176,505 research outputs found

    Turbine design review text

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    Three-volume publication covers theoretical, design, and performance aspects of turbines. Volumes cover thermodynamic and fluid-dynamic concepts, velocity diagram design, turbine blade aerodynamic design, turbine energy losses, supersonic turbines, radial-inflow turbines, turbine cooling, and aerodynamic performance testing

    Techno-economic comparison of operational aspects for direct drive and gearbox-driven wind turbines

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    The majority of wind turbines currently in operation have the conventional Danish concept design-that is, the three-bladed rotor of such turbines is indirectly coupled with an electrical generator via a gearbox. Recent technological developments have enabled direct drive wind turbines to become economically feasible. Potentially, direct drive wind turbines may enjoy higher levels of availability due to the removal of the gearbox from the design. However, this is only a theory: so far not substantiated by detailed analytic calculation. By providing such a calculation, this paper enables us to quantitatively evaluate technical and economic merits of direct drive and gearbox-driven wind turbines

    Select Committee on Wind Turbines final report

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    The committee recommends the Commonwealth Government create an Independent Expert Scientific Committee on Industrial Sound responsible for providing research and advice to the Minister for the Environment on the impact on human health of audible noise (including low frequency) and infrasound from wind turbines. Recommendation 1: final 6.5 The committee recommends that an Independent Expert Scientific Committee on Industrial Sound (IESC) be established by law, through provisions similar to those which provide for the Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development. 6.6 The provisions establishing the IESC on Industrial Sound should state that the Scientific Committee must conduct \u27independent, multi-disciplinary research into the adverse impacts and risks to individual and community health and wellbeing associated with wind turbine projects and any other industrial projects which emit sound and vibration energy\u27

    High Frequency Radar Wind Turbine Interference Community Working Group Report

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    Land-based High Frequency (HF) Radars provide critically important observations of the coastal ocean that will be adversely affected by the spinning blades of utility-scale wind turbines. Pathways to mitigate the interference of turbines on HF radar observations exist for small number of turbines; however, a greatly increased pace of research is required to understand how to minimize the complex interference patterns that will be caused by the large arrays of turbines planned for the U.S. outer continental shelf. To support the U.S.’s operational and scientific needs, HF radars must be able to collect high-quality measurements of the ocean’s surface inand around areas with significant numbers of wind turbines. This is a solvable problem, but given the rapid pace of wind energy development, immediate action is needed to ensure that HF radar wind turbine interference mitigation efforts keep pace with the planned build out of turbines

    The small wind turbine field lab

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    The emerging market of small wind turbines (SWT) is characterised by a large variety of turbine types as well as turbine performance. The abundance of more ‘exotic’ types of vertical axis wind turbines (VAWT) next to the more traditional horizontal axis wind turbines (HAWT) shows that this market is still developing. However, some technologies have proven to possess the same potential typically only found in larger wind turbines. To study the (lack of) performance of current small wind turbine but also to demonstrate their potential, Ghent University decided to launch the Small Wind Turbine Field Lab (SWT Field Lab). This fully scientifically equipped field lab, funded by the Hercules Foundation, offers the possibility to not only monitor the energy yield of the turbine, but also collect information on how to optimise the grid integration, measure mechanical stress and structural strength of turbine components, assess the generator design and tower construction, perform acoustic measurements and finding ways to reduce noise production, even simulate siting of wind turbines, e.g. in rural areas or on industrial parks. All of these parameters are correlated with meteorological data measured on-site. The field lab, based in the inner port of Ostend, provides provisions for placement of up to ten small wind turbines, with seven turbines already partaking in the field trials. The project members aim to use the project results to identify and remove performance limiting factors in the design of small wind turbine, and to demonstrate the feasibility of using small wind turbines for decentralised renewable energy production. With this and similar research projects, the emerging market of small wind turbines can grow beyond its current state of infancy, comparable to the market evolution of large wind turbines

    Dynamics and stability of wind turbine generators

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    Synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Integration between adjacent wind turbines in a wind farm is also considered

