using the finite element software ADINA. Nonlinear face-face contact model between sampler and sediment is established by adopting the Mohr-Coulomb constitutive model as sediments material properties, and the friction and contact in the interface of sampler wall and sediment are well simulated. The impact load is applied, and the impact sampling finite element simulation model is obtained by nonlinear transient dynamic analysis. The condition of deformation, stress and strain in sampling sampler is well discussed, the results show that the axial compression of sediment samples is largest on the bit lip surface and is smallest in the center part of the sediment samples, the impact disturbance on the soil samples is within a small scope nearby the bits.
Study on the Hydrodynamics of a Single-Acting Pendulum Wave Energy Converter
Authors: Wang Dong Jiao , Qiu Shou Qiang , Ye Jia Wei
Published: February 2014

Based on the three dimensional potential theory, numerical studies were carried out to investigate the hydrodynamics of a single-acting trapezoidal pendulum wave energy converter in regular waves by using time domain analysis. The nonlinear viscous damping was also taken into account, and the influence of power take-off damping on the motion responses and output performances were analyzed. Comparisons of experimental and numerical results were performed as part of the validation process.
A Research on Strength Criteria Based on Material Structure
Authors: Wei Zhen Hai , Wang Meng Shu , Zhang Ding Li
Published: February 2014

Strength criteria for materials in the classical elastoplastic theory are formed mostly based on experiments and some assumptions [1, . However, no concensus has been achieved though many strength models were put forward to explore the applicable material strength criteria previously. Even the influence of material structures on strength has not been realized. In this article, the tensile failure strength criterion, shear strength criterion and strength criterion of friction materials are explored on the basis of the model of material with a structure of uniformly random distribution. Through analysis, it can be discovered that the strength criteria in the classical elastoplastic theory can be derived from the complex material theory based on the concept of material structure. However, as the theoretical basis, conditions of derivation and assumptions of concepts are totally different, it is proved that the complex material theory used for studying the material structures can fully cover the contents and conclusions obtained in classical elastoplastic theory.
Adsorptive Removal of Cr(VI) from Aqueous Solution over Material: Optimisation through Response Surface Methodology
Authors: Wang Shu Dong , Cheng Song , Zhang Jian , Zhao Hai Ying , Ma Xun Jing , Zhu Xiao Min
Published: February 2014

In the present study, organic-inorganic hybrid mesoporous material (HMC) were used to optimize the removal rate for Cr (VI) by applying Response Surface Methodological approach. Batch mode experiments were also carried out to assess the adsorption equilibrium in aqueous solution. The effect of three parameters, that is pH of the solution (1.52.5), initial concentration (100500 mg/L) and adsorbent dose (0.050.15 g/ 50 mL) was studied for the removal of Cr (VI) by HMC. BoxBehnken model was used as an experimental design. The optimum pH, adsorbent dose and initial Cr (VI) concentration were found to be 2.0, 0.05 g/L and 500 mg/L, respectively. Under these conditions removal adsorption capacity of Cr (VI) was found to be 337..
Impact Loading Analysis of Light Sport Aircraft Landing Gear
Authors: Chen Pu Woei , Chang Shu Han , Chen Chan Ming
Published: February 2014

This paper examined the critical loading condition of a light sport aircrafts main landing gear during the impact loading condition. The new category airplane was established by the FAA in 2004. The light sport aircraft has great market demand for personnel entertainment purpose and regional transportation. The main object of this research was to establish a static and dynamic loading simulation model for the aluminum alloy landing gear of a light sport aircraft. This work also examined the critical loading parameters of the main landing gear, including the maximum take-off weight and maximum stall speed. The analysis was performed using ANSYS and LS-DYNA to establish the finite element model after simplifying the geometric characteristics and verifying the results by energy conservation, hourglass energy, and sliding energy. The study tested aluminum plates with a thickness from 15~25 mm. The results showed all the samples could sustain the required loading condition, except for the thickness of 15mm that failed under impact loading. The simulation model provides a cost-saving process compared to a real crashworthiness drop test to test the main landing gears compliance with regulations.
Effect of Rotation Speed and Eccentricity on Dynamic Movement Characteristics of BTA Deep-Hole Boring Bar
Authors: Zhao Wu , Sun Chao Fan , Hu Zhan Qi
Published: February 2014

