bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Dispatcher Interactive Platform Based-on Text Technology
Authors: Wang Chong , Liu Rao , Chang Ye Kui , Zhang Xin , Li Wei Dong
Published: October 2013

Recently, voice dispatching telephone is applied as one of information interactive by power grid dispatching in China, playing a significant role in the progress of power grid dispatching. However, with the increasing of grid scale, more and more information should be figured out by dispatchers. Conventional dispatching telephone in communication presents enormous challenge, thus, much effort should be made to solve this problem. In the article, the shortcomings of dispatching telephone in communication are systematically analyzed by the point of our actual country power grid dispatching. To remedy telephones shortcomings, text technology is introduced and a uniform dispatcher interactive platform is formed. This platform meets the requirements of interactive in power grid dispatching perfectly.
Control Method of Inverter for Large-Scale Grid-Connected Photovoltaic Generation System
Authors: Zhang Zhuo , Li Hong Wei
Published: October 2013

A grid-connected inverter control method to analyze dynamic process of large-scale and grid-connected photovoltaic (PV) power station is proposed. The reference values of control variables are composed of maximum power output of the photovoltaic array in the photovoltaic power plant and power factor specified by dispatching. Control strategy of dynamic feedback linearization is adopted. Nonlinear decoupling controller is designed for realizing decoupling control of real-and reactive-power. The cascade PI regulation is proposed to avoid inaccurate parameter estimation which generates the system static error. Simulation is carried out based on the simplified power system with large-scale photovoltaic plant model, the power factor, and solar irradiation, and bus fault are considered for the further research. Its demonstrated that the parameter adjustment of PI controller is simple and convenient, dynamic response of system is transient, and the stability of the inverter control is verified.
Parameter Identification Method for Turbine Speed Governor System Based on Particle Swarm Optimization
Authors: Sun Wen , Kong Xiang Yu , Yang Qun , Zhang Fang
Published: October 2013

A parameter identification method for generator speed governor system, which combines decoupling parameter identification and overall recognition with measured data, was proposed in the paper. The method bases on particle swarm optimization, and takes parameter identification as a parameters optimization problem under evaluation function. According to an intelligent optimization algorithms evolutionary strategy, the individual's status is continuously adjusted until the identification system and actual system output error is sufficiently small. Case studies show that the proposed method can be applied to the measured parameters and model validation work.
Power Load Prediction Based on a Hybrid Forecast Algorithm
Authors: Zou Min , Tao Huan Qi
Published: October 2013

Power load prediction is an important task for the electrical power system. The nonstationary, nonlinear and volatile characteristics of power load data make more difficult for the accurate load prediction. This paper presents a hybrid forecast algorithm based on wavelet transform and support vector machines for power load prediction. The hybrid algorithm firstly decomposed the load series to several subseries with obvious tendency by wavelet transform. Then these subseries are forecasted with least square support vector machines (LS-SVM), an extension of standard support vector machines, respectively. Finally these forecast results were reconstructed as the prediction of original power load series. The effective simulation results of above algorithm were testified based on a sample load series.
Study on the Control Strategy of the Third Frequency Adjustment with the Participation of the Nuclear Power
Authors: Chang Ye Kui , Liu Rao , Wang Chong , Zhang Xin , Li Wei Dong
Published: October 2013

The third frequency adjustment is the key link of the grid frequency regulation. The admission of high capacity and rejection of small capacity policy on thermal power cause the lack of capacity of the third frequency adjustment. Wind power brings about a certain impact to the frequency stability of the power system, particularly, increasing the difficulty of the third frequency adjustment. The introduction of nuclear power into the third frequency adjustment has been proposed after analyzing the characteristics of the energy generation of different forms. This paper formulate the control strategy with the core of wind power decomposition, generator units grouping in the third frequency adjustment, after elaborating the technical feasibility and economic feasibility, and, come to a conclusion that the participation of the nuclear in the third frequency adjustment would guarantee the stability of the frequency of the power system with this control strategy in the case of the introduction of wind power to the system, by simulation analysis.
Study on Control Strategy for Micro-Grids’ Interconnection
Authors: Duan Li Ming , Liu Nian , Liu Zong Qi
Published: October 2013

Multi-microgrid extended from the concept of Micro-Grid (MG), with the rapid development of MGs, in which case, the interconnection between MGs brought new benefits technically and economically. In this paper, the control strategy of MG will be discussed respectively in the stage of before interconnecting, interconnecting, and after interconnecting. Then, simulation by PSCAD is operated to verify the correctness of proposed control strategy.
Evaluation Method for Urban Distribution Network Planning in City Taking the City Cluster Development Strategy
Authors: Bao Hai Long , Fang Chen , Yang Jian Lin , Bai Yang
Published: October 2013

