Table of Content

18 July 2014, Volume 47 Issue 7

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Generation Technology

Guiding System for Boiler Combustion Optimization Based on Artificial Neural Network and Its Application

LI Hai-shan, JU GANG, MAO Xiao-fei, YU Ting-fang

2014, 47(7):  1-5.  DOI: 10.11930/j.issn.1004-9649.2014.7.1.4

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In this paper, a real-time guiding system for boiler combustion optimization based on artificial intelligence technology is proposed, in which the NSGA-II mathematical model is established by adopting neural artificial intelligence network in combination with the data of coal-fired boiler combustion adjustment test and historical operation. By using this approach, the modeling of the field combustion adjustment test data and the operator’s daily experience is realized, and the expert knowledge and experience are obtained with the multi-objective genetic algorithm. Consequently, through the online computational guidance for the adjustment of combustion air and fuel, the goal of improving the boiler efficiency and reducing the NO_x emissions are also reached simultaneously.

Unit Commitment Based on Improved CDPSO Algorithm Combining Equal Incremental Rate Principle

CHEN Jing-hua, ZHOU Jun, GUO Zhuang-zhi, LIU Guo-xiang, ZHOU Guang-chuang

2014, 47(7):  6-11.  DOI: 10.11930/j.issn.1004-9649.2014.7.6.5

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In this paper, considering the characteristics of the unit commitment problems such as nonlinearity, discreteness, randomness, high-dimension and non-convexity, an improved chaotic discrete particle swarm optimization(CDPSO) algorithm, suitable for solving large-capacity thermal power unit combinatorial optimization issues, is proposed . The improved discrete particle swarm algorithm is used to determine the unit commitment decision variables. Furthermore, by tracking load changes and introducing amendments, the variables are revised to improve the efficiency of the algorithm and the accuracy of the solutions. The equal incremental rate principle is then improved by using Kuhn-Tucker optimality conditions to satisfy the climbing requirements as well as the upper and lower limits of generations. The unit startup and shutdown variables in the outer loop and the load dispatch in the inner loop are optimized through alternating iterations by embedding the improved chaotic particle swarm algorithm with the equal incremental rate principle. The simulation examples show that the proposed algorithm has strong global searching capability and adaptability in solving the unit commitment problems.

Elechemical Research on the Effects of pH and Dissolved Oxygen on Corrosion Rate of Hollow Strands of Water-Cooled Generators

LI Jun-wan, CAO Jie-yu, SONG Jing-xia, WANG Hong-wei, WANG Si-hua

2014, 47(7):  12-15.  DOI: 10.11930/j.issn.1004-9649.2014.7.12.3

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The corrosion rates of hollow strands under different simulated and onsite operation conditions were obtained by electrochemical test method in order to investigate the effects of pH and dissolved oxygen content on corrosion rate of hollow strands of water-cooled generators. Results showed that copper corrosion rate reduced with the increase of pH and the optimal pH value was around 8.5; Low-oxygen condition was more advantageous than rich-oxygen condition with regard to overall corrosion protection of copper bars. Rich-oxygen condition could also guarantee the safe operation of copper bars when the pH value was around 8.5 and a protective oxidation film had existed on the copper surface.

The Application and Test of RB Control Strategy in Pressurized Water Reactors

PEI Zhen-kun

2014, 47(7):  16-20.  DOI: 10.11930/j.issn.1004-9649.2014.7.16.4

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The runback(RB) test shall be carried out for the newly built pressurized water reactors prior to commercial operation to verify the completeness of RB control strategy, proper protection parameters and the compatibilities of dynamic response. Through the in-depth study on the unit control mode, RB control strategy, load reduction runback rate and the loop of objective load formulation in CPR1000 in combination with the special requirements of nuclear power station control, detailed emergency plan and precaution measures of the test are made before the test. The RB dynamic response characteristics of the CPR1000 unit are obtained through the analysis on the test results. The testing process can also provide a reference for RB test on other units. It is demonstrated from the operation of the unit that the normal operation of RB control function can greatly improve the safety and economic benefit of the pressurized water reactor. It also creates favorable conditions for the stable operation of the power grid simultaneously.

