• 한국기계가공학회지
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• 제15권3호
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• pp.21-27
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• 2016

The static and dynamic structural integrity qualification was performed through the seismic analysis of a small-size Savonius-type vertical wind turbine at dead weight plus wind load and seismic loads. The ANSYS finite element program was used to develop the FEM model of the wind turbine and to accomplish static, modal, and dynamic frequency response analyses. The stress of the wind turbine structure for each wind load and dead weight was calculated and combined by taking the square root of the sum of the squares (SRSS) to obtain static stresses. Seismic response spectrum analysis was also carried out in the horizontal (X and Y) and vertical (Z) directions to determine the response stress distribution for the required response spectrum (RRS) at safe-shutdown earthquake with a 5% damping (SSE-5%) condition. The stress resulting from the seismic analysis in each of the three directions was combined with the SRSS to yield dynamic stresses. These static and dynamic stresses were summed by using the same SRSS. Finally, this total stress was compared with the allowable stress design, which was calculated based on the requirements of the KBC 2009, KS C IEC 61400-1, and KS C IEC 61400-2 codes.

• 한국유체기계학회 논문집
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• 제9권2호
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• pp.7-12
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• 2006

This study is to develop a system of electric power generation utilizing the wind resources available in the domestic wind environment. We tested drag-type vortical wind turbine models, which have two different types of blades: a flat plate and circular arc shape. Through a performance test, conditions of maximum rotational speed were found by measuring the rpm of wind turbine. The rotational speed was measured by a tachometer in a wind tunnel and the tunnel wind speed was by using a pilot-static tube and a micro manometer. The performance test for a prototype was accomplished by calculating power, power coefficient, torque coefficient from the measurement of torque and rpm by a dynamometer controller From the measurements for miniature turbine models with two different blades, the circular arc shape was found to Produce a maximum rotational speed for the same wind velocity condition. Based on this result, the prototype with the circular arc blade was made and tested. We found that it produces 500W at the wind velocity of 10.8 m/s and the power coefficient was 20%.

• 한국태양에너지학회 논문집
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• 제32권2호
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• pp.95-104
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• 2012

This study purposed to predict wind energy for small size wind power generators at 50m above the ground in each area using mean wind speed data for 10 minutes collected from 2001 to 2011 by meteorological data in large cities having over 60% of 15 story (50m) or higher apartments including Seoul, Daejeon, Gwangju and Daegu representing the inland region, and Busan, Incheon and Ulsan representing the coastal region. In the results of analysis, we confirmed close agree ment between observatory weather data and probability density distribution obtained using Weibull's parameters, and this suggests that Weibull's parameter is applicable to the estimation of wind energy. Hourly output energy using the mean wind speed for 10 minutes and output energy obtained from Weibull's parameter showed an error less than 5%, and thus it was found that wind energy can be evaluated using Weibull's modulus.

• 한국태양에너지학회 논문집
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• 제30권4호
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• pp.1-8
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• 2010

The mechanical parts of small windp ower generator less than 10kW are manufactured in the form of removing most of the accelerators. The braking system to protect blade from damages caused by high wind speed is manufactured in a manner having apparatus system(furling), manual brake or no brake. This study is on braking system in small size wind power generator, and carried out survey as following steps by applying electric braking system which uses armature reaction. We explained the principle of electric braking system and the principle of existing braking system. Also, this paper interpreted short circuit current through open circuit and short circuit, as well as checking brake system's action using armature reaction with real construction of control device.

• 산업기술연구
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• 제26권A호
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• pp.75-80
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• 2006

A vibration monitoring is performed on a 1kW class stand alone wind turbine(W/T). When a W/T model is developed, general performance under various wind condition should be verified to introduce the product in the market. Especially, vibration characteristics within operating speed range are very important in the aspect of structural stability as well as generator's electrical efficiency. This paper examines the vibration performance of a home made 1kW W/T. Various data of the W/T model are acquired in real time using a remote vibration monitoring system installed in Daekwanryung test site. Vibration stability of the W/T structure is diagnosed based upon the data and the result is used to estimate the applicability of the W/T model.

