• KIEAE Journal
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• 제12권1호
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• pp.127-132
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• 2012

The energy consumption in the world is growing rapidly. And the environmental issues of climate become a important task. The interest in renewable energy like wind and solar is increasing now. Especially, by reducing power transmission loss, a small wind power is getting attention at the residential areas and campus of university. In this study, we attempted to estimate and compare the wind energy density using wind data of AWS (Automatic Weather Station) of H University. In this case of a campus, the weibull distribution parameter C is 2.27, and K is 0.88. According to the data, the energy density of the small wind power is 12.7 W/m2. We did CFD(Computational Fluid Dynamics) simulations at H University campus by 7 wind directions(ENE, ESE, SE, NW, WNW, W, WSW). In the results, we suggest 4 small wind powers. The small wind power generating system can produce 4,514kWh annually.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1066_1067
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• 2009

Wind power is one of most promising renewable energy. The output capacity of large wind turbine has been increased for off-shore application. Number of installation of small wind turbine also has been increased for the stand-alone and off-grid application of remote area and recently small wind turbine equipped with lamp on the pole is used for street lamp. Maximum wind energy must be extracted by wind turbine within rated wind speed. Power must be controlled to protect the system such as blade, generator, and power system above the rated wind speed. In this paper, small wind power system of 800W rating for battery charging is implemented and output power control by furling system is verified at wind tunnel test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.959-960
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• 2007

The wind power has been used steadily since long ago, but the importance of it has been faded because of the abundant and convenient fossil energy. Now, due to the energy crisis, experiencing the environmental problems etc, the necessity of using it growing bigger. Because the small wind turbines under a few kW grade has the merits of setting up with low costs by individuals, and get the energy saving effects that, it has the secured, separate markets from the range systems, and the developing of it is continuously proceeding. The small wind turbine system must have the output power regulating system for the over wind speed, to run steadily in the various wind speed environment. In case of the small wind turbine system, to prevent the breaking and for safety, at the over wind speed, additional system is required, and in most cases, output power is restricted by mechanical means. In this paper, the furling system makes the tail and the head move to make the blades to the wind in slanted angle, restrict the output power at the over wind speed. In thesis, small prototype wind turbine is made, and analyzing the output power characteristics at the over wind speed, and to verify, through the logical study and tests.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 추계학술대회 논문집
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• pp.65-68
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• 2002

Most of the present demand in the world is met by fossil and nuclear power plants. A small part is met by renewable energy technologies. Among the renewable power sources, wind and solar energy have experienced a remarkably rapid growth in the past 10 years. Recently the utilization of wind power has been receiving close attention in this country, especially for the electrification of off-shore islands. The objective of this study is to demonstrate a small wind energy system as a stand-alone power source.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.32-38
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• 2013

In an efforts to encourage renewable energy deployment, the government has initiated so called 1 million green homes program but the accumulated installation capacity of small wind turbine has been about 70kW. It can be explained in several ways such that current subsidy program does not meet public expectations, economic feasibility of wind energy is in doubt or acoustic emission is significant etc. The author investigated annual energy production of Skystream 3.7 wind turbine using measured power curve and wind resource data. The measured power curve of the small wind turbine was obtained through power performance tests at Wol-Ryoung test site. AEP(Annual Energy Production) and CF(Capacity Factor) were evaluated at selected locations with the measured power curve.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.19-25
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• 2013

Energy generation from an instrumented Skystream 3.7 small wind turbine was used to investigate the effect of ambient turbulence levels on wind turbine power output performance. It is widely known that elevated ambient turbulence level results in decreased energy production, especially for large sized wind turbine. However, over the entire wind speed range from cut in to the rated wind speed, the measured energy generation increased as ambient turbulence levels elevated. The impact degree of turbulence levels on power generation was reduced as measured wind speed approached to the rated wind speed of 13m/s.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1605-1614
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• 2013

This paper presents a probabilistic methodology for small signal stability analysis of power system with correlated wind sources. The approach considers not only the stochastic characteristics of wind speeds which are treated as random variables with Weibull distributions, while also the wind speed spatial correlations which are characterized by a correlation matrix. The approach based on the 2m+1 point estimate method and Cornish Fisher expansion, the orthogonal transformation technique is used to deal with the correlation of wind farms. A case study is carried out on IEEE New England system and the probabilistic indexes for eigenvalue analysis are computed from the statistical processing of the obtained results. The accuracy and efficiency of the proposed method are confirmed by comparing with the results of Monte Carlo simulation. The numerical results indicate that the proposed method can actually capture the probabilistic characteristics of mode properties of the power systems with correlated wind sources and the consideration of spatial correlation has influence on the probability of system small signal stability.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.8-13
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• 2015

Recently, because a renewable power source must operate as a constant rate in accordance with RPS(Renewable Portfolio Standard), the study of the renewable power sources has been ongoing. Especially because of noise of wind turbine, troubleshooting, and urban greening business, research related with small wind turbine are underway. The economics and reliability are important parts for the activation of small wind turbine, such as solar energy. In this paper, by analyzing the temperature variations for each location and efficiency of power conversion devices in accordance with short period wind speed changes in simulation test, we reviewed the safety about temperature variations of wind generator and the method of selection of power converter.

• 공업화학
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• 제26권4호
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• pp.489-494
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• 2015

점차적으로 지구의 화석연료가 고갈됨에 따라, 효율적인 에너지 저장과 함께 그린에너지에 대한 기술과 수요가 절실히 요구된다. 풍력에너지는 현재 세계에서 가장 빠르게 확장되는 에너지원이다. 하지만 엄청난 가격의 대형풍력발전기 설치비와 정격풍속인 12 m/s 이상을 요구하는 상황에 따라 내륙에서의 풍력발전의 설치는 어려운 상황이다. 따라서 위의 문제를 해결하기 위하여, 저풍속에서도 발전가능한 소형풍력발전기를 실험하고자 하였다. 본 연구에서는 내륙에서의 풍황조건을 분석하고, 300 W와 1 kW 용량의 소형풍력발전기를 옥상에 설치한 후, 그들에 대한 발전효율 특성을 비교하였다.

• Wind and Structures
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• 제23권6호
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• pp.577-594
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• 2016

In this paper a practical modelling methodology is presented for a series of aero- servo- elastic- coupled numerical analyses of small wind turbine operation, with particular emphasis on variable speed generator modelling in various wind speed conditions. The following characteristics are determined using the available computer tools: the tip speed ratio as a function of the generator constant (under the assumption of constant wind speed), the turbine coefficient of power as a function of the tip speed ratio (the torque curve is modified accordingly and generator speed and power curves are plotted), turbine power curves and coefficient of power curve as functions of the incoming wind speed. The last stage is to determine forces and torques acting on rotor blades and turbine tower for specific incoming wind speeds in order to examine the impact of the stall phenomena on these values (beyond the rated power of the turbine). It is shown that the obtained results demonstrate a valuable guideline for small wind turbines design process.