bluuebunny/crossref_metadata_2025 huggingface dataset:
Shifosi Reservoir Water Environmental Assessment Based on Grey Clustering
Authors: Pan Jun , Leng Te , Liu Yang
Published: December 2012

Reservoir water quality assessment plays an important role in water environmental treatment. This takes Shifosi reservoir as example, using water quality monitoring data in 2010, selecting monitoring indexes. It applied grey clustering method to water quality assessment, concluded the assessment result and discussed the result. Through this water quality assessment,it provided basis for the reservoir water environment research.
Comprehensive Water Quality Evaluation Based on Variable Fuzzy Model
Authors: Ke Li Na , Wang Quan Ming , Li Yong Hua , Cao Yong Qiang
Published: December 2012

The environmental quality evaluation of seawater is a multicomponent and multi-factorial one, the water environment quality classification standards and the level of water pollution and so on are some vague concepts .Currently available evaluation models of water quality have more or less some shortage, Based on the variable fuzzy theory, the paper is to establish the variable fuzzy evaluation model of seawater quality and apply the approach to the comprehensive evaluation of Jiaozhou Bay seawater quality. The practice indicates that the model is simple, and can reasonably determine the sample's the relative membership degree and the relative membership functions to the different index standard ranges and be able to properly rate the sample by taking the stable result as the result of the comprehensive evaluation of seawater quality through changing the model and its parameters (a and p parameters change, change for four models, including a linear, three nonlinear) thereby providing a new approach and method for multi-objective comprehensive evaluation and decision-making in marine environmental field
Fluid-Solid Coupling Analysis on Aquatics Hub Cutter
Authors: Wang Yong Ding , Shen Wen Lei
Published: December 2012

Hub cutter is a new kind of plant cutters with a good capability of anti-blocking and stability of operating performance. Hub cutter was simulated by using Coupled FEA/CFD analysis in order to get the hydrodynamic pressure value , static pressure and natural frequency. The results show that the change of hydrodynamic pressure on the hub cutter is large. Furthermore, the static pressure was measured focusing on both ends of the aquatics hub cutter. It provides a theoretical basis for designing hub cutters. The study shows that it is feasible to use Coupled FEA/CFD analysis results to predict the performance of hub cutter. This method can be applied in engineering practice and is an innovative design with coupled FEA/CFD analysis.
Assessment on Water Environment Quality of Jilongshan Sea Area in Zhanjiang in Winter
Authors: Liu Ya Yun , Li Zhi Hong , Liang Xiao Jian , Lin Yan Peng , Wu Rong Hao , Ye Guang Ping
Published: December 2012

Based on the water quality investigation data in December of 2010, the water environment quality of Jilongshan sea area in Zhanjiang in winter was assessed using single water quality parameter model, integrated water quality index model, organic pollution index model and eutrophication assessment model. The results show that the key pollutants are dissolved inorganic nitrogen (DIN) and chemical oxygen demand (CODmn), with their average concentrations of 1.39 and 3.74mg/L, respectively. And the averages of their single parameter pollution index are 3.48 and 0.93. Jilongshan sea area is seriously polluted by DIN. None of the sampling stations are able to meet the third-rate seawater standard in the sea area. From the evaluation results, the N/P ratio is higher than Redfield ratio. DIN is the most important contribution factor to the eutrophication. The averages of single parameter pollution index, integrated water quality index, organic pollution index and eutrophication index are 1.09, 2.58, 3.78 and 22.5, respectively. Most parts of Jilongshan sea area are polluted moderately. According to the evaluation mode of organic pollution and eutrophication index, the organic pollution degree reaches the forth level and the eutrophication degree in Jilongshan sea area is very serious.
Fuzzy Synthetic Evaluation for Wetland Water Quality Appraisal in Poyang Lake, China
Authors: Yao Liu , Hui Jiang
Published: December 2012

Traditional evaluation methods of the water quality parameters exist more deficiency. Entropy right process and fuzzy mathematics method are combined to establish an improved fuzzy synthetic evaluation method. Total phosphorus (TP)、total nitrogen (TN) and index of permanganate (CODMn) are selected as observed indicators in this paper. According to Mensal measured data of water quality at 5 points from 2008 and 2009 years，based on fuzzy synthetic evaluation method for water quality assessment analysed in Poyang lake. The assessment results showed that Water quality of measure stations in different water seasons changed to take turns: normal water season > flood season > dry season. the pollution`s degree at town`s stations was smaller than counties` stations, at which sample were affected greater by industry and agriculture, and we must pay attention to let contamination in counties.
Study on Planning of Recycling Reverse Logistics System and the Campus Based Case Study
Authors: Jiang Tian Yi , Teng Jing , Sha Di , Qiao Jun Jie
Published: December 2012

