bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydraulic Turbine Blades Modeling Based on Two-Dimensional Wooden Patterns
Authors: Zhang Si Qing , Ma Guo Hua , Zhang Yun Long , Wang Dong
Published: December 2013

There are many difficulties to design, processing and research on numerical simulation for Francis turbine because of the complexity of blade shape and the difficulty of solid modeling. Based on two-dimensional wooden patterns of Francis turbine blades, this article aims to complete blades three-dimensional modeling for Francis turbine runner with long and short blades by means of Pro-E software which has powerful 3D modeling function. After comparing three kinds of available methods to generate blade across section which provided by Pro-E, finally completed blades three-dimensional modeling by method of generating across section with point files, established a smooth and accurate three-dimensional model. The method provides an accurate physical model for the numerical simulation of the Francis turbine with long and short blades, as well as provides a feasible approach for hydro-mechanical blades modeling.
Study on BP Neural Network PID Control for Hydro-Viscous Drive System
Authors: Meng Qing Rui , Wang Jian , Wang Dao Ming , Wang Kai , Song Bao Cheng
Published: December 2013

Establish simulation model based on BP neural network PID control to solve the issue of hydro-viscous drive speed regulating start control strategies, experimental verifications prove its adaptability through AMESim/MATLAB co-simulation, research shows that: BP neural network PID control for hydro-viscous drive has a good self-correcting effect, the output speed adjusts towards the opposite direction according to the error and the error rate, while maintaining the smoothness of the output curve, thereby it can avoid over-large mechanical shocks, it indicates the BP neural network PID control is suitable for speed regulating start.
Experimental Investigation and Theoretical Analysis on Galloping of Iced Conductors
Authors: Ma Wen Yong , Li Xiao Na , Gu Ming
Published: December 2013

The aerodynamic forces of two typical iced conductor models are obtained by high frequency balance technique in wind tunnel test. The effects of wind directions and turbulence intensity on aerodynamic forces coefficients are discussed. An analytical expression for predicting the galloping instability trends in arbitrary directions is derived. An aerodynamic model considering the dynamic swing is developed according to the quasi-steady theory. Galerkins procedure is employed to discrete the governing equations of transmission line, which is modeled as a suspended homogeneous elastic cable having a small equilibrium curvature and neglecting the shear deformation. The forth order Runge-Kutta method are applied to obtained the approximate numerical results of iced transmission line galloping.
Experimental Research on Pressure Loss of an Olivary Flowmeter
Authors: Feng Guo Zeng , Sun Shao Zhe
Published: December 2013

The olivary flowmeter, a new type of differential pressure flowmeter, was presented. Its pressure loss was explored through experimental research. The experimental medium is diesel. In the condition of the same effective area of circulation, the pressure loss of the olivary and the orifice plate flowmeter was compared. As a result, the pressure loss of the olivary flowmeter is 14.9% of the orifice plate flowmeter at most, 7.2% on average. The olivary flowmeter can reduce energy consumption.
Analysis and Application of Radius Calculation Model for Boilover in Crude Oil Tank Fire
Authors: Li Qing Gong , Chen Zhen , Zhang Miao , Song Wen Hua , Lv Ling Yue
Published: December 2013

With the development of oil storage tank is towards large-scale, boilover is becoming a greater threat to surroundings. The main damage form of boilover is high-temperature thermal radiation and boil-over in oil tank fires. Among them, boil over can cause great casualties and property losses, and easy to cause the disaster spread. This article first analyzes the influence factors of boilover and the intensity, then further creates radius calculation model for boilover. By calculating and analyzing the boilover radius of tank with different sizes and oils stored, the accuracy of model is verified. The results also indicate that the model is effective and the calculating error is fairly small when the tank diameter is less than 10m, otherwise is suitable for simple estimate only. The influence of water content in oil and the viscosity on boilover radius is non-linear, and there is a maximum.
Numerical Simulation of Internal Flow Field in Mixed Flow Fan
Authors: Zhai Yan Zhao , Zhang Hong Ming
Published: December 2013

The numerical simulation of internal flow field of a mixed-flow fan was carried out on the star-CD platform. Three-dimensional steady turbulent flow is calculated using the standard k-ɛ turbulence model, and the pressure distribution, velocity distribution and other important flow phenomenon inside the fan are obtained. The number of meshes has important influence on the result, meanwhile, fan inlet, impeller, outlet interact with each other. The results of numerical simulation can accurately analyze the fan flow field. The results of numerical simulation can accurately analyze the fan flow field structure, and provide guidance for further optimization and improvement of the fan.
Carbon Footprint Analysis and Environmental Impact Evaluation of Air Conditioning System
Authors: Liu Chang Rong , Wang Zhi Yong , Wang Han Qing
Published: December 2013

