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Wind Energy and Energy Policy in Germany
이승민(Lee, Seungmin),이수갑(Lee, Soogab) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05
As eco-friendly energy is in the spotlight, lots of countries are out to develop and disseminate renewable energy. However, Korea still remains in relative newcomer position for renewable energy. To overcome the present condition, it is necessary to carry out a study of establishment of renewable energy policy that is appropriate the present situation of Korea from examples of advanced countries. Among several renewable energies, wind energy is known to be the most reliable energy. Germany that has increased the share of wind energy in total energy supply is a representative leading country for wind energy. Therefore wind energy policy in Germany will be a role model for that in Korea. In this study, as a research of portfolio for wind energy policy of advanced countries, a wide survey for current status of wind energy and energy policy in Germany is carried out.
Perception of amplitude-modulated noise from wind turbines
이승훈(Lee, Seunghoon),김호건(Kim, Hogeon),김규태(Kim, Kyutae),이수갑(Lee, Soogab) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06
Wind turbine noise is generally lower than that from other environmental noise sources such as road and railway noise. Nevertheless, some residents living more than 1km away from wind turbines have claimed that they suffer sleep disturbance due to wind turbine noise. Several researchers have maintained that residents near a wind farm may perceive large amplitude modulation of wind turbine noise at night, and this amplitude modulation is the main cause of the noise annoyance. However, to date only few studies exist on the prediction of the amplitude modulation of wind turbine noise. Thus, this study predicts amplitude modulated noise generated from a generic 2.5MW wind turbine. Semi-empirical noise models are employed to predict the modulation depth and the overall sound pressure level of the wind turbine noise. The result shows that the amplitude modulation is observed regardless of atmospheric stability, but the modulation depth in a stable atmosphere is 1~3dB higher than that in an unstable atmosphere near the plane of rotation where the blades move downward. Moreover, using the result of the noise prediction, this study estimates the maximum perceptible distance of the wind turbine noise cause by amplitude modulation. The result indicates that the wind turbine noise can be perceived at a distance of up to 1600m in the range of about 30~60 degree from the on axis in a extremely low background noise environment.
Prediction of broadband noise signal from a large wind turbine
이승훈(Lee, Seunghoon),이승민(Lee, Seungmin),이수갑(Lee, Soogab) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.05
This study predicted broadband noise from a generic 2.5MW wind turbine blade in the time domain. The rotor blade was modeled as thin rectangular flat plates. A simplified analytic model proposed by Amiet was used to model the unsteady surface pressure distribution. The acoustic pressure was calculated by using the loading term of Formulation 1A proposed by Farassat. The validation was also performed by comparing with an experiment of Brooks, Pope, and Marcolini. By using these numerical methods, the broadband noise signal of the wind turbine was successfully predicted in this study.