Since the actual boring bar physical system is characteristic of strong nonlinear, it is difficult to apply analytic method to solve. For studying the effect of dynamic characteristics induced by speed changing and eccentricity, simulations are completed for bifurcation of displacement with the variable rotation speed, no matter whether there exists cutting force. It is shown that with the speed increasing, the system's dynamic characteristic become complicated, namely, the dynamic periodic motion varieties from single, multiple to quasi periodic in turn. Analogously, eccentricity leads to the increase of the complexity of systems dynamic characteristics. The periodic motion also transforms from single, quasi, triple to quasi periodic in sequence. The cutting force variation plays an importance role on the movement stability of the system.
Principal Stress and Principal Strain Response in Thin-Walled Cylinder
Authors: Zhu Yun , Zhao Xue You
Published: February 2014

The thin-walled cylinder internal pressure is common in practice. In the determination of air on the surface of thin-walled cylindrical principal stress and principal strain, and the resistance strain measurement technique was used for the direct measurement. This paper deals with the function relations of principal stress and principal stain of a thin-walled cylinder varying with time, and the relations between the principal stain rate and the thickness of a thin-walled cylinder, as it is subjected to internal pressure.
Product Development Model Oriented for the R&D Projects of the Brazilian Electricity Sector
Authors: Pereira João Adalberto , Canciglieri Osiris
Published: February 2014

This paper, through a wide approach of Product Development Process (PDP) renowned methodologies, proposes a conceptual model to serve as a guide in the elaboration, management and implementation of research and development (R&D) projects classified by the R&D Program of Brazilian Electricity Sector which is regulated by the Brazilian Electricity Regulatory Agency (ANEEL). Product development methodologies can be applied to narrow the relationship between academy and industry ensuring results directed to the product, with reduction of costs and development time better suited to the customers needs, fulfilling integrally, at the same time, the Innovation Chain proposed by ANEEL R&D Program in the achievement of new technologies for the electricity sector.
Microstructural Characteristics of Punica granatum Fruit at Dynamic Temperature inside the Fibre Insulation Materials
Authors: Li Xi Hong , Li Li , Liu Xia , Wang Wei , Han Jiu Chun
Published: February 2014

Differentiation in microstructural characteristics ofPunica granatumfruit in response to different dynamic temperatures (2 oC, 4 oC, 6 oC, and 8 oC) during cold storage inside the fibre insulation materials was investigated. The results from Fourier Transform Infrared Spectroscopy (FTIR) measurements showed that the polyester fibre exhibited an advantage and the radiation heat transfer was analyzed in the area of far-infrared. By evidence, the examination by scanning electron microscope (SEM) revealed that effect of dynamic temperature onPunica granatumfruits was structurally different. The fruits stored at higher temperature (6 oC and 8 oC) were associated with fractured cell walls and collapse of cells.
Parallel Scheduling Algorithms Investigation of Support Strict Resource Reservation from Grid
Authors: Chen Jun , Li Bo , Wang Er Fei
Published: February 2014

This paper studies resource reservation mechanisms in the strict parallel computing grid,and proposed to support the parallel strict resource reservation request scheduling model and algorithms, FCFS and EASY backfill analysis of two important parallel scheduling algorithm, given four parallel scheduling algorithms supporting resource reservation. Simulation results of four algorithms of resource utilization, job bounded slowdown factor and the success rate of Advanced Reservation (AR) jobs were studied. The results show that the EASY backfill + firstfit algorithm can ensure QoS of AR jobs while taking into account the performance of good non-AR jobs.
A Multi-Redundancy Structure Model of Cloud Computing Digital Library
Authors: Xu Lin
Published: February 2014