Regarding low-carbon and sustainable development as themes of the era, people concentrate more on resources recycling. However the current social recycling system loses substantial potential recyclable resources and causes additional waste of energy and resources itself, due to the lack of an appropriate and effective mechanism. Based on the studies of modern logistics and reverse logistics, this article proposes a technique as Recycling Reverse Logistics System to solve the problem in order to improve the situation. Combined with E-business and IT technology, the technique provides measures to construct and assess the system. In addition, the article provides a case-study of the campus paper recycling system, so that the technique is tested and validated.
Optimal Wind&Coal Plant Capacity Distribution among the Sending&Receiving Nodes Based on Quantum PSO Algorithm
Authors: Wang Zhi Dong , Liu Gang , Liu Zi Fa
Published: December 2012

This paper established the comprehensive optimal objective function considering the construction cost, operation cost and the peak regulation capacity limitation to optimize capacity allocation of wind and coal power ,according to the peak regulation capacity limitation. Based on construction cost and the limitation of peak regulation capacity, the objective function reflects the essence of the transportation of wind and coal power thoroughly. A quantum particle swarm optimization (QPSO) algorithm was put forward to solve the objective function. The algorithm takes advantage of its probability expression and superposition state, which potentially improves the searching ability. Besides, mutation operation of QPSO helps maintain population diversity. The analysis of result proves scientificity and feasibility of proposed model and algorithm in this paper.
Emergency Power Support and Voltage Stability Analysis of the AC/DC Hybrid Transmission System
Authors: Hong Yuan Xin , Bao Guang Qing
Published: December 2012

With the completion of Three Gorges Project, the power system in China is forming a huge AC/DC network. In the hybrid AC/DC parallel transmission system, a line fault will cause fluctuations even crash of the system. The HVDC transmission system based on the emergency DC power support (EDCPS) can provide a fast emergency power support for the interconnected AC power grid flexibly and improve the stability of AC power. A model of AC/DC hybrid transmission system is established in the PSCAD/EMTDC simulation environment. An improved PID controller is firstly introduced to the hybrid AC/DC transmission system. The simulation result shows the EDCPS has an obvious effect on keeping the voltage stability of the system.
An Integrated Protection of Micro-Grids Based on Bi-Directional Blocking Principle
Authors: Liu Yuan , Sun Ming , Ge Gao Fei
Published: December 2012

Reliable and accurate microgrid protection is significant for micro-grid operation.traditional proection methods can not meet the requirements of microgrid.this paper discusses the problems of the existing micro-grid protection methods. Then proposed a new microgrid protection scheme which uses integrated protection as the main protection of microgrid. this protection scheme is based on bi-directional blocking principle,which will send blocking signal if there is no fault .thus protects microgrid. The proposed method is proved to be an effective method for microgrid.
The Finite Element Analysis of the Leakage Inductance for High Frequency Switching Mode Power Supply Transformer
Authors: Sun Peng , Huang Jun
Published: December 2012

In order to improve the stability and reliability of switch mode power supply, the mathematical model of high frequency transformer is established with considering the effects of the leakage inductance of the high frequency transformer on the working state of DC-DC full bridge converter circuit. A finite element analysis method for two dimensional transient field circuit directly coupled of transformer in the case of full bridge inverter is proposed. Transformer inductance parameters are calculated using the method of field energy, which may provides the basis for the design of switching mode power supply transformer.
A New-Type Contact Structure of Vacuum Interrupters with the Saddle-Shaped Axial Magnetic Field Distribution
Authors: Sun Peng , Xue Cong Jun
Published: December 2012

The Axial Magnetic Field (AMF) applied to the arc vacuum column in the vacuum tube can make the vacuum arc keeping in diffusion state, provided that the short circuit current to be interrupt is within a critical value. In the results, the breaking ability of Vacuum Interrupters can be highly improved with the help of the AMF. The experimental study has proved that the AMF should be sufficient strong and have optimum distribution, in order to improve the breaking capacity of vacuum circuit breaker. This paper presents a novel axial magnetic contact with the concave axial magnetic field distribution and its 3-d simulation.
Study of EM Wave Propagation for Transformer PD Monitoring Using FDTD Method
Authors: Liu Ming Jun , Li Yang Lin , Zhou Qiu Kuan , Yan Nian Ping , Zou Jian Zhang
Published: December 2012

Ultra high frequency (UHF) partial discharge (PD) detection technique is drawing attention to transformer insulation accident prevention. However, the configuration of a large oil-immersed transformer is very complicated, so the reflection, refraction and absorption phenomena between PD sources and UHF sensors need to be considered. The phenomena make it difficult to calibrate the magnitude and locate the source of a PD activity. Therefore, detailed investigation of EM wave propagation inside the tank is carried out to enhance the performance of UHF method. Numerical simulations are performed on the 3D models using finite difference time domain (FDTD) method. From the results, the effects of transformer oil, cores and the tanks are clarified.
Finite Element Analysis on Eddy Current Field of a Large Inner Feedback Motor
Authors: Zeng Lin Suo , Tong Jin Ling
Published: December 2012