The Turbine Heat Rate Model Based on Accurate Online Support Vector Regression Algorithm

LI Hui

2014, 47(7):  21-25.  DOI: 10.11930/j.issn.1004-9649.2014.7.21.4

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An online regression model of the steam turbine heat rate is established by using the accurate online support vector regression (AOSVR) algorithm. The model updating process, which includes how to add new samples and delete redundant samples, is also presented. Moreover, the AOSVR-based regression model of the heat rate for a 1 000-MW steam turbine is built and compared with the normally used offline models of SVR and LS-SVR. The comparison indicates that the AOSVR-based regression model can be continuously updated according to the new samples, which shows strong self-adaptive and generalizing capabilities and is suitable for online application. Then, further analysis by adding a disturbance to the input parameter shows that the AOSVR model has strong robustness and can overcome the abnormal fluctuation of the input parameters and guarantee the reliability of the heat rate computation.

Power System

Research and Application of Auto-Gyro Power Line Inspection Technology

ZHENG Gui-lin, ZHANG Li

2014, 47(7):  26-31.  DOI: 10.11930/j.issn.1004-9649.2014.7.26.5

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The characteristics of an auto-gyro light aircraft and the feasibility, advancement and economical efficiency of its application to high-voltage transmission line inspection were introduced. Base on the construction of an auto-gyro space platform supported with IR, UV, conventional video monitoring technology and BeiDou navigation satellite system (BDS), the inspection program for electricity lines and facilities was discussed, which will greatly improve the efficiency of routine inspection and abnormal emergency regulation, save the cost of aerial transmission line and reduce labour intensity massively. Moreover, the foundation for transmission line inspection to go into Big Data era will be laid, at the same time, a new path will be opened for power system to achieve the Big Running strategy.

Corrosion-resistant Concrete Formula and Life Prediction on the Pile Foundation of Transmission Line

ZENG Cong, LI Sheng-long, HAO Dong-xue, CHEN Rong, LIU Chun-cheng

2014, 47(7):  32-34.  DOI: 10.11930/j.issn.1004-9649.2014.7.32.2

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A corrosion-resistant concrete formula for transmission line pile foundation, which is applicable in western saline soil area, is proposed. Besides adding high-performance water-reducing agent, 50% fly ash and cinder powder are added in the concrete. The tests, including sulfate solution attack test, sulfate-chloride compound attack test, chloride ion permeability test and freeze-thaw test etc were carried out. The service life of the concrete is predicted based on the method presented by Jin. Based on the results, it can be concluded that the pile foundation can perform excellent durability and the requirements of the expected designed-life are satisfied by applying the formula proposed.

Control Strategy of Constant Current Discharging for Storage Battery for V2G Application

MA Li-xin, MU Qing-lun, FEI Shao-shuai, WU Xing-feng

2014, 47(7):  35-38.  DOI: 10.11930/j.issn.1004-9649.2014.7.35.3

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The storage battery is a the key part of V2G (Vehicle to Grid) technology, which not only acts as an energy storage for power grid to supply power to electric vehicles, but also realizes the function of power transmission integration to grid. Deep discharge of the battery may reduce the battery life and make the power system instable. Based on these damages, a control strategy of constant-current power transmission combined with automatic disconnection of the inverter circuit is proposed. According to this control strategy, a discharging model of storage battery is built and simulated. Simulation results show that, by controlling the PWM wave of the full controlled device, the discharging current of the battery can be controlled effectively to avoid its deep discharge and achieve a stable and reliable discharge process. The simulation validates the correctness of the model and the feasibility and effectiveness of the control strategy.

Evaluation and Optimization of Measurement Configuration in Distribution System

GAO Ya-jing, ZHANG Zhan-long, WU Wen-chuan, GUO Kun-ya

2014, 47(7):  39-44.  DOI: 10.11930/j.issn.1004-9649.2014.7.39.5

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In this paper, the influence characteristics of different types of measurements which aim to improve the accuracy of the state estimation in distribution system are studied through numerical tests. The causes for these influence characteristics are preliminary analyzed and discussed. Then, an optimization method for measurement configuration is proposed according to the foregoing analysis. The results of the numerical tests show that the proposed method can get promising results and is able to be used in optimizing the configuration of real-time measurement in distribution system.