Aiming at three frequently used air conditioning systems of an actual building, the system boundary under simplified and hypothetical conditions was built according to different research objectives and scopes. And the life cycle assessment model frame was created and the carbon footprint of three plans was analyzed. To collect relative data of energy consumption and emission which were produced in the stages of units operating, the resources obtaining and manufacturing, then the obtained data were arranged into inventory analysis table. In accordance with the characterized model environmental exhaust was transformed to environmental load while normalization and weighted evaluation were also made, from which different environmental impacts potential values could be attained. So as to the environmental impact of life cycle of air conditioning systems could be quantitatively described by the environmental impact load. Ultimately the study conclusions were procured as follows: electric water chiller plus natural direct-fired lithium-bromide absorption chiller/heater makes the least environmental impact followed by the electric water chiller plus gas boiler and water source heat pump makes the most.
Energy Measurement Method for VRV Air Conditioning Systems in Existing Commercial Buildings: A Case Study from Southeast University
Authors: Peng Chang Hai , Wang Chen Yang
Published: December 2013

Allowing users to track the household metering energy consumed by their central air conditioning system is an extremely effective strategy for saving energy in commercial buildings. This paper presents several methods of measuring the energy consumed by a central air conditioning system, such as using time-based and energy-based models. The accuracy and reliability of these models are also compared with each other. Finally, a novel energy metering method, the improved electricity-based model, for a variable refrigerant volume (VRV) air conditioning system in commercial buildings is proposed based on a case study of the Li Wenzheng building at Southeast University.
Keywords: energy; measurement method; VRV air conditioning; existing commercial buildings
The Analysis of the Feasibility of Summer Air Conditioning Cooling Using Shallow Surface Water in Zhejiang Province
Authors: Li Guo Jian , Chen Meng Ting
Published: December 2013

Compared with the water source heat pump system and the water air-conditioning system, and analyzed climatic characteristics and the status of water resources utilization in Zhejiang Province. The shallow surface water used for feasibility of summer air-conditioning cooling is analysis. As an example, testing water of a village in Zhejiang province Lin'an city, the shallow surface water can be directly used for the feasibility of the summer air conditioning cooling from the angle of water temperature, water quality, and the investment cost and operation cost.
A Double-Layers Energy Efficiency Evaluation Method of Central Air-Conditioning System
Authors: Wang Bing Wen , Liu Yuan Yuan , Shi Shan Shan , Zhou Gan , Wang Shuang Hu
Published: December 2013

It is necessary to monitor and optimize work status of central air-conditioning system (CACS) due to its high energy consumption. According to national standard, this paper designed a practical energy-efficiency evaluation method with double-layers structure. The upper-layer indicator reflects the whole energy efficiency of CACS. The lower-layer indicators reflect the energy efficiency of each subsystem of CACS, such as refrigeration system, chilled water system and terminal system. Using this double-layers evaluation system, the managers of CACS can not only observe the whole energy efficiency level but also find out the weak point of the system.
Study of an Atmospheric Freeze Drying Refrigeration System
Authors: Xia Peng , Tian Kun , Ma Xiao Lu , Tao Le Ren , Cai Ying Ling
Published: December 2013

High-pressure air compressed by air compressor, is isobarically cooled and adiabatically expanded and is turned to low temperature air, which enters the adsorbent fluidized bed to freeze the materials. After the freezing of the materials, adsorbent will adsorb water vapor, which can play the effect of atmospheric freeze drying. The recovery power of the expander can be used as input power of the subsidiary refrigeration cycle. In order to adjust the temperature of the fluidized bed, evaporator coils of the affiliated refrigeration system are directly wound on the outer wall of the fluidized bed. This paper studies the combined refrigeration system, and analyzes the influence of different refrigerant pressure ratio, fluidized bed outlet air temperature, and refrigerant selection of subsidiary refrigeration cycle on the performance of the system.
Development and Performance Evaluation of EGR System on Light Duty Vehicle
Authors: Gu Jing Jing , Lin Xue Dong , Li De Gang , Zhang Miao Miao , Peng Cheng Cheng
Published: December 2013

According to performance characteristics and functional requirements of EGR system, a set of EGR system was designed for supercharged diesel engine on light duty. This system employed continuous current dynamo EGR valve, and hardware circuit of control unit was designed and control software was authored implementing on Freescale MC9S12XS128. The universal characteristics of EGR ratio was tested after this system calibration and matching. Compared to traditional system, new EGR system has better actual control accuracy, improves the motorcycle economical efficiency under common duty and decreases NOx emission simultaneously.
Numerical Simulation Study of the Influence of Structural Parameters of Combustion Chamber on In-Cylinder Flow Field of Diesel Engine
Authors: Li Guo Cheng , Sun Ping , Hu Peng
Published: December 2013

