• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.186.3-186.3
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• 2010

본 논문은 우리나라와 같이 평균풍속이 낮고 바람 방향이 수시로 변하는 지역에 적합한 풍력발전 시스템에 관하여 논한다. 특히, 풍향에 상관없이 효율을 보장하고, 아주 약한 풍속 조건에서도 기동(Cut-in)되며, 낮은 평균풍속 5~6m/s인 지역에서도 경제적으로 풍력발전 단지의 구축이 가능하며, 다양한 지역에 설치가 가능하고, 소음이 적고 친(親) 환경적이며, 양산이 가능해 납기를 예측할 수 있으며 그리고 모든 부품 및 시스템의 국산화가 가능해야 한다는 7가지 조건을 만족하는 풍력발전시스템으로 이를 실현시키기 위하여 현재 풍력발전시스템의 가장 앞선 요소기술(state-of-the-art technology)인 직접구동 방식, 적층식, STR 블레이드, AFPM동기발전기, 자기부상 및 전자브레이크 등 5가지 기술을 복합 융합하여 최고의 효율 및 성능을 보장해 주는 적층 연곡형 시스템이다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.35-38
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• 2008

Our country need to introduce wind force power generation system that country is small and narrow and becomes positioning with the other country because there are many mountainous regions. power generation efficiency of existent wind force power generation system is droping rapidly and connote much problem in country quality in case of a low wind. We proposed wind force power generation system that use oil pressure motor and synchronous motor that can improve choice of suitable suspension style and country quality in Korean methods special qualify to improve this.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.369-372
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• 2003

풍력발전 시스템은 계통에 전력을 공급하는 분산형 전원형태가 대부분이어서 어느 분산형 전원보다 계통 연계시 선로에 미치는 영향이 큰 발전설비이다. 특히 가변속 시스템인 경우 풍속이 낮은 영역에서도 운전이 가능하다는 장점이 있지만 저풍속 영역에서 풍속 변동시 터빈 회전자 출력의 리플이 직류단 전압을 변동하게 만든다. 기존의 직류단 전압 일정제어기를 사용하는 경우 인버터 출력전류는 정현파가 아닌 고조파 리플을 포함하는 문제가 발생한다. 본 논문에서는 이러한 문제점을 해결하고자 직류단 전압에 저역통과 필터를 사용하여 인버터 출력전류의 리플 개선을 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.88-92
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• 2017

Owing to the depletion of fossil energy, wind power is attracting attention as a promising environmentally friendly alternative energy source, because it is abundant, renewable, and non-polluting. Wind turbines are divided into horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) according to the direction of the rotating shaft. VAWTs have a low power generation efficiency, but are not affected by the wind direction and, thus, no yaw system is required and their structure is simple. Small VAWTs are attracting much attention because they can generate power even at low wind speeds. In this study, the output voltages and output currents of small VAWTs with gyromill type, hinge type and double door type blades capable of generating power even at low wind speeds were analyzed at variable wind speeds in the range of 1~11 m/s. At the maximum wind speed of 11m/s, the application of the double door type blades achieved 67% and 9% higher wind turbine output voltages than that of the gyromill type and hinge type blades, respectively. As regards the wind turbine output currents, the application of the double door type blades gave rise to 93% and 5% higher results than that of the gyromill type and hinge type blades, respectively. Through this study, the excellent output characteristics and commercialization potential of the double door type blades, which can generate power both at low and high wind speeds, were confirmed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.431-438
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• 2008

An updated Monte Carlo procedure for Typhoon simulation is presented to estimate the extreme wind speed at typhoon prone southern and western coasts in Korea. The reconstructed wind field model for typhoon in this study is compared with measured typhoon data for validation. The fitness of the proposed probability distribution models for typhoon parameters are tested by using data for the typhoon passed near the specific site. The simulated maximum wind speed associated with various return periods along southern and western coasts indicate that the extreme wind speed gradually increases inversely according to latitude of the coast, and that the basic wind speeds given in Korea Bridge Design Code are excessive compared with present results.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.179.1-179.1
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• 2010

This paper has represented about the wind power industry of the west-south seashore with leading industry development for Honam Economic Region. These projects have composed of wind power industry of the west-south seashore, offshore wind turbine(2MW, 3MW) and onshore wind turbine(3kW, 5kW, 10kW), 11 projects, during 3 years- with honam leading industry development for economic region. The contents of these project are 3 favorable products and 3 business support projects. The favorable products are the MW offshore wind system with Outer-rotor type PMSG, the 3MWoffshore wind system with adaptation type of west-south sea, the hybrid generator system with wind turbine technology basis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.663-667
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• 2017

