Advanced Materials Research Vols. 608-609

Abstract: A major problem in the current biomass gasification systems is the formation of tar. The condensed tar at low temperatures may cause blockage and pollution of downstream equipments, as well as environmental pollution. Therefore, the removal and conversion of tar are the key issues for biomass gasification. At present, the common methods of tar removal are mainly mechanism methods, thermal cracking and catalytic cracking. In this paper, the catalytic cracking method and its advantages and disadvantages are discussed.

Abstract: 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.

Abstract: 30 MW straw power turbines are most suitable in the major corn producing areas in Northeast China. This paper takes straw power plants that are already used in practice as examples to demonstrate the technological and economical analysis of straw power-generating projects. The research results show that straw cogeneration is advantageous in energy utilization rate, economic profits, and etc.

Abstract: This paper summarizes the research results of the structural parameters which have effects on the performance of Savonius wind turbine. Savonius wind turbine being used in wind power and tidal power belongs to vertical axis wind turbine (VAWT). Recently, more and more research have placed on it for its advantages such as: being able to accept wind from any direction, long fatigue life of the blades, high starting torque, wide working wind speed range, easy to install, manufacture and maintain and low noise etc. The performance of Savonius wind turbine is affected by many factors. Different structural parameters can bring huge differences in turbine performance. Especially the differences in the maximum wind energy utilization (Cp-max) can be more than 30% with different structure. Many new turbines get higher Cp-max by improving the structural parameters. In this paper, the structural improvement information of Savonius wind turbine is summarized in order to provide useful knowledge for the researchers in the structural design and improvement.

Abstract: As the wind is random and intermittent, the output power of the wind turbine will also be changing, causing the generator output power fluctuation and voltage fluctuation, flicker, and early deterioration of battery. In order to improve the stability of the off-grid power systems, power quality, and better to protect the energy storage devices, the paper analyzes the main factors of the impact of fluctuations in output power from the off-grid wind power systems and energy storage technology to mitigate the off-grid wind turbine power fluctuations.

Abstract: Although the world wind generation capacity is in constant growth, the technology of wind generation is not perfect. Therefore, the research on wind power technology research is very neces-sary .Research on the design scheme of test platform of hardware, design wind turbine simulator, the power electronic converter device, platform detection circuit, drive circuit and control circuit and other parts, and build the direct-driven type of wind generation experimental platform. It by the generator commissioning, the analysis result has demonstrated that the design of the system is rational.

Abstract: 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.

Abstract: In order to improve the frequency stability of grid, new control strategy for wind turbines need to be developed with high wind power penetration. This work analyzes the requirements of frequency control for wind turbines in some countries, and the characteristics and methods of typical frequency control strategy are analyzed. To meet the requirements of frequency control of wind turbine and to improve wind energy utilization efficiency, a method of optimization scheme of frequency control on wind turbine is given in the paper, and the operating curve of wind turbine with the control method is determined, at the same time this work gives a general method about how to determine some key parameters.

Abstract: To search effective technical solutions to control fire risk of wind turbines, based on the risk system composed of “Human- Equipment - Environment – Management” in safety systems engineering theory, the four main aspects of wind turbines fire risk, i.e., lightning strikes and bad weather, mechanical and electrical equipment failure, human errors and poor management and fire protection systems missing, were pointed out. The fire risk and fire risk control measures of wind turbines were analyzed, the progress of fire detection technology and fire protection solutions of wind turbines were reviewed. The results show that, to develop and equip with high-performance automatic fire detection, alarm and extinguishing systems is the inevitable choice to effectively control the fire risk of wind turbines.

Abstract: 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.