1,770,460 research outputs found
Select Committee on Wind Turbines final report
No full textThe 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
Optimal Management of a Wind/CAES Power Plant by means of Neural Network Wind Speed Forecast
No full textSome of the major limitations of renewable energy sources are represented by their low power density and intermittent nature, largely depending upon local site and unpredictable weather conditions. These problems concur to increase the unit costs of wind power, so limiting their diffusion and the benefits due to the reduced exploitation of fossil resources. By coupling storage systems with a wind farm, some of the major limitations of wind power, such as a low power density and an unpredictable nature, can be overcome.
Furthermore, the use of time-series neural network-based prediction models aims at reducing the stochastic uncertainty of wind power.
A Matlab/Simulink model of a hybrid power plant consisting of a wind farm coupled with Compressed Air Energy Storage (CAES) is presented.
In CAES energy is stored in the form of compressed air in a reservoir during off-peak periods, while it is used on demand during peak periods to generate power with a turbo-generator system. Such plants can offer significant benefits in terms of flexibility in matching a fluctuating power demand, particularly when coupled with renewable sources.
The model employs neural network-based wind speed forecasting to determine the optimal daily operation strategy for the storage system.
Without predicting the incoming wind energy, the net load, above that provided by wind turbines, would be known only in real time. Thus, the only way to manage CAES storage/generation would be to follow the net load for a prefixed number of hours; the operation of CAES would be function of the load, of the wind power generation and the energy prices. Because wind speed is variable and not predictable, plant management can be a problem. Mainly, user demand might not be satisfied during some periods. So, forecasting the wind contribution could be very helpful for proper system management. Knowing the incoming wind power several hours in advance helps in estimating the net load for the current day and thus determining the management strategy.
As shown in the paper, the knowledge of the expected available energy is a key factor to optimize the management strategies of the proposed hybrid power plant.
A detailed economic analysis has been carried out: investment and maintenance costs are estimated based on literature data, while operational costs and revenues are calculated according to the energy market prices
Motion-induced wind forces of a slender prism
No full textThe motion-induced wind forces of a slender prism were investigated using a forced vibration technique. The prism was driven to oscillate by an actuator in cross-wind direction and the unsteady distributed pressures, under different wind velocities and oscillations, were measured. The unsteady generalized and local aerodynamic force coefficients and the motion-correlated force coefficients of the prism, which are functions of reduced wind velocity and oscillation, were analyzed. It shows that the effects of structural motion on the unsteady force coefficients are significant in the cross-wind direction while the effects are slight in the along-wind direction. Furthermore, in the cross-wind direction, the coefficients tend to increase with oscillating amplitudes at low wind speeds while they are at a quasi-steady state at high wind speeds. The study advances the understanding of the effect of structural motion on three-dimensional prisms, which can be utilized to improve response predictions of the prisms
Experimental study of yawed inflow around wind turbine rotor
No full textIn this article, we present an experimental study in a wind tunnel of a three-bladed, Rutland 503 model, horizontal axis yawed wind turbine. Power measurement and an exploration downstream wake of the turbine using particle image velocimetry measurements are performed. The variation of power coefficient as a function of rotational velocity is presented for different yaw angles. The results show a loss of power from the wind turbine when the yaw angle increases. The velocity field of the downstream wake of the rotor is presented in an azimuth plane, which passes through the symmetry axis of the rotor. The instantaneous velocity field is measured and recorded to allow for obtaining the averaged velocity field. The results also show variations in the wake downstream due to decelerating flow caused by the yawed turbine rotor. Analysis of this data shows that the active control of yaw angles could be an advantage to preserve the power from the wind turbine and that details near rotor wake are important for wake theories and topredict the performance of wind turbines as well
Performance analysis of a small wind turbine mounted inside a tall building
No full textUsing CFD simulations, a small conventional horizontal axis wind turbine (HAWT) Ampair 300 was installed in a confined flow space: through-building openings embedded at different levels of a tall building. The openings were located at 1/3, 1/2, 2/3 and 5/6 of the height of the building. The flow characteristics within the through-building openings when the building is exposed to a realistic wind profile have been investigated and applied to a single through-building opening including the small HAWTs. Four small HAWTs were located in the middle of each opening with a 3m × 3m cross-section area. Power generation and performance of the small turbines operating in the opening was investigated and compared with when installed in the free stream condition. It is shown that a confined space prevents flow from bypassing the turbines and increases the flow rate passing through it which results in power generation augmentation. For further flow enhancement, a compact diffuser was also integrated with the turbine and significantly enhanced its performance and power generation. This study shows that integration of wind turbine in a confined space with suitable design can enhance its performance and offers a potential location for integrating small wind turbines in an urban building
