• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.184.3-184.3
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• 2010

This study suggests a modeling of grid-connected wind turbine generation systems and performs simulation according to increase/decrease of real wind speed. MATLAB & SIMULINK implemented modeling of grid-connected wind turbine generation system. Terminal voltage, grid voltage, and active/reactive power shall be observed following the performance of simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.725-727
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• 1998

It is difficult to determine the controller parameters that we can get optimum response of the controlled process variable. In this paper we investigate the effects of various elements of which a gas turbine MW control loop is consists. And we describe the result of actual adjustment on the parameters of these elements to improve the speed regulation of a gas turbine.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.253-256
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• 2006

This paper shows operating characteristics of DFIG(Double Fed Induction Generator) for wind turbine. The back to back PWM voltage-fed inverter connected between the rotor and grid network operated sub and super-synchronous operating mode, and the vector-controlled DFIG enables the decoupling between active and reactive power as well as between torque and power factor. This paper is validated by simulations and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1309-1312
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• 2002

The electric power network paralleled with wind turbine generator may have the negative impacts on the protection, operation, and management caused by the operation of wind turbine generator. Therefore, it is necessary to investigate the operating characteristic of wind turbine generator. This paper describes model of a squirrel-cage type wind turbine induction generator and the soft cut-in connection method for reducing the transient state on power network, and simulates various cases of wind turbine operations. The radial distribution network of IEEE 13-bus are modeled and tested by PSCAD/EMTDC.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.191.1-191.1
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• 2010

Global concerns about environmental issues such as a greenhouse effect are increasing gradually. Quantity of emission of carbon dioxide by Hydro-Power Plants is smaller than those by power plants of other renewable energy sources. Manufacturing costs of hydro turbine is relatively very expensive because the structure of hydro turbine is very complex. Therefore, cross-flow turbine is adopted in this study because of its simple structure and high possibility of applying to small hydropower. The result shows that as effective head increases, tangential and radial flow velocities increase and thus, the increased tangential velocity contributes to the increase of angular momentum and output torque.

• Journal of Advanced Marine Engineering and Technology
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• 제25권1호
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• pp.182-190
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• 2001

The aerodynamics of the Wells turbine has been studied using 3-d, unstructured mesh flow solver for the Reynolds-averaged Navier-Stokes equations. The basic feature of the Wells turbine is that even though the cyclic airflow produces oscillating axial forces on the airfoil blades, the tangential force on the rotor is always in the same direction. Geometry used to define 3-D numerical grid is based upon that of an experimental test rig. The 3-D Wells turbine model, consisting of approximate 220,000 cells is tested of four axial flow rates. In the calculations the angle of attack has been varied between 10˚ and 30˚ of blades, Representative results from each case are presented graphically andy analysed. It is concluded that this technique holds much promise for future development of Wells turbines.

• International Journal of Fluid Machinery and Systems
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• 제6권3호
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• pp.144-151
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• 2013

In this paper, the design method of a low-head propeller-type hydro turbine is studied for various numbers of blades on an axial propeller. We also investigate the relationship between geometrical parameters and internal performance parameters, such as angular velocities (100, 200, 300, 400 rpm) and 2.5~4m low heads through a three-dimensional numerical method with the SST turbulent model. The numerical results showed that the blade number had a more dominant influence than the change in heads and rotational speed on the flow characteristics of the turbine. The distributions of pressure and velocity in the streamwise direction of the propeller turbine were graphically depicted. Especially, the relationship among dimensionless parameters like specific speed ($N_s$), flow coefficient (${\phi}$) and power coefficient (P) were investigated.

• 항공우주기술
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• 제7권2호
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• pp.151-156
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• 2008

1차원 설계에서 설계된 2단형 터보펌프 터빈에 대한 유동해석을 수행하고 결과를 비교 분석하였다. 1단 동익에 대한 계산결과로부터 가장 우수한 1단 익형을 선정한 후 정익의 입 출구 높이 변화에 따른 터빈의 성능변화를 고찰하였다. 2단 전체에 대한 계산을 수행하고 같은 출력의 단단형 터빈에 비해 높은 비출력을 갖는 터빈의 설계가 가능함을 확인하였다.

• 동력기계공학회지
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• 제3권4호
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• pp.16-21
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• 1999

Numerical simulation on two-dimensional turbine cascade flow has been performed using compressible Navier-Stokes equations. The flow equations are written in a cartesian coordinate system, then mapped into a generalized body-fitted ones. All direction of viscous terms are incoporated and turbulent effects are modeled using the extended ${\kappa}-{\epsilon}$ model. Equations are discretized using control volume SIMPLE algorithm on the nonstaggered grid sysetem. Applications are made at a VKI turbine cascade flow in atransonic wind-tunnel and compared to experimental data. Present numerical results are shown to be in good agreement with the experimental results and simulate the compressible viscous flow characteristics inside the turbine blade passage.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.206.1-206.1
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• 2011

Recently, various developments in the area of small hydropower have being made and small hydro turbines are suitable for domestic use because it is a clean and renewable energy source. A small hydropower generator produces power by using the different water pressure levels in pipe lines and energy which was initially wasted by use of a reducing valve at the end of the pipeline is instead collected by a tubular-type hydro turbine in the generator. In this study, in order to acquire the performance of tubular-type hydro turbine applied, the output power, head, efficiency characteristics due to the different guide vane and runner vane angle are examined in detail. Moreover, influences of pressure and velocity distributions with the variation of guide vane and runner vane angle on turbine performance are investigated by using a commercial CFD code.