Novel Algorithm of Active Control for Transformer Noise based on Adaptive RBF Neural Network

JIANG Hong-yu, MA Hong-zhong, LIANG Huan, JIANG Ning, LI Kai

2014, 47(7):  45-50.  DOI: 10.11930/j.issn.1004-9649.2014.7.45.5

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For the deficiency of the existing active noise control algorithms for transformers, a new algorithm for noise suppression is proposed, which is based on the combination of several algorithms, i.e. adaptive algorithm, particle swarm optimization, improved gradient descent algorithm and RBF neural network algorithm. Firstly, the algorithm applies the adaptive algorithm to determine the number of nodes and the corresponding parameters of the hidden layer of RBF neural network in system controller; Then, according to the switching strategy, particle swarm optimization or improved gradient descent algorithm are selected adaptively to optimize the node number and parameters; Finally, the optimized nodes and parameters of the hidden layer are fed back to the system controller. As a result, the infrasound source of the system is able to better offset the initial sound source. By comparing the improved RBF neural network proposed with the conventional RBF neural network and BP neural network, it is shown that the proposed algorithm can effectively improve the adaptive ability and the anti-interference capability of the system, by which the transformer noise can be controlled within the relatively low range and the improved ability of noise reduction is obtained.

Control Strategies and Interactions of UHVAC and UHVDC Transmission Systems in North China-Central China-East China Power Grid

QI Yi-tao, PENG Hui-min, YANG Ying, ZHOU Hai-feng, PAN Xue-ping

2014, 47(7):  51-56.  DOI: 10.11930/j.issn.1004-9649.2014.7.51.5

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Study on the interplay between UHVAC and UHVDC systems and providing reasonable control strategies are of great significance for the security and stability of the interconnected grid of the North China-Central China-East China Power Grid. Therefore, impacts of AC system faults on DC system, and that of DC blocking faults on the whole system were simulated based on software FASTEST that is a kind of software for analyzing security and stability of power system quantitatively, by which a strategy of emergency DC power support was proposed when DC double-pole blocking occurs, which may lead the instability of the grid. The simulation results show that the AC line faults nearby the inverter side have the greatest impact on the DC system, moreover, the larger the short-circuit current of a fault point within the same province is, the more harmful to UHV tie line power will be. Also it is shown that this proposed control strategy is applicable and effective.

Operation Data and Feature Analysis of the Main Natural Disasters of Power Network in China

CHEN Peng-yun, CAO Bo, LUO Xian, CHEN Rui-zhen

2014, 47(7):  57-61.  DOI: 10.11930/j.issn.1004-9649.2014.7.57.4

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In order to study the risks of main natural disasters in power network and the corresponding prevention strategies, the general situation of natural disasters in power network in China is analyzed according to the failure statistics of high voltage power networks. Based on the spatial-temporal distribution characteristics of natural disasters and their damage on the power network, it is concluded that the main safety risks of the high-voltage network in China are large-area icing accident, large-scale pollution flashover and large-scale ice coating galloping. And the main way for improving the anti disaster ability of power networks is to increase the design standards and make differential designs with a comprehensive consideration of the spatial-temporal distribution and frequency of disasters, as well as the importance of transmission lines.

Saturated Power Consumption Forecasting Based on Extended Solow Long-Term Equilibrium Model

GU Jie, XUE Ji-liang, YANG Zhong-lin, CHENG Hao-zhong

2014, 47(7):  62-66.  DOI: 10.11930/j.issn.1004-9649.2014.7.62.4

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Saturated power consumption is a pivotal index in determining the final network scale in power system planning, which can provide significant information for system planning and give guidance for gird construction and rational distribution of power transmission lines. From the inspiration of Solow model which is successfully applied to economic problems, power consumption forecasting was done with extended Solow long-term equilibrium model through broadening and revising the Solow model, in which industrial structure and power consumption structure were used to represent the structural effects; meanwhile, several scale effects and the progress of technology was combined into extend Solow mode. The new model has high forecasting accuracy, which is able to solve future saturated power consumption problems with the consideration of social and economic data, power grid status and future policies. From the example of Eastern China, saturated power consumption was explored which proves a meaningful reference on saturated load forecasting of regional grids.

Study on the Sensitivity Problem of Transformer’s Over Current Protection Interlocked by Compound Voltage

LI Zi-feng

2014, 47(7):  67-70.  DOI: 10.11930/j.issn.1004-9649.2014.7.67.3

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Based on the sensitivity problem of transformer’s over current protection interlocked by compound voltage, a comprehensive comparison analytical method is used to simulated the operating conditions of transformers with various parameters, to calculate the short currents of different types of power faults, and to find out the causes for the insufficient sensitivity of transformer’s over current protection interlocked by compound voltage according to the changes of transformer’s running mode, and some solutions are proposed. The method is proved to be comprehensive and practical.