• 한국기계가공학회지
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• 제17권1호
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• pp.122-129
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• 2018

This study conducted a seismic qualification analysis of small savonius style vertical axis wind turbine(VAWT) using finite element method(FEM). The modal analysis was performed on the wind turbine structure to check the occurrence of resonance caused by the rotation of gearbox and windmill blades. Next, it conducted a seismic response spectrum analysis due to horizontal and vertical seismic load of required response spectrum of safe shutdown earthquake with 5 % damping(RRS/SSE 5%) of KS C IEC 61400 and conducted a static analysis due to deadweight and wind load. The total maximum stress of the VAWT structure was calculated by adding the maximum stresses due to each load case using the square root of the sum of the squares(SRSS) method. Finally, the structural safety of the VAWT structure was verified by comparing the total maximum stress and the allowable stress.

• 한국태양에너지학회 논문집
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• 제29권4호
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• pp.41-47
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• 2009

Wind/diesel hybrid operation can be one of the most effective option for electrical power production at a remote area such as Antarctica. The king Sejong station at Antarctica relies its power production on diesel engines and diesel oil is supplied every other year by ships. However, the oil transportation processes are liable to potential oil spillage caused by the floating ice around the King George island. The long-term storage of the oil at the station can also contaminate the surrounding soils. A l0kW wind turbine has been installed to save oil consumption and operated in connection with the diesel generators since 2006. The diesel engine that operated poorly during the first year of installation was replaced in 2008 to enhance power production an recent measurements indicate that both diesel power quality and the wind turbine availability have been dramatically improved by the replacement. This report discusses electrical power qualities of wind/diesel hybrid system operating at an isolated micro gird located in the king Sejong station. Our experience reveals that the similar technologies can be applied to domestic islands, for example, in the south sea.

• 대한기계학회논문집B
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• 제33권8호
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• pp.580-588
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• 2009

This paper summarizes the experimentally-measured performance of small-scale, vertical-axis wind turbine for the purpose of improving the aerodynamic efficiency and its controllability. The turbine is designed to have a Savonius-Type rotor with an inlet guide-vane and an side guide-vane so that it achieves a higher efficiency than any lift- or drag-based turbines. The main design factors for this high-efficient, vertical wind turbine are the number of blades (Z), and the aspect ratio of Height/Diameter (H/D) among many. The basic model has the diameter of 580mm, the height of 464mm, and the blade number of 10. The maximum power coefficient of 0.50 was experimentally measured for the above-mentioned specifications. The inlet-guide vane ensures the maximum efficiency when the angle of attack to the rotor blade lies between $15^{\circ}$ and $20^{\circ}$. This experimental results for the vertical-axis wind turbine can be applied to the preliminary design of turbine output curve based on the wind characteristics at the proposed site by controlling its aerodynamic performance given as a priori.

• 한국유체기계학회 논문집
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• 제16권4호
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• pp.22-27
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• 2013

The purpose of this paper is to perform the structural design of the small scale vertical-axis wind turbine (VAWT) blade using a response surface method(RSM). First, the four design factors that have a strong influence on the structural response of blade were selected. Analysis conditions were calculated by using the central composite design(CCD), which is a typical design of experiment for the response surface method(RSM). Also, the significance of the central composite design(CCD) was verified using analysis of variance(ANOVA). The finite element analysis was performed for the selected analytical conditions for the application of response surface method(RSM). Finally, a optimization problem was solved with a objective function of blade weight and a constraint of allowable stress to achieve a optimal structural design of blade.

• 대한기계학회논문집A
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• 제36권1호
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• pp.117-124
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• 2012

본 논문에서는 유한요소법을 이용하여 블레이드에서 발생하는 동력을 발전기로 전달하는 체결부에 대한 연구를 수행하였다. 블레이드 체결부의 유한요소 모델을 수립하기 위하여 실험적 모드해석을 이용하여 각 부품의 고유진동수 및 고유모드를 추출하였으며, 사용프로그램인 ANSYS를 이용한 모드해석을 통하여 추출된 유한요소 모델의 고유진동수와 고유모드 비교를 통하여 모델을 검증하였다. 검증된 유한요소 모델을 이용하여 정격풍속 상태와 한계풍속 상태에서 응력해석을 수행하였으며, 해석 시 작동상태의 경계조건과 중력 및 바람에 의한 하중이 고려되었다.