• Journal of Environmental Impact Assessment
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• v.20 no.4
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• pp.425-434
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• 2011

The energy produced by wind power generation is a clean energy product because it is acquired by using renewable resource. Wind power plants("wind farms), in Korea, have been built and operated as 345.6MW facilities from 2001 until now 2009. Nevertheless, environmental issues regarding construction of wind power plants have arisen. accordingly it is time to consider the environmental and social issues of wind power in accordance with the government's policy objectives of increased wind power production. In this study, we investigated the influence that noise and low frequency noise caused by Wind power plants have on neighborhood and residents. We also sought solutions to these issues. In order to analyze the issues of wind power facilities, we compared and examined precedents and the solutions for noise and low frequency noise in Europe, the United states and Japan. We intended to examine the influences of wind power facilities and propose alternative in dealing with these issues.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.104-110
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• 2013

In this paper an application of centralized pitch angle controller for fixed speed wind turbines based wind farm to mitigate load frequency fluctuation is presented. Reference signal for the pitch angle of each wind turbine is calculated by using proposed centralized control system based on wind speed information. The wind farm in the model system is connected to a multi machine power system which is composed of 4 synchronous generators and a load. Simulation analyses have been carried out to investigate the performance of the controller using real wind speed data. It is concluded that the load frequency of the system can be controlled smoothly.

• Journal of Wind Energy
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• v.4 no.2
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• pp.17-24
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• 2013

Idealized PID-controlled rotor-speed error for blade pitch control of wind turbines responds as a second-order system with natural frequency and damping ratio for closed-loop system. RISO National Laboratory has recommended specific natural frequency(=0.6 rad/s) and damping ratio(=0.7) for 2 MW wind turbine. The baseline controller for 5 MW wind turbine of NREL(National Renewable Energy Laboratory) is designed based on the same values of RISO recommendation. This study investigates the effect of the natural frequency and damping ratio of the controller for NREL 5 MW wind turbine. It is confirmed that RISO recommendation shall be tuned for each wind turbine.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.434-438
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• 2006

The purpose of this paper is that investigates the Natural Frequency behavior characteristic of Wind Turbine Jacket Type Tower model, and calculated that the stress values of Thrust Load, Wave Load, Wind Load, Current Loda, Gravity Load, etc., environment evaluation analysis during static Operating Wind Turbine Jacket Type Tower model, carried out of Natural Frequency analysis of total load case to stress matrix, Frequency calculated that calculated Add Natural Frequency to stiffness matrix for determinant to stress results. The finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.2 s.119
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• pp.130-135
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• 2007

The purpose of this paper is that investigates the Natural Frequency behavior characteristic of wind turbine jacket type tower model, and calculated that the stress values of thrust load, wave load, wind load, current loda, gravity load, etc., environment evaluation analysis during static operating wind turbine jacket type tower model, carried out of natural frequency analysis of total load case to stress matrix, frequency calculated that calculated add natural frequency to stiffness matrix for determinant to stress results. The finite element analysis is performed with commercial F.E.M program (ANSYS) on the basis of the natural frequency and mode shape.

• Wind and Structures
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• v.38 no.6
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• pp.461-475
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• 2024

A reliable wind speed forecasting method is crucial for the applications in wind engineering. In this study, the generalized S-transform (GST) is innovatively applied for wind speed forecasting to uncover the time-frequency characteristics in the non-stationary wind speed data. The improved grey wolf optimizer (IGWO) is employed to optimize the adjustable parameters of GST to obtain the best time-frequency resolution. Then a hybrid method based on IGWO-optimized GST is proposed to validate the effectiveness and superiority for multi-step non-stationary wind speed forecasting. The historical wind speed is chosen as the first input feature, while the dynamic time-frequency characteristics obtained by IGWO-optimized GST are chosen as the second input feature. Comparative experiment with six competitors is conducted to demonstrate the best performance of the proposed method in terms of prediction accuracy and stability. The superiority of the GST compared to other time-frequency analysis methods is also discussed by another experiment. It can be concluded that the introduction of IGWO-optimized GST can deeply exploit the time-frequency characteristics and effectively improving the prediction accuracy.