To solve the problem of electromagnetic coupling of the main winding and the inner feedback winding, this paper built a 2D finite model of the inner feedback motor and simulated the magnetic field on rated load. Distribution of flux density and flux line is obtained, which provides the reference for optimization, controlling and fault analysis for these motors.
3-D Finite Element Investigation of Flux Regulation Performance of a Novel Hybrid Excitation Brushless Claw-Pole Alternator
Authors: Qiao Dong Wei , Wang Xiu He , Zhu Chang Qing
Published: December 2012

In consideration of low power density of electric excitation claw-pole alternator (EECA) and some difficulties in magnetic field regulation of permanent magnet claw-pole alternator (PMCA), a novel hybrid excitation brushless claw-pole alternator (HEBCA) is proposed in this paper. Its structure and ﬁeld control principle are described. Three dimensional ﬁnite element analysis is used to obtain the no-load magnetic ﬁeld distributions and ﬁeld control capability under different ﬁeld currents. The result shows that the ﬂux of the prototype machine can be adjusted over a wide range with a relatively low ﬁeld current
The Development of a New Full-Wave Induced Excitation Synchronous Generator
Authors: Wei Bei , Wang Xiu He , Zhong Hui
Published: December 2012

This paper presents the development of a new induced excitation system in the synchronous generator. The induced excitation system is a relatively new type of brushless and exciterless machine, which offers an excellent balance between cost, reliability, power density, and high-speed capability. Aiming at the low efficiency problem of the construction of excitation system, this paper presents an improved construction method for excitation system. The result showed that it has superiority in effect.
The Complete Exact Linearization Control of PMSM Chaotic Motions
Authors: Liang Jian Hua , Li Xiao Cong , Lin Chun Ying , Xiao Ming , Zhao Ya Nan
Published: December 2012

The permanent magnet synchronous motor take place under certain conditions chaotic phenomenon, according to the differential geometry theory, using the method of linear completely accurate, to design the control chaotic control law, and then through the experiments to verify its validity.
The Combustion Analysis of Coal under Deflagration
Authors: Duan Yu Long , You Qing Shan , Zhang Qing Hua
Published: December 2012

The products of coal under fast pyrolysis experiments were carried to study the mechanism of coal products under the fast heat effects of deflagration. Several coal were studied here, such as young lignite, old lignite, long flame coal, coke and young anthracite. The experiments temperature is between 588~1313K, experiments heating velocity is 5000K/s, and with normal pressure, experiments time are 1s, 2s, 5s, 10s. Through fast pyrolysis experiments, products separated out from coal was got. There are CH4, CO, CO2, C2H4, C2H6, C4, C5, C3H6, C3H8. This mixed gas is flammable. The results could be used to study the combustion efficiency and mechanism of this special combustion course of different rank coal. This work is useful for study the coal using in the field of energy using and combustion. It may provide one new method to protect our environment tomorrow.
Piston Stopping Position Detecting System of Gasoline Direction Injection Engine
Authors: Dong Yu Bing , Li Ming Jing , Li Xue Jun
Published: December 2012

The piston stopping position after engine shutdown is the key factor for idling stop technology, the next starting process of the engine is decided by the piston position. The piston stop position detecting system is designed based on the gasoline direction injection 4G15. The system is composed of a high-speed data acquisition card, two optical sensors, an encoder, a cylinder pressure sensor, an amplifying circuit and an industrial computer. The state signals of the crankshaft and the camshaft are collected by the detecting system, the distribution probability of piston position is obtained. The crankshaft reversal after shutdown and the crankshaft position can be detected and judged.
Multiple CMOS Intersection Measuring System Modeling and Analysis
Authors: Li Ming Jing , Dong Yu Bing , Cheng Guang Liang
Published: December 2012

Multiple high speed CMOS cameras composing intersection system to splice large effect field of view(EFV). The key problem of system is how to locate multiple CMOS cameras in suitable position. Effect field of view was determined according to size, quantity and dispersion area of objects, so to determine camera position located on below, both sides and ahead to moving targets. This paper analyzes effect splicing field of view, operating range etc through establishing mathematical model and MATLAB simulation. Location method of system has advantage of flexibility splicing, convenient adjustment, high reliability and high performance-price ratio.
Power Transformers Fault Diagnosis Based on Fuzzy-RBF Neural Network
Authors: Duan Hui Da , Yao Xin
Published: December 2012

Dissolved Gas Analysis (DGA) is a popular method to detect and diagnose different types of faults occurring in power transformers. Improved three-ratio is an effective method for transformer fault diagnosis used in recent years. This paper applies appropriate Artificial Neural Networks (ANN) to resolve the online fault diagnosis problems for oil-filled power transformer based on improved three-ratio. Because of the characteristic of improved three-ratio boundary is too absolute, a method using fuzzy math theory to deal with the data of the neural network input is also proposed. A major kind of neural network, i.e. radial basis function neural network (RBFNN), is used to model the fault diagnosis structure. In addition, to improve the convergence speed, an improved gradient descent algorithm is used in training RBFNN. Through on-line monitoring the concentrations of the dissolved gases, the proposed diagnostic system can offer a way to interpret the incipient faults. The simulation diagnosis demonstrates the effectiveness and veracity of the proposed method.
The Design of Railway Wagon Anti-Theft System Based on the CC2430
Authors: Zhao Li Hui , Yang Hong Zhe , Huo Chun Bao
Published: December 2012