Digital library has been a part of our modern life. It is clear of the importance of cultural resources and its pushing on history. In a certain area, digital library can solve the problem of dynamic catalogue, permutation and combination, which helps to serve the public in time. We propose the cloud computing digital library in the background of the development of cloud computing during these years.Cloud computing digital library can settle in a local area and can sort cultural resources barcode rapidly. It can organize small virtual Cultural Center for special purpose,also can provide real-time audio and video transmission service. It can also arrange the redundancy cultural resources from all the library in the area to online service process. This paper propose: a multi-redundancy structure model of cloud computing digital library and analyze the reasonability and the feasibility of the model. This model can be used in big libraries of university and social.
The Design and Implementation of an Optimized MPTCP Data Scheduling Algorithm
Authors: Li Xi Ming , Wang Wen Dong
Published: February 2014

Mobile devices are emerging with multiple interfaces with diverse access technologies. Using multiple interfaces simultaneously can bring lots of benefits to users. Multi-Path TCP is proposed in recent years, which aims to provide the capability for a TCP host to simultaneously use its multiple interfaces to transmit in one TCP connection. However the original MPTCP data scheduling algorithm has some defects and cannot fit multiple kinds of applications to achieve maximize throughput. We thus proposed and implemented an optimized MPTCP data scheduling algorithm. We used the type of service of an application and quality parameters of each interfaces measured in real time to calculate the best path dynamically. The results of the experiment showed that our algorithm had better performance than the original one in achieving higher data throughput, resource utilization and more rationality during an MPTCP transmission.
Cloud Security System Construction and its Concrete Realization
Authors: Wu Jing , Zhao Feng Zhi , Dong Yu Dan
Published: February 2014

As a new cloud computing services and computing model itself does not break away from traditional concepts of information security coverage, still faces a variety of traditional security threats, including physical physical security, network security, host security. Because of their characteristics of cloud computing will lead to generate some new security issues, such as internal virtual machine to attack each other, the super administrator rights and other issues. In this paper, cloud computing security problems faced by specific solutions.
Simple Encryption Research Based on Heterogeneous System
Authors: Wan Xing
Published: February 2014

For the widespread application of XML technology in network, the security of XML documents is particularly outstanding. XML encryption technology can ensure the confidentiality and integrity of an XML document effectively, and provide important technical for the safety of the XML document transmission. This paper will first introduce the XML encryption technology and encryption standard, and three models of XML document encryption, and then the paper will give three simple implementation of the XML encryption document in the. NET Framework platform. It preliminary ensures the safety of XML document and shows the flexibility and simplicity of XML encryption technology.
Research on P2P Network Resource Search Method
Authors: Zhang Qian
Published: February 2014

The peer-to-peer (P2P) Computing is one of the key technologies of next generation network, how to search resources efficiently on the P2P network is the most critical problem in the design of P2P network. This paper introduces the characteristics and classification of P2P network. On the basis of analyzing the basic search methods of P2P network, all kinds of search methods are analyzed and studied.
Research on the Integration Technology of Marine Environmental Protection Data
Authors: Ye Na , Qin Ru Fu
Published: February 2014

The multi-source and Heterogeneous of Marine Environmental data and the independence of different business system of marine environmental protection cause the marine environmental protection to be information isolated island and bring inconvenience to the its Supervision Department. In this paper, the author points out to apply the virtualization methods to process the Marine Environmental Protection Data Integration, and adopt the WII technology frame to integrate the Marine Environmental Business System. This technology solution has been applied in the course of practical projects research.
Research and Realization of Custom Form Realization Method Based on HTML and XML Technology
Authors: Wang Qian Qian , Wang Yong , Chen Xin , Wang Ying
Published: February 2014

To solve the problems of low efficiency and poor flexibility in modify the form in traditional forms technology, A method of custom form is proposed. The method which is based on the current popular CKeditor open source tools generate the XML file using DOM4J, at the same time generate HXML files to define the form process as the basis of form show page, finally realize the custom form by separating the realization form data control. Experiences show that it can create and modify more flexible and convenient in the model.
Research on SQL Performance Optimization of CRM Stored Procedure
Authors: Wang Rui , Wang Na
Published: February 2014

