• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.58-62
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• 2001

Photovoltaic and wind power generation have an advantage of unlimited and unpolluted amount of energy resource. In conventional wind generation systems, since the blade rotates at low speed when the velocity of wind decreases their operations are possible only under limited conditions. Therefore they are in trouble of self-generation without the help of auxiliary generation devices outside. The system driven by the wind force in this paper consists of a generator, an invertor, batteries and sets for power storage with a spring. In this paper, the operation characteristics of system were analyzed through experiments for a trial product.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 추계학술대회 논문집
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• pp.74-77
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• 2002

Combined generation system of Photovoltaic and wind generation have shortcoming that is different output power according to change of weather. So, the combined generation system is required backup system that such as a storage battery to supply energy, when not enough photovoltaic and wind power source for power supply equally and continually, because the energy source is changeable and stable through change of weather as irradiation, temperature, wind speed, wind direction, seasons, etc..

• KIEAE Journal
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• 제8권1호
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• pp.19-24
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• 2008

The wind-power among the new and renewable energies uses the wind, a limitless, clean and pure energy which is available at any place. It requires low installation cost compared to the generation of other renewable energies, and is easy to operate, and furthermore, can be automated for operation. Korea has been taking a great deal of interest in the development of renewable energy generating equipment, specifically wind power generation as the nation has a nearly total reliance on imported petroleum. A measuring poll 30m high was installed at a location with an altitude of 142m above the sea level in order to measure and analyze the wind power potentiality at H University's Asan Campus, and the wind velocity and wind direction were measured for 1 year. As for the wind power resource of the area adjacent to Asan campus, the Weibull Distribution coefficient was C=2.68, K =1.29 at H30m. Weibull Distribution coefficient was modified on the basis of compensated wind velocity (=3.1m/s) at H 60m, and the energy density was $42W/m^2$. AEP 223,750 KWh was forecast based on the simulation of an 800KW grade wind turbine. It is considered that the wind power generation has to be studied further in the inland zone with low wind velocity to cope with the possible exhaustion of fossil fuel and ensure a sustainable environmental preservation.

• 한국유체기계학회 논문집
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• 제4권3호
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• pp.62-77
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• 2001

The modern wind turbines are widely used as important natural energy sources for the electric generation in western countries and some Asian nations. They are commercially matured and progressive and clear policy for the more development with higher technical purposes is maintained throughout the world. Modern wind turbines produce nearly 2000 kW output in their largest sizes and this trend increases up to more powerful power and ultimate utilization of wind energy favoured by clean natural energy. This article has the points of reviewing the states of the art of modern wind turbines with their present technical directions toward next generation version. Some descriptionsare given for easy understanding of the turbine components and related fluid mechanics concerned. The general outlines of policy taken over some countries are also introduced.

• 전기학회논문지
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• 제64권4호
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• pp.505-514
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• 2015

This paper proposes a probabilistic generation assessment model of renewable energy generators(REGs) considering uncertainty of resources, mainly focused on Wind Turbine Generator(WTG) and Solar Cell Generator(SCG) which are dispersed widely in South Korea The proposed numerical analysis method assesses the one day-ahead generation by combining equivalent generation characteristics function and probabilistic distribution function of wind speed(WS) and solar radiation(SR) resources. The equivalent generation functions(EGFs) of the wind and solar farms are established by grouping a lot of the farms appropriately centered on Weather Measurement Station(WMS). First, the EGFs are assessed by using regression analysis method based on typical least square method from the recorded actual generation data and historical resources(WS and SR). Second, the generation of the REGs is assessed by adding the one day-ahead resources forecast, announced by WMS, to the EGFs which are formulated as third order degree polynomials using the regression analysis. Third, a Renewable Energy Generation Assessment System(REGAS) including D/B of recorded actual generation data and historical resources is developed using the model and algorithm predicting one day-ahead power output of renewable energy generators.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.487-490
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• 2002

