Table of Content

18 August 2014, Volume 47 Issue 8

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Power System: Condition Assessments and Monitoring

Reliability Evaluation for Bulk Power Systems by Using Stochastic Response Surface Method

SU Xiao-lan, ZHAO Yuan, ZHONG Jia-hua, YANG Gao-feng, ZHANG Ya-wei

2014, 47(8):  1-7.  DOI: 10.11930/j.issn.1004-9649.2014.8.1.6

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In order to quantify the effect of the uncertainty of component reliability parameters in reliability assessment of bulk power systems, a method called stochastic response surface method and with the considerations of the factors of the stochastic nature of fault rate and MTTR, was proposed, which can rapidly induce polynomial expressions for risk indices as well as formulas and calculate the relevant expectation value and its variance. Moreover, to enhance the velocity of convergence, the generalized polynomial chaos expansions were developed in case that the component parameters don’t follow the normal distribution. By taking the advantages of the proposed method, the vulnerable points in a power system can be identified, which can provide guides for system planners and operators. Finally, the reliability of the RBTS test system was evaluated and analyzed and the simulation results verify the validity of evaluation method mentioned above.

A Selection Method of Optimal Criteria for Transformer Condition Assessment

YAO Sen-jing, WEN Zheng-qi, ZHANG Lin, LYU Qi-shen

2014, 47(8):  8-12.  DOI: 10.11930/j.issn.1004-9649.2014.8.8.4

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Currently, selection of criteria for transformer condition assessments is mostly based on experience without a comprehensive measure index, which makes condition assessment models lack of data or difficult to reflect potential failure in applications. Therefore, a novel selection method of criteria was presented. Firstly, the transformer common failure modes were analyzed by the failure mode and effect analysis (FMEA), and the occurrence and severity of failure modes and their detection methods were obtained. Secondly, the priority index of detection method was derived by using AHP, which considered the sensitivity, elusiveness, reliability and cost factors of each failure mode detection method. Thirdly, the model of selection optimal criteria was established. Finally, by selecting optimal criteria to evaluate the mechanical and thermal properties of a transformer, the feasibility of the method was verified, and the results show that the criteria selected by this method can effectively reflect the transformer condition. This method is proved to have good engineering values.

Application of Ultrasonic-Based PD Monitoring System in the Test of Withstanding Voltage and PD

ZENG Xiong-jie, LIU Xu-ming, HUANG Wen-wu, ZHOU Ju-gen, ZHANG Xiao

2014, 47(8):  13-20.  DOI: 10.11930/j.issn.1004-9649.2014.8.13.7

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The principles of ultrasonic-based PD monitoring system are introduced. At the same time, it is elaborated that the PD impulse can be imitated by SEAOW and DEAOW in the theoretical analysis. And then, it is described how to apply the ultrasonic-based PD monitoring system in locating the discharge position in the withstanding voltage and PD test of 500 kV GIS, which proves that the ultrasonic-based PD monitoring system is effective in detecting PD points in the withstanding voltage test. Therefore, it is an effective method and basis for timely finding defects in GIS.

Measurements of Capacitance and Dielectric Loss of 500 kV Auto-Transformer Bushings Without Disconnecting Leads

ZHANG Zhen-xing, CHEN Quan

2014, 47(8):  21-26.  DOI: 10.11930/j.issn.1004-9649.2014.8.21.5

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In the measurement of 500 kV auto-transformer, it is difficult to connect and disconnect measuring lines to the transformer because of its large size and high placed bushings. However, the bushings at the ends of high- and medium-voltage and the neutral are connected by the same winding. If the low voltage winding is short-circuited and grounded, it is possible to achieve the values of bushings’ capacitance and dielectric loss by measuring neutral voltage and current from the bushing end without connecting or disconnect measuring lines. Through the computation of the simplified equivalent circuit model of 500 kV auto-transformer, the deviation of the capacitance and the dielectric loss of the testing bushing by using neutral voltage can be calculated. The proposed method is evaluated by using two 500 kV autotransformers in Xiangshan substation located in Zhongshan, Guangdong province, which demonstrates that the proposed method is effective and can be implemented in practice.