As the urbanization in China accelerates, metropolitan regions are tending to change their spatial expansion mode from traditional satellite city mode to city cluster development strategy. Under this situation, the paper proposes the method and steps of evaluation for urban distribution network in city which takes the city cluster development strategy. The method takes city cluster as the unit of network planning and evaluation, firstly analyze the functional orientation and the land allocation of the target cluster for evaluation, then take other clusters with the similar function in other metropolis by analogy, finally a more instructive evaluation index system and evaluation standard will be obtained. The practical application in the medium voltage distribution network of Mazhai Industry Park in the city of Zhengzhou has proved that the method proposed is able to meet the demand of practical work in distribution network evaluation under new situation.
Research and Application of the Power Network Planning Methods Oriented to the Clustered City Planning
Authors: Bao Hai Long , Fang Chen , Yang Jian Lin , Yin Qiang
Published: October 2013

As the urbanization of cities is rapidly developing in China, metropolitan regions establish the clustered power network planning scheme on the background of the clustered city planning of the adjacent areas. Base on the functional orientation and difference of clusters, as well as the theory of hierarchical clustered city planning, the article puts forward the power network planning thoughts and methods. As cluster becomes a planning unit, the load density method is applied in the differential load forecast and the location of substations as well as the path of transmission lines is selected with the thoughts of separation according to different layers and areas. And then, the results will be compared and verified with the planning scheme of the other clustered cities which have the similar function orientation and planning strategy. Finally, the planning methods will be standardized. The application in the power network of Cluster of Livable Education City in Zhengzhou has proved that the methods and steps of the power planning method proposed is able to meet the demand of the network development under the situation of the rapid growth of load.
Analysis of Power Planning Model Based on Minimizing the Operation and Maintenance Cost
Authors: Hong Yuan , Tian Shao Yu , Liu Zhong Jing , Chen Fang
Published: October 2013

This paper establishes a power planning model based on minimizing operation and maintenance cost. The model take into account the costs of the wind turbines, photovoltaic cells, batteries, biomass generators, diesel generators, power electronics devices and communications facilities operation and maintenance, credit them in the objective function, and considering some certain constraints, use particle swarm algorithm model, by calculating and, simulating examples , to find the optimal solution, Finally to find the conclusion that to use wind turbines, photovoltaic cells and batteries for electric as much as possible.
A Method of Data Integration Check Based on Online Operation Data of Large-Scale Power System
Authors: Ren Guo Wei , Ren Rui , Dai Hong Yang
Published: October 2013

An important part of power grid voltage stability online intelligent warning system was to research into the current Energy Management System real-time power grid operation parameters and power networks offline data splicing integration, form a set of online dynamic simulation trend data, and implement preventive voltage stability calculation. A splicing model of power grid online data integration and practice was established, and a grid online data splicing method was proposed, which had been verified by actual data. The method of practical data online and offline networks data integration can significantly improve the accuracy of the simulation data.
Multi-Dimensional Model Version Management System Based on Model Cloud Technology
Authors: Li Li Xin , Wang Zian , Yuan Rong Chang , Di Fang Chun , Li Da Peng , Dai Jiao
Published: October 2013

Due to the poor openness between grid models at different levels in existing dispatching centers, theres lack of unified device naming conventions, data exchange standards and interface specifications, making it difficult to easily implement the exchange and sharing of network model parameters and data. In this article, a multi-dimensional grid model version management system is promoted based on model cloud technology with centralized and integrated deployment. Taking advantage of model cloud storage and service technology, unified maintenance and management technology, model subscribing and extracting technology as well as its releasing methods and standardized access technology, the system can construct a cloud service unified in the whole grid, covering all dispatch services with the integration of the grid model information, therefore realizing the unified management, maintenance, generation, release and subscriptions.
A Novel Reconfiguration Strategy for Active Distribution Network Considering Maximum Power Supply Capability
Authors: Liang Wei , Jin Xiao Long , Mu Yun Fei , Jia Hong Jie , Wang Ming Shen , Wang Nan
Published: October 2013

In this paper, a novel reconfiguration strategy for active distribution network considering maximum power supply capability (PSC) is proposed. Firstly, a PSC index (PSCI) is proposed to evaluate the real-time security level of distribution network. Then, a novel reconfiguration strategy is developed for enhancing the PSCI of distribution network when the PSCI is lower than a pre-defined warning value. The reconfiguration strategy can be integrated to distribution management system (DMS) as a preventive control method to prevent outages of customers, which can significantly increase the reliability of distribution network. Case studies are carried out by using a typical 33-bus distribution network, and simulation results verify the effectiveness of the proposed reconfiguration strategy, which has a good engineering application prospect.
A Comprehensive Model for Monthly Prediction of Energy Output of Run-of-River Small Hydropower Station in Electricity Market Environment
Authors: Liu Zhi Jian , Huang Rong , Yang Zhi Hua
Published: October 2013

According to generated output characteristics of run-of-river hydropower station in electricity market environment,a comprehensive model for monthly prediction of energy output based on Partial Least-Square (PLS) and improved Grey Model (GM) is established.The PLS model takes full advantage of the relationship between monthly energy output and its correlation affecting factors,and then using improved grey model to forecast its main factors to get final predictive results further.The comprehensive model not only can effectively use the limited sample,but also can weaken the random impact.The actual prediction results shows that the effect is better than common methods.
Experiment Analysis on Two Outlets of Horizontal Open Cryogenic Refrigerated Showcases
Authors: Ji Amin , Li Fu Liang , Wang Chang Jiang , Niu Xin Chao , Han Dan
Published: October 2013