Real-time Simulation Method for Large-Scale Power Grid Based on BPA Computing Model and SVG Topology

TANG Wei

2014, 47(7):  71-76.  DOI: 10.11930/j.issn.1004-9649.2014.7.71.5

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Based on the analysis and managing method of electric data in power dispatching and communication center, a novel real-time simulation method for large-scale power grid based on BPA data computation model is presented in this paper, which is used to develop the grid computation model with BPA format, while SVG(Scalable vector graphics) is used for the secondary graphical modeling. Combined with the domestic BPA software, online chart-module integration editing and real-time simulation can be implemented. The application on the real system verifies the effectiveness of the proposed method. Besides, this method can provide theoretical guide for the grid researching, planning and operating.

Study on the Influence of Shielding Net Partial-Grounding on Internal Voltage of Substation Building

AN Shuai, DAN Shu-heng, CAI Li-chuan

2014, 47(7):  77-80.  DOI: 10.11930/j.issn.1004-9649.2014.7.77.3

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The outer wall surface of a smart substation ,in wich there are a lot of with electric power secondary equipments, needs to be covered with a grounded shielding net which can suppress induced voltage in the building. The shielding net is made up by several rectangular wire-nettings of one meter wide and several meters long,which are that connected with each other and grounded. However, because of geographical, the incomplete connection may exist between the wire-netting and the ground in actual construction. In order to study their impacst on induced voltage in the building in the situation of incomplete connection, the method of finite element analysis is used to build the model, and finally conduct the following conclusions. In case that one piece of the top shielding net is ungrounded , the average induced voltage of each observation points is 62.4 V, and If one side is unground, the average induced voltage of each observation points is 10.8 V; While a total of two pieces of shielding nets are unground on the top or the side of the building, two adjacent ungrounded shielding net on the top would take a largest efface on the induced voltage, the average induced voltage reaches 182.4 V; two non -adjacent shielding nets ungrounded on the side of the building would have a minimal influence on the voltage, the average induced voltage is 19.4 V. The above conclusions can provide the theoretical guide for solving relevant problems in the actual construction.

Analysis for a Trip Fault in a Series Compensation Circuit

LI Zhen-dong, LI Dai-jun, ZANG Bin, SHANG Dong-hui, SHI Xin

2014, 47(7):  81-85.  DOI: 10.11930/j.issn.1004-9649.2014.7.81.4

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A three-phase trip fault in a series compensation circuit of 500 kV caused by the selected-area deflection was analyzed, which took into account of the behaviors of the series compensation relay and line relay. Based on the real circuit, a simulation model was established and the simulation with the parameters corresponding to the operation condition was conducted by using RTDS. It was found that the behaviors of relays were in accordance with the principles of design and recorded data. When a single phase fault through the transition resistance and transient conduction in phase B of series compensation’s MOV occur, the selected-area deflection will take place and the two-line relays will select different phases, which will amplify the fault area. Based on case analyses, the phase-to-ground faults at single or double circuits, when the series compensation works or not, were researched, respectively. The error conditions of zero and negative current areas were obtained. Moreover, some feasible solutions in the actual situation were proposed as well.

Case Study on GIS Internal Latent Fault

LUO Hong-tao, HUANG Wen-wu, ZOU Hong-min, LI Si, CHEN Zhi-xiong

2014, 47(7):  86-90.  DOI: 10.11930/j.issn.1004-9649.2014.7.86.4

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Based on gaseous DPD (decomposition products detection) and PD(partial discharge) detection, three typical cases of internal latent fault cases of GIS are introduced, which have different characteristics: the gaseous DPD result is abnormal but the PD signal is not detected; the gaseous DPD result is normal but the PD signal is detected; the gaseous DPD result is abnormal and the PD signal is detected. The equipment are verified to have defects through disintegration examination. Therefore, gaseous DPD and PD detection technologies have expectable application prospect in the internal latent fault detecting of GIS.