Electric Field Analysis and Experimental Study of Defective Basin Insulators Within SF₆- Gas-Insulated Current Transformers of 500 kV

HE Da-meng, YAN Nian-ping, WANG Zhong-yi, TONG Jun-xin, MA Jian-cang

2014, 47(8):  27-32.  DOI: 10.11930/j.issn.1004-9649.2014.8.27.5

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The number of faults of SF₆-gas-insulated current transformer notably increases in recent years. By analyzing an accident of a 500 kV SF₆ current transformer, it is shown that the cause is the internal defects of the basin insulators in the current transformer during operating. In order to investigate the insulation characteristics of gas-insulated current transformers and find the root causes for the sudden faults, three dimensional electric-field simulations and partial discharge tests based on the accident analysis of SF₆-gas-insulated current transformer with the insulators those have the defects of air bubbles, cracks and sheet metal were carried out. The results illustrate that the electric field of the defective basin insulator is distorted. Especially, in case of metal pollution, the electric field is seriously distorted and partial discharge voltage drops sharply. The investigation data and conclusions provide a theoretical reference for the insulation design, structural optimization, operation maintenance and fault analysis of SF₆-gas-insulated current transformers.

Transient Analysis on Circuit Breaker Explosion Caused by Lightning Overvoltage

LI Shuang, LI Guan-hua, ZHU Yi-dong, HAN Hong-gang

2014, 47(8):  33-37.  DOI: 10.11930/j.issn.1004-9649.2014.8.33.4

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In order to quantitatively describe the whole course of the circuit breaker explosion caused by lightning and to find some relevant measures, by taking a 220 kV substation in China for a case study, the lightning overvoltage on the circuit breaker contact after lightning striking on the tower is calculated by using the EMTP. Meanwhile, based on thermodynamics theory and gas condition function, the energy produced by arc across the contacts and the pressure in extinguisher are calculated. Eventually, the effects of arcing time and lightning current amplitude on arc energy and pressure in extinguisher is analyzed, and some measures for preventing extinguisher explosion and suggestions for insulation coordination are proposed. The research demonstrates that the extinguisher explosion is resulted from the large pressure generated by arc energy in the extinguisher and reducing the arcing time can reduce the arc energy. The magnitude of lightning current is not the determining factor for extinguisher explosion but the inducing condition for breaker contact breakdown. Mounting a MOA on the inlet/outlet line of the substation can effectively reduce the amplitude of lightning overvoltage.

Performance Test and Analysis on RTDS-Based SVC Controllers for Wind Farms

WU Tao, XIE Huan, CAO Tian-zhi, JIN Hai-feng, LIANG Yu-zhi, LI Shan-ying, LAN Hai-bo, LIU Hai-tao

2014, 47(8):  38-44.  DOI: 10.11930/j.issn.1004-9649.2014.8.38.6

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Performances of SVC controllers have critical impacts on voltage quality and operation stability of local grid integrated with large-scale wind power. A digital real-time model is built for power grid connected with wind farms and TCR based SVCs by real-time digital simulator(RTDS), which constitutes a closed-loop test system, and can carry out the performance tests on actual SVC controllers. The results show that this kind of closed-loop test system is capable of testing SVC controllers’ dynamic characteristics more comprehensively. And it is found that, for manufacturers, some functions of SVCs, such as signal measurement, regulator model design, coordination of the auxiliary controls and its switching modes still need to be improved and refined.

Power System

Online Application of Power System Analysis Software Package (PSASP)

XIAN Yi, WANG Xiao-ru, LIU Yue-xian, LI Ze-qi

2014, 47(8):  45-50.  DOI: 10.11930/j.issn.1004-9649.2014.8.45.5

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At present, power system analysis software package(PSASP) has only offline applications because some problems existing in online software have not been solved yet. Therefore, the structure of database, construction of software and operational mechanism of PSASP were analyzed and interfaces for accessing database and calling calculation modules were developed, through which the SCADA’s data can be imported into PSASP’s databases after the system status assessment. Moreover, the real-time data of power network can be processed by calling different functional modules through PSASP interfaces according to the requirements. By the application to an assistant decision-making system of a practical power system, it is shown that the proposed technology can provide a new thinking for PSASP users to extend its computing ability further.