This paper proposed a railway wagon anti-theft system based on ZigBee technology. The system was consisted of Handheld device, Router and End device. The Handheld device was mainly used for the configuration of the net and initialization. The Router was used to relay the message between the Handheld device and End device. The End device was a monitoring node. The CC2430 microprocessor was the controller of the system. The magnetic sensor was used to monitor the status of the wagon door. The alarm information would be transmitted to the Handheld device to display and alarm. RFID technology was used to mark the number of train carriages. In addition, GPRS module was used for transmitting the wagon information to the remote PC, and finishing wireless long-distance monitor. The experiments verify the reliability of the system. It is proved that the system has a certain application value.
Research on the MPPT Control Strategy Based on the Former DC Convertor
Authors: Qi Chun Qing , Ruan Yi , Cao Feng Wen
Published: December 2012

Maximum Power Point Tracking (MPPT) method is an important technology to improve the system efficiency of PV power generation system. This paper analyzes the methods and the principle of the MPPT. It proposes the mean of the incremental conductance to achieve the control strategy of the MPPT. The simulation study of boost circuit applied in the MPPT is completed based on Simulink simulation model. Based on those researches, this thesis can reduce the main drawbacks commonly related to the other method, at the same time, the simulation results verify that the novel MPPT algorithm can track PV array’s MPP efficiently and keep the system stabilize. The simulation result shows the validity of control strategy proposed.
A Research and the Application of a New Graphite Grounding
Authors: Wang Rui , Yang Hui Chen , Lv Yue , Xu Zheng Yu , Gao Yan
Published: December 2012

As the corroded metal grounding usually has a high resistance, the paper presents a new kind of effective graphite grounding conductor to solve the related problems during the reform or construction process. By discussing the ratio of raw material, the structure designs, the principle of reducing resistance and the installation methods in detail, it proves the effectiveness of this grounding conductor. The formula made up with graphite, high-grade cement, small stones and sands, the graphite grounding conductor can show the characteristics of stable performance, excellent corrosion resistance, non-toxic and pollution-free. In addition, the structure of corrugation or cavity can effectively reduce the ground resistance, and it is quite significant for the safe and reliable operation of the power grid.
Design of Multi-Performance Monitoring and Control System for an Experimental BIPVs/BAPVs
Authors: Zhang Jin Jiang , Zheng Yong Ping
Published: December 2012

Photovoltaics systems effectively used in buildings will contribute to reduce electrical energy consumption and carbon emissions significantly. Main characteristics and recent development of BIPVs and BAPVs and is analyzed firstly. The system structure and major equipment for an experimental BIPVs/BAPVs system is presented. And a multi-performance comprehensive monitoring and control system integrated both BIPVs and BAPVs is designed as well. It established an important system platform for further analysis of the interaction mechanism among the electrical performance, component reliability, and environmental adaptability of BIPVs particularly.
Design of Manchester Codec Based on FPGA
Authors: Xu De Cheng , Lu Ji Feng
Published: December 2012

Manchester code is a linear code of the data communication,Because of its good self-synchronization capability and robustness ,it is often used in data synchronization.The design of high-speed stability Manchester codec directly affect the efficiency of data transmission.The programmable logic device has brought a lot of flexibility for the design of digital systems.This paper introduces the application of programmable logic device design Manchester encoder and decoder.And giving the corresponding simulation waveforms while debugging successful with CYCLONE chip of ALTERA.
Power System Reactive Power Optimization Based on Improved Genetic Agorithm
Authors: Su Ai Ning , Deng Hui Qiong , Xing Tian Wei
Published: December 2012

Reactive power optimization is an effective method for improving the electricity quality and reducing the power loss in power system, and it is a mixed nonlinear optimization problem, so the optimization process becomes very complicated. Genetic algorithm is a kind of adaptive global optimization search algorithm based on simulating biological genetic in the natural environment and evolutionary processes, can be used to solve complex optimization problems such as reactive power optimization. Genetic algorithm is used to solve reactive power optimization problem in this study, improved the basic genetic algorithm, included the select, crossover and mutation strategy, and proposed a individual fitness function with penalty factor. The proposed algorithm is applied to the IEEE9-bus system to calculate reactive power. The results show the superiority of the proposed model and algorithm.
Study on Electricity-Theft Criterion Based on the Unchanged Line Resistance of the Distribution Network
Authors: Yang Jia , Bao Hai , Wang Ling
Published: December 2012

