bluuebunny/crossref_metadata_2025 huggingface dataset:
The Engineering Properties of Kaolinitic Clay and Burning Shell Activated by Alkali Solution
Authors: Vardhanabhuti Barames , Kamhangrittirong Parames , Amornworawit Korakot
Published: December 2012

The use of kaolinitic clay, which chemical compound consists of mainly silica (SiO2) and alumina (Al2O3), mixing with charred seashells, consisting of mainly calcium oxide (CaO), could be improved by polymerization process. The ratio of kaolinitic clay and charred seashells used in the study ranges from 1: 0.6 to 1: 1.6 by weight. After curing for 28 days, the improved material has the ultimate compressive strength in the range of 3.7 to 7.9 MPa. In additions, the improved material has good heat resistance property. The utilization of natural waste materials together with polymerization technique could improve the material properties to meet the demand of construction industry in the future.
SWOT Analysis on Chinese Photovoltaic Industry
Authors: Ma Chi , Zhang Jue Ying , Hu Ying De , Dong Chen Xuan
Published: December 2012

The photovoltaic (PV) industry in China has been developed at a remarkable speed, being supported by the governments and the PV product demand from the international market especially in the developed countries. However, the PV industry in China, now, is coped with a severe challenge due to the several causes. The analysis in the way of SWOT was conducted to figure out the appropriate strategies not only for photovoltaic industry survival but also for the sustainable development.
Model and Analysis of the Output Characteristics of Photovoltaic Module
Authors: Wang An Na , Wu Biao , Zhang Chen Xing , Song Yan Li
Published: December 2012

The model based on matlab S-function of the photovoltaic module describes the relationship between temperature and light intensity of the output characteristics of PV module from the UI and PU curves; This paper further analyzes and discusses the mechanism of hot spot phenomenon of the PV modules and gives reasonable solutions for different situations.
Steam Gasification for Biomass Tar with Natural Ores of Limonite and Dolomite
Authors: Li Liu Yun , Kunii Hiroo , Yamauchi Masamitsu , Kim Hee Joon , Shimizu Tadaaki
Published: December 2012

Light gases were produced from biomass tar gasification using limonite and dolomite as catalysts. Experiments were performed in a fixed bed reactor with the gasification temperatures of 600–800 °C. Limonite gave the obvious effect on the tar gasification, and the light gases of hydrogen and carbon oxides were mainly obtained. Also, the gas yields depended on the catalytic temperature. Hydrogen yields tend to increasing with temperatures from 650 to 800 °C. The reaction equilibrium was changed by dolomite addition in the reactor system; hydrogen gas was doubled with the limonite and dolomite mixture compared to limonite only.
Erosion in the Rectangular Biomass Circulating Fluidized Bed
Authors: Song Jing Hui , Wang Tao , Gao Jing , Xiao Xian Bin , Dong Chang Qing , Hu Xiao Ying
Published: December 2012

Through MFIX software, a three-dimensional numerical gas-solid flow models without chemical reactions is developed to the distributions of solids phase volume fraction and velocities in a 220t/h rectangular cross-section biomass CFB with a height of 3m. The maximum of erosion occurs at the near-wall side at y=0.95m on the front-wall and back-wall. In transition region(0.8-1.4m) of the left-wall and right-wall, typical core-annular regime can be observed, particle in the core region have the tendency to move to the corner. The maximum of erosion occurs at the corner formed between the walls in the role of downward movement of particle. And the lateral movement of particles are obvious enhanced between the core region and back-wall in the role of exit effect, which lead a certain degree of lateral erosion between the core region and back-wall at the left-wall and right-wall.
Study on Combustion Adjustment Characteristics of 50MW CFB Biomass-Fired Boiler in Zhanjiang Biomass Power Plant
Authors: Fang Jiang Tao , Song Jing Hui , Zhan Zhi Gang , Li Ji
Published: December 2012

Circulating Fluidized Bed (CFB) biomass-fired technology is emerging biomass utilization technology for its advantages of wide adaptability of fuels, stable combustion, low-pollutants emission, and high boiler efficiency. This paper first makes literature survey of on-site combustion adjustment and performance tests and analyzes main influenced factors on combustion adjustment for CFB biomass-fired boiler, including unit load, bed temperature, bed pressure, fuel characteristics, primary air, secondary air, air ratio, circulating ash. Then combustion adjustment characteristics are studied on the largest-scale biomass-fired power project in China - 2×50MW CFB biomass-fired power plant in Zhanjiang by Guangdong Yudean Group. Main influenced factors and principle problems of combustion adjustment tests such as unit load, bed temperature, fuel deflagration, oxygen content, and exhaust gas temperature are tested and analyzed. Optimized operation suggestions are proposed according to the combustion adjustment tests.
Study on the Emission Properties of Biodiesel Fueled on Medium-Sized Diesel Engine under Steady Working Conditions
Authors: Xue Yun , Liu Hongwei , Liu Wu Quan
Published: December 2012

As a kind of renewable resource, biodiesel can relieve the shortage of oil resources. This paper tests the emission performance of biodiesel fueled on 4102ZL diesel engine and makes a contrastive analysis with the emissions of 0# diesel fuel. The test result shows improvement of varying degrees in the emission indexes of the engine fueled with B100 soybean biodiesel.
Optimization of Dilute Acid Hydrolysis of Corn Stover for Separate Production of Xylose and Glucose by Response Surface Methodology
Authors: Zhi Su Li , Yang Jing , Yao Yan , Zhang Shu Ting , Lu Xue Bin
Published: December 2012