Based on the entity model of the type 4B26 diesel engine, calculated by CFD FIRE and combined with the software BOOST for the initial boundary conditions, the influence of combustion chamber structural parameters, such as boss height, surface-volume ratio and diameter-depth ratio of combustion chamber, on in-cylinder flow field of diesel engine was investigated. The results show that the influence of the boss height on flow field in the cylinder and the transient swirl ratio is obvious, and increasing the boss height is beneficial to urge the formation of mixture rapidly. Reducing the surface-volume ratio is beneficial for improving the maximum transient swirl ratio, and the air strength maintains well also, but has little influence to the retentivity of the swirl intensity. Meanwhile, reducing the diameter-depth ratio does not only improves the air flow movement strengthen in the combustion chamber, but also enhances the maximum transient swirl ratio, and the retentivity of swirl flow movement is satisfying.
Investigation on the Match between the Nozzle Tip Penetration and the Double-Layers Diffluent Combustion Chamber Geometry
Authors: Qi Kun Peng , Li Ming Hai , Long Wu Qiang
Published: December 2013

In order to investigate the match between the nozzle tip penetration and the double-layers diffluent combustion chamber geometry, a simulation model was developed which was based on the 135 diesel engine to simulate the equivalence ratio distribution of air-fuel mixture and the temperature distribution during combustion process. At the same time, an experiment was executed by a 135 diesel engine equipped with the high-pressure common rail fuel injection system. The research results show that the air-fuel mixture becomes more uniformed and the combustion process is improved when the nozzle tip penetration is reasonable selected which lead to higher in-cylinder pressure and better brake specific fuel consumption while NOX emission is increased and soot emission is decreased for the double-layers diffluent combustion system.
Research on Transmission Principle of Gearless Reducer
Authors: Wu Lin , Dong Ming Wang
Published: December 2013

Propose cylindrical cam lateral transmission mechanism for the first time, define the agency's three specific types. Design gearless reducer type A, B and C for construction elevator by the application of the agency to reducer industry. Conduct physical prototype processing manufacture based on cylindrical cam lateral transmission theory and virtual prototype design of gearless reducer. By contrast processing and experimental tests to determine that the theory of cylindrical cam lateral transmission mechanism is feasible. Gearless reducer have the advantage of high efficiency and energy saving, low cost, small volume, light weight, saving raw materials resources.
Research on the Solar Water Heating System Based on the Internet of Things
Authors: Jiang Ping , Ge Ming Jie , Zhou Gen Rong , Xiao Hong Sheng
Published: December 2013

The solar water heating system based on the Internet of things (IOT) was designed, and the IOT communication module was studied. The topological structure of IOT system and the hardware and software design of communication module have been introduced. The GPRS and GSM coding analysis and the receiving and sending process of the communication module were introduced.
The Impact Analysis of Regenerative System in Turbine Modeling
Authors: Sun Yue Tai , Qiu Xiao Zhi , Chen Yu Zhen , Huang Bao Hua
Published: December 2013

The simulation of the reheat condensing steam turbine model that BPA and integrated power system stability calculation procedure given, has a large deviation with the actual experimental data. This model does not consider the regenerative steam extraction module, thus ignoring the storage effect of the regenerative steam extraction module. By analyzing the principles of reheat condensing steam turbines thermal process, based on the real turbine structure, establish multi-stage regenerative steam extraction model. Through dynamic simulation of the model was analyzed and compared with the actual data showed good results. Improved model is more realistic, more suitable for grid stability calculations.
The Determination of Stagnant Rate of Servo System Based on Adaptive Chatter Algorithm
Authors: Zhao Ting , Qiu Xiao Zhi , Cai Ding , Huang Bao Hua
Published: December 2013

The current determination of stagnant rate cannot eliminate the dynamic effects, especially the change rate of speed. Consider the problem of the current determination of stagnant rate, this work presents one determination method based on adaptive chatter algorithm .Simulation shows it can eliminate the impact of dynamics effectively. The method achieves the measurement online due to the signal of chatter can adapt to the dead zone of servo system. At last, the selection of the signal frequency is discussed.
The Research of the Jam Fault Features and Diagnostic Methods of the Slide Valve Oil Motive Based on DEH Data
Authors: Feng Yong Xin , Cai Sun , Song Chong Ming , Wei Si Jia , Liu Jin Fu , Yu Da Ren
Published: December 2013

The jam fault diagnosis of slide valve oil motive has great significance on the safe and stable operation of steam turbine. As limited data available from DEH, the jam fault is difficultly diagnosed directly by DEH data. This paper defines insensitivity to represent the level of the jam fault of slide valve oil motive system. Through the simulation and research of the jam fault features of the slide valve oil motive, the relationship between the rate of change of the input signal and the insensitivity of the jam fault diagnosis is be found . Then jam fault diagnosis strategy based on DEH data was put forward and it shows good results with verification by the actual data.
The Measuring Method of Static Delay Rate Based on the Frequency Step Disturbance
Authors: Jin Ge , Zhang Ke Hao , Niu Xiao Yang , Liu Shu Chang
Published: December 2013