A Novel Hybrid Control Strategy for VSC-MTDC Transmission System

LIU Long-long, MA Xiao-chun

2014, 47(8):  51-56.  DOI: 10.11930/j.issn.1004-9649.2014.8.51.5

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To improve the operation reliability of VSC-MTDC system, a novel hybrid control strategy based on principal and subordinate control and voltage drop control was presented, on which the corresponding controller of VSC was designed to switch the transmission system freely according to system disturbance strength. Finally, a four-terminal VSC-MTDC model was developed in PSCAD/EMTDC to validate the feasibility of the proposed control strategy. The simulation results prove that the system is able to maintain the desired power distribution automatically without losing the stability and each converter can independently regulate DC power transferred to DC network, which shows the feasibility of novel hybrid control strategy.

Harmonic Measurement Characteristics of Capacitor Voltage Transformer (CVT) of 110 kV

LI Lin, DUAN Xiao-bo, LIU Guan-qi, ZHOU Wen

2014, 47(8):  57-61.  DOI: 10.11930/j.issn.1004-9649.2014.8.57.4

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Considering the harmonic distortion from the primary circuit to the secondary circuit of capacitor voltage transformers (CVT), the harmonic measurement characteristics of CVT are analyzed with testing and the simulations. By taking a certain type of 110 kV CVT for case study, a high frequency equivalent circuit of CVT is constructed, which takes consideration of stray capacitance, coupling capacitor, dielectric loss of capacitive divider and equivalent resistance of compensation reactor. By using Matlab, the CVT’s harmonic model is built and its amplitude-frequency characteristic curves are obtained. To prove the correctness of the simulation model, harmonic measurement tests are carried out for CVT in the field, and the testing results are compared with the simulation results. It is concluded that the voltage harmonic content and the amplitude of the fundamental voltage have no impacts on the measurement characteristics of CVT.

Reactive Power Planning in Distribution System Based on Capacitor’s Voltage-Dependent Characteristics

LI Ke, QIAN Xiao-jun, TAI Neng-ling, HU Biao, PENG Jiang

2014, 47(8):  62-66.  DOI: 10.11930/j.issn.1004-9649.2014.8.62.4

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The actual compensation of capacitor capacity has a very close relationship with the voltage level of the access points. Therefore, based on the power flow analysis, a compensation method, which considers the capacitor’s voltage characteristics, is proposed to use the sorting method for node reactive power margins to find the best configuration for reactive power source access. The method is applied to the distribution system of a region for analyzing the reactive compensation and the results of simulation and actual testing proves the method’s high efficiency.

Pricing Mechanism of Green Power Subscription Marketing

PAN Yan-xia, WANG Yu-fei, WANG Hui

2014, 47(8):  67-71.  DOI: 10.11930/j.issn.1004-9649.2014.8.67.4

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Based on the analysis of the price forming mechanism of green electricity, this paper studied the impacts of the differences in generation prices, transmission and distribution price, tax cost, administrative cost and rotating standby compensation on sales-price of green electricity. Taking the top sales as the target function and linearizing the impact of sales price on users’ willingness, the pricing model and the corresponding calculation method of green electricity, which is based on users’ willingness, was put forward innovatively. The green electricity price of wind power in Shanxi was taken as a study case to prove the model mentioned above to be of great practical values.

Research and Determination of Reserve Requirements in Power System with Significant Wind Power Penetration

GAO Feng, MA Shuo, ZHANG Shuang, XU Xiao-yan, GU Yu-jia

2014, 47(8):  72-78.  DOI: 10.11930/j.issn.1004-9649.2014.8.72.6

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The determination of system reserve is a key factor for optimal dispatching of renewable energy and generation planning. The principle of conventional reservation arrangement ignores the impacts of high penetration of renewable energy, which may cause a high risk in system operating. Meanwhile, the current method is too rough that might reduce the acceptable capacity of renewable energy. So, by analyzing the influence of the high penetrated wind power on system reserve and considering the requirements of safe and economic operation and optimal dispatching of the renewable energy, a new method, which is functional in wind power prediction, analysis and determination of system reserve and spinning reserve, is proposed. The feasibility of proposed method is validated by using the real operation data.