In this paper, we research the stored procedure combined with the bank CRM system. Mainly introduces how to improve the efficiency of the stored procedure in ORACLEs PL/SQL in the banks CRM system.
A Framework for Processing Water Resources Big Data and Application
Authors: Ai Ping , Yue Zhao Xin
Published: February 2014

The development of information technology expands the spatial and temporal scale and types of elements of the water resources information, making the water resources data show the characteristics of multi-source, heterogeneous, massive, and the traditional data processing method is difficult for fine processing and dynamic analysis. Combined with the "4v" characteristics of big data, we put forward a framework for processing water resources big data, to process and analyze modern water resources data for real-time and rapid, and discuss the related application. Based on the features of modern water resources data, this paper discusses the characteristics and application technology of big data, and briefly describes a framework for processing water resources big data and application.
Research and Implementation on Compression, Encryption, Storage and Retrieval System for Massive Data
Authors: Xu Yong Kang , Zhao You Qiao , Lu Song Feng
Published: February 2014

A compression, encryption, storage and retrieval system for massive data is proposed and designed which can be used in these enterprises and institutions in which the business data, which need be protected, increases rapidly. In the system, XML file format is adapted as the intermediate switching format so that the detail of the multiple types of files can be omitted. A special index supporting compression and encryption is presented in the paper. In the process, the documents are stored in the server after compressed and encrypted; an end-user can retrieve the need documents efficiently by helping of the index structure. The security of the data is guaranteed since the data is not needed to be decompressed and decrypted in the retrieval process.
Analysis of Distributed Computing Architecture Search Principle Based on Hadoop
Authors: Duan Ai Ling , Cao Dan , Si Hai Fang
Published: February 2014

Distributed search techniques of Hadoop are researched and analyzed. Combined with Lucene indexing objects, a search engine system IS successfully built. Efficiency of the system in both time and space is investigated. Merit of distributed processing architecture for a single architecture in data handling is verified. The access and update of file information in distributed search technology are further explored. The research plays a positive role in promoting study of related fields
Research on PPHIIS Based on Ontology Model
Authors: Liu Xiao Yan , Li Xiao Bao , Fu Xiao Dong , Zhang Jia Chao
Published: February 2014

As statistics from different software are heterogeneous and cannot be shared, an ontology model-SOsRCE based on Integrated System for health Information of Peoples Police (abbreviated to PPHIIS) was investigated. The method was combined with agents cooperation. Meanwhile, the model not only solved the problem of semantic integration in PPHIIS but also enabled medical staff to extract detailed medical information more efficiently.
Comparison of Parallel Computing Methods for Fast Cone-Beam Reconstruction with Similar Optimization Strategies
Authors: Zhang Xiang , Yan Bin , Li Lei , Zhang Feng , Xi Xiao Qi , Wei Xing
Published: February 2014

To investigate the performance of acceleration technologies for FDK algorithm, two of the most common high-performance computing hardware, multi-core CPU and GPU, are involved in our experiment. Both runtime and accuracy are regarded as the standards to evaluate the performance of four different programming methods: OpenMP, GLSL, CUDA and OpenCL. All the methods are estimated with comparable optimization strategies. The experimental results show that GPU has higher efficiency than multi-core CPU for fast cone-beam reconstruction, meanwhile CUDA is the best choice for programming on the multi-processor featured GPU.
Numerical Investigation on Film Cooling Effectiveness of Stator Blade with Different Density Ratio
Authors: Zhang Ling , Jin Quan Heng , Guo Da Fei
Published: February 2014

The Realizable k-ε turbulence model was performed to investigate the film cooling effectiveness with different blowing ratio 1,1.5,2 and different density ratio 1,1.5,2.The results show that, cooling effectiveness increases with the augment of blowing ratio. On the pressure side, cooling effectiveness increases with the augment of density ratio. On the suction side, with higher density ratio the leading edge cooling increases, the middle section reduces, and the trailing edge cooling effectiveness increases first decreases.
Method of Wind Power Prediction Based on ANN and Improvements
Authors: Song Shao Shuai , Li Ran
Published: February 2014