This article introduces the definition of delay rate in turbine electro-hydraulic control system and its significance in practical applications, and builds the simulation model to measure it. By introducing and analyzing the principal of current domestic delay rate measuring method that uses uplink and downlink ramp signal, it can be found that this kind of determination is affected by the speed largely, and simulation experiments show its validity. Aiming at solving problems of this method, a measuring method of static delay rate based on the frequency step disturbance has been put forward and simulated.
Development of Empirical Equations for Irradiance Profile of a Standard Parabolic Trough Collector Using Monte Carlo Ray Tracing Technique
Authors: Islam Majedul , Karim M. A. , Saha Suvash C. , Miller Sarah , Yarlagadda Prasad K. D. V.
Published: December 2013

This article explains a technique in which equations are developed to produce the irradiance profile around the receiver of LS2 collector using a vigorouslyverified MCRT model. A large range of test conditions including daily normal insolation, selective coatings and glass envelop conditions were chosen from the published data by Dudley et al. [1] for the job. The R2 value is excellent that varies between 0.9857 and 0.9999. Therefore, these equations can be used confidently to produce boundary heat flux profile of the collector at normal incident for conjugate heat transfer analyses of the receiver.
Rolling Bearing Fault Diagnosis Method Using Glowworm Swarm Optimization and Artificial Neural Network
Authors: Xu Qiang , Liu Yong Qian , Tian De , Long Quan
Published: December 2013

Fault diagnosis has long been recognised as one of the most effective methods of reducing operation and maintenance cost in rotating industry, especially in bearings. A method based on BP neural network modified by glowworm swarm optimization (GSO) was proposed for fault diagnosis of rolling bearings. Six fault features were selected as the input of network. GSO algorithm was applied to simultaneously optimize the initial weight and threshold values of BP neural network. The reliability of the proposed technique was confirmed by experimental data, which indicated the potential applications of this method in the field of rolling bearing fault diagnosis.
Labyrinth of High Parameter Valve Technology Application and Prospects in the Power Plant
Authors: Chen Da Wei , Li Zhuang , Lu Kun
Published: December 2013

In order to solve the domestic sub and super-critical unit import the high cost of procurement of high parameters of valves and valve operation in the common issues such as defects, and introduces the new valve of the Sino-ROK cooperative project--the labyrinth of high parameter control valve. First elaborates its structure characteristics, the core technology and application, and introduces concrete application for the settlement of condensate water pump recirculation valve defect. And we can see the labyrinth of high parameter control valve important role and development prospects in the future power plant.
CFX Modeling of an Axial Turbine with Symmetrical Blades and Reversible Flow for Tidal Power Plants
Authors: Tiago Filho Geraldo Lúcio , Barkett Botan Antonio Carlos , Villa Nova Helcio Francisco , Mambeli Barros Regina , Braga da Silva Fernando das Gracas , Saavedra Osvaldo R.
Published: December 2013

From studies of a reversible flow turbine for using in tidal power plants it was obtained a model with symmetrical blades that shows this characteristic. For the obtaining of more accurate results of this type of turbine it was proposed the manufacturing of a physical sample to be used in a testing bench at the Hydromechanical Laboratory of Small Hydropower Plants LHPCH, at Centro Nacional de Referências de PCH, (National Centre of Reference in SHP) CERPCH, in Universidade Federal de Itajubá (Federal University ofItajubá) UNIFEI, and also a mathematic sample modeled on CFD/CFX platform with the ANSYS software. This paper aims to describe one of the tests of the proposed rotor on mathematic model, to be used tidal power plants turbines.
Research on Application of Synchronized Phasor Measurement Unit (PMU) for Smart Substation
Authors: Zheng Wen , Zhang Yun Bo , Xue Ye , Xu Yong
Published: December 2013

Synchronized phasor measurement unit (PMU) has become the important monitoring device in power networks for high precision and accurate time tag of measurement data. This paper presents the PMUs suitable for smart substation which adopt embedded software-hardware platform. The differences between the common PMUs and PMUs for smart substation are introduced, and the software modules design is put forward, too. The key technology of PMUS is introduced including receiving and processing of sampling data message based on IEC 61850 standard and phasor calculation based on discrete Fourier transform.
The Comprehensive Efficiency Evaluation of Electrical Power System of China Based on Data Envelopment Analysis
Authors: Long Wang Cheng , Wang Xiao , Peng Dong , Wang Qiao
Published: December 2013

With the power system of China continuous expanding recently, the electric power generation, transmission and supply capacity increased dramatically. In order to improve economic operational efficiency and realize scientific development, the Input-Output efficiency between the input of the power system facilities and the output of the power supply becomes a critical issue that government, business and academia have to face up to. In this paper, we used the DEA (Data Envelopment Analysis) model and tested the Input-Output efficiency of power system development and study the trend of important development segment. The relative efficiency of power system is closely related to the electricity management system and economic situation, the elements of reduce the efficiency were been found out by analyzing the DEA results. And a series of suggestions were proposed to increase the comprehensive efficiency.
Study on Reliability Evaluation Method of Components without Enough Fault Data
Authors: Wu Wen Fu , Tian Hong Xun , Ma Lin Qi , Su Juan , Du Song Huai
Published: December 2013