Contrast experiment on different outlets for horizontal open cryogenic refrigerated showcases. Under the same environment conditions, the temperature field and thermal fluctuation of sheet metal deflectors and hexagonal honeycomb outlets were determined through experiments. Experiments show that the average outlet measurement point temperature of the hexagonal honeycomb was reduced by 11% ~ 27.28% than the average outlet temperature of sheet metal deflectors, and all measurement points transients have reached cabinet temperature requirements.
Design of Energy Storage Station Grouping Energy Management Strategies to Balance Short-Term Wind Power Fluctuations
Authors: Li Jun Hui , Zhu Xing Xu , Yan Gan Gui , Mu Gang , Luo Wei Hua
Published: October 2013

This paper designs a grouping energy management strategy to reduce the influence of wind power fluctuations on the power system. To improve operational technicality and economy of energy storage stations, this paper designs a grouping energy management strategy with SOC correction. According to physical constrains of battery energy storage systems, technical and economic evaluation index of energy storage stations are established. Reasonable limit bands to an energy storage station installed 5MW×2h can balance the output power of a wind farm installed 49.3MW achieved through example analysis. Then the energy management strategy designed is proved to be able to control the change range of the battery SOC and distribute control tasks efficaciously, improving operational technicality and economy of the station effectively. This research provides a theoretical reference to design of energy management strategies for energy storage stations installed small at wind farms.
Research Progress on Assessment and Prediction Models of Joint Toxicity of Chemical Mixtures
Authors: Ge Hui Lin , Su Bing Xia , Zheng Xue Hong , Lin Jing Ling , Liu Chun Hua , Li Ping Ping
Published: October 2013

In this paper we give an overview of the main methodologies available today to estimate the human health risk of environmental chemical mixtures, including joint effect indices, concentration addition, independent action, two-step prediction, INFCIM model, ICIM model, integrated addition model, median-effect equation, hazard index, point of departure index, margin of exposure, relative potency factor, toxic equivalence quantity, cumulative risk index, and toxic unit summation.
A New Power Electronic Transformer Applied to Distribution System
Authors: Yang Xing Wu , Xiong Xin Hua , Ouyang Wu , Yuan Shuai
Published: October 2013

This paper proposes a new power electronic transformer (PET) to be used for distribution system, which is composed of the three-stage power circuits. The input stage uses Modular Multilevel Converter (MMC) to reduce the voltage stress rating of components, meanwhile, the harmonic components in the current will be deduced significantly, to make DC capacitor voltage of MMC rectifier balance, a control method is proposed. The isolation stage use a middle-frequency transformer to realize voltage conversion and isolation of the low-voltage side from the high-voltage side. In the third-stage, a inverter outputs the desired voltage and power to the load. The simulation results are presented to show the validity of the proposed PET system.
Applications of Non-Thermal Plasma Technology in Methane Combustion
Authors: Fu Rui , Bai Ya Qin , Buyankhishig Enkhtsetseg , Hu Jia Nan , Hu Rui Sheng
Published: October 2013

Applications of non-thermal plasma in methane catalysis combustion have attracted a lot of attentions in recent years due to its outstanding and unique properties. We summarized two kinds of hybrid systems of plasma and catalysts for methane combustion reaction and compared these two figurations. Results prove that combining non-thermal plasma and catalysts has an excellent performance for methane total oxidation compared with single ones.
The Structures and Preparation Methods of Perovskite-Type Oxide Catalysts for Natural Gas Catalytic Combustion
Authors: Hu Jia Nan , Bai Ya Qin , Fu Rui , Li Chun , Zhao Wen Yan , Hu Rui Sheng
Published: October 2013

Catalytic combustion technology can effectively reduce the temperature of the combustion reaction and significantly inhibit the formation of NOx. Perovskites catalyst materials have high stability, varied chemical composition, and low cost etc. A combination of catalytic combustion technology and perovskite catalyst materials has great significance for energy industry and environment protection. However, improving lower temperature catalytic activity and high temperature thermostability performance of perovskite catalyst is still major problem. Some researchers have improved the activity and stability of perovskite catalysts for methane combustion by different preparation methods. The structure and preparation methods of perovskite-type oxide catalysts are presented.
Effect of Doped Metal Ions on the Electrochemical Performance of Nickel Hydroxide Electrode for Nickel/Metal Hydride Battery
Authors: Gao Xiao Rui , Jiang Kang Le , Wang Yu Qiao , Hao Yong Jing
Published: October 2013

Positive materials for nickel/metal hydride battery, nickel hydroxide doped by different metal ions were synthesized by coprecipitation, and subsequent hydrothermal treatment and anion exchange method. The structure of the samples was analyzed by XRD test, and the electrochemical performances were studied by galvanostatic charge-discharge, cyclic voltammetry and impedance tests. The obtained electrode material shows mainly β-Ni (OH)2structure when only doping Zn2+, while α-Ni (OH)2structure was obtained by only doping Al3+or co-doping Al3+and Zn2+. Ni (OH)2co-doped Al3+and Zn2+had fine cyclic stability, high number of exchanged electrons per nickel atom (the maximum is 1.93), small charge-transfer and proton-diffusion resistances.
Synthesis and Characterization of Li2FeSiO4/C Composite as Cathode for Lithium Ion Batteries from Silica Waste
Authors: Wang Xiao Mei , Mei Jun Tao , Zhang Qing Tang , Feng Hui Xia , Li Ming Yang , Guo Yong Liang , Zhao Yong Le
Published: October 2013