Effect of Metal Particles in the Environment on the Transmission Line’s Corona

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

2014, 47(8):  79-82.  DOI: 10.11930/j.issn.1004-9649.2014.8.79.3

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Corona loss is the major component of transmission line’s power loss and is affected by the wire’s surface roughness. The paper investigates the effect of metal particles with different shapes and sizes on the corona and describes the areas in which metal particles may cause corona. The effect of particles on the corona loss can be reflected in terms of the area’s sizes. The study shows that the electric field intensity around the line will increase significantly when there are metal particles adhering to the line. Comparing the particles of given shapes indicates that the cubic particle have a significant influence on the corona loss and the hemispherical metal particles of a certain radius cause the largest corona loss.

Analyses of the Impulse Characteristics of Tower Grounding Devices Based on Electromagnetic Field

ZHU Chang-cheng, XING Peng-xiang, LU Hai-liang, LAN Lei, FENG Zhi-qiang

2014, 47(8):  83-87.  DOI: 10.11930/j.issn.1004-9649.2014.8.83.4

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Potential rise of the transmission line towers depends on the grounding resistance when the lines or towers are stricken by lightning,which determines the overvoltage between the terminals of an insulator string and the performance against lightning strike of the transmission lines. Impulse characteristics of the grounding conductors manifest as spark effect and inductive effect, which make it different from the characteristics of the power frequency. Based on electromagnetic theory, a mathematical model was built to calculate the impulse grounding resistance of a typical grounding grid for towers with different length in different soil resistivity. The accuracy of the proposed model was verified by model tests and a comparison with the calculated grounding resistance at power frequency by the well-known grounding software CDEGS further reveals the difference between power and impulse characteristics, and confirms that there is an effective length for grounding system under impulse current.

Generation Technology

Case Study on High Temperature Oxidation in Supercritical/Ultra-Supercritical Boilers

LI Zhi-gang, ZHANG Yu-bo, YAO Bing-yin

2014, 47(8):  88-93.  DOI: 10.11930/j.issn.1004-9649.2014.8.88.5

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In this paper, the influencing factors of high temperature oxidation are investigated and analyzed based on the typical high temperature oxidation cases of the supercritical/ultra supercritical boilers with 600-MW and above capacities in 2013. The factors which affect the boiler high temperature oxidation and oxide scale exfoliation are sorted out and categorized from the aspects of tube material, wall temperature and medium composition. The study indicates that, firstly, the material of TP347H with coarse grain size exhibits low resistance to water vapor oxidation at high temperatures; secondly, early oxide scale exfoliation tends to appear when the steam temperature of the boilers is lower than its designed value; thirdly, the alarm level of wall temperature provided by boiler manufactures cannot effectively guide the unit operation to prevent the formation and exfoliation of oxidation scale; and finally, there is no direct relationship between the oxygenation treatment of boiler feedwater and the broad exfoliation of oxide scale. Therefore, the suggestions on further studies and preventive measures on high temperature oxidation are proposed.

Bending Fault Caused by Steam Turbine HP-IP Rotor Materials

LI Heng-hai, AN Zheng-feng, WANG Bao-yu, GU Zhi-de

2014, 47(8):  94-97.  DOI: 10.11930/j.issn.1004-9649.2014.8.94.3

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Aiming at the HP-IP rotor bending faults which frequently happened in the operation of 600-MW turbine generating units in recent years, the reason and mechanism of the rotor bending are analyzed through the bending characteristics of the similar HP-IP rotor bending examples of two 600-MW supercritical units. It is concluded that the defect of HP-IP rotor materials is the key factor causing the bending. The uneven material makes the elastic bending happen in the high temperature steam and the stress relaxation caused by the excessive and asymmetrically axis distributed residual stress in high temperature steam heating leads to permanent bending. The secure and economic operation problems caused by rotor bending are summarized. The processing methods and prevention strategies are also included.