The reliability assessment of power system components is the key to power system safe and reliable operation. According to the record of actual operation of power system components characteristics, a practical method of reliability evaluation for fault date which is missing components is introduced in this paper. The method is based on Weibull distribution model. It is also a calculation and solving methods of reliability evaluation fault system of missing data components. The system mainly includes sample selection of data, parameter calculation, model checking and failure rate curve drawing. So the transformer as an example, verify the effectiveness of this method. In addition the paper analyses the influencing factors in the transformer reliability, such as voltage grade, manufacturer and product types. In a word, this model provides a systematic and effective method for the practical application of the reliability evaluation of the electrical components.
Comprehensive Assessment System and Method of Smart Distribution Grid
Authors: Song Ying Wei , Liu Jian , Ning Liao Yi , Han Zhen Tao , Liu Hong , Wang Shi Ju
Published: December 2013

According to key values and demands of smart distribution grids in China, a smart distribution grid comprehensive assessment index system and method is established. The index system is divided into the demand index set and assessment index set. As the former represents the macroscopic features while the latter represents the microscopic factors of the smart distribution grid. A causal connection exists between them. Also a hierarchical optimization model with combination weight, which is based on the DEMATEL-ANP-anti-entropy weight method and the improved Grey incidence approach, is proposed. The DEMATEL-ANP-anti-entropy weight method is used for demand indices weight analysis, while the improved Grey incidence approach is put forward for the evaluation on assessment indices. Results of applying the proposed method in practical case shows that the proposed method is valuable in following aspects: scientifically assessing the intelligent development level and effectiveness of distribution grid, analyzing and recognizing the grids operation condition and weak link, giving reference to planning and construction of smart distribution grid, and so on. Index Terms Smart distribution grid; comprehensive assessment; index system; combination weight; hierarchical optimization.
Study on a Service Mechanism that Wind/Photovoltaic/Energy Storage Power Station Help Wind Farms Tracking Generation Schedule Curve
Authors: Xu Hai Xiang , Wang Peng , Ren Xiao Meng
Published: December 2013

At present, the technology of wind power forecasting isn‘t mature enough in china, so some grid-connected wind farms will be assessed when theirs power forecasting accuracy cant reach the assessment standard. In response to the situation, combined with the characteristics of WPSPS and wind farms, this paper designs a service mechanism that WPSPS help wind farms tracking generation schedule curve, namely, encouraging WPSPS to supply output compensation service for wind farm by market means to increase the accuracy of wind power forecasting. By this mechanism, not only WPSPS and wind farms will achieve win-win, but also the impact on the grid caused by fluctuations of wind powers output will reduce.
Short-Circuit Current Criterion under Condition of Protection Action in Low Voltage Power Supply System
Authors: Su Yi Rong , Yu Jie , Liu Jun , Zhou Gan , Zhan Li Ping , Wang Shuang Hu
Published: December 2013

In order to improve the level of automation and security of the low voltage power supply system, this paper proposed the calculation method of short-circuit current criterion under condition of protection action. Firstly, the impact of circuit breakers on the short-circuit current is analyzed. Then, the current criterion under condition of short-circuit protection are given. Finally, using a special case, the calculation process of aforementioned current criterion is given in detail.
The Interconnection Protection of the MV Multiple Microgrid
Authors: Sun Ming , Ma Ming Min
Published: December 2013

The MV multiple Microgrid includes not only a lot of DGs, and may also contain some small microgrids. To the large scale MV multiple microgrid, the interconnection protection problems of different levels microgrid will decide the safe and stable operation of the maximum range. In this paper, list the challenges which are crucial to the microgrid protection, put forward a protection scheme based on the digital integrated protection terminal (DIPT) to solve these problems according to the structure characteristics, analyze the basic principle with comparing composite modulus of fault currents in a DIPT control zone to identify the fault branch and the necessary communication scheme between DIPTs is discussed. At last, build the system model in PSCAD/EMTDC and verify the theory feasibility in different operation modes and different fault types.
Multi-Level Fault Diagnosis of Power Transformer Based on Fusion Technology
Authors: Li Zhi Bin , Li Qi Ben
Published: December 2013

Traditional transformer fault diagnosis based on single source of information has significant limitation in identification of transformer fault type because of power transformers complex structure and changeable operating environment. So fusion technology is introduced into the fault diagnosis of power transformer. This method divides the progress of transformer fault diagnosis into two fusion levels. The first level is to ascertain whether it is overheated or discharged by content of gases dissolved in transformer oil. The second level is to ascertain the location or cause of the fault by electric data. The intelligence algorithms which are used in these two levels are both the improved BP neural network algorithm. Finally, the effectiveness is validated by the result of practical fault diagnosis examples.
A New Fast Method Used For Calculating Power Flow Based on ODE
Authors: Zhang Fang , Han Tian Min
Published: December 2013