Li2FeSiO4/C composites were prepared from silica waste by a traditional solid-state reaction method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), elementary analyzer, galvanostatic charge-discharge test and electrochemical impedance spectroscopy. XRD results reveal that Li2FeSiO4/C composites fabricated from silica waste have some impurity. SEM results indicate that the particle size of Li2FeSiO4 composites is nearly accord with the particle size of silica waste. Electrochemical measurements indicate that Li2FeSiO4/C composite prepared from silica waste have comparatively good electrochemical performance. It can deliver a specific discharge capacity of 137.6 mAh g-1 at a charge-discharge rate of 0.1 C.
Preparation and Characterization of the PdW/MWCNT Anode Catalyst for Alkaline Direct Ethanol Fuel Cells
Authors: Chen Wei Min , Zhang Yu
Published: October 2013

The tungsten modified Pd-based nanocatalyst for ethanol oxidation in alkaline media was prepared by an ethylene glycol reduction method, and the catalytic performances of the prepared catalysts were evaluated. The results show that the addition of tungsten improved the dispersion of metal nanoparticles on the support surface and thus increased the current density of Pd-based catalyst for ethanol electrooxidation. In addition, it was found that in the tungsten modified Pd-based catalyst, tungsten interacted with palladium, leading to a low onset potential and a decreased active energy for ethanol oxidation. On the other hand, it was also observed that the addition of tungsten improved the poison resistance of Pd-based catalysts for ethanol oxidation.
Element Transformation and Gaseous Products Distribution for Lignite Gasification in Supercritical Water
Authors: Chen Gui Fang , Zhang Yong , Chen Shou Yan , Ma Chun Yuan
Published: October 2013

Effects of factors on efficiencies of elements (C/H/N/S) and gaseous products were studied for lignite gasification in supercritical water. CO2, CH4and H2are main gaseous products. Temperature plays the most important role. With higher temperature, total efficiencies of lignite and elements have linear increasement, and yields of CO2, CH4and H2rise significantly while CO stays constant almostly. With pressure increasing, total efficiencies of lignite and elements are enhanced, and yields of CO2and CH4rise while change of H2and CO is small. With increasing of equivalence ratio of oxygen, efficiencies of C/H/N and lignite, yields of CO2and H2rise, but yield of CH4reduces. Increasing equivalence ratio of oxygen plays positive role in fixation of S on residues.
The Comparative Analysis of Two Homologous Genomic Islands Associated with the Noncoding Sequence in Enterobacter cloacae
Authors: Zhang Jiao , Song Lei
Published: October 2013

The genomic islands (GIs) are usually the products of horizontal gene transfer (HGT) that is evolution pattern in prokaryote. Two homologous GIs (WSU1GINoand KU01GINo) containing the homologous integrase of Bacteriophage P2 were determined inEnterobacter cloacaethrough flanking sequence alignment of the homologous integrase. The homologous GIs were integrated into the noncoding sequence. Their common flanking sequence is 5-AAGGCTCCCTCAGGAGC-3, and their integrases share 97% similarity. About two-thirds of the nucleotide sequences between WSU1GINoand KU01GINoare highly similar. The different regions between WSU1GINoand KU01GINomainly include hypothetical gene, Phage-related tail gene, capsid gene, and baseplate assembly gene. In conclusion, the tandem arrangement of WSU1GINoand KU01GINowill be artificially constructed because of their similar structural characteristics, and phage coat protein assembly will also be analyzed.
Effect of Temperature on Phase Composition of Sintering Coal Fly Ash with Ammonium Sulfate
Authors: Wu Yu Sheng , Chen Jiao , Li Lai Shi , Li Ming Chun , Xu Ping , Ning Zhi Qiang
Published: October 2013

The new processing technology of extraction alumina by sintering coal fly ash with ammonium sulfate was studied. The phase evolutions of the sintered coal fly ash in different temperature schemes were characterized by X-ray diffractometry. The alumina extraction efficiency of sintered coal fly ash obtained from different sintering temperature schemes had also been investigated. The results show that the sintering temperature and holding time markedly influence the phase composition and alumina extraction efficiency of sintered coal fly ash, while the temperature rising time has little influence on it. The optimal temperature scheme for sintering coal fly ash with ammonium sulfate has been eventually confirmed that increasing temperature from ambient temperature to 400 °C for 1 h and heating for 3 h in air and the alumina extraction efficiency from as-sintered coal fly ash can reach 85.6%.
Design and Simulation of a Hybrid Power System for a Bus Start-Stop Working Condition
Authors: Wang Qian , Zhang Jian , Liu Wei , Lou Yu Wan , Xie Xiao Hua , Xia Bao Jia
Published: October 2013