Characterisation of large changes in wind power for the day-ahead market using a fuzzy logic approach
No full textWind power has become one of the renewable resources with a major growth in the electricity market. However, due to its inherent variability, forecasting techniques are necessary for the optimum scheduling of the electric grid, specially during ramp events. These large changes in wind power may not be captured by wind power point forecasts even with very high resolution Numerical Weather Prediction (NWP) models. In this paper, a fuzzy approach for wind power ramp characterisation is presented. The main benefit of this technique is that it avoids the binary definition of ramp event, allowing to identify changes in power out- put that can potentially turn into ramp events when the total percentage of change to be considered a ramp event is not met. To study the application of this technique, wind power forecasts were obtained and their corresponding error estimated using Genetic Programming (GP) and Quantile Regression Forests. The error distributions were incorporated into the characterisation process, which according to the results, improve significantly the ramp capture. Results are presented using colour maps, which provide a useful way to interpret the characteristics of the ramp events
Pedestrian level wind environment around isolated buildings resulted from twisted wind profiles
No full textThe pedestrian-level wind environment influenced by twisted wind profiles were evaluated through a series of wind tunnel tests. In the tests, more than 200 Irwin sensors were installed to measure the wind speeds at pedestrian level around five isolated buildings, each with different dimensions. Two twisted wind profiles, with a maximum twist angle of 13° and 22° respectively, were simulated in boundary-layer wind tunnel. A conventional log-law type turbulent a boundary layer profile was employed to repeat the wind tunnel test to act as a control case. Based on the wind speeds measurements, the velocity ratios (VR) were calculated to show the influence of the twisted profiles. By comparing the VR distributions under the influence of the two twisted profiles to the VR distributions in the conventional wind profile, it is observed that (a) the VR distribution in the wake zone is skewed according to the maximum twisted angle, (b) the over-speed area (VR>1.2) decreases and the shelter area (VR<0.8) increases in the pedestrian-level wind field under the influence of the twisted profiles
Determination of wind turbine far wake using actuator disk
No full textThe growth in size of wind turbines over the last years is significant. The rotor diameter becomes somehow comparable to atmospheric boundary layer at the land surface. In this case the assumption of uniform velocity of upcoming wind cannot be valid. The aim of this paper is to create a simplified model of wind turbine rotor which can represent the aerodynamic inter-action of atmospheric boundary layer with a horizontal axis wind turbine. Such model will be also useful for the study of optimal placement of wind turbines in a wind farm when a large number of calculations is needed and when the time required for full CFD calculations be-comes prohibitive. In this study we adopt actuator disk model which takes in account with sufficient precision the influence of blade geometry on wind turbine aerodynamic performance. The proposed actuator disk model is tested in the case of horizontal axis wind turbine using wall-modelled large eddy simulation. The obtained results of aerodynamic performance and wake show the rapidity of calculation and the reliability of proposed approach
Improved cost energy comparison of permanent magnet generators for large offshore wind turbines
No full textThis paper investigates geared and direct-drive permanent magnet generators for a typical offshore wind turbine, providing a detailed comparison of various wind turbine drivetrain configurations in order to minimise the Cost of Energy. The permanent magnet generator topologies considered include a direct-drive machine and single stage, two-stage or three-stage gearbox driven generators. The cost of energy calculations are based on initial capital costs, the costs of manufacture, installation, operations and maintenance, with particular focus on improved calculations of the annual energy yield with better availability estimations and gearbox loss modelling
Modelling and control of a variable-speed switched reluctance generator based wind turbine
No full textThis paper studies the system modelling and control aspects of switched reluctance generator (SRG) based variable speed wind turbines. A control system is implemented to provide proper operation of the SRG as well as power tracking capabilities for varying wind speeds. The control system for the grid side inverter that will allow the SRG to properly generate power to the system is also presented. Studies are presented of both the SRG and inverter control systems capabilities during a balanced three-phase fault. The paper will demonstrate that the SRG based wind turbine presents a feasible variable wind speed solution with good fault response capabilities
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