New Energy

Design of Control Strategies of Energy Storage for Peak Shaving to Restrain Wind Power’s Influence on Power Grid

LI Jun-hui, ZHU Xing-xu, YAN Gan-gui, MU Gang, GE Wei-chun

2014, 47(7):  91-95.  DOI: 10.11930/j.issn.1004-9649.2014.7.91.4

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The essential problem of peak shaving of large-scale wind power is uncontrollability of wind power. Because of the ability of charging and discharging, battery energy storage systems are considered as an effective mean to control wind power output and improve the wind power acceptance capability of a grid. Aiming at insufficient peak shaving capacity of power systems caused by anti-peak shaving character istics of wind power output, the influence mechanism of large-scale wind power integration on generation schedules for traditional generators in load valley period and the regulatory mechanism of the participation of energy storage systems in peak shaving were analyzed. Control strategies of the energy storage system that includes dead-zone control were designed in case of low load. Example result shows that control strategies of energy storage system mentioned above is effective to renduce the start-up times of thermal power units when the large-scale wind power is integrated to the grid and the economic benefit of power grid operation is greatly improved.

A Computing Method for Maximum Annual Wind Energy Curtailment

SU Xin-yi, HAN Xiao-qi, XU Dong-jie, LI Juan-ping

2014, 47(7):  96-100.  DOI: 10.11930/j.issn.1004-9649.2014.7.96.4

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In order to guarantee the wind energy consumption, it’s necessary to analyze the relationship between the installed wind power capacity and the wind curtailment rate, the proportion of wind energy consumption to the total electricity consumption, during the wind power planning phase. This paper proposed a concept of maximum annual wind energy curtailment. Based on the output of the wind power and the load duration curves, a method for computing the maximum annual wind energy curtailment was proposed. With the maximum annual wind energy curtailment, an estimation formula was derived to obtain the indices like the maximum wind energy curtailment rate and the guaranteed wind energy consumption rate. And this can be seen as the reference for wind power planning and design.Finally, the effectiveness of the proposed method was verified in the case study.

Research on the Impact of the Air Density on the Wind Power in Guizhou Plateau Mountainous Region

WEN Xian-kui, XIAO Yong, LIN Cheng-hui, XU Mei-mei

2014, 47(7):  101-103.  DOI: 10.11930/j.issn.1004-9649.2014.7.101.2

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Most of the wind farms in Guizhou are located in the mountainous areas of high altitude and high air humidity. The air density is deduced and calculated considering the altitude and humidity. It is found that the above two factors are inversely proportional with the air density. At present, the air in the mountainous area is usually considered to be dry in wind power calculation and the effects of humidity are ignored. With the same wind turbine and wind speed, the output power is proportionally reduced with the air density. Therefore, the humidity should be considered in wind power unit design, generation estimation, power prediction.

Modeling and Simulation of Dish Solar Thermal Power Tracking System

YANG Ying, LIU Xiao-guang

2014, 47(7):  104-107.  DOI: 10.11930/j.issn.1004-9649.2014.7.104.3

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This paper presents a model of the azimuth and altitude of dish solar condenser by the research on the dish solar thermal power tracking execution system. The system builds a dynamic model of electromechanical coupling using matlab / Simulink tools. The modeling method has a good tracking ability through simulating analyzing of the dynamic response characteristics. This article studies the moment of inertia influence on tracking accuracy by analyzing the relationship between the load moment of inertia and the angular velocity and angular acceleration of tracking system. This model provides a theoretical basis of hardware design.

Information and Communication

Summary on Cloud Computing and Its Application Prospect in Power Sector

WANG Ji-ye, CHENG Zhi-hua, PENG Lin, ZHOU Ai-hua, ZHU Li-peng

2014, 47(7):  108-112.  DOI: 10.11930/j.issn.1004-9649.2014.7.108.4

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Cloud computing is one of the popular new information technologies and it is developing fast from concept into practice. The usage of cloud computing by global public utilities also shows a rapid growth trend. Based on the core literatures in recent years, the current research status of cloud computing related technologies, such as virtualization technology, parallel computing, distributed technology is summarized and analyzed in this paper. Furthermore, combined with the business development of smart grid and the intensive management in State Grid Corporation of China, the cloud computing applications demand and prospect for electricity enterprises are analyzed comprehensively, which can provide a useful guidance for the electric power enterprises about cloud computing de-velopment and application.