A promising applied technology on hybrid power system for electric vehicle was proposed in this paper. Considring the actual bus working conditions, a testing system of multi-stage pulse discharge was designed. The separated LiFePO4series, lead-acid battery and the paralleled battery pack, constituted by the lithium battery and lead-acid battery with equal capacity, were tested to compare the voltage and power characteristics, as well as temperature rise. The results indicate that the lithium-ion batteries provide momentary high currant at high rate pulse discharge while keeping the lead-acid stay at a higher state of charge and improving its cycle life. During the intermittent, spontaneous capacity redistribution is achieved in the paralleled system, which helps to relieve the potential polarization and avoid the over-discharge of lithium-ion battery. Systematic analysis of the paralleled system demonstrats that it is benefitial to the circuit control, cost, cycle life and safety.
Dynamic Contact Analysis of Power Spilt Device in Energy Coupling and Decoupling
Authors: Kong Long , Wang Zhong Da , Wang Xiao Yu , Wang Ji Xin
Published: October 2013

Power Spilt Device (PSD) is the key power component of Hybrid Electric Vehicle (HEV), and it affects dynamic performances and fuel consumption of HEV. The dynamic contact analysis of PSD gear train is difficult, as it is time-consuming and complex to set calculation parameters. This paper presents a method for dynamic contact analysis of PSD gear train using ABAQUS software. Three working conditions are chosen to simulate the dynamic contact pressure. The work in this paper provides an effective simulation method for obtaining dynamic contact characteristics of PSD gear meshing.
The Effect of Battery Recharge Spat for Electric Vehicle Car on the Grid
Authors: Lu Xin Biao , Yuan Yue
Published: October 2013

Adaptive strategy of directed dynamical networks with switching topologies is proposed to eleminate the harmonic superposition, which is brought by the use of the electric vehicle chargeing spats. It is found that if there exists a directed spanning tree in the fixed time-average of network topology and the time-average is achieved sufficiently fast, then harmonic superposition of the network will be suppressed effectienly. A sufficient condition is derived. Several numerical simulations show the effectiveness of the adaptive strategy.
Numerical Research on Self-Sustained Oscillation and Chaos of Natural Convection in Horizontal Fluids Layer
Authors: Zhan Nai Yan , Li Bo , Xiao Y.
Published: October 2013

Numerical simulation was conducted to study self-sustained oscillation and chaos of natural convection in horizontal fluids layer heated from below. The numerical simulation was conducted using SIMPLE algorithm with a QUICK scheme. Discrete time series was analyzed to study stability problem. Correlation dimension was calculated, their frequency characteristics were analyzed and chaos attractor was extracted. The results showed that oscillation appeared when Ra was over 2×104 and chaos appeared when Ra was over 5×106. When parameter was varied, chaos appeared. Strange attractor was used to describe chaos system. Fractal dimension of strange attractor was 1.19. Saturated embedding dimension of phase space reconstruction was 5. The time delay was selected for 5.
Research and Application of Intelligent Control Technology for Main Steam Temperature Regulation in Ultra-Supercritical Thermal Power Plants
Authors: Li Shan Shan , Liang Zheng Yu , Ren He
Published: October 2013

Main steam temperature regulation is one of the most demanded control loop in modulating control system of thermal power plant. According to the characteristics of main steam temperature, an intelligent control technology has been proposed. To eliminate lag and inertia in main steam temperature regulation process, the intelligent control technology integrates several advanced algorithms. The application effects in several ultra-supercritical thermal power plants prove that the control technology has outstanding robustness and excellent adaptability in both variable load and steady state condition.
Research of Calculation Parameters Selection of Line-by-Line Model and Narrow Band K-Distribution Model
Authors: Liu Chao , Wang Qiang , Hu Hai Yang
Published: October 2013

The selection of the cutting wavenumbers within the line-by-line model and the integral method within the narrow band k-distribution model has been discussed. By conducting numbers of computational calculations and contrasting the related results, the fitting formula used to select the cutting wavenumbers of the line-by-line model is obtained. For the k-distribution model, in order to improve computational accuracy when applying the model to various computational conditions, especially when the optical path length is thin, we divide the curve of the reordered absorption coefficient into two parts according to the point where the cumulative distribution function g (k) =0.95 within the narrow band and integrate the curve separately, thus the computational accuracy is significantly improved.
Prediction Model of Power Frequency Electric Field Intensity of Typical Transmission Line
Authors: Zhao Xin , Chen Tao , Wang Wei , Huang Fu Yan Hong
Published: October 2013

The power frequency electric field and Electric radiation generated by high voltage transmission line have a great impact on the surrounding environment, which is one of the important research topic on environmental protection and electromagnetic compatibility technology field. In this paper, the information database of typical transmission line and tower established,and the prediction of power frequency electric field intensity of high voltage transmission line has been given by using the 3-D computational method.Then, the major factors affecting the calculation results of electric field is discussed based on the measured data and the error analysis is given.
Simulation of Flow and Heat Transfer in the MTPV Systems
Authors: Wu Ge Ping , Wang Jun , Lu Ping
Published: October 2013