Dilute sulfuric acid pretreatment of corn stover was used to obtain a solution of high concentration of xylose from the hemicellulosic fraction and a relatively low concentration of glucose, which not only saved the hemicellulase but also made a full use of corn stover. Then the study considered the selectivity (xylose-glucose ratio) as an important parameter to optimize the hydrolysis conditions. The results optimized by response surface methodology (RSM) showed that the optimum conditions for pretreatment were found to be H2SO4 concentration of 2.4% and reaction time of 100min at 100°C. Under these conditions, 78.8% of xylose yield was achieved and the glucose yield was lower than 11.6%. To confirm these results, the optimum condition was performed and the actual results of xylose yield and glucose yield were 78% and 11.3%.
Theoretical Study on Solar-Driven Air-Cooled LiBr/Water Absorption Refrigeration System
Authors: Zhao Dan Dan , Hu Hong Bo , Wan Lu Chun , Zhang Bao Huai
Published: December 2012

In the study, LiBr absorption refrigeration machine runs in the air-cooled condition, combined with temperature and humidity independent control and the air condition end with radiant cooling, improving the system operation mode. Calculation and simulation were carried out to study the performance of the system, and effects of the cooling air inlet temperature and flow rate, refrigerant water outlet temperature on system performance, which will have the important theoretical significance for the development and application of the minitype solar lithium bromide unit.
Hot Utilization of Fuel Gas in Fluidized Bed Biomass Gasification
Authors: Fan Xiao Xu , Chu Lei Zhe , Ma Guang Yao , Yang Li Guo
Published: December 2012

The characteristics of hot gas utilization are analyzed in the thesis and experiments on rice husk were done in 6 MW bubbling fluidized-bed positive pressure gasification system. The results showed that the positive rice husk gasification system can work well and no tar condensed on the pipes. As sensible heat of hot gas accounting for 11.7% of fuel, the method of hot utilization of fuel gas can make full use of gas energy.
Optimization of Multi-Enzyme Hydrolysis Process for Efficient Corn Gluten Meal Hydrolysis
Authors: Wang Yuan Xiu , Zheng Ming Yang , Yang Xiao Hong , Sun Na Xin , Zhang Gui Xiang
Published: December 2012

In order to hydrolyze corn gluten meal efficiently, combinations of two or three out of three hydrolysis enzymes (protex6L, protex7L and papain) were used and the process parameters were optimized in this paper. The degree of hydrolysis of corn gluten meal was assayed by using pH-stat method. The ratio of enzymes was optimized and the effect of multi-enzyme hydrolysis was compared with that of single-enzyme hydrolysis. The result showed that the optimal ratio of protex6L and protex7L was 3:1, protex6L and papain was 6:5, protex7L and papain was 1:1, and the optimal ratio of protex6L, protex7L and papain was 4:1:1.The degree of hydrolysis and soluble protein content of multi-enzyme hydrolysis and single-enzyme hydrolysis were approximately equal, but multi-enzyme hydrolysis was timesaving.
The Simulation Research of the Five Level Photovoltaic Grid-Connected Inverter Based on Repetitive and PI Control
Authors: Liu Jie , Yuan Song Zhen
Published: December 2012

Introducing a kind of bidirectional switch type five level inverter, and put forward the compound control scheme which repetitive control and PI adjustment are combined. And a detailed analysis of the repetitive control algorithm. Through the Matlab/simulink to simulate under different control modes. The results show that, the five-livel inverter which using repetitive PI control, its output grid-connected current waveform stability, harmonic distortion rate is small, and can real-time tracking the network voltage.
The Study of Heating Value and Rate of Return of Biogas Production in King Mongkut’s University of Technology North Bangkok (Prachinburi Campus)
Authors: Somjai Thanutyot , Yingtawee Anurak , Chawanawet Weerayut , Chaiyat Sumitra
Published: December 2012

This research aims to study biogas production in King Mongkut's University of Technology North Bangkok Prachinburi Campus. Information of biogas energy from the food waste fermented in 2,000 liters capacity tank was analyzed to determine the heating value in order to calculate the Net Present Value (NPV), Internal Rate of Return (IRR) and Discount Payback Period (DPB). All the measured values from 15 days testing period are the gas quantity of 0.5-0.9 m3 and the average heat value of 10 MJ/m3.Ten fertilization chambers that have capacity of 6,000 liters each for biogas production should be replaced the original size of 2,000 liters tank because using the original tank could not reach breakeven point. By using 10 champers of 6,000 liters capacity each, the payback period has yielded within 5 years and 5 months and given the rate of return 22.48 percent per years throughout 20 years of recovery period.
Steam Reforming of Biomass Tar Model Compounds over Monolithic Catalysts
Authors: Chen Lei , Zhang Xiao Dong , Zhao Bao Feng , Meng Guang Fan , Si Hong Yu , Xu Min
Published: December 2012