Correlation Between Oxide Skin Formation and Plasma Ignition Boiler Startup

LIU Xin, LI Ming, SUN Shu-weng, CUI Xing-yuan, ZHANG Jing-wu

2014, 47(8):  98-102.  DOI: 10.11930/j.issn.1004-9649.2014.8.98.4

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The formation and exfoliation of oxide skin on the high temperature heating surfaces have become a worldwide problem that may threaten the secure operation of electric power generating units. It is widely agreed that the formation and exfoliation of oxide skin may be accelerated by the plasma igniter for boiler startup. In fact, the oxide skin formation and exfoliation are indeed related to the startup and shutdown rates of the boilers. In this paper, the detailed analysis on this problem is conducted from the aspects of boiler startup and shutdown methods, the initial and succeeding loading rates and operational adjustment. Based on the experience on hundreds of boilers that are equipped with plasma igniter in pulverized coal burners, especially in supercritical and ultra supercritical units, if the startup process satisfies the temperature and pressure rising curves and the initial and succeeding loading rates as well as the operation style are appropriate, the formation and exfoliation of oxide skin in the tubes of high temperature heating surfaces will not be accelerated.

Study on Ignition and Flame Stabilization Mechanism of Down-Shot Firing Boiler with Swirl Burners

WEI Tong-sheng, YANG Peng-she, DAI Xin, NIE Jian-ping

2014, 47(8):  103-106.  DOI: 10.11930/j.issn.1004-9649.2014.8.103.3

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The experimental study is conducted on the problems of instable combustion and high combustibles in fly ash which exist in two 600-MW down-shot firing boilers of a power plant equipped with swirl burners. Based on the analysis of the experiment phenomena, the ignition and combustion stabilization mechanisms are discovered, The experimental and theoretical analysis show that: first, it is not the inner gas recirculation of the high temperature flue gas in the swirl burners but the radiation heat absorption plays the important role in the ignition process of the primary air jet, which happens far from the burner nozzle; second, the combustion stability is enhanced and the economics of the combustion is improved with the lower swirl intensity setting and deeper penetration into the lower furnace.

The Domestically Made DCS System to Realize FCB in 1 000-MW Unit of Taishan Power Plant

GONG Guang-zheng

2014, 47(8):  107-112.  DOI: 10.11930/j.issn.1004-9649.2014.8.107.5

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The 1 000-MW unit in Taishan Power Plant did not possess the fast cut back(FCB) function in the original design. The existing FCB function is achieved through the local retrofit based on the margin of the original design. Firstly, the configuration of the unit is analyzed to determine whether the unit is capable of implementing the FCB function. Secondly, the orientation and strategy to realize the FCB function are fixed through the performance test to further verify that the performance and design of the main and auxiliary equipments can satisfy the requirements of the FCB function. Finally, the modification of the equipments and the improvement of the control logics are conducted during unit shutdown to realize the FCB function under 100% load condition. The FCB test results show that the unit has the capability to run with the auxiliary power load and can be restored to power delivery quickly in case of major abnormalities of power grids.

Analysis and Precautions for High-Speed Mixed Bed Flow Leaning of Condensate Polishing Treatment System

LI Xiao-jun, HE Hui-yong, YE Mao, YAN Kun

2014, 47(8):  113-115.  DOI: 10.11930/j.issn.1004-9649.2014.8.113.2

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Shortly after the commitment of the condensate polishing treatment system, the problem of insufficient cyclic water production emerged because of high-speed mixed bed flow leaning. Through the inspection after shutting down the equipment, the damaged water porous plate turned out to be the culprit. Subsequent analysis of the mixed bed equipment structure, the configuration of the polishing treatment system, and the operation procedures demonstrated that the water hammer shock caused the damage of water porous plate. Therefore, all of the water porous plates have been replaced with the water porous plates and their connection to the mixed bed strengthened. After such improvements, the system performance is back to normal and the problem of flow leaning is completely solved. Besides, in terms of the problem arising from the mixed bed, several suggestions are proposed to prevent flow leaning for the high-speed mixed bed equipment of newly-built condensate polishing treatment systems.