The power, voltage and current will change along with the change of grid’s operation mode; however, the line resistance is unchanged. This paper analyzed the limitation and inadaptability of the existed methods used for anti-electricity-theft. And most of the criterions are based on the variable electrical quantities. In order to establish a criterion that can find out the position of electricity-theft accurately, it chose line resistance as a reference value, and calculated the equivalent resistances of each node and branch combining with the actual measurement system. To verify the validity of this criterion, a medium and low voltage distribution network was structured in the Matlab/Simulink simulation platform. The results, which are basically consistent with the actual situations, show that the criterion based on line resistance can well investigate electricity-theft, and also verify that the introduction of this method will bring great benefits to engineering applications.
Based on the Principle of Approximate Model Established Model Test Rig Simulation of the Actual Test Bench
Authors: Xue Min , Ma Zhu , Li Yan Jun , Yang Long Bin , Zhu Fang
Published: December 2012

For Marine pressurization boiler dynamic system, when the boiler provide steam for air storage, boiler drum pressure and steam pressure will have produced a wave phenomenon; In order to research this a wave phenomenon, considering similar principles , establish the model experiments to simulate the wave process. Due to boiler provide steam for air storage that involves in many complex physical processes, including two phase flow, heat transfer, braising physical phenomena. By a simple analysis, to be completely similar to the model, model must be the same as the real situation; it will lose the small model experimental significance. According to this problem, we consider use approximate modeling method which usually used in engineering, seize the pressure fluctuations of the main contradictions; Put forward in the process of considering only reflect pressure fluctuations of local fluid dynamic field project of similar approximation, Finally we get the fluctuation relationship of the actual conditions and small model experiment of main steam pressure.
Application of IEC61850-80-1 in Peer-to-Peer Communication between Feeder Terminal Units
Authors: Shao Qing Hua , Wang Xiao Li , Liu Bing , Yan Zhong Hua , Jiang Ping
Published: December 2012

The trend towards using IEC61850 standards in feeder terminal unit (FTU) design is inexorable, but at present in China, IEC60870-5-104 is mostly used in distribution automatic system (DAS) information exchange. Thus it can be seen that IEC61850 standard will coexist with IEC60870-5 standard for a long time. IEC61850-80-1 provides the method of exchanging information from IEC61850 CDC-based data model using IEC60870-5-101 or IEC60870-5-104. This paper makes a brief analysis on the structure of DAS based on IEC61850, proposes the information model of FTU in accordance to IEC61850 and maps the information model to IEC60870-5-104 using IEC61850-80-1, which takes the advantage of IEC60870-5-104’s excellent real-time performance to realize peer-to-peer communication between FTUs.
Current Situation of Research on the Application of the Piezoelectric Energy Harvesting Circuit
Authors: Zhu Shi Sha , Qian Xue Peng , Zhou You Hang
Published: December 2012

In recent years, with the development of smart materials as well as smart structure technologies, and the research on piezoelectric energy harvesting technology deepens, the low power application circuit along with highly-efficient storage circuit optimization and design has become one of the essential parts in this field. The author made a systematic conclusion on the piezoelectric energy harvesting circuit, and put forwards a feasible plan for sustainable research in the future.
Interharmonic Analysis Using MDL and TLS-ESPRIT
Authors: Gao Pei Sheng , Fan Guo Ying , Guo Lei , Wang Chun Hua
Published: December 2012

Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) is applied to analyze the interharmonics in Electric Power System (EPS). First, the signal received by one A/D convertor forms a signal vector through time shift; second, the number of sinusoidal components which compose the analyzed signal is estimated by calculating Minimum Descriptive Length (MDL), and then ESPRIT utilizes the rotational invariance of two sampling linear arrays to obtain frequency information by Total Least Squares (TLS) algorithm; and finally the rest amplitudes and phase angles are estimated by a simplified Support Vector Regression Machine (SVRM). TLS-ESPRIT aided by MDL as a super-resolution algorithm can overcome resolution limit and achieve better results compared with FFT and PRONY algorithms. Computer simulations prove that the proposed method is feasible and applicable.
A Generic PWM Scheme Be Used for CSC
Authors: Cao Tai Bin , Chen Man Lin
Published: December 2012

In order to overcome the drawbacks of the conventional SPWM for three-phase CSC, this paper presents a generic novel PWM scheme. In the novel PWM scheme, one line cycle is divided into six 60° intervals, and during each interval, only two references are used to compare with the carriers to directly generate the required switching patterns. Because of the optional modulation signal, the modulation technique has the advantages of flexible and easy digital implementation. It is shown that, compared with the conventional SPWM, the novel PWM scheme has lower switching frequency, higher dc current utilization ratio and in-phase transfer between the three-phase line currents and the reference signals. Finally, the propositions are verified by the experimental results.
The Design of Active Power Filter Based on Power Line Carrier Communication
Authors: Lin Jian Yi , Zhao Ting , Liu Gong Quan
Published: December 2012