Biomass tar was an inevitable by-product during biomass pyrolysis and gasification. The existence of biomass tar was a significant drawback for the use of biomass produced gases. At present, catalytic steam reforming was one of the most effective ways for tar conversion and elimination.In this paper, the coke-resistance Nickel-based monolithic catalyst and the Nickel-based monolithic catalyst were prepared, using cordierite as the catalyst carrier. Toluene and n-heptane were selected as two typical tar model compounds for the evaluation of catalyst performance in a fixed-bed reactor. The influences of temperature on the tar conversion efficiency were experimentally investigated. The results show that the two prepared monolithic catalysts have excellent performance for tar conversion. At 800°C, the conversion efficiency of toluene reach 82% and 80.4% over the coke-resistance Nickel-based monolithic catalyst and the Nickel-based monolithic catalyst, respectively. The addition of Cerium as the coke-resistance component remarkably reduces carbon deposition tendency with prolonged catalyst lifetime. monolithic catalysts have excellent performance for tar conversion. At 800°C, the conversion efficiency of toluene reached 82% and 80.4% over the coke-resistance Nickel-based monolithic catalyst and the Nickel-based monolithic catalyst, respectively. The addition of Cerium as the coke-resistance component remarkably reduces carbon deposition tendency with prolonged catalyst lifetime.
A Preliminary Study on DeNOx Technologies for Biomass Power Plant
Authors: Shi Fei , Meng Fan Qiang , Sun Bao Min
Published: December 2012

The aim of this paper is to discuss and find proper technologies to meet the new deNOX demand for biomass power plants in China. One of the outstanding features of these power plants is the emission of NOX at times which fails to meet the new standard. However, even if it’s above the emission standard, the value is not too high due to its low combustion temperature. Another feature is the large alkali content in the straw which forms fly-ash with vapour in flue gas. The traditional methods of SNCR and SCR will not fit bio-fuel boilers because of their low combustion temperature, small volume of furnace, high humidity and alkali metal in bio-fuel. Active coke adsorption maybe fit the installed boilers for its simple system and high efficiency. The recirculation of flue gas through a char layer needs to change the design of the boiler combustion system, which can cut immensely the deNOX operation cost of the biomass power plants.
The Experimental Study of the Influence of Mg-Based Additives on Wheat Ash Melting Point
Authors: Zhang Yun , Zhao Ying , Dong Chang Qing , Wei Jun
Published: December 2012

In this paper, the influence of additives on the wheat straw ash melting point was studied. Four kinds of Mg-based additives are added to wheat ashes, including MgCl2•6H2O, MgO, MgSO4 and C4H6O4Mg•4H2O. The results show that MgO is the most effective additives, MgCl2•6H2O and MgSO4 in the next place, while C4H6Subscript textO4Mg•4H2O makes ash melting point decreased. The effective additive amount of the MgO, MgCl2•6H2O and MgSO4 are: 0.35 g/g ash, 0.5 g/g ash, 0.75 g/g ash especially.
Syngas Production from Biomass: A Review
Authors: Lan Wei Juan , Chen Guan Yi , Wang Chao , Zhu Xin Li
Published: December 2012

Biomass is a promising energy resource, due to it is renewable and potentially zero carbon dioxide emissions. Biomass gasification is a major technical option to produce syngas, syngas can be further used as feedstock to product heat and power or bio-gasoline. A lot of research works have been made in biomass-derived syngas production for many years. In this paper, the state-of-the-art biomass-derived syngas production technologies in terms of technical performance are summarized. Many kinds of gasifier types are briefly stated.
The Exploration and Practice of Using Additive to Inhibit the Heating Surface Deposition in Biomass-Fired Boiler
Authors: Huang Fang , Yu Chun Jiang , Wang Qin Hui , Fang Meng Xiang , Luo Zhong Yang
Published: December 2012

In response to the deposition problem in biomass-fired boiler, inert addictive was tested to inhibit the possibility of coking. The deposition samples collected from final and primary superheater of biomass-fired CFB (circulating fluidized bed) boiler were grinded into fine powder. The inhibitive ability of additive was tested by mixing the deposition sample with different proportions of inhibitor under high temperature. By means of scanning electron microscope (SEM), X-ray diffraction (XRD) and other analytical procedures, the properties of the samples with inhibitor such as microstructure, composition were studied. The inhibitor was also introduced to the industrial biomass CFB boiler to verify its inhibition effect on superheater deposition. Unfortunately, the effect of adding inhibitor in industrial boiler is not certain, though the inhibitor added to the samples is obviously effective in weakening coking in the laboratory scope.
Effect on Different Modes to Ethanol Fermentation of Energy Beet
Authors: Shi Shu Zhi , Cheng Da You , Dai Cui Hong , Lu Zhao Xin , Luo Cheng Fei
Published: December 2012

In order to meet the needs of industrial mass production,people began to explore the effect on different modes to ethanol fermentation.Ethanol fermentation with energy beet was done by using batch fermentation and continuous fermentation.Results showed that batch fermentation was better than continuous mode,but its technology was cockamamie.The residual glucose content in fermenting mash was high when fermentation was continuous.And the fermentation was halfway.But continuous fermentation was convenient for industrialization producing.Although the residual glucose content in continuous fermentation mode was high through 0.06 h-1 sugar concentration,the last translation rate of ethanol was high.
Existing Problems and Countermeasures in the Development of China’s Biomass Energy Industry
Authors: Zhao Yu , Suo Chen Xia
Published: December 2012