With the growing of the system size, rapid, accurate method used for calculating power flow is an important task for the real-time analysis of power system. This paper puts forward a new fast method used for calculating power flow based on ODE(ordinary differential equation).The power flow problems are transformed into solving the differential equations, which avoids calculating Jacobian matrix, and doesn’t need any preprocessing. In order to accelerate the computing speed, the diagonal elements of Jacobian matrix is approximately calculated using the node voltage amplitude and the node admittance matrix. Numerical examples show that the method is simple. Compared with Newton's method, GMRES, MA ,this method has a distinct advantage in computing speed.
Modeling Methods of Impact Load on PSASP
Authors: Xiao Shi Wu , Shen Ze Yuan , Wang Shuai , Wang Cong
Published: December 2013

Models of impact load of steel enterprises play an important role in the stability influence of impact load on power system. Take a certain steel enterprise for an example, two modeling methods of impact load are proposed, which can be easily integrated with power system analysis software package (PSASP). These two methods have certain practicality and can be used in most of impact load.
Calculation of Short Circuit Current Based on Equipment Graphics Database
Authors: Li Hui Qi , Ding Qian
Published: December 2013

According to the structural characteristics of the electrical one-line diagram at substation, Its proposed that designing the database which stores electrical properties and graphics properties of the equipment in the paper. And an intelligent graphical modeling and automatic implement of main electrical connections are achieved based on the database. By means of the graph database integrated platform, a topology analyzing method based on bus for main electrical connections is presented, which is capable of not only computer graphics processing easily, but also describing accurately and reliably the topological structure of the main electrical connections. Finally the node admittance matrix is generated and the calculation of short circuit current is completed automatically.
Calculation Method Research about Theoretical Line Loss' Boundary of Distribution Network
Authors: Zhang Xiang Hua , Zeng Jiang , Chen Chang Ming , Xiao Shao Hua
Published: December 2013

Based on mastering the supply power and the maximum load of the 10kV distribution transformers, this paper calculated the maximum and minimum load shape coefficient of the transformers and segmented lines, and obtained the upper and lower limitation of the theoretical line loss with average current method. In the largest variable loss calculating process, this paper put forward an effective iterative fitting algorithm. Firstly, it fitted out the ultimate load curve of the transformer high voltage side, then it fitted through iteration out the ultimate load curve of the superior branch lines and calculated the maximum shape coefficient, considering the influence of transformers loss on the line load curve in the calculation process. The calculation method provided theory evidence for enterprise line loss management level evaluation and vulnerable spot location in the line loss management and enterprise future line loss rate indicator setting.
Optimization Design on Experimental System for Space Heating of a Ground Coupled Heat Pump with Solar Thermal Collectors
Authors: Cai Ying Ling
Published: December 2013

Experimental system for space heating of a ground coupled heat pump with solar thermal collectors at Songjiang district in Shanghai was designed and built on the basis of precise calculation and simulation of each part in the system. Through simulating the project, the best azimuth of solar collectors in Shanghai is south by east 22.5 °. Programmable control technology, frequency conversion technology and sensor technology applied to the design of the detection and control system.
Realization of Economic Load Dispatch of the Electric Power System Based on Artificial Fish Swarm Algorithm
Authors: Huang Ke , Wang Xin , Zheng Yi Hui , Li Li Xue , Xiu Shi Hong
Published: December 2013

Economic Load Dispatch (ELD) is a critical matter of improving the operating efficiency of power system and reducing the cost of generating electricity. In this paper, an Artificial Fish Swarm Algorithm (AFSA) which takes network loss into account is designed to search the optimization. Firstly convert the capacity of the generating units in decimal into a binary number which means the location of an artificial fish. And then foraging behavior of fish school algorithm is utilized to make a successive comparison of fitness within the visual distance of current fish. Additionally to avoid getting into local optimization, the position of current fish is changed with a small probability. The simulation results suggest that the algorithm is efficient and feasible in the case of less precision.
Economic Load Dispatch Using Bacterial Foraging Optimization Algorithm Based on Evolution Strategies
Authors: Feng Xiao Hua , He Yu Yao , Yu Juan
Published: December 2013

This paper presents a novel modiﬁed bacterial foraging optimization(BFO) to solve economic loaddispatch (ELD) problems. BFO isalready successfully employed to solve variousoptimization problems. However original BFOfor small problems with moderate dimensionand searching space is satisfactory. As searchspace and complexity growexponentially in scalable ELD problems, it shows poorconvergence properties. To tackle this complex problem considering itshigh-dimensioned search space, the Evolution Strategies is introduced to thebasic BFO. The chemotactic step is adjusted to have a dynamic non-linearbehavior in order to improve balancing the global and local search. Theproposed algorithm is validated using several thermal generation test systems.The results are compared with those obtained by other algorithms previouslyapplied to solve the problem considering valve-point effects and power losses.
Technology for Transformer Fault Diagnosis with Detection and Monitoring Data Fusion
Authors: Niu Lin , Wang Gui Ming , Zhan Jie , Cui Jin Tao , Huang Jin Xin , Sun Wan Jun
Published: December 2013