This paper puts emphasis on studying on artificial neural network (ANN) method. Following that a model of wind power prediction is established based on back-propagation neural network. In order to improve the learning speed of ANN, a revised BP algorithm is adopted by using variable step and the combination of GA and BP algorithm. This method has a good effect in practice.
The Optimized Charge-Discharge Strategy of EVs Considering the Fluctuation of Wind Power
Authors: Tang Sheng Wei , Tan Yi , Liu Juan , Sun Jian Wei
Published: February 2014

The fluctuation is an important factor that limits large-scale integration of wind power into power grid. In order to improve penetration level of wind power, the EVs based on V2G are considered to participate in regulating wind power while considering charge-discharge characteristics of EV battery. Thus, in this paper, an optimized EV charge-discharge control model is proposed to reduce output fluctuation of wind power. The Monte-Carlo method is used to simulate the stochastic wind speed based on Weibull probability density function. Finally, Genetic Algorithm (GA) is adopted to solve the problem. Results indicate that the EVs based on V2G can reduce the wind power fluctuation level to some extent, absorbing the wind power surplus and compensating the of wind power shortage.
Overview of Generator Out-of-Step Prediction
Authors: Xu Yan , Huang Guo Lin
Published: February 2014

With the development of power system, the main unit is gradually becoming larger and larger, thus length of time that large generators after experiencing disturbances in power grid needed to adjust and maintain the stability is more important than ever. Generator out-of-step prediction which is a part of security and automaticity equipment of power system, sends out the corresponding operation instructions in order to keep the whole system stay stability, according to the initial system state and fault severity. The paper analyzes and classifies several schemes and principles on generator out-of-step prediction. The actual advantages and disadvantages are pointed out. At last, the development of out-of-step prediction is also presented.
Power Quality Analysis Software Based on LabVIEW
Authors: Kong Long Guang , Zhou Yong
Published: February 2014

This paper introduces the design and development of a LabVIEW-based power quality analysis software, focusing on the four important indicators of power quality: frequency deviation,voltage deviation, three-phase unbalance and harmonics. Accuracy of the software is proven through experiment, demonstrating the high efficiency of LabVIEW in the development of power quality analyzer.
A Modified Nonlinear Hydro Turbine Model
Authors: Ding Li Jie , Tang Xiao Jun , Li Xing Yuan
Published: February 2014

The power system simulation software usually use ideal hydraulic turbine model in transient stability simulation. Ideal model is the linearization of turbine steady state equation, it can hardly adapt to the various operation conditions in power system. In this paper, a modified nonlinear model of hydraulic turbine is proposed based on basic hydraulic turbine equations, the model can better reflect the dynamic behavior of the turbine since transient component are taken into account. Field test data verify the validity of the proposed model. The model can greatly improve the accuracy. Furthermore, the model is very simple so that it can be easily used in power simulation software
A Study on DG Control Strategy and Grid Protection
Authors: Wang Xin Chao , Yang Chen Xin
Published: February 2014

DG integration reduces the selectivity and sensitivity of grid relay protection. A new control algorithm is proposed. It shows that the negative sequence current will not be affected by DG when the DG is designed as a symmetric three-phase current source. In this case, the negative sequence characteristic can be utilized for grid protection during short-circuit faults. If DGs maximum power capacity is restricted to be lower than total load capacity, DG terminal line-voltage and the negative sequence voltage can be used as the criteria for islanding detection. Then it is possible to cutoff DG in order to fulfill the reclosing requirement. A complicated simulation system is designed using PSCAD/EMTDC program. Different short-circuit faults are simulated to verify the proposals. The test results confirm well with the conclusions.
Heat Efficiency of Trough Solar Vacuum Receiver
Authors: Liang Jun Ming , Lu Jian Feng , Ding Jing , Yang Jian Ping
Published: February 2014