Biomass energy, a kind of new energy like solar energy and wind energy, is always highly acclaimed globally. The development of China’s biomass energy industry has the following benefits: improve land utilization rate and promote positive cycle of ecosystems in China; improve rural energy utilization efficiency and promote sustainable development of rural economy; develop low-carbon economy and protect the environment; and address energy crisis and guarantee national energy security. However, problems existing in the development of China’s biomass energy industry hamper further development of this industry. This paper summarizes the five problems existing in the development of biomass energy industry development and offers corresponding countermeasures and suggestions.
Sapium Sebiferum(Chinese Tallow), a Promising Energy Plant for Green Diesel(hydrocarbon Fuel）
Authors: Ma Wen , Liu Yu Huan , Ruan Prof. Roger , Jiang Xiang Mei , Wang Yun Pu , Wan Yi Qin , Wu Xiao Dan , Li Yun
Published: December 2012

Sapium Sebiferum is a multiple functional tree with application in energy, pharmaceutics, materials and sightseeing. China is the source land of Sapium Sebiferum. In this paper, the potential of establishing a Sapium Sebiferum based bioenergy industry clusters was discussed. Among all, preparing green diesel (hydrocarbon fuel) from Sapium Sebiferum oil seed via microwave assisted pyrolysis process is the key technology. An ambitious project was described, also foreground of this bioenergy-ecosystem remediation plan was estimated.
Analysis of Current Situation and Countermeasure of Solar Energy Photovoltaic Power Generation in Beijing
Authors: Zhang Xiao Hong , Li Xin , Liang Jin Ping
Published: December 2012

As the world economic development, environmental problems are increasingly serious and renewable energy use by the peoples of common concern. Beijing as the capital of China, is a densely populated city, the increasingly serious environmental problems, the energy consumption also increases, which not only affects people's daily life, but also influence the whole nation's image. The development of solar photovoltaic (PV) generation in Beijing has certain inevitability; its development is mature day after day. But in the course of its development there still exist various problems, therefore, the development of photovoltaic power generation system in Beijing also need further perfect and corresponding support.
Hybrid Energy Storage System to Stabilize the Power Fluctuation of Wind Power
Authors: Xing Zuo Xia , Zhang Guan Feng , Liu Jin Song , Yao Xing Jia
Published: December 2012

Since distributed power generation equipment such as wind power contain electric power fluctuation connected into the power grid, hybrid energy storage (HESS) equipment for power compensation is used to solve the problems of reliability and operation of the utility power grid. Constant power control and Fuzzy-Rules-based control of AC-DC and BESS is proposed for smoothing the random wind power fluctuations, considering the operating constraints of the HESS, such as state of charge (SOC) and wind power (Pout). The simulation is accomplished by using a 9MW wind farm and the HESS in Matlab, The results show that by the proposed control methods of the bi-directional DC-DC converter and the DC-AC converter, the energy storage system can smooth the wind power outputs and provide reactive power support to the grid.
Effect of Coherence Function on Rotational Fourier Spectrum of Wind Turbine
Authors: Tian De , He Wei , Wang Ning Bo
Published: December 2012

In order to consider the rotational effect of rotor and determine the exact loads of wind turbine generator system, rotational Fourier spectrum was deduced, and the physical nature of the rotational Fourier spectrum was indicated. Importance of coherence function to the rotational Fourier spectrum was analyzed according to physical nature, as well as the parameter sensitivity analysis of decay factor. The result shows that there is a sharp dip of rotational Fourier spectrum at the integer multiple rotational frequencies with Davenport exponential coherence function while it's eliminated with coherence function supplied by IEC international standard. The rotational Fourier spectrum energy removes to the high frequency bands, the amplitudes of peak at the integer multiple rotational frequencies are increased with decay factor increased, which results in rotational effect more obvious.
Analysis and Control of Maglev Flywheel Rotor in the Wind Generator
Authors: Wu Hua Chun , Lv Xu Jun , Gong Gao
Published: December 2012

The application of maglev flywheel in wind generator is investigated. The dynamics analysis of maglev flywheel rotor has been performed including the critical speed analysis and unbalance response analysis, which took into account the gyroscopic effect by using of finite element analysis method. Based on the model reduction method, the modeling and LQR control of maglev flywheel rotor is presented, the simulation results show stable levitation and good levitated rotation.
Safety Design of Wind Turbine’s Mobile Low Voltage Ride through Test Device
Authors: Zhang Jin Ping , Wang Rui Ming , Li Qing , Sun Yong , Chen Chen
Published: December 2012

Wind turbine’s Low Voltage Ride Through(LVRT) ability must be verified by site-test, safety design was key factor of wind turbine’s mobile LVRT test device design and development. Based on research of protection scope, design principal of safety design, this paper realized five aspects of safety design: switchgear selection, relay configuration and setting value, routine operation, self-check failure lock, operation regulations. Safety design realized by this paper did not affect normal test process, colud provided perfect protection to operator, wind farm facilities and test device. Test device complied with this design had been used in wind turbine site-test and perfected well.
Research on early Fault Prediction of Wind Turbine Gearbox
Authors: Zhao Hong Shan , Liu Yan Sheng , Zhang Xiao Tian , Guo Wei
Published: December 2012