Wind farm paralleled with electric power network can supply the power into a power network not only the normal conditions, but also the fault conditions of distribution network. If the fault happened in the power line with wind farm, the fault current level measured in a relaying point might be lower than that of distribution network without wind turbine generator. Consequently, it is difficult to detect the fault happened in the distribution network connected with wind generator. This paper describes the influence of wind turbine generator on the protective relaying system for detecting the fault occurred in a power line network. Simulation results shows that the fault current depends on the fault impedance, location, and the capacity of wind farm and distribution network load.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.35-38
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• 2008

우리나라는 비교적 국토가 협소하고 산악지방이 많아 다른 나라와는 차별화 된 풍력발전시스템을 도입할 필요가 있다. 기존의 풍력발전시스템은 저풍속의 경우 발전 효율이 급격히 떨어지며 전원 품질에도 많은 문제점을 내포하고 있었다. 이를 개선하기 위하여 한국의 풍속특성에 적합한 현수형의 채택과 전원품질을 개선할 수 있는 유압모터, 동기발전기를 이용한 풍력발전시스템의 모델을 제시하였다.

• 전력전자학회논문지
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• 제6권1호
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• pp.43-48
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• 2001

기존의 풍력발전시스템은 풍속이 감소되면 블레이드가 저속으로 회전하기 때문에 보조발전의 도움이 없이는 자가 발전이 어려워서 한정된 풍속 조건에서만 작동이 가능하며, 풍속의 특성 때문에 풍력에너지의 이용효율이 대부 분 매우 낮다는 문제점이 있다 이와 같은 종래의 문제점을 해결하고 지역이나 지형에 크게 구애됨이 없이 풍속에 의해 발전이 이루어지다가 풍속의 저하로 출력된 전력이 적어지면 태엽에 저장된 회전에너지로 소형발전기를 운전 하여 축전지에 전력을 저장하여 부하에 전력을 연속적으로 공급하게 한다. 본 논문에서는 동력저장장치와 풍력발전기로 구성된 시스템을 설계 제작하여 풍력발전의 보상을 위한 동력저장 장치 시스템의 동작 특성을 분석하였다.

• 한국태양에너지학회 논문집
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• 제35권3호
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• pp.17-25
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• 2015

The main objective of this study is to predict the wind power generation at the wind farm using various wake models. Modeling of wind farm is a prerequisite for prediction of annual energy production at the wind farm. In this study, we modeled 20 MW class Seongsan wind farm which has 10 wind turbines located at the eastern part of Jeju Island. WindSim based on the computational fluid dynamics was adopted for the estimation of power generation. The power curve and thrust coefficient with meteorology file were prepared for wind farm modelling. The meteorology file was produced based on the measured data of the Korea Wind Atlas provided by Korea Institute of Energy Research. Three types of wake models such as Jensen, Larsen, and Ishihara et al. wake models were applied to investigate the wake effects. From the result, Jensen and Ishihara wake models show nearly the same value of power generation whereas the Larsen wake model shows the largest value. New positions of wind turbines are proposed to reduce the wake loss, and to increase the annual energy production of the wind farm.

• 조명전기설비학회논문지
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• 제20권10호
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• pp.41-46
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• 2006

상업용으로 계통에 연계되어 운전되는 대부분의 풍력발전기는 유도발전기가 주로 사용되고 있으며 동기발전기와 다른 양상을 보이고 있어 계통에서의 사고발생 후 정상상태로 복귀할 수 있는 최대의 시간(임계 제거시간)을 이용하여 과도상태를 해석하고 있다. 본 연구에서는 풍력 발전시스템이 연계된 계통에 대해 임계 제거시간에 미치는 요인을 분석하였으며 계통해석 프로그램인 Digsilent Power Factory를 이용하였다. 임계 제거시간에 미치는 요인으로는 연계되는 계통의 단락용량(단락전류). 풍력발전 용량, 풍력발전기 역률, 풍력 발전시스템과 연계되는 계통사이의 전용선 길이, 부하 용량이나 역률 등이 있으며 이들의 변화에 대한 임계 제거시간의 영향을 분석하였다.