The heat loss and thermal performance of solar parabolic trough vacuum receiver were experimentally measured and analyzed by heat transfer model. According to the present experiments, the heat loss of solar parabolic trough vacuum receiver has good agreement with the heat loss of vacuum receiver from Solel company. As the wall temperature increase from 108°C to 158°C, the heat loss of solar parabolic trough vacuum receiver remarkably increases from 35 Wm-2to 57 Wm-2. The heat transfer model of parabolic trough solar receiver is then theoretically investigated due to the energy balances between the heat transfer fluid, absorber tube, glass envelope and surroundings. When solar radiation flux is constant, the heat efficiency of solar parabolic trough system decreases with the wall temperature and oil temperature. When solar radiation flux or solar concentration ratio increases, the heat efficiency of solar parabolic trough system increases.
Study on the Balance Control Method of Instantaneous Power for the Converter in the DFIG
Authors: Xu Jian Yuan , Wu Guan Nan
Published: February 2014

For the operating safety of the integrated doubly-fed induction generator (DFIG), this paper proposes an instantaneous power balance control method for the converter. It bases on the optimal rotor current control. A simulation model is built in PSCAD/ EMTDC for analyzing the integration stability of the integrated doubly-fed induction generator system when the power grid voltage drop fault is occurring, and the simulation data verified the correctness and effectiveness of the converter control strategy.
Research on the Voltage Stability of the Microgrid
Authors: Xu Jian Yuan , Wu Guan Nan , Bai Qin Yu
Published: February 2014

In allusion to the grid structure and operation characteristics of the microgrid, in this paper a static voltage stability index for microgrid was deduced based on the existence of the power flow. The index has taken the node voltage into account and is free from the influence of the grids R/X; besides, it has a smaller error for it has no network loss equivalent during its deduction. Then one 13-node microgrid system was established to validate the deduced index, finally the index was used to analyze the influence of distributed sources including the PV, PI, P-Q(V) node types as well as heir locations and capacities on the static voltage stability of microgrid.
Mobile Electric Power Energy Efficiency Detection System and Test Method
Authors: Chen Song Song , Zhong Ming , Yan Hua Guang
Published: February 2014

Energy efficiency detection system plays a important role in energy conservation service market, which is applied in lots of enterprises. Mobile detection system can save manpower and financial resources especially for energy conservation service agencies and energy efficiency assessment institutions, which consists of the portable devices, self-organizing communication network, reliable data collection ability, strong data analysis and display tools. The physical architecture, function architecture of the system was designed and key technologies about the system were also specially studied. The test method about the system was designed, which is used to guide the technicians in the field. The thesis results supply a practical measure for the work of the above mentioned related agencies and institutions.
Selection of Online Electric Quantities for Converter Condition-Based Maintenance
Authors: Ding Zhi Lin , Wang Yu Hong , Qiu Da Qiang , Zhu Yan , Liu Xiao Han , Xiao Ping
Published: February 2014

Converter is the core of a HVDC transmission system. In order to recognize the converter fault, the state of electric parameters is measured by real-time online monitoring method. It has great significance for making condition-based maintenance strategy. In the paper, the basic structure and fault type of the converter are discussed. Based on the ETSDAC of ADPSS simulation package, a HVDC transmission system is established, and the essential characteristics of each electrical quantity in main circuit when fault occurs are analyzed. Under different fault conditions, energy gradient is used to characterize changes of electric parameters. Finally, according to the energy variation, the online monitoring electrical quantities of each fault state are determined. Simulation results show that this method can be used to choose electric quantities for online monitoring.
An Indirect Air Cooling System with Compound Refrigerating Cycle for CSP Plants
Authors: Zhao Bo , Yang Shan Rang , Hu Ya Cai
Published: February 2014