Fault of gearbox is one of the significant causes which lead to high cost of wind farm, so early fault prediction of gearbox is meaningful for ensuring reliable running and reducing maintenance costs. With condition monitoring data, the relation between gearbox temperature and potential faults was researched and a new method for online fault prediction of wind turbine gearbox was presented. First, the temperature prediction model for normal behavior of gearbox was built up by non-linear regression analysis. Then, a detecting function which can indicate the deviation between actual running state and prediction state of gearbox was introduced. The condition of gearbox could be monitored by comparing the real-time value of detecting function with the chosen threshold. Theoretical analysis and simulation results demonstrated that this method could predict the abnormality of gearbox in time, and it can be applied to monitor the running condition of gearbox.
Study on Characteristics of Wind Power Output in Jing-Jin-Tang Grid
Authors: Liang Yu Zhi , Li Shan Ying , Li Qun Ju , Zhao Weiwei
Published: December 2012

In this paper, the wind resources and planning in Jing-jin-tang grid are firstly introduced. The focus is on the analysis of characteristics of wind power output in Jing-jin-tang grid. The analysis data is from the actual wind running power and load in the whole year. The indicators considered are wind power penetration, proportion of wind output power, guaranteed capacity, effective output, etc. The results studied have the important significance for grid planning and operation.
Low Voltage Ride-through Analysis and Control for Doubly Fed Wind-Power Induction Generator Using Finite State Machine Method
Authors: Wang Yun , Gong Wen Ming , Fu Xun Bo
Published: December 2012

Low Voltage Ride through (LVRT) technology of Doubly Fed Wind-Power Induction Generator (DFIG) is a very important issue for grid-connection of wind power system. The paper analyzed and simulated dynamic response of DFIG under balanced and unbalanced gird voltage dip. Then proposed a whole set of LVRT control strategies based on finite state machine method for DFIG and carried out a detailed experimental validation on a 22KW DFIG driving system test platform on balanced grid voltage dip, which was connected to a voltage-dip generator. The experimental waveforms indicated that the proposed control strategy could effectively met LVRT requirement under different dip depth and time.
Study on Reactive Power Compensation of Single Wind Farm
Authors: Li Yue , Liu Bao Zhu
Published: December 2012

With the proportion of wind turbine generation system(WTGS) in power grid is highly increasing, which produces a great effect on the security and stability of the electric power network. Considering the current condition and characteristic of wind form, we built a simulation model in the imitative situation with different wind turbine outputs and different feeder types, obtained the reactive power loss of wind farm and key node voltage, as well as the ability of fixed compensation device. By using the reactive power generated from wind turbine, it can reduce capacity of the reactive compensation device in collection station, which realizes the balance of reactive power, increases the voltage stability.
Small-Capacity Experimental Prototype of VSC-HVDC for Offshore Wind Farm
Authors: Wu Jie , Wang Zhi Xin , Jiang Chen Hui , Wang Guo Qiang
Published: December 2012

VSC-HVDC is one of the proven solutions for the transmission problem of offshore wind power. The structure of back-to-back with two-level converters was adopted for wind farm and grid side, in this paper. PI controllers and SVPWM modulation strategy were used for control system. The double closed-loop vector control method was used for converters of two ends, one end controlling DC voltage and the other controlling active power. The reactive power was controlled by both ends independently. The designed system was verified by simulation and experiment based on a small-capacity experimental prototype.
Dynamic Evaluation of Wind Turbine Health Condition Based on Multi-Source Information Fusion
Authors: Dong Yu Liang , Wang Cheng Cheng , Pan Qi Yun
Published: December 2012

Due to highly complex and non-stationary operation condition, a dynamic wind turbine health condition evaluation approach based on multi-source information fusion is recommended. The uncertainty and incompletion of evaluation factors are fully considered, both qualitative and quantitative evidences are integrated. A case study is provided to illustrate the implementation process of the dynamic evaluation approach for wind turbine health condition. It is shown that the proposed approach offers a flexible and effective way of wind turbine health condition evaluation and the result can be used as a support for condition based maintenance decision.
Analysis Model of Wind Power Cost Based on Two-Factor Learning Curve
Authors: Kang Jun Jie , Duan Wei , Yao Ming Tao
Published: December 2012

The components of wind power cost are analyzed firstly, which provide an intuitive explanation for understanding the composition of wind power generation. And then a two-factor learning curve model is developed for forecasting future price of wind power. We use the model for practical forecasting and simulating wind power cost from 2012 to 2020, the results obtained demonstrate the credibility and validity of the model.
The Crucial Issues in Low-Level Wind Predicton that Used for Wind Energy Forecasting
Authors: Liu Xiao Lin , Jin Shuang Long , Wang Li
Published: December 2012

The WRF model is employed to simulate the low-level wind field of a wind farm that located in the arid regions in northwest of China for February and October 2008. We presented some difficult issues using mosescale numerical model in low-level wind predicting, meanwhile, corresponding solutions are proposed. Some conclusions and achievements in wind forecasting are summarized; the planning and prospects of next phase also are illustrated.
High Voltage Ride through of PMSG-Based Wind Turbines
Authors: Wang Ling Ling , Hu Shu Ju , Li Feng Lin , Li Nian Hong
Published: December 2012