A Novel Early-warning Method for the Network Public Opinion of Power Grid Emergency

ZHU Chao-yang, LIU Jian-ming, WANG Yu-fei

2014, 47(7):  113-117.  DOI: 10.11930/j.issn.1004-9649.2014.7.113.4

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In order to achieve accurate early-warning of network public opinion for electric power grid emergency, various kinds of influencing factors leading to the network public opinion of electric power grid emergency were gotten with the information security risk assessment theory, and a novel network public opinion early-warning index system was also proposed based on support vector machine. The designing process of early-warning system was abstracted into the classification problem by the way that the values of all indices were treated as the inputs of classification, and the early-warning levels were treated as the outputs of classification. Support vector machine was used to solve the classification problem, which can effectively avoid the subjective shortcomings of the traditional methods. Finally, the validation experiment based on the network monitoring data of the Shenzhen blackouts on April 10, 2012 shows that this support vector machine-based early-warning system has good performance in time consuming and alarm accuracy.

Study on Hierarchical Regional Protection of Power System Based on MAS Information Fusion

ZHAI Dang-guo, FU Zhou-xing, YUN Bao-ji, LI Zhong, LI Lei

2014, 47(7):  118-121.  DOI: 10.11930/j.issn.1004-9649.2014.7.118.3

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A multi-agent units-based coordinated protection method is proposed based on analyzing the methods for realizing hierarchical regional protection of power system. The fault information of each measurement point’s agent unit is firstly optimized by Kalman filter, and then the fault direction information and the fault correlation matrix can be obtained. Finally, the fault location can be determined according to the correlation matrix and the criterion. Numerous theoretical analysis and simulation results show that such method can effectively locate the fault components. This regional protective system can match with the traditional point protection and solve the override trip problem in the power supply system.

Smart Grid

A Test Template and Its Generation Method for Protection Devices in a Intelligent Substation

XIE Jun, LI Feng, LI Yong, LU Wei, LI Zhong-min

2014, 47(7):  122-127.  DOI: 10.11930/j.issn.1004-9649.2014.7.122.5

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With the development of digital intelligent technologies in substations, the efficiency and quality of inspection for digital protection devices need to be improved urgently. The test procedures of digital protection devices in intelligent substations were analyzed, a universal test template of digital protection devices, which is based on XML, was developed, and accordingly its generation method was put forward. Practical application shows that the universal test template has excellent extensibility, self-explanatory capacity, transportability and adaptability. Therefore, it can be concluded that the test template can play an important role in reducing labour costs, improving test efficiency and management normalization.

Application of Certificateless Signcryption Scheme to Smart Grids

FAN Ai-wan, LIU Yu-kun, ZHAO Wei-ting

2014, 47(7):  128-133.  DOI: 10.11930/j.issn.1004-9649.2014.7.128.5

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In order to reduce storage space and computational cost of the digital certificate security system in smart grids and increase the coupling degree of encryption and signature, the mapping method of smart grid and certificateless signcryption scheme of role is put forward, and the application environment of certificateless signcryption on smart grids is constructed, which is based on the analyses of security of data transmission in smart grid. By using the elliptic curve cryptography, a digital signcryption scheme for smart grids is developed. In order to improve the communication security, the trusted third party is introduced into communication of the smart grid. Combined with the intelligent nodes, a key pair is produced. By taking encryption process into the signing process, this method improves the transmission efficiency of communication. Compared with the security of the existing algorithms, the proposed scheme has the advantages on confidentiality, integrity, nonrepudiation and antiforgery. The application test results show that the scheme can meet the requirements of real-time data transmission in smart grids.

Enery Conservation and Environmental Protection

The Influence of Oxygen on NO Removal by Non-equilibrium Plasma

CAO Chun-mei, DING Qing-wei

2014, 47(7):  134-136.  DOI: 10.11930/j.issn.1004-9649.2014.7.134.2

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On the basis of the physical and chemical models of NO in non-equilibrium plasma based gas removal system NO-N₂, the numerical simulation of NO removal process is conducted under different O₂ initial concentrations to study the evolution of NO and NO₂ concentrations varying with time. The influence of O₂ initial concentration on the concentrations of main particles and NO removal is studied. The calculation results show that the presence of O₂ has negative impacts on NO removal by non-equilibrium plasma. The NO removal efficiency reduces in the presence of O₂. The higher concentration of O₂ will lead to more decrease of NO removal efficiency. The adding of O₂ increases the NO₂ production as the result of the coexistence of non-equilibrium plasma and O₂. In the presence of O₂, the higher electron average energy will lead to further decrease of NO removal efficiency.