The geographical contradictions between plenty of water and high solar radiation constitute are hindering the development of concentrated solar power (CSP) plants, dry cooling systems are compelled to adopt to solve the contradictions for the CSP plants. This paper analysis the feasibility of a novel indirect air cooling with compound refrigerating cycle (CRC-IAC) system used in CSP plants. The solar field and power block in the analysis are modeled using NREL’s Solar Advisor Model (SAM), excluding heat rejection system. Thermodynamic simulations and optimizations for operation exhaust pressure with the changes of ambient dry-bulb temperature are presented. The ideal cycle performance for CRC-IAC system is evaluated and quantified. Moreover, the system was compared with circulating wet cooling (CWC) and air cooling condenser (ACC) in terms of electricity generation and levelized electricity cost (LEC). The results show that the LEC of CRC-IAC is increased by 6.44% and reduced by 5.38%.
Research on Detection Method of Transformer Interturn Short Circuit Based on Wavelet Analysis
Authors: Quan Yu Sheng , Zhang Zong Cheng , Chen Guang , Wang Dai Juan
Published: February 2014

Distribution transformer is an important device in the power supply system, once its failure can cause power outages. According to statistics, 70% -80% of the transformer accident was caused by a short circuit between the transformer turns. Based on the large number of experimental data analysis and processing, a new inter-turn short circuit transformer diagnostic methods is proposed. In this paper, the ground current of transformer core as the signal source, Using wavelet multi-resolution technology the signal wavelet multiscale decomposition, the decomposition of different signals of the same scale, get the high frequency components of the signal, achieve short-circuit fault diagnosis between transformer winding turns by comparing the number of the high-frequency component contained in different signals in the decomposition of the same scale. To illustrate the effectiveness of the method, the paper through a series of experiments and data processing, verify the effectiveness and feasibility of the method.
Research on Spectral Characteristics of GIS Partial Discharge Ultrasonic Signal
Authors: Yan Jie , Wang Tian Zheng
Published: February 2014

The traditional partial discharge detection method is difficult to be use in the scene charged detection because of its low frequency and vulnerable to test interference, need to power outages. Partial discharge detection technology has been international recognized in the application of the technology and research. This paper develop a system which can test the PD and manage the information. This method provide a precise and effective means of detection for charged equipment. Through the simulation of several typical defects, choose the best center frequency of ultrasound.
Experimental Study on Solar Energy Added Kang Heating System
Authors: Li Gang , Wang Huan , Niu Run Ping , Chen Qi Zhen , Li Zhen
Published: February 2014

In this paper, the author use solar energy with capillary network systems as the added heating measure of kang . The influence of the system on the surface temperature of Kang and the indoor temperature was researched by experiment. The tested data shows that the average temperature of the head、medium and tail of traditional Kang in a normal room are 65.7°C、43.28°C and 39.82°C. The difference of temperature on Kang surface is higher than 20°C. The average temperatures of the head、middle and tail of the Kang using this system are 51.34°C、38.26°C and 33.79°C. Comparing the two groups of data, we can get the conclusion that the distribution of temperature in the new system Kang is more balance than traditional Kang, which improves the surface comfort of Kang. The average indoor temperature with solar energy auxiliary Kang is 18.5 °C, which is 6.3°C higher than ordinary room. Due to the small thermal inertia of capillary network, the indoor temperature rises quickly when the system is running. It can make quality improvement of indoor thermal environment realtime at will, which greatly improves the thermal comfort of the Kang surface and indoor temperature.
Rules Mining of Power System Transient Stability Assessment Based on Clustering Analysis and Rough Set Theory
Authors: Xu Yan , Chen Xin
Published: February 2014

Transient Stability Assessment (TSA) aims at assessing stability of power system operation state quickly. This paper introduces rough set theory and clustering analysis to assess power system transient stability. At first, the stability operation parameters and fault places are taken as feature attributes based on the trait of power system transient ability. K-means algorithm is used to make continuous attributes among feature attributes discrete. Then feature attributes and stability types are taken as conditional attributes and decision attributes respectively. Initial decision table is established. Finally, rough set theory is used to form final decision table and rules of TSA are obtained. The IEEE 9-Bus system is employed to demonstrate the validity of the proposed approach.
The Influence of External Climate Environment on Safe Operation of Power System
Authors: Pan Ling Ling , Li Feng , Yang Sheng Chun , Feng Shu Hai , Wang Yong
Published: February 2014