The fault ride through capability of wind turbine is becoming more important with the rapid growth of wind power installed capacity. Among several grid faults the voltage swell is a critical event. Thus, to enhance the high voltage ride through capability of popular PMSG-based wind turbine, the behavior of the PMSG wind turbine when subjected to a voltage swell was analyzed and a strategy was proposed. The overvoltage results in an increasing converter DC bus voltage. By analyzing the vector diagram of line-side converter, the paper recommends increasing inductive current assisted with chopper resistors to ride through the overvoltage safely, and the reactive current reference calculation method is given. The analysis of the performance and the strategy is presented and verified by simulations with a 1.5MW PMSG wind turbine simulation model.
Predictive Condition Monitoring and Fault Diagnosis Techniques for Offshore Wind Turbines
Authors: Zheng Xiao Xia , Ye Cong Jie , Fu Yang , Li Dong Dong
Published: December 2012

Wind energy conversion is the fastest-growing source of new electric generation in the world. The unforeseen damages of a component in a wind turbine have significant impact on the wind turbines, especially offshore ones. There has been a trend towards adoption of various forms of condition monitoring and fault diagnosis to know the deteriorating condition for both mechanical and electrial components, well in advance of a breakdown. This paper review the most recent advances in these areas with a special focus on offshore wind turbines. Different type of faults on offshore wind turbines are reviewed, including gearbox and bearing failures, generators failures, rotor failures and electrical failures. And then two widely-used methods(vibration analysis and oil monitoring) for predictive condition monitoring and fault diagnosis in offshore wind turbines are reviewed.
Research on Steric and Multilevel Concentrator for Photovoltaic Generation
Authors: Yang Xiao Fan , Xu Zhi Long , Li Chao , Huang Zhong Ming
Published: December 2012

As the development trend of solar energy, which is a green way of energy utilization, photovoltaic power generation has been a research hotspot of solar energy utilization technologies. Using the concentrating and tracking technology to increase the illumination intensity, and obtain more electrical energy, that will reduce the cost of the photovoltaic power generation system sharply. A kind of steric and multilevel concentrator for photovoltaic generation is introduced in this paper, whose concentration ratio is 3. The operating factor of plane mirrors and performance price ratio of the system is increased for optimizing the condensation parameters and structure of the concentrator.
MPPT of Doubly-Fed Induction Generator in Wind Farm Using SPSA Algorithm
Authors: Kuang Hong Hai , Wu Zheng Qiu , Li Sheng Qing
Published: December 2012

In order to make wind power generation system be free from outside interference, and make doubly-fed induction generator (DFIG) easily operate at maximum power point under variable wind speed, simultaneous perturbation stochastic approximation (SPSA) algorithm for tracking maximum power of wind power generation system is proposed in this paper. SPSA algorithm indirectly controls DFIG speed through adjusting duty cycle of power converter, makes system operate at maximum power point under any wind speed, thus the maximum power output is transmitted to the load. SPSA algorithm not only does not need to set up PID three parameter values, but also does not anemometer and tachometer in practical applications. Simulation results show no matter how wind speed changes, SPSA algorithm can effectively improve power output of wind power generation system, and make tip speed ratio and power coefficient be near optimum value, reduce system cost.
The Low Voltage Ride through Simulation Analysis for Wind Turbines to Grid
Authors: Zhang Ze Xin , Bao Guang Qing
Published: December 2012

According to the provisions of low voltage ride through capability of wind turbines in the “large-scale design and technical specifications for wind farm to grid” of china, proposed a method to simulate this low voltage ride through grid voltage by computer simulation software. The simulation method is mainly used to simulate whether the wind turbines grid can meet the low voltage ride through requirements. In order to obtain the required grid voltage, the fault simulation circuit is divided into voltage dip part and voltage recovery part, which were used to simulated 20% & 90% voltage dip and the 20% grid voltage gradually recovered to 90% grid voltage. Three-phase fault modules for the voltage dip part, Three-phase programmable voltage source module for the voltage recovery part. The simulation results show that simulation system we build can simulate the required grid voltage.
Evaluation of Low-Level Winds from WRF Model that Driven by Different Background Field Data with Applications to Wind Energy Forecasting
Authors: Liu Xiao Lin , Yang Zhao Ming , Jing Shuang Long , Wang Zhi Qiang , Wang Shi Gong
Published: December 2012

With the large-scale and rapid development of wind power in China, the accuracy of wind power prediction is asked for higher. So how to improve the accuracy of numerical weather prediction models which forecast wind has become an important and critical issue. That the accuracy of numerical prediction models as well as the bias of background data is main cause why generate simulated error. This paper attempted to employ the advanced WRF model to simulate the low-level wind in arid region of northwest China, and then evaluated the impact size that using FNL and GFS background data. The results show that using FNL and GFS data simulated wind is very close. It is found that simulation results driven by the FNL assimilated data are worse sometimes. Consequently, we can conclude that FNL assimilated data as well as GFS forecast data are close and the assimilation of FNL data is still need to improvement in northwest China.
Aerodynamic Design and Finite Element Modelling of Mixed Aerofoil Wind Turbine Blades
Authors: Tang Xin Zi , Peng Rui Tao , Liu Xiong Wei
Published: December 2012