Flow and heat transfer characteristics in the microchannel cooling passages with three different types of the MTPV systems are numerically investigated. Reynolds ranged from 100 to 1000 and hydraulic diameter from 0.4mm to 0.8mm. The steady, laminar flow and heat transfer equations are solved in a finite-volume method. The local heat transfer characteristics, thermal resistance, Nusselt numbers, friction factor and pressure losses of the different types are analyzed. A comparison of the heat transfer coefficient, pressure losses and friction factor of the different microchannels are also presented. The heat transfer performance of the rob bundles microchannel is found to be much better than others. However, the rectangular passage has the lowest thermal resistance than the other types of microchannels.
Condition Assessment of Wind Turbine Based on Cloud Model
Authors: Song Yu , Zhang Jian Mei
Published: October 2013

In order to detection wind turbine equipment and accurately assess the the equipments condition, this paper combines cloud theory, and propose a new comprehensive evaluation method about wind turbine operating status. Use AHP to establish wind turbine evaluation system, and taking advantage of variable weight mode correct quantitative indicators right weight. Adopt Cloud model function represent the indicator data, and establish improved evaluation model, finally, an example verify the effectiveness of the method.
Nonlinear Finite Element Analysis of the Piston Rod under the Impact Load
Authors: Wang Xiao Yu
Published: October 2013

This paper traverses failure phenomenon about the piston rod of rapping device. Through the ANSYS/ls-dyna software, the finite element analysis was carried out on the piston rod ,force of the impact on the piston rod was taken as the form of triangular pulse load, whose time was lasting 0.05s, and it can get the maximum load in 0.025s. Maximum stress occured at the fillet of the piston rod are obtained. Based on nonlinear finite element method for transient dynamic analysis of the piston rod , analysis results are consistent with the actual conditions, and demonstrates the feasibility of finite element analysis.
Qualitative Analysis and Calculation of Planetary Gear Mechanisms Based on the Method of Speed Triangle
Authors: Gong Wen Zi
Published: October 2013

Starting with the degree of freedom, constraints, instantaneous center and other basic knowledge points, the size of transmission ratio and direction of a single-row planetary gear mechanism were qualitatively analyzed and calculated by using the method of speed triangle, and a new approach to the kinematic analysis on planetary gear mechanisms is provided after eight kinds of single-row planetary gear transmission schemes have been summed up.
Study on the Strength of Axial Fan Blades Based on Fluid-Solid Coupling
Authors: Wang Song Ling , Liang Shou Fang , Hu Bin , Zhang Lei
Published: October 2013

Based on one-way fluid-solid coupling, a variable pitch axial fan was simulated through ANSYSY Workbench platform. With the software Fluent to describe the flow field and the software Mechanical to describe the structure field, the static structure analysis of the blades was carried out to study the strength of the blades. The flow field data were applied on the blades by interpolation. The results show that the centrifugal force plays an important role on the strength characteristics of the blades. Considering the aerodynamic load, the distribution of stress of the blades tends to be more uneven, the maximum equivalent stress reduces by 4.5% and the maximum deformation decreases by 26.6%. With the increase of flow, the maximum equivalent stress and the maximum total deformation of the blades decrease gradually.
Structure of Swirl Chamber of Turbulent Combustion Diesel Engine
Authors: Yuan Wen Hua , Ma Yi , Long Wu Qiang , Fu Jun , Liu Yu Mei
Published: October 2013

Numerical simulation was conducted on three types of swirl chamber of turbulent combustion diesel engine, i.e. cone-shaped flat-bottomed, cylindrical flat-bottomed and spherical shape. The characteristics of flow field in cylinder were studied within the time range for the piston to move from BTDC 108°CA to BTDC 8°CA (at the instant of fuel injection), thus analyzed the changes of flow field in swirl chambers of such three different structures prior to fuel injection based on the velocity vector diagram at all times and the final temperature characteristic diagram of the flow field. The results show that: in the process of piston motion, an organized fierce vortex can be developed inside the swirl chamber, while in the vicinity of fuel nozzle, the air flow rate is 111.14m/s, 83.01m/s or 175.76m/s and the air temperature is 1384.15K, 1337.38K or 1350.46K respectively. A small fluid stagnation zone will be formed in the lower right end of the cone-shaped flat-bottomed swirl chamber or the cylindrical flat-bottomed swirl chamber and is adverse to the mixing of fuel and air. In comparison with the swirl chambers of other two structures, the smaller temperature gradient of fluid and the larger high-temperature area in the cylindrical swirl chamber are beneficial to the mixing of injected fuel and air.
Research on Fitting Method for Flow Characteristics of Small Injection Pulse Width of Injector
Authors: Yang Tie Zao , Xue Hai Bo , Wang Chang Sheng , Wang Xin Yang , Yuan Lei
Published: October 2013