Frequency and severity of some extreme weather events are increasing, and weather can impact the power system and its components in a number of ways. This paper identifies key technical issues facing the electric power industry, related to global climate change. The technical challenges arise from: 1) impacts on supply and demand balance; 2) impacts on system operating strategies, and power generation scheduling; 3) impacts on power grid structure, and power infrastructure response to extreme weather events; and 4) impacts on operation parameters of power system. The objective of this paper is to facilitate continued discussion of power systemclimate change interactions. To this end, this paper identifies key issues relating to the interactions between the electric power industry and global climate change. These issues will not be resolved quickly, and it requires sustained attention if they are to be resolved successfully.
Design of Electric Energy Monitoring System Based on MAXQ3180 Chip
Authors: Han Cheng Hao , Wang Xiang Tong , Li Hao , Qin Ying , Liu Dong Yu , Chen Peng
Published: February 2014

To solve the problems of bulky, high cost and difficult maintenance existing in the electric parameters monitoring system currently, a new electric energy monitoring system is designed. In the system, MAXQ3180 chip can collect the voltage, current, power factor, harmonic and other parameters of the load. Then the relevant data can be collected and sent to AT89S52 microcontroller through SPI bus to saving and manipulating. Meanwhile, to achieve the goal of decentralized control and centralized management, the system can exchange the relevant data with upper computer by CAN bus communication mode. Then the accurate measurement and intelligent management of the electric parameter can be achieved.
Design of Demand Response System Based on OpenADR
Authors: Guo Yan Kai , Qi Bing , Chen Song Song , Zhong Ming
Published: February 2014

The double pressures of resources and environment have brought the global power industry into the era of Smart Grid. In order to better promote the development of Demand Response of Smart Grid and to offer new regulation resources for the safe and stable operation of electric power system, OpenADR, the Open Automated Demand Response Communications Specification, has been discussed in detail, which aims at the problems of energy efficiency and the contradiction between power supply and demand. And a design scheme of Auto-DR system which introduces in detail the system architecture and the communications architecture based on OpenADR was proposed to realize the two-way communications between Utilities and end-users, and the problems such as the peak, the gap between supply and demand and the electricity structure management would be consequently solved. This scheme has a certain reference value to the Demand Side Management under the framework of Smart Grid.
Study on Control Strategy of Microgrid in Islanded Operation Mode
Authors: Wu Mei Rong , Tao Shun , Xiao Xiang Ning
Published: February 2014

The droop control strategy is only considered the frequency stability during the islanded operation mode of microgrid. So a cooperative control strategy based on two-layer hierarchical control structure is proposed in this paper. In islanded operation mode, Single master operation (SMO) or multi master operation (MMO) is decided by microgrid management system (MMS). When power changes during islanded operation, the master unit (s) with v/f control can balance the energy production and consumption quickly. Based on detecting instantaneous power of master unit (s),The secondary control of MMS sets renewed reference values of instantaneous power of slave unit (s) with PQ control. After that the output power of master unit (s) will return into zero. The simulation studies demonstrate that the proposed cooperative control strategy not only implements no-error frequency control and voltage stability control, but also provides enough spinning reserve margin for master unit (s) to keep the system energy balance all the time.
Reliability Evaluation of Main Electrical Connection for the Smart Substation with DCB
Authors: Huang Yang Qi , Zhang Jian Hua , Lu Xin Yi , Liu Nian
Published: February 2014

As an important part of smart grid, smart substation is the acquisition source of operating data and command execution unit, and also acts as the important foundation and support of smart grid. With the continuous deepening of smart substation construction in State Grid Corporation, the overall integration design concept of the new generation smart substation based on research and development of new equipment has been put forward, realizing the main electrical connection optimization and improvement of reliability .Concerning the characteristic and application of DCB in smart substation, reliability of three kinds of typical main electrical connection schemes in existing substation and smart substation is calculated by the minimal cut-set method in this paper.