Both rotor aerodynamic characteristics and structural performance of the blade are critical to the wind turbine system service life; an accurate loading model of the blade is extraordinary complex due to the complexity of the geometry shape and variety of blade thickness. In this paper, a 10KW fixed-pitch variable-speed wind turbine blade with five different thickness of aerofoil shape along the span of the blade is presented as a case study, main parameters of the wind turbine rotor and the blade aerodynamic geometry shape are determined based on the principles of the blade element momentum (BEM) theory, a specific blade internal structure and layup schedule are designed. Based on the FE method, deflections and strain distributions of the designed blade under extreme wind conditions are numerically predicted. Theoretical and numerical results indicate that aerodynamic characteristics of the designed blade meet the requirement, the tip clearance is sufficient to prevent collision with the tower, and the blade material is linear and safe.
FLUENT-Based Numerical Simulation of Fan Blade of the Scenery Tower Power Generation Device
Authors: Yang Wei Min , Bai Wen Juan , Li Shu Jiang
Published: December 2012

The blade is the most important and the most basic component in a wind turbine. Testing its river basin through the physical experiment is difficult, because this test system is complex and workload is heavy, and through the macroscopic observation result far from the actual value.According to this problem, this study employs UG 3d entity software modeling, using computational fluid dynamics software FLUENT to simulate the speed changes of fan blade rotating basin and the pressure distribution.The simulation results show that the airflow velocity in the impeller increases with impeller radius increasing,static pressure with air from entry to export flow decreases gradually.
Research on Wind Power Industry Development in Xinjiang
Authors: Wang Zhi Jian , Lang Hui , Cao Jia
Published: December 2012

This document explains the development of wind power; especially the wind power energy in Xinjiang. At the same time the paper demonstrates the difficulties, wind power technology, Wind power is a fixed tariff and tariff subsidies lag, the grid company lack of acquisition of wind power and the trading system is incomplete and hampered a wide range of consumer satisfaction, which faced in the further development of Wind power industry and finds some factors. The good news is National policy began to tilt to the solar, wind and other clean energy, which is a good opportunity for the wind power industry in Xinjiang.
The Influence of Rotor Arrester on Low Voltage Ride through Behavior of Doubly-Fed Induction Generator
Authors: Chen Chen , Wang Rui Ming , Zhang Jin Ping
Published: December 2012

Low voltage ride through (LVRT) behavior is one of the key indices of wind turbine grid-integration evaluation. The key electric components of wind turbine, such as converter, control system had been researched. While other components of wind turbine, such as the rotor arrester, are also non-ignorable. Firstly, overvoltage of rotor during the LVRT is analyzed and one failure test has been presented because of rotor arrester performance. Finally, the rotor arrester has impact not only on the LVRT ability of wind turbine, but also damage to other hardware by on-site testing.
Research of Embedded Control System of DFIG Wind Generation
Authors: Liu Jin
Published: December 2012

This paper presents an embedded control system for wind power generation based on DFIG (Doubly-fed Induction Generator). DSP was used as the core of the control system, which can meet the requirement of high precision and real time. An embedded real-time operation system (RTOS) was transplanted into the hardware platform and some function blocks in common use were added into the RTOS. The control system software in the computer was programmed with LabVIEW, which perform the control function and can process the data came from the A/D in the platform. By using this experiment platform, many control arithmetic of wind power generation can be tested in the laboratory.
A Study on the Solar-Thermal Performance in PV/T System
Authors: Zhou Qing Shan , Zhang Zhi Gang
Published: December 2012

Based on the thermal equilibrium between the PV panels and the glazing cover of PV/T system, the influence of the spacing between PV panels and glazing cover on the solar-thermal efficiency is discussed. The heat release and solar-heat conversion efficiency of the photovoltaic panels, under different plate spacing, in the PV/T systems in summer are calculated, according to the typical annual meteorological parameters of Tianjin area. The results show that the photo-thermal efficiency of the PV/T system can be improved by appropriate setup of the plate spacing, and the optimal plate spacing is affected by the temperature of photovoltaic panels.
Reliability Assessment of Wind Power System Considering Multi-Objective Models
Authors: Zhao Chun Hong , Liu Lian Guang , Liu Zi Fa , Chen Ying
Published: December 2012

The integration of wind farms has a significant impact on the power system reliability. An appropriate model used to assess wind power system reliability is needed. Establishing multi-objective models (wind speed model, wind turbine generator output model and wind farm equivalent model) and based on the non-sequential Monte Carlo simulation method to calculate risk indicators is a viable method for quantitatively assessing the reliability of power system including wind farms. The IEEE-RTS 79 test system and a 300MW wind farm are taken as example.The calculation resluts show that using the multi-objective models can improve accuracy and reduce error; the higher average wind speed obtains the better system reliabitity accordingly.
Research on Single Neuron Adaptive PID Control for MPPT of Wind Power System Using Switched Reluctance Generator
Authors: Wang Hong Hua , Wang Cheng Liang
Published: December 2012