The development of street lamp control system has set a higher demand of more energy-saving and more effective which urges us to research the data transmission method based on Power Line Carrier between lamps and control center.By analyzing the influences on power line channel and signals burdened which produced by high harmonics and pulse interference from power supplies,we designed the active power filter fitted our demands.Besides, object oriented design method has been taken,combined software calculation and emulation,having effectively avoided complex computations in analogue filter design.
The Design of Automobile Collision Avoidance System Based on ARM
Authors: Yao Yi , Jia Jin Ling , Chen Guang Jian
Published: December 2012

By the research of highway accidents, a automobile collision avoidance intelligent system was designed and a reasonable minimum safety distance model was developed .The main control unit hardware of the system and the functions of all software modules were given. By the experiments, it is an effective solution to controlling distance between vehicles, and drivers gain the response time.
A Paralleled Integrated Control Device of Squirrel-Cage Induction Wind Generator LVRT
Authors: Xiao Shuo Shuang , Yin Zhong Dong
Published: December 2012

To minimize the influence of power grid with wind power generation resulted by voltage sags with short duration, a paralleled integrated control device of squirrel-cage induction wind generator LVRT (Low Voltage Ride Through) is proposed which adds paralleled module circuits to conventional wind generator. With closed-loop hysteresis current control based on instantaneous reactive power theory and rated voltage control, this device can achieve reactive power compensation in normal operation and voltage stability when voltage sags. Power produced by wind generator is consumed during the sag and wind power generation system is connected to grid all the time. Simulation models about the device were built based on PSCAD / EMTDC platform and the analysis verifies the device’s achievement of LVRT.
Research on Power Consumption Model Directing at the Intelligent Residential Quarters
Authors: Shao Yang , Li Huai Liang
Published: December 2012

According to the intelligent residential quarters, the power consumption model is put forward to supply scientific strategy of the power consumption and influence the users’ habits actively so as to conserve energy and peak load shifting. Using this model we design the intelligent power consumption master station and establish a comprehensive evaluation index to inspect the operating effect of this model.
Application Research on TD-LTE Technology in Communication System of Power Distribution and Utilization Network
Authors: Wang Ben , Sun Feng Jie , Yang Meng , Li Xiang Zhen , Zeng Ling Kang
Published: December 2012

Firstly the current situation and demand of power wireless communication was analyzed, and the technical characteristics of a variety of wireless communication applicated in the area of distribution were summarized, then, Considering strict requirement for QoS, high data rate, mass uplink data, and a large number of users, a solution based on TD-LTE Technology is purposed for 230MHz broadband wireless transmission. Therefore, MIMO, OFDMA and Carrier Aggregation Technology are all improved to realize the broadband wireless transmission of power communication under the condition of discrete, narrowband carrier.
Three-Dimensional Numerical Study on Thermal Performance in a Natural Draft Wet Cooling Tower
Authors: Zheng Shui Hua , Jin Tai , Fan Jian Ren
Published: December 2012

Based on the heat and mass transfer theory and characteristics of the CFD software, a three-dimensional numerical simulation platform had been developed to study the thermal performance in a natural draft wet cooling tower. This platform was validated using the measured results of a running cooling tower. The flow and temperature field in the cooling tower were investigated. It is found that the water temperature and flow field can be correctly calculated using this platform. The cooling efficiency could be improved due to non-uniform fill and water distribution methods.
The Development of Load Transfer Decision Assistant System for Regional Power Grid
Authors: Zhao Kun , Men De Yue , Jia Yu Pei , Lang Yan Sheng , Ma Zhi Min
Published: December 2012

According to the features of distribution network, this paper designed the implementation scheme of load transfer decision assistant system. Based on the load transfer path search method and expert system method to analysis the load transfer path, the economic index and safety index evaluate function was established by the switching times , the grid loss, impulse current, load rejection and off-limit value. Through the economic security indicators, the feasibility and risk of load transfer scheme was determined.
Study on Classification of Information to Realize Grid Intelligent
Authors: Li Wei Liang , Liu Ji , Tian Wei
Published: December 2012

The accsess of large numbers of new energy and the difference of application requirements make information more huge and complex, different application system and different grid link has also a different protocol standards,All these make the visual display of information, unified modeling for power grid automation become complicated and trival. This article according to analysis the power grid stability and control theory, from the power grid stability and controlling ,the needed information and IEC61968 / IEC61970 / IEC61850 and other international standards are analyzed, and propose a power network information classification method, and get a power information classification, accord with smart grid construction and new energy access requirements. It can effectively direct building of power automation control model, control information interaction. Provide foundation support for grid unified modeling and the method of unified describe model.
Scheme for on-Line Monitoring System of Converter Transformer
Authors: Shi Lin , Mu Long Hua , Xu Xu Feng , Liu Xiao Ming
Published: December 2012