The Abrasion and Corrosion of Slip-Ring in Large Hydrogenerators

LI Guang

2014, 47(8):  116-118.  DOI: 10.11930/j.issn.1004-9649.2014.8.116.2

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The analysis on the abrasion and corrosion phenomenon of slip-ring in large hydrogenerators is conducted, and it concludes that this phenomenon is mainly caused by the mechanical wear, electric spark corrosion and electrochemical corrosion. Therefore, the prevention and mitigation measures are proposed as follows. Firstly, choose natural graphite carbon brush; secondly, eliminate the brush sparking in time; thirdly, strengthen the shutdown protection; fourthly, improve the running environment of the ring room; and finally, keep the ring surface smooth. These measures have been applied to the 125-MW units of Gezhouba Hydropower Plant. It demonstrates that the operating state of slip-ring in the hydrogenerators gets improved substantially, and the sparking and overheating caused by the abrasion and corrosion are eliminated.

Regeneration of Turbine Oil Using Strong Polar Molecules as Sorbents

WANG Juan, MENG Rui-jun, LI Wei-guo, TANG Jin-wei, CHANG Zhi-jun

2014, 47(8):  119-122.  DOI: 10.11930/j.issn.1004-9649.2014.8.119.3

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This paper introduces the adsorption mechanism of high polar molecule sorbents. The results from the on-site and laboratory experiments of turbine oil regeneration conducted in a power plant adopting the high polar molecule sorbent show that the color of the regenerated turbine oil turns lighter, and it looks transparent and sludge free. Moreover, the levels of demulsification and acid value are restored to the levels of fresh oil with improvement in oxidation stability. Therefore, it will be beneficial for the safe and stable operation of power plants to take advantage of filter elements made of high polar molecule sorbents in online turbine oil regeneration process.

Information and Communication

Implementation of OpenGL-based Visualization Techniques for Safety Warning of Power System

WANG Jian-bo, WU Yao-hao, LIU Wen-ying

2014, 47(8):  123-128.  DOI: 10.11930/j.issn.1004-9649.2014.8.123.5

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With the power system expansion and the increase of the amount of data, highly effective and intuitionistic techniques need to be achieved for the monitoring and safety warming of the system. Therefore, power system visualization techniques are highly concerned in this background. A method to achieve safety warning visualization by drawing power flow animations and voltage bitmaps was conducted by hybrid programming of OpenGL and VC++. Besides, a comprehensive safety warning visualization system was developed, by which the power flow distribution, voltage distribution and the information of out-of-limit and risk component on the screen can be revealed vividly. This warning system has been successfully applied to one domestic grid. Through the interaction of man-machine interface, it does bring great convenience for the dispatchers’ work.

Development of Intelligent Time-Frequency Test and Analysis System

ZHOU Wei, NING Wen-hui, LIU Peng, LI Qiu-xia

2014, 47(8):  129-134.  DOI: 10.11930/j.issn.1004-9649.2014.8.129.5

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The accuracy of the time-frequency test in a power system is directly related to the consistency and validity of data acquisition, storage and analysis. On the basis of introducing time-frequency test techniques and aiming at the deficiencies of the current time- frequency test in the power system, an intelligent time-frequency test and analysis system combining software and hardware was developed in this paper. Firstly, the design scheme of the hardware and its characteristics were introduced. In the following section, the development environment, function features and design processes of the software were described. Then the functions of the intelligent time-frequency test and analysis system as well as its business processes were described. Finally, the functionality and performances of the system were verified by a test example.

Secondary Development of BPA Programming Based on Knowledge Base

LI Peng-fei, ZHOU Zhi-yong, ZHANG Hang, ZHOU Ting-hui, YAN Zheng

2014, 47(8):  135-138.  DOI: 10.11930/j.issn.1004-9649.2014.8.135.3

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For modern power system, the difficulty of using N-2 principles to execute the power system simulation increases constantly. The conventional way to rehearse the contingency manually is laborious and prone to omissions. Therefore, a new method is developed to identify the severest faults and the weakness of the power system, which makes a smooth combination of the N-2 security and stability calculation software with the BPA software and brings in the knowledge base. For the same side of grids, the new method needs only a few cases to simulate, which shortens the total simulation time, and thus achieve a fast simulation of the power system.