Due to the fact that it is generally difficult to accurately calculate the nonlinear section of flow characteristics curve of small injection pulse width of electronic control injector, it is impossible for electronic control unit (ECU) to accurately control fuel injection quantity when the small engine such as motorcycle is under a working condition of idle speed or small load. This paper introduces the principle and method to make a fitting for flow characteristics of nonlinear section in the developed software system in details. Take the electronic control injector of motorcycle as an example, the programming method combined with LabVIEW and MATLAB is utilized to make a fitting treatment for accurate fuel injection quantity obtained via measuring single-chip microcomputer through Smoothing Spline method, so as to obtain the flow characteristics of small injection pulse width and normal injection pulse width of electronic control injector of motorcycle.
Research on Development Trends for Grinding Equipment and Grinding Automation in Home and Abroad
Authors: Chen Jin Quan , Liu Zhi Lin , Hu Ming Zhen , Yu Xin Yang
Published: October 2013

The paper summarizes the technology development status of ore crushing and grinding from many angles, and analyzes the future development trend. The development of mineral processing automation at home and abroad are introduced, and points out the new progress of particle size analyzer and grade analyzer and other important mineral analysis instruments.
Tractor Electro-Hydraulic Hitch System Design Based on DSP
Authors: Xu Huang , Song Yan Dong , Lu Zhi Xiong , Pang Hong Lei
Published: October 2013

To achieve electro-hydraulic control requirements of tractor hitch system, TMS320F2812 was chosen as control chip, to collect sensor signals and control the hitch system. Hardware system was designed to finish the signal collections of force sensor, position sensor and PWM signal output. Through the simulation, the reliability of design was verified, meeting the work requirements of electrohydraulic hitch system.
The Tentative Study on Exhausting Performance of Diesel Engine Burning Ethanol-Diesel Mixture
Authors: Jia Yan Hua , Wu Gui Fu , Fan Wen Wu , Zhen Ying Shan , Wang Yi Lin
Published: October 2013

Advancements were made to the fuel supply system on the basis of the original X195 Diesel Engine correlating its structure features, and we designed exhausting performance experiments on the injection diesel engine burning the mixture of ethanol and diesel. The results show that: the exhaust smoke and the NOx emission could be significantly reduced by ameliorating the engine.
Implementation of Multi-Sensor Information Fusion in the Mobile Robot Control
Authors: Qiu Guo Qing , Yu Yong Can , Li Ming , Long Yi
Published: October 2013

Multi-sensor information fusion is that fuses information of multiple sensors gained through use of redundant, complementary, or timelier information in a system can provide more reliable and accurate information. Under the research of mobile robot environmental information, a control method of fuzzy neural network based on T-S (Takagi-Sugeno) type is given, it can fuses effectively collected information from multiple ultrasonic sensors and a CCD camera, and realize the real-time control for mobile robot. The results on mobile robot obstacles avoidance verified the effectiveness of the method.
Freeway Ramp Metering Based on Cell Transmission Model and Fuzzy Control
Authors: Shi Qian Jin , Liu Yan Yan , Liang Xin Rong , Dong Chao Jun
Published: October 2013

Aiming at the nonlinear and time variant characteristics of a ramp control system, a fuzzy control method is applied to freeway ramp metering in this paper. A cell transmission model (CTM) to describe the freeway flow process is firstly established. Based on the model and in conjunction with nonlinear feedback theory, fuzzy control based ramp controllers are then designed. The ramp metering rates are determined by fuzzy control according to density tracking errors and error increments. Triangle curves are used for the membership functions of the fuzzy variables. The rule base including 56 fuzzy rules is also established. Finally, the controllers are simulated in MATLAB software. The results show that this method can achieve a perfect density tracking performance and eliminate traffic congestion. This approach is quite effective to freeway ramp metering.
Pattern Recognition of Finger Joint Angle for Intelligent Bionic Hand Using sEMG
Authors: Xu Zhuo Jun , Tian Yan Tao , Yang Zhi Ming , Li Yang
Published: October 2013

Finger joint angle pattern recognition is significant for the development of an intelligent bionic hand. It makes the intelligent prosthesis understand the users intension more accurately and complete movements better. Surface electromyography signals have been widely used in intelligent bionics prosthesis research and rehabilitation medicine due to its advantages like high efficiency, convenient collection and non-invasive access. An improved grid-search method using a support vector machine has been proposed for the finger joint angle pattern recognition issue in surface electromyography signals. Pattern recognition for surface electromyography signals of index finger movement and metacarpophalangeal joint angle has been performed. Better classification performance was achieved through screening of feature vector combined with an improved grid-search support vector machine classification algorithm.
Alpha-Band EEG Synchronization during Electrical Acupuncture
Authors: Li Xiao Xia , Xu Gui Zhi , Shang Xiu Kui
Published: October 2013

In the present study, the patterns of phase synchronization in an acupuncturing task were investigated. Neiguan (PC6) and Shenmen (HT7) are the main acupoints, they are both the main points for heart diseases and insomnia, epilepsy, mental disorder. The task was divided up into the following parts, the resting condition; needling sensation; needling with power on for 20 minutes; needling retaining and needling extraction. The index of phase synchronization in different parts was calculated and compared. Phase synchronization was increased in alpha band in many cognitive, attention tasks. These findings suggest that the transient network of coupled cortical regions maybe mediated through neural synchronization. The result in this paper shows that during electro-acupuncture about 15 minutes, the index between the available electrodes in the hindbrain, especially after electrode CP6, and all the available electrodes in the brain increased. That means phase synchronization increased between the hindbrain regions and whole brain during the electrical-acupuncture about 15 minutes. It could be an evidence of regulating both the peripheral nervous system and central nervous system with stimulating these two points.
Fuzzy Passivity Non-Fragile Control of Flexible Joint Robot
Authors: Zhang Bin
Published: October 2013