To achieve a smart converter station, an on-line monitoring system for converter transformer is needed. Furthermore, it is the requirement for transition of maintenance strategy from ‘time-based maintenance’ to ‘condition-based maintenance’. This paper proposes a configuring of converter transformer on-line monitoring system based on the principle and application of on-line monitoring system for transformer, and the characteristics and operating environment of converter transformer. Architecture of converter transformer on-line monitoring system is also proposed on the basis of the 3-layer & 2-net structure applied in new smart substations and reconstruction. The designed scheme is suitable for transformation or new of smart converter transformer on-line monitoring system, which with good reference significance and application value.
Present Situation of Research on Microgrid and the Necessity of Developing DC Microgrid
Authors: Ge Gao Fei , Sun Ming , Liu Yuan
Published: December 2012

As the most efficient way of connecting distributed generations which are mainly based on renewable resources to the power grid, the microgrid has been in fast development in recent years. The paper is based on the summary of the present situation of research on microgrid all over the world and the key technology urgently to be solved, and then the advantage and the necessity of developing DC microgrid is analysed in terms of components as well as operation and control of microgrid. At last, an AC/DC hybrid microgrid structure is proposed according to the present circumstances in the distribution network.
The Design of an Independent Power Supply Applied to the Isolated Island
Authors: Chen Yi Cheng , Wang Zhi Xin
Published: December 2012

This article aims to make a design of the power supply for an isolated island that has difficulty in realizing the connection with the mainland power grid. An independent hybrid power system consisting of varieties of renewable power sources including solar power, wind power, wave energy and batteries are introduced. This system is dedicated to make the forecast of the electricity load of the island according to the environmental factors and the electricity demand of the island. Then it builds the basic framework and models of hybrid power system on the basis of the forecast and finds out the appropriate method to optimize the power supply.
A New Calibration Method for Digital Power Metering System
Authors: Hu Hao Liang , Li Qian , Li He , Li Deng Yun
Published: December 2012

Currently in the smart substation, the traceability method of the digital metering system is a sub-component traceability method, which means that the electronic transformer and the digital power meter are calibrated separately. However, the calibrations of the electronic transformer and the digital power meter have been the problem of measuring department, its traceability having been unable to be a good solution. In this situation, this paper proposes a new digital metering system calibration method, and the overall error of the digital metering system can be calibrated. An on-site calibration of digital metering system was carried out on the heihe xigangzi substation. The result showed that this digital metering system error was 1.013%, which is consistent with the theoretical value.
The Review of Demand Response Programs in Smart Grid
Authors: Zhang You You , Ma Rui , Xu Zi Heng
Published: December 2012

Demand response (DR) has become an important part of smart grid, mainly for modulating load curve, emergency treatment, balancing the demand and supply of power system. The features of smart grid-self healing and interactive-give the new meaning to DR. In smart grid, the promotion strategies of ISO/RTO in energy and auxiliary service markets implement DR programs in the project of auxiliary services and can reduce energy consumption. This paper summarizes the global related researches and practices, including the classification, progress of each subclass, the future development potential and DR program outlook in China, and puts forward the following two ideas: 1) The DR for single market cannot satisfy the needs of smart grid, advanced measurement and remote sensing technologies shall be made to implement the DR programs combining with multiple markets; 2) The service agency of DR on transmission and distribution shall be conducted and supervised by the government departments.
A Practical Method for 10kV Overhead Line Fault Detection and Location Based on Real-Time Online Wave-Recording Devices
Authors: Zhong Qing , Li Rui , Cai Ze Xiang , Yu Nan Hua , Li Chuan Jian
Published: December 2012

The fault detection and location technology for the neutral non-effectively grounded system is one of the power-system research areas over the years. This paper describes a practical method for 10kV overhead line fault detection and location by using a real-time online wave recording device. By the proposed method, the run-time health state of the distribution overhead lines can also be monitored easily.
Analysis of Rogowski Coil with Passive Compensation
Authors: Li He , Hu Hao Liang , Xiong Qian Zhu , Yang Chun Yan
Published: December 2012

The influences of the position of the primary conductor to the mutual inductance of a test Rogowski coil were studied. The test results show that the deviation of the mutual inductances can not be neglected. Manufacturing variations affect the mutual inductance much and make the coils have bad interchangeability. A potentiometer is suggested to be placed in the coil to provide a passive compensation, enabling coil manufacturers to produce coils with uniform performance increasing interchangeability while reducing manufacturing complexity. The error analysis shows that the coil with potentiometer has very good performance.
Review on Grid Connection Technologies of DFIG
Authors: Zhou Xue Song , Li Su Yang , Ma You Jie
Published: December 2012

Doubly fed induction generator (DFIG) is receiving more attention nowadays due to growing power demand and environmental concerns. In this paper, five main issues of the DFIG associating with the grid-connection, low voltage ride-through (LVRT), maximum power point tracking (MPPT) control strategy, operation in unbalanced voltage condition, contribution to frequency regulation of grid and influence on power system stability are discussed.
Scheme of Intelligent Building Based on Distributed Generation and Micro-Grid
Authors: Liu Jia Lu , Yang Guang , Wang Hong Hao , Min Wei
Published: December 2012