Switched reluctance generator (SRG) has a promising prospect for variable speed wind energy application because of its ruggedness, advantage cost, simplicity and ability to work over wide speed ranges. This paper presents the application of a single neuron adaptive PID algorithm to the problem of maximum power point tracking (MPPT) control in the wind power system using SRG, and a 750W, three phase (6/4) SRG prototype is chosen for the study. The nonlinear characteristics of the SRG and the wind turbine are described firstly, then the optimal speed tracking strategy based on the single neuron adaptive PID control for MPPT of the wind power system using SRG is investigated in the paper. Based on the developed model in MATLAB environment, simulation studies are performed in various conditions including a step change in the wind speed or in the load of SRG. Simulation results show the control system can quickly and steadily track the optimal curve to realize the MPPT with excellent dynamic and static performances, which verify the effectiveness of the control strategy investigated in the paper.
Analysis of Aerodynamic Performance for Wind Turbine Based on Amended Calculation of BEM Theory
Authors: Tian De , Dai Shuo Ming , Liu Si , Wang Ning Bo
Published: December 2012

Effects of tip losses, hub losses, amended attack angle, and amended thrust coefficient are taken into consideration to analyze aerodynamic performance of wind turbine blades based on the blade element momentum (BEM) theory. Based on amended calculation of BEM theory, a program code is developed by software named Matlab. Using a 1500kW wind turbine as an example, aerodynamic information, performance coefficients and blade load distributions are calculated. Compared with the well-known international wind power design software called Garrad Hassan (GH) Bladed, the results have good consistency, which further verifies amendments to the model algorithms and accuracy of the calculation. As a result, the amended calculation of BEM theory can reflect blade aerodynamic performance characteristics under actual operating condition, which has good reference and practicality for the wind turbine design and evaluation.
Short-Term Wind Speed and Power Prediction Using Fuzzy Information Granulation-Support Vector Machine
Authors: Fu Xiao , Jiang Dong Xiang
Published: December 2012

The power fluctuation of wind turbine often causes serious problems in electricity grids. Therefore, short term prediction of wind speed and power as to eliminate the uncertainty determined crucially the development of wind energy. Compared with physical methods, support vector machine (SVM) as an intelligent artificial method is more general and shows better nonlinear modeling capacity. A model which combined fuzzy information granulation with SVM method was developed and implemented in short term future trend prediction of wind speed and power. The data, including the daily wind speed and power, from a wind farm in northern China were used to evaluate the proposed method. The prediction results show that the proposed model performs better and more stable than the standard SVM model when apply them into the same data set.
Assesment of Quality Classification of Green Pellets for Nuclear Power Plants Using Improved Levenberg-Marquardt Algorithm
Authors: Kusumoputro Benyamin , Prarizky Rozandi , Wahab Wahidin , Sutarya Dede , Na Li
Published: December 2012

Cylindrical uranium dioxide pellets, which are the main components for nuclear fuel elements in Light Water Reactor, should have a high density profile, uniform shape and quality for the safety used as a reactor fuel component. The quality of green pellets is conventionally monitored through a laboratory measurement of the physical pellets characteristics followed by a graphical chart classification technique. However, this conventional classification method shows some drawbacks, such as the difficulties on its usage, low accuracy and time consuming, and does not have the ability to adress the non-linearity and the complexity of the relationship between the pellet’s quality variables and the pellett’s quality. In this paper, an Improved Levenberg-Marquard based neural networks is used to classify the quality process of the green pellets. Robustness of this learning algorithm is evaluated by comparing its recognition rate to that of the conventional Back Propagation neural learning algorithm. Results show that the Improved Levenberg-Marquard algorithm outperformed the Back Propagation learning algorthm for various percentage of training/testing paradigm, showing that this system could be applied effectively for classification of pellet quality.
The Study of Surface Modification 304 Stainless Steel in Simulated PEMFC Environments
Authors: Wang Jian Li , Shi Hui Yun
Published: December 2012

In order to increase the corrosion resistant and reduce the interfacial contact resistance of the stainless steel, the duplex treatment technology of electroplating Cr and plasma-assisted nitriding process for AISI 304SS is exploited. X-ray diffraction (XRD), scanning electron microscopy (SEM) and the electrochemical tests such as potentiodynamic and potentiostatic polarization in the simulation PEMFC environments are measured. XRD showed that the surface layer of the 540 ° C and 550 ° C were Cr and Cr2N; the 580 °C was the CrN and Cr2N. The nitride sample of the 550 °C could see the closure process of the mesh crack. Compared with the simulated PEMFC anode environment, higher corrosion resistance was showed in the simulated PEMFC cathode environment. The current density of the 540°C, 550°C and 580°C samples were negative at the operating potential -0.1V, which would provide cathodic protection to the metallic bipolar plates. In the simulated cathode environment, the current densities of the three samples were quickly stabilized, the surface quickly formed a stable passive film.
Preparation and Electro-Catalytic Performance of Pt-Ag/C as Electro-Reduction Catalysts for H2O2
Authors: Guo Zhang Fei , Zheng Dan
Published: December 2012

Using impregnation-chemical reduction method, we prepared Pt/C and Pt-Ag/C nano-catalysts. Both of them are with the same platinum content. The composition of the two catalysts was analyzed by XRD technique. The electrochemical performance was studied by cyclic voltammetry and current-time curve. The results show that: the existence of Ag in the Pt-Ag/C catalyst makes Pt crystallinity decreased; compared with Pt/C, Pt-Ag/C has a higher reductive peak current. In addition, both catalysts show the excellent catalytic stability.