Fault diagnosis is an effective means to assure the safe operation of power system. In this paper, a detection and monitoring of transformer fault diagnosis of multi-source data fusion technology is introduced. Based on the correlation distance, to calculate the relationship between detection and monitoring data and equipment failure, using the weight function to set fault indicators, status online monitoring data over the fault indicators, judging the equipment what kind of failure is happened, improving the precision of fault diagnosis.
An Adequacy Decision Model Incorporating Wind Power and Electric Energy Storage at the Distribution Level
Authors: Xue Zhi Ying , Zhou Ming , Li Geng Yin
Published: December 2013

The electric company of a distribution system purchases different kinds of electric energy including wind power energy to serve the load. Therandomness of wind power adds to the uncertainty of system reliability.Meanwhile electric energy storage at distribution level has the benefit of electric energy time shift and power supply capacity. Combining the two of them, an adequacy decision model is proposed to solve enerating capacity purchase scheme and charging and discharging schedule of the electric energy storage as well. The results of simulation show that the proposed method works well.
Fault Location Method Based on Wide-Area Voltage
Authors: Xu Yan , Ying Lu Man , Zhi Jing , Feng Ren Qing
Published: December 2013

Backup protection chain tripping caused by flow transferring is one of the most concerned issues in power system. The introduction of wide area backup protection is an effective way to solve the problem. However, in wide area protection system, an effective fault location puts forward a high demand for the location algorithm. This paper presented a method which combined effective mathematical methods with fault location calculation in power system together: firstly used fuzzy clustering analysis method for fast classification of voltage, locked the fault area, and prevented the occurrence of even jump accident at the first time. Then determined the fault location by calculating additional nodal current ratio in the fault area. The method avoids the repeated modification of network structure after fault. It lock the fault to the component quickly and improves the efficiency of fault location greatly.
Review of Power System Analysis Methods Considering Correlation of Wind-Photovoltaic-Load
Authors: Fang Pan Yu , Fan Xue Feng , Ren Jie , Xia Yi , Chen De Zhi , Zhang Zhong Dan , Chen Xi Ying , Chen Yao , Wang Zeng Ping , Song Yun Ting
Published: December 2013

Close attention has been paid to the power generation using renewable energy such as the widespread energy and solar energy. After the integration of large-scale renewable energy, more uncertain factors are brought to the power system, which badly influences systems planning and operation. The wind power, photovoltaic power and load are random but correlative, therefore, it is more logical to study the influence exerted by the integration of renewable energy when considering the uncertainty and it is meaningful to the power systems planning and operation. Based on the summary and survey of previous studies, the technical route of power system analysis concerning the correlation of wind power, photovoltaic power and load is proposed in this paper and some key technologies are discussed. The study of correlation offers valuable analysis and recommendations to the connection of large-scale wind and solar power base.
Application of Real-Time Risk Assessment Method in Dispatching Operation
Authors: Liu Yan , Song Ying Wei , Zhao De Wei , Zhao Lin , Zeng Yuan , Zhao Cong
Published: December 2013

Dispatchers dispatch power system with real-time data, but big data causes inconvenience to them. The paper introduces risk theory into dispatching operation quantitative assessment, and proposes a real-time risk analysis method for dispatching operation. Fault Tree theory is used to simulate practical operation process and to analysis the risk under successful and failure state of dispatching operation. The paper proposes some power system dispatching risk indices to help dispatchers to learn dispatching effects from different aspects pre-operation. Finally, the method is validated by IEEE 118-bus testing system.
Feasibility Boundary Evaluation Using Eigenproperties of Jacobi Matrix from the Power Flow Routine
Authors: Chusovitin Pavel V. , Pazderin Andrey V. , Shabalin Grigory S. , Taschilin Valery A.
Published: December 2013

The paper is devoted to the stability and feasibility boundary evaluation. New technique for evaluating shortest distance to feasibility boundary is described and tested. The technique is based on analysis of Jacobi matrix form the power flow routine. Described technique can be applied together with PMU-based identification procedures leading to new opportunities for on-line power system stability monitoring.
Low-Frequency Oscillations Identification in Interconnected Power System Using PMU
Authors: Chusovitin Pavel V. , Pazderin Andrey V. , Shabalin Grigory S. , Taschilin Valery A.
Published: December 2013

This paper presents the result of identification of low-frequency oscillations in 9-bus test model of power system. The identification is achieved by novel technique developed by authors. The technique is described in detail in [1. It is based on treating synchronized phasor measurements. Applicability of identified state matrix for electromechanical oscillations monitoring is demonstrated in the paper.
Complex Urban Distribution Network Wiring Pattern Matching Research Related to the Load Density
Authors: Yao Gang , Liu Su Fei , Jin Jia
Published: December 2013