• Wind and Structures
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• v.5 no.1
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• pp.61-80
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• 2002

Wind tunnel aeroelastic model tests of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building were conducted using a three-degree-of-freedom base hinged aeroelastic(BHA) model. Experimental investigation into the effects of coupled translational-torsional motion, cross-wind/torsional frequency ratio and eccentricity between centre of mass and centre of stiffness on the wind-induced response characteristics and wind excitation mechanisms was carried out. The wind tunnel test results highlight the significant effects of coupled translational-torsional motion, and eccentricity between centre of mass and centre of stiffness, on both the normalised along-wind and cross-wind acceleration responses for reduced wind velocities ranging from 4 to 20. Coupled translational-torsional motion and eccentricity between centre of mass and centre of stiffness also have significant impacts on the amplitude-dependent effect caused by the vortex resonant process, and the transfer of vibrational energy between the along-wind and cross-wind directions. These resulted in either an increase or decrease of each response component, in particular at reduced wind velocities close to a critical value of 10. In addition, the contribution of vibrational energy from the torsional motion to the cross-wind response of the building model can be greatly amplified by the effect of resonance between the vortex shedding frequency and the torsional natural frequency of the building model.

• Journal of Ocean Engineering and Technology
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• v.35 no.5
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• pp.347-359
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• 2021

This study aims to evaluate the dynamic responses of the jacket-type offshore wind turbine using FAST software (Fatigue, Aerodynamics, Structures, and Turbulence). A systematic series of simulation cases of a 5 MW jacket-type offshore wind turbine, including wind-only, wave-only, wind & wave load cases are conducted. The dynamic responses of the wind turbine structure are obtained, including the structure displacement, rotor speed, thrust force, nacelle acceleration, bending moment at the tower bottom, and shear force on the jacket leg. The calculated time-domain results are transformed to frequency domain results using FFT and the environmental load with more impact on each dynamic response is identified. It is confirmed that the dynamic displacements of the wind turbine are dominant in the wave frequency under the incident wave alone condition, and the rotor thrust, nacelle acceleration, and bending moment at the bottom of the tower exhibit high responses in the natural frequency band of the wind turbine. In the wind only condition, all responses except the vertical displacement of the wind turbine are dominant at three times the rotor rotation frequency (considering the number of blades) generated by the wind. In a combined external force with wind and waves, it was observed that the horizontal displacement is dominant by the wind load. Additionally, the bending moment on the tower base is highly affected by the wind. The shear force of the jacket leg is basically influenced by the wave loads, but it can be affected by both the wind and wave loads especially under the turbulent wind and irregular wave conditions.

• International Journal of High-Rise Buildings
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• v.8 no.4
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• pp.313-324
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• 2019

This paper presents the analysis of wind speeds data measured on top of three neighboring high-rise buildings close to a beach in Xiamen city, China, during Typhoon "Usagi" 2013. Wind tunnel simulation was carried out to validate the field measurement results. Turbulence intensity, turbulence integral scale, power spectrum and cross correlation of recorded wind speed were studied in details. The low frequency trend component of the typhoon speed was also discussed. The field measurement results show turbulence intensity has strong dependence to the wind speed, upwind terrain and even the relative location to the Typhoon center. The low frequency fluctuation could severely affect the characteristics of wind. Cross correlation of the measured wind speeds on different buildings also showed some dependence on the upwind terrain roughness. After typhoon made landfall, the spatial correlation of wind speeds became weak with the coherence attenuating quickly in frequency domain.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.186-192
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• 2014

Recently wind energy penetration into power systems has increased. Wind power, as a renewable energy source, plays a different role in the power system compared to conventional power generation units. As long as only single and small wind power units are installed in the power system, wind power does not influence power system operation and can easily be integrated. However, when wind power penetration reaches a significantly high level and conventional power production units are substituted, the impact of wind power on the power system becomes noticeable and must be handled. The connection of large wind turbines and wind farms to the grid has a large impact on grid stability. The electrical power system becomes more vulnerable to and dependent on wind energy production, and therefore there is an increased concern about the large wind turbines impact on grid stability. In this work, a new type of fuzzy logic controller for the frequency control of wind farms is proposed and its performance is verified using SimWindFarm toolbox which was developed as part of the Aeolus FP7 project.