The scheme of intelligent Building based on distributed generation and micro-grid is presented in this paper. There are five parts in the scheme: distributed generation, storage device, charge-discharge device of EV, micro-grid control and energy management system, smart home system. The scheme of the intelligent building in this paper has been realized in displayed project of intelligent community in china. The feasibility of establishing a micro grid system at the branch of power grid is analyzed after evaluating the performance of the micro grid system on saving power, reducing cost in transmit line, and increasing the security. Due to the analysis, this micro system has good performance in these aspects and has a great future in the power grid.
A Meta-Model of the CIM Update Process for Smart Grid Information Integration
Authors: Lu Yi Ming , Liu Dong , Yu Wen Peng
Published: December 2012

The common information model (CIM) is crucial to the Smart Grid. However, its updates always cause the unmatched data mapping and model ontology confusion among integrated systems because of the ambiguous and unintuitive CIM update processes. The CIM meta-model was specifically designed to solve these problems. Its XSD-based ontology consisted of basic modeling steps and process information that bridged the gap among CIM UML/RDFS/RDF in compliance with the IEC 61968 standard. The corresponding scheme and application scenarios also presented to support the novel model transformation between different versions of the CIM for data integration.
Power Demand Side Management Based on the Sensitivity Analysis
Authors: Xiong Wei , Su Shi Wei
Published: December 2012

In the current energy relative tension of the environment, through implementation of power demand-side management improvement of energy efficiency in the use and reasonable distribution of energy in the solution of the current energy issues are more important significance. Power Demand-side management of the program's design is a more complicated issue of decision-making. This article by sensitivity analysis of cost-effectiveness of power users and power users for response analysis of power demand side management schemes, provided for the implementation of the demand side management programmers must be based on.
The Economy and Environmental Benefit of the Microgrid
Authors: Qu Tian Yi
Published: December 2012

Microgrid which solves effectively access of distributed generation taking renewable energy as a leading is one of the development direction of China’s power system. This paper introduces structure and characteristics of microgrid. And reducing line loss, dropping carbon emissions, promoting utilization of distributed generation and improving power security and reliability of power system for microgrid is analyzed. On the basis, economic benefit model which can reduce line loss and carbon emissions for microgrid is established. The model provides some help for relevant departments to formulate reasonable incentive mechanism.
The Coordination Relationship Analysis of Demand Response and Orderly Power Consumption in the Smart Grid
Authors: Chen Lu , Huang Kun , Huang Li , Song Jie
Published: December 2012

Both Demand Response (DR) and Orderly Power Consumption are important methods in shifting peak demand, where DR is in favor of market regulation, while orderly power consumption prefers administrative coordination. The implementation conditions of DR and orderly power consumption in China were discussed, and the obstacles encountered during the implementation process were analyzed from the view of the power companies and users. Then in the smart grid, the similarities and differences of the two were analyzed from the aspects of action mechanism, participation pattern, incentives and so on, and the implementation principles and coordination mechanisms of the two adaptable to the real situation in China were proposed. Finally, the related implementation recommendations were put forward for better development.
Application of Public Geographic Data in Power Engineering Survey and Design
Authors: Jiang Jun Yi , Yu Lei , Gao Xing Guo
Published: December 2012

More public geographical resource data appears in recent years, and its accuracy is improved with a good application value. So this paper aims to research on the application of public geographic data in power engineering survey and design, and tries to find a useful method which can develop the power engineering survey and design in a timely, convenient and low-cost way, as well as highlights the application value with these public data.
The Equilibrium Model of Electricity Market with Consideration of the Pumped Storage GenCo
Authors: Yang Jian Lin , Lu Hui Qing , Shi Fang Di
Published: December 2012

Pumped storage is the largest-capacity form of grid energy storage available. A multi-period oligopolistic model for analyzing the bidding strategies of pumped storage GenCo (PSG) is proposed in this paper. In the pumping periods, the pumped storage unit (PSU) is simulated as a special load. While in generating periods, PSU is treated as a normal generator. In this model, all GenCos are assumed to exercise Cournot strategies to maximize their own profits. The resulting equilibrium formulation is established in terms of a mixed linear complementarity problem. The purpose of this paper is to provide an efficient simulation tool for the PSG to determine its bidding strategy in an oligopolistic environment. The proposed model can also be used to study various factors that may impact PSG’s profit. Results of a six-bus test system are analyzed to illustrate the characteristics of the proposed model.
Research on Integrated Management Method for Intelligent Community
Authors: Zhang Chen Guang , Jiang Chao
Published: December 2012

The Intelligent Community is an important part of building a strong and smart grid.This article mainly bases on the business analysis of intelligent community,accords to its technical features,puts forward the system design of power management platform,and gives out design ideas,logical structure,physical structure and software structure.Through the construction of intelligent community power management platform,it provides a comfortable power environment.It improves the electric service and reflects the excellent electric management of China State Grid corporation.