With the rapid advance of the urbanization process, the majority of cities come into the size of millions or more population. Therefore, the urban distribution network are becoming complex increasingly accordingly.How to meet the needs of complex urban distribution network safety and reliable power supply quality, reasonable construction investment better is one of the problems that plagued powered enterprise.It is an important research topic that wiring mode are choosed with good indicator of safe and high reliability, power supply quality and reasonable construction investment, combination load density characteristics of different medium-sized cities in the electricity sector. We have constructed a wiring mode analysis platform in this paper, it can calculate various operation indicators in different wiring mode by load density as the basic parameter variables.The adaptability of different wiring mode can be assessed comprehensively, and the optimal distribution network connection mode is selected in the different load density.
The Assessment of the Overload Capacity of Transformer Based on the Temperature Reverse Extrapolation Method
Authors: Liu Wei Jia , Wang Xin , Zheng Yi Hui , Li Li Xue , Xu Qing Shan
Published: December 2013

The assessment of the overload capacity of transformer has a certain practical significance. In this paper, a temperature reverse extrapolation method is proposed to assess the overload capacity of transformer. Firstly, the top oil temperature is monitored by the online monitoring system. Secondly, the temperature distribution model and the calculation methods of hot spot temperature in the PTP7 (Power Transformers. Part 7: Loading guide for oil-immersed power transformers) guide are analyzed. Then, a new method called temperature reverse extrapolation which can calculate the overload factor of transformer is composed. And based on the overload factor, two meaningful data about overload capacity are obtained. Finally, an assessment system of transformer overload capacity based on the online monitoring is developed.
Improved Algorithm on Wide Range Positioning for Partial Discharge in Substation
Authors: Wang Xi Ran , Liu Huai Dong , He Yi Fan , Zhao Qi Ming , Wu He
Published: December 2013

This paper proposes a Improved positioning algorithm of electrical partial discharge applied for substations. This algorithm is based on received signal strength indication, and taken practical condition of sensors into consideration by replenishing beacon nodes. Compared with traditional trilateral weighting positioning algorithm, this paper introduces indefinite amount of localization perpendicular lines and combined them with trilateral districts to calculate the weighting result, which can reduce error. This model meets the requirement of reality that the height of electrical discharge spots differentiate from the height of the plane formed by beacon nodes (signal sensors). The experimental result indicates that the revised position model proposed by this paper can effectively fit the condition of monitoring hardware. Error of this algorithm is less than that of traditional trilateral localization.
The Research and Establishment of GIS Fault Simulation Test System
Authors: Yang Xiao Ku , Kang Jun , Qu Quan Lei , Li Jun Hao , Li Yan Ming
Published: December 2013

Abstract. In order to accurately analyze the field test results of the partial discharge in GIS and study on the partial discharge characteristics of typical insulation defects in GIS, this paper constructs a set of failure simulation test system which is based on the entity 363kV GIS which contains all the Main equipments. These system has artificial defect setting units and can applied voltage and current at the same time, it also can manually set a variety of GIS typical insulation defects at the defect setting units. The partial discharge detection and analysis in the case of the applied voltage and current can simulate actual field operating conditions of GIS.
Influence Factor Study of Oscillating Impulse Voltage Generator
Authors: Kang Jun , Jie Shen , Li Yu Hai , Li Jun Hao , Li Yan Ming
Published: December 2013

Abstract. The aperiodic impulse voltage generator is huge and difficult to move in field, thereby limits its application in field significantly. For this problem, the oscillating impulse voltage (OIV) is recommended in standard IEC60060-3. In order to study the influence factor of oscillating impulse voltage generator, the simulation circuit is set up using ATP software. The influence of parameters such as shaping resistors, load capacitance and shaping inductance are study in this paper.
A Study on Magnetism-Driven Gliding Arc Discharge
Authors: Zhao Yu Han
Published: December 2013

The diameter of non-thermal arc plasma is one of the main parameters that determine the current density of arc, so as to the temperature and the density of electrons. The imagines of gliding arc discharge driven by magnetism at atmosphere are captured observed and its dimension is measured by commercial CCD. The diameter projecting in the direction of motion of the arc (diameter in positive direction) is attained. And the relationship between diameter and current, magnetic field is analyzed, too.
Techno Economic Evaluation of Biogas Integrated Parabolic Trough Solar Energy Combined Cycle
Authors: Zhao Bo , Yang Shan Rang , Ding Yu Ming , Liu Zhi Chao , Hu Ya Cai
Published: December 2013

This paper presented a biogas-solar hybrid system and investigated the feasibility of using biogas to increase the enthalpy of parabolic trough collectors steam so as to increase the cycle efficiency and power production. High temperature anaerobic digestion (AD) was adopted to produce biogas by using corn straw, manure and sewage. Biogas fraction and energy-to-electricity efficiency were used to evaluate the biogas contribution to the electricity generation and the energy utilization efficiency based on off-design performance analysis respectively. A comprehensive levelized electricity cost (LEC) and life cycle assessment (LCA) for the hybrid system power production were performed. The simulation calculation results show that biogas utilization plays an important role in the decrease in systemic LEC and greenhouse gas emissions. Improvement is achieved in both of generation cost and greenhouse emissions for biogas-solar hybrid plant compared to solar-only plant.