Fuel depletion and environmental problems due to the use of fossil fuels have been worsening of late, and the development of alternative energy sources is urgently required to address these problems. Among the alternative energy sources, wind energy is attracting much attention as a clean energy source, because it can be used unlimitedly without any pollutant emissions. In wind power generation, wind energy is converted to kinetic energy through rotor blades and this kinetic energy is converted to electric energy through generators. The design and manufacturing of the blades, which are the major parts of wind power generators, are very important, but South Korea still lacks the requisite basic data and key technologies and, therefore, has to import the blades from overseas. In this study, multi-layered blades capable of generating power at low wind speeds were applied to a small wind power generator and the output characteristics of the generator according to the wind speed and the number of blades were analyzed. As a result, at the maximum wind speed of 8m/s, the application of three blades achieved up to 33% and 18% higher generator output voltage, up to 33% and 15% higher generator output current, and up to 23% and 13% higher generator RPM than the application of one or two blades, respectively. In this study, the application of multi-layered blades to a small wind power generator was shown to improve the output characteristics of the generator and make the collection of electric energy possible even at low wind speeds.

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.797-810
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• 2017

The Korean peninsula is exposed to typhoons every year. Typhoons cause huge socioeconomic damage because tropical cyclones tend to occur with strong winds and heavy precipitation. In order to understand the complex dependence structure between strong winds and heavy precipitation, the copula links a set of univariate distributions to a multivariate distribution and has been actively studied in the field of hydrology. In this study, we carried out analysis using data of wind speed and precipitation collected from the weather stations in Busan and Jeju. Log-Normal, Gamma, and Weibull distributions were considered to explain marginal distributions of the copula. Kolmogorov-Smirnov, Cramer-von-Mises, and Anderson-Darling test statistics were employed for testing the goodness-of-fit of marginal distribution. Observed pseudo data were calculated through inverse transformation method for establishing the copula. Elliptical, archimedean, and extreme copula were considered to explain the dependence structure between strong winds and heavy precipitation. In selecting the best copula, we employed the Cramer-von-Mises test and cross-validation. In Busan, precipitation according to average wind speed followed t copula and precipitation just as maximum wind speed adopted Clayton copula. In Jeju, precipitation according to maximum wind speed complied Normal copula and average wind speed as stated in precipitation followed Frank copula and maximum wind speed according to precipitation observed Husler-Reiss copula.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.796-800
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• 2011

As the increasing integrity of VLSI, the BIST(Built-In Self Test) is used as an effective method to test chips. Generally the pseudo-random test pattern generation is used for BIST. But it requires too many test patterns when there exist random resistant faults. Therefore we propose a mixed test scheme which applies to the circuit under test, a deterministic test sequence followed by a pseudo-random one. This scheme allows the maximum fault coverage detection to be achieved, furthermore the silicon area overhead of the mixed hardware generator can be reduced.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.278-278
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• 2020

감조하천이 위치한 연안 지역의 경우, 강우 및 태풍과 발생과 동시에 만조위가 겹치게 되면 큰 홍수 피해를 입는 지역이다. 감조하천은 조석의 영향으로 인해 물의 흐름 및 수위가 주기적으로 진동하는 특성을 보이고 있다. 조석 현상은 주로 기조력에 의한 주기적인 운동이 발생하지만, 풍속, 저기압 등의 영향도 함께 포함되어 있다. 연안 지역에 대한 홍수 위험 관리를 위해, 본 연구에서는 연안 지역 내 위치한 조위 관측소의 조위 자료를 주기적인 운동을 보이는 조석 성분과 확률론적인 운동을 보이는 파고 성분으로 분리하고자 하였다. 자료 내 각각 세부적인 특성을 확인하기 위해 주파수 대역별 필터링이 가능한 이산형 웨이블릿 변환을 통해 자료를 6단계로 분해하였다. 분해된 각 성분 별 주기성 및 주파수 분석을 실시하여 조석 성분 및 파고 성분으로 분리하였으며, 최종적으로 자료 내 각각 66% 및 34%의 비중을 차지하고 있음을 확인하였다. 본 연구의 결과를 활용한다면, 파고의 영향을 고려한 연안 지역의 홍수 관리의 기초자료로 활용할 수 있을 것으로 판단된다.