The paper proposes a fuzzy passivity non-fragile control approach for flexible joint robot. The T-S fuzzy model is applied to approximate the flexible joint robot at first, and then the fuzzy controller is developed based on parallel distributed compensation principle. The passivity non-fragile performance of controller is also employed to limit the influence of model error. The conditions for the stability of the flexible joint robot control system are proposed by using Lyapunov function, and linear matrix inequality is applied to resolve the controller parameter. The simulation experiment results show the effectiveness of the proposed method.
Safety Monitoring System Design and Key Technologies for Wide Area Nuclear Power Generation
Authors: Wan Shi Xin , Li Lan Xin , Song Shu Fang
Published: October 2013

To improve the safe operation level of nuclear power plants, the design principle and overall architecture of safety monitoring system for nuclear power generation were proposed from the aspect of technology development and wide area security. The constitution, monitoring scope and main functions including image surveillance, alarm, data storage and processing, security protection and network management etc., were designed. The key technologies involved, such as image recognition, data compression, remote transmission and monitoring and so on, were analyzed. The target technical indicators were put forward.
Personalized Layer Retrieve for M-Learning Resources on Users Interest
Authors: Xu Hong Hua , Tian Ye , Hu Lin , Gao Quan Bao
Published: October 2013

Because of a big amount of m-learning resources, the thesis puts forward the technique of learning resources integration based on granular computing. Then introducing personalized concept into the system, the paper puts forward a personalized layer retrieval method based on users interest. Users information retrieval is opposed to ant colonys foraging action. One-time scanning process of each node of the website is opposed to once ant colonys foraging action period. According to users scanning log information, users interest mode can be dynamically identified. This method is easy to realize and can capture the short-term and long-term changes of users interest quickly and accurately.
An Improved Delay-Dependent Stability Criterion for Power System with Double Time Delays
Authors: Jiang Yi Lang , Jiang Tao , Jia Hong Jie
Published: October 2013

In this paper, a Direct Method-based delay-dependent stability criterion is presented. Initially, the Lyapunov-Krasovskii functional of power system with double time delays is simplified, then the derivative of Lyapunov-Krasovskii functional along time is converted into the pattern of linear matrix inequality (abbreviated as LMI). During the process of derivative construction, an integral inequality is introduced to magnify the derivative, thus no free-weighting matrix is utilized in the new criterion. It can be proved that the new criterion, in comparison with the former ones with free-weighting matrix, has the same conservativeness and much fewer unknown variables. Finally, the proposed criterions effectiveness is validated by the typical second-order delay system and WSCC-3-generator-9-bus system. Numerical results indicate that the proposed criterion can obtain the same stability margin with the former ones with free-weighting matrix, but the improved criterion can remarkably curtail the calculation time.
Research on Related Technology of Content-Based Image Retrieval
Authors: Dong Yu Bing , Li Ming Jing , Li Bai Chuan
Published: October 2013

Content-Based Image Retrieval (CBIR) system existed a gap between high-level concepts and low-level features. As an effective solution, the Relevance Feedback (RF) technique has been used on many CBIR systems to improve the retrieval precision. In order to further improve convergence speed and retrieval accuracy, a novel relevance feedback method was proposed. According to feedback from user, image feature was weighted and adjusted in the novel method.
Research and Development of Multi-Scale to Pixel-Level Image Fusion
Authors: Li Ming Jing , Wang Xiao Li , Dong Yu Bing
Published: October 2013

Image fusion method based on image multi-scale decomposition is a kind of fusion method of multi-scale, multi-resolution image fusion. Its fusion process realize in different scales and different spatial resolution and different decomposition layer. Fusion effects based on multi-scale decomposition algorithm can obviously improve compared to the simple fusion methods. Among the fusion algorithm based on multi-scale to pixel-level image fusion, Pyramid decomposition and wavelet decomposition are widely used, the original image is decomposed to convert the original image domain to transform domain, and then, fusion process realized in transform domain according to certain rules of image fusion. Basic principle of fusion process was introduced in detail in this paper, and pixel level fusion algorithm at present was summed up. Simulation results on fusion are presented to illustrate the proposed fusion scheme. In practice, fusion algorithm was selected according to imaging characteristics being retained.
Classifications of Generalized Linear Control Systems
Authors: Li Jing
Published: October 2013

We concern with the classification problem of generalized linear control systems, which might be useful for some engineering applications. Inspired by the work of Shayman and Zhou in 1987, we give the definition of linear, differentiable and topological equivalence for a special class of generalized linear systems in a unified way. Then we derive some properties on these three kinds of equivalences and show the canonical forms through a concrete example. In this paper, we obtain natural generalizationsof the Brunovsky's feedback equivalence theorem and the Willems' topological classification theorem for usual linear control systems.