    Review of the development of small- and medium-capacity gas turbines at the Motoren- und Turbinen Union

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    Small- and medium-capacity gas turbines under development for turboprop aircraft and helicopter, as well as for armored and commercial vehicle propulsion, are discussed. Design problems related to axial turbines, ceramic components, regenerative gas turbines, and the optimal expansion ratios for turbines with capacities from 250 to greater than 800 kW are considered; in addition, combustion chamber technology is mentioned. Prototype gas turbines with capacities of 500 to 600 kW or 800 to 1800 kW are described

    Provision of Ancillary Services with Variable Speed Wind Turbines

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    In recent years, the amount of wind turbines in the power system has increased tremendously. As the current wind turbines do not participate in the provision of ancillary services such as frequency control and voltage control, this may compromise the proper functioning of the electric power system. However, since the modern wind turbines are equipped with a power-electronic converter, they can assist in the provision of ancillary services. To achieve this, additional control loops have to be added to the wind turbine controller. In this paper, an overview of the different ancillary services is given. The ability to provide them with wind turbines is discussed. Since frequency and voltage control are the most important, these two services are further elaborated. It can be concluded that wind turbines are suited to provide frequency control, especially when they are operated slightly below their maximum power point. They can also assist in voltage control, while operation in the maximum power point is usually possible, so few energy is lost. These are important outcomes, since wind turbines which provide ancillary services can contribute in allowing a higher penetration of renewable energy in the power system without compromising its proper functioning

    The influence of blade curvature and helical blade twist on the performance of a vertical-axis wind turbine

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    Accurate aerodynamic modeling of vertical-axis wind turbines poses a significant challenge, but is essential if the performance of such turbines is to be predicted reliably. The rotation of the turbine induces large variations in the angle of attack of its blades that canmanifest as dynamic stall. In addition, interactions between the blades of the turbine and the wake that they produce can exacerbate dynamic stall and result in impulsive changes to the aerodynamic loading on the blades. The Vorticity Transport Model has been used to simulate the aerodynamic performance and wake dynamics of vertical-axis wind turbines with straight-bladed, curved-bladed and helically twisted configuration. It is known that vertical-axis wind turbines with either straight or curved blades deliver torque to their shaft that fluctuates at the blade passage frequency of the rotor. In contrast, a rotor with helically twisted blades delivers a relatively steady torque to the shaft. In the present paper, the interactions between helically twisted blades and the vortices within their wake are shown to result in localized perturbations to the aerodynamic loading on the rotor that can disrupt the otherwise relatively smooth power output that is predicted by simplistic aerodynamic tools that do not model the wake to sufficient fidelity. Furthermore, vertical-axis wind turbines with curved blades are shown to be somewhat more susceptible to local dynamic stall than turbines with straight blades

    The Significance of Wind Turbines Layout Optimization on the Predicted Farm Energy Yield

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    Securing energy supply and diversifying the energy sources is one of the main goals of energy strategy for most countries. Due to climate change, wind energy is becoming increasingly important as a method of CO2-free energy generation. In this paper, a wind farm with five turbines located in Jerash, a city in northern Jordan, has been designed and analyzed. Optimization of wind farms is an important factor in the design stage to minimize the cost of wind energy to become more competitive and economically attractive. The analyses have been carried out using the WindFarm software to examine the significance of wind turbines’ layouts (M, straight and arch shapes) and spacing on the final energy yield. In this research, arranging the turbines facing the main wind direction with five times rotor diameter distance between each turbine has been simulated, and has resulted in 22.75, 22.87 and 21.997 GWh/year for the M shape, Straight line and Arch shape, respectively. Whereas, reducing the distance between turbines to 2.5 times of the rotor diameter (D) resulted in a reduction of the wind farm energy yield to 22.68, 21.498 and 21.5463 GWh/year for the M shape, Straight line and Arch shape, respectively. The energetic efficiency gain for the optimized wind turbines compared to the modeled layouts regarding the distances between the wind turbines. The energetic efficiency gain has been in the range between 8.9% for 5D (rotor diameter) straight layout to 15.9% for 2.5D straight layout
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