Virtual Resources Dispatching Algorithm Based on Multipath Traversal Priority Selection in Cloud Computing

XU Bing-yuan, ZHANG Yi

2014, 47(8):  139-143.  DOI: 10.11930/j.issn.1004-9649.2014.8.139.4

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With the increasing demands on processing and storaging capability of power system computation, the virtualized cloud computing has become the development trend for future smart grid, in which virtual resource dispatching is one of the key technologies. So, a novel heuristic algorithm for virtual resources dispatching based on multipath traversal priority selection was presented. By constructing the task of DAGs and undirected graph for finite virtual machines and applying numbers of methods, such as the path traversal and task priority setting, the scheduled task selection, virtual resource planning and application and allocation of the physical resource, the proposed algorithm can effectively increase the dispatching efficiency and reduce system operation cost on the premise of satisfying the performance requirements of the committed tasks.

Energy Conservation and Environmental Protection

Technical and Economic Evaluation of Whole-Process CCUS

NIU Hong-wei, GAO Shi-wang, LIU Lian-bo, WANG Jin-yi

2014, 47(8):  144-149.  DOI: 10.11930/j.issn.1004-9649.2014.8.144.5

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The economics of the carbon capture, utilization and storage(CCUS) technology is determined by the suitable technologies selected in the stages of the whole process of CCUS in coal-fired power plants. In this paper, the technologies adopted in the CO₂ capture, compression, transportation and enhanced oil recovery under different conditions are derived through itemized comparison. Then the influencing factors of the technologies are analyzed in the aspects of construction investment and operation costs with some optimization measures proposed. Through the comparison between three CCUS schemes assuming each with the capacity of 1 million tons per year for different power plant and oil field compositions, it is concluded that the CO₂ transmission distance is the major factor influencing the total construction cost. However, the cost increase from the average transmission distance may be compensated by the completion of medium-long term plan for common CO₂ transmission piping networks.

Experimental Study on Regeneration of SCR De-NO_x catalysts

PAN Si-wei, YANG Jian-bo, CHEN Dong-lin, DENG Tao

2014, 47(8):  150-153.  DOI: 10.11930/j.issn.1004-9649.2014.8.150.3

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The catalyst adopted in the selective catalytic reduction (SCR) flue gas denitrification for thermal power plants is very expensive, which makes it necessary to regenerate the used catalyst. Seven regeneration liquids were prepared and used to regenerate the typically used SCR De-NO_x catalyst samples from coal-fired boilers. Then the denitrification efficiency and SO₂/SO₃ conversion rate of the regenerated catalysts were tested. SEM and EDS analyses on the micro structure and element composition of the fresh and regenerated catalysts were also conducted to evaluate the regeneration efficiency and figure out the reasons for the decrease of catalytic efficiency. The results show that the De-NO_x efficiency of the used catalyst regenerate by the optimum formula regeneration liquid is up to 72.2%, which is 92.8% of fresh catalyst efficiency and 10% higher than that of the catalyst before regeneration. This means that optimum formula regeneration liquid has a promising perspective for the engineering applications.

Economic Evaluation of Wind Power Generation Based on Benefits of Carbon Dioxide Emission Reduction

ZHAO Xiao-li, WANG Shun-hao

2014, 47(8):  154-160.  DOI: 10.11930/j.issn.1004-9649.2014.8.154.6

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The deterioration of the environment has forced policymakers to substitute conventional energy with renewable energy. However, the high cost of renewable energy power generation constrains the development of renewable energy. In this paper, considering the benefits of carbon dioxide emission reduction, we calculated the total cost(including the economic cost and the environmental cost) of coal fired power generation and wind power generation using the life-cycle approach and the straight-line method with the data from coal-fired power plants and wind farms in the year 2012. The result shows that when taking the benefits of carbon dioxide emission reduction into account, the cost of wind power generation is only 0.027 yuan/(kW·h) higher than that of thermal power generation. Especially under the condition that the annual utilizing hours of wind farms are kept at 2 200 hours or above, the total cost of wind power generation will be lower than that of coal-fired power generation.