Research on a Multi-regional Inter-industry CO₂-emission Trading Model based on Interval Programming

WU Chuan-bao, LI Wei, XIE Yu-lei, XU Yi, HUANG Guo-he

2014, 47(7):  137-143.  DOI: 10.11930/j.issn.1004-9649.2014.7.137.6

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Carbon dioxide(CO₂) emission trading is a market mechanism for the promotion of greenhouse gas mitigation. Considering the uncertainties of the processes of emission trading, a multi-regional inter-industry CO₂-emission trading model, based on CO₂ mitigation targets in the regional and industry level, is proposed by using interval programming. The model is applied to a case study in order to provide an effective technical support for the management decision-making of CO₂-emission trading in the regional and industry level.

Analysis on of the Driving Forces Impacting SO₂ Removal in Electric Power Industry

FAN Chang-jian, LI Yuan, HAI Re-ti·tuerxun, WANG Shou-he

2014, 47(7):  144-149.  DOI: 10.11930/j.issn.1004-9649.2014.7.144.5

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In order to investigate what exactly leads to the increase of the SO₂ removal volume and find out the drawbacks in SO₂ emission reduction during the period of the 11th Five-Year, the major driving factors of SO₂ removal in electric power industry are analyzed by using the LMDI method in which the factors are decomposed into terminal treatment effect, structure effect, technological progressing effect, policy effect and investment effect. The research results illustrate that during the period of 2005-2011, the terminal treatment effect contributes the most to the increase of SO₂ removal volume, and the structure effect contributes the second most. In addition, the regression equations of the SO₂ removal volume and its driving factors are set up by adopting partial least squares to provide a reference not only for the governments to make their policies but also for the enterprises to implement energy-saving and emission reduction.

The Industrial Application and Technical Optimization of First Domestically-Made Urea Hydrolysis Unit in Large Power Plants

HUI Run-tang, WEI Fei, YAN Shi-ping, LIU Shu-dong, YANG Ai-yong, JIANG Yan-liang, ZHENG Wei

2014, 47(7):  150-155.  DOI: 10.11930/j.issn.1004-9649.2014.7.150.5

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With the promulgation of the national standard of Emission Standard of Air Pollutants for Thermal Power Plants(GB 13223-2011), the selective catalytic reduction (SCR) flue gas denitrification devices shall be built in a large number of coal-fired generating units, Ammonia will be gradually replaced by urea for safety. In the past, the urea hydrolysis technology is mainly dependent on importation. The domestically-manufactured urea hydrolysis devices can reduce the operating costs and avoid the dependence on the imported technology. In this paper, the characteristics, operating results and key technical optimization of the first set of domestically-made ammonia preparation system for two 330-MW units in Dongsheng Power Plant with urea for denitrification are introduced. The operating practice shows that the reliability of the system is quite good; the overall system operation is stable and can meet the design requirement of load following. The project can be a reference for the design, installation and debugging of the flue gas denitrification systems of the same kind.

Experimental Study on Carbon Removal by Aqueous Ammonia under Oxy-enrich Combustion

CUI Cai-yan, WANG Chun-bo, BAI Yan-fei, ZHOU Xing, LIU Hui-min

2014, 47(7):  156-160.  DOI: 10.11930/j.issn.1004-9649.2014.7.156.4

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Experimental studies on carbon removal by aqueous ammonia under oxy-enrich combustion flue gas(30%~40% v/v CO₂) in a packed column were carried out. Effects of different operating and design parameters on CO₂ removal efficiency, including concentration of CO₂ in flue gas, concentration of aqueous ammonia, pH value of absorbent, aqueous ammonia flow rate, flue gas temperature, total flue gas flow rate and packing height, were investigated. The research results show that: ① improving concentration of aqueous ammonia, improving pH value of absorbent and increasing flow rate of aqueous ammonia can increase removal efficiency of CO₂ respectively; but when pH value is 10.5, a certain volatility of removal efficiency occurs; ② when gas temperature is 50 ℃, the removal efficiency is the highest; ③ when concentration of aqueous ammonia is greater than 4%, the removal efficiency is above 90%. Under oxy-enrich combustion 1 kg NH₃ can absorb 0.32 kg CO₂, which is twice greater than conventional combustion. Therefore using oxy-enrich combustion mode contributes to reducing the volume of the absorber and regeneration column, as well as energy consumption.