• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.3
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• pp.266-273
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• 2003

A wind turbine simulator is developed for the emulation of variable input torque from the wind energy without actual rotor blades using motor-generator set. The torque command of dc motor is calculated from the characteristic equation of rotor blade during the change of wind speed. Especially the proposed control algorithm takes into account the fact that the moment of inertia of blade is much larger than that of driving motor. If you select the desired value of inertia, the stored/restored energy of the inertia during acceleration/deceleration can be compensated effectively resulting the only net torque is delivered to the generator. The simulator set-up has been designed and implemented using a do motor and drive. Feasibility of the proposed algorithm is verified by computer simulations and experiments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6A
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• pp.369-378
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• 2012

In this study, direct-search based optimization methods are applied for blade shape optimization of wind turbines and the optimization performances of several methods including conventional genetic algorithm, micro genetic algorithm and pattern search method are compared to propose a more efficient method. For this purpose, the currently available version of HARP_Opt (Horizontal Axis Rotor Performance Optimizer) code is enhanced to rationally evaluate the annual energy production value according to control strategies and to optimize the blade shape using pattern search method as well as genetic algorithm. The enhanced HARP_Opt code is applied to obtain the optimal turbine blade shape for 1MW class wind turbines. The results from pattern search method are compared with the results from conventional genetic algorithm and also micro genetic algorithm and it is found that the pattern search method has a better performance in achieving higher annual energy production and consistent optimal shapes and the micro genetic algorithm is better for reducing the calculation time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.884-890
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• 2007

The procedure for the aerodynamic design of the rotor blades for 10 kW-level HAWT (horizontal axis wind turbine) has been investigated to be practiced systematically. The approximately optimal shape was designed using an inverse method based on the momentum theory and the blade element method. The configuration was tested in the wind tunnel of the Korea Air Force Academy, and the data was compared with those obtained from the real system manufactured from the present design. From this research, the authors established the systematic technolo for wind turbine blades, and set up the technical procedure which can be extended for the future design of middle and large sized wind turbines.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.609-617
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• 2014

Even though the variable pitch control of a wind turbine blade is known as an effective component for power control over the rated wind speed, it has limited applicability to small wind turbines because of its relatively high cost on the price of small wind turbine. Instead, stall control is generally applied in the blade design without any additional cost. However, stall delay can frequently be caused by high turbulence around the turbine blade, and it can produce control failures through excessive rotational speed and overpowering the electrical generator. Therefore, a passive pitch control module should be considered, where the pitch moves with the aerodynamic forces of the blade and returns by the elastic restoring force. In this study, a method to calculate the pitch moment, torque, and thrust based on the lift and drag of the rotating blade wing was demonstrated, and several effective wing shapes were reviewed based on these forces. Their characteristics will be estimated with variable wind speed and be utilized as basic data for the design of the passive pitch control module.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.59-65
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• 2011

The aerodynamic power and torque of wind turbines are extremely nonlinear. Therefore, the overall dynamic behavior of a wind turbine exhibits nonlinear characteristics that are dependent on the magnitude of the wind speed. The nonlinear aerodynamic characteristics of the wind turbine also affect the characteristics of the control system of the wind turbine. Therefore, the analysis of the nonlinear aerodynamic characteristics of wind turbine is essential in designing the wind-turbine controller. In this study, the nonlinear aerodynamic characteristics and the effects of these characteristics on the closed-loop pitch system with PI controller for an 1-mass model of the wind turbine are investigated above rated power.

• 기계와재료
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• v.19 no.2 s.72
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• pp.28-47
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• 2007

• 기계와재료
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• v.19 no.2 s.72
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• pp.48-61
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• 2007

• 기계와재료
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• v.20 no.4
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• pp.79-93
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• 2009

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.182.1-182.1
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• 2010

본 논문에서는 3kW 영구 자석형 동기발전기(PMSG)를 이용한 풍력 터빈 시뮬레이터 개발에 대해 기술하였다. 풍력발전 시스템은 블레이드를 포함한 회전부, 동력 전달부, 발전기, 전력변환기로 크게 나눌 수 있으며, 시뮬레이터는 유도 모터와 PMSG, 인버터-컨버터와 제어 시스템으로 이루어진다. 시뮬레이터를 운전하기 위해서는 특정 속도의 바람 모델을 적용하여 풍력 발전기의 회전부에 걸리게 되는 토크와 회전 속도 값이 요구된다. 풍력 터빈 모델로부터 계산값을 시뮬레이터에 맞게 스케일링하여 유도 모터를 구동 한다. 발전기측 컨버터는 MPPT(Maximum Power Point Tracking) 알고리즘을 통해 제어하고 계통측 인버터는 유효 전력과 무효 전력을 제어하도록 한다. PSIM과 MATLAB/SIMULINK를 이용하여 컴퓨터 시뮬레이션으로 그 결과를 증명하였다.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.173-176
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• 2007

본 논문에서는 풍속이 가변하는 상황에서 풍력 발전 시스템의 동작을 모의 할 수 있는 풍력 터빈 시뮬레이터를 설계 구현하였다. 실제 풍속과 회전 속도를 실시간으로 입력받으며, 토크 계산에 필요한 블레이드의 효율을 주속비에 관한 함수로 처리하여 사용함으로써 복잡한 조작 없이 가변 풍속조건에서 블레이드에 의한 토크입력을 모의할 수 있게 하였다. 또한 풍력터빈 시뮬레이터를 이용하여 농형 유도발전기식 풍력발전시스템을 구성하여 계통에 연계하였을 경우 발생되는 무효전력을 보상하기 위해 펄스 다중화 보조브리지회로를 이용한 새로운 구조의 36-펄스 전압원 컨버터방식의 실시간 무효전력보상기(STATCOM)를 적용하였다. 그리고 동작특성을 분석하고 제어시스템의 성능해석을 위하여 시뮬레이션 프로그램인 EMTDC/PSCAD를 이용한 시뮬레이션을 실시하였으며, 축소모형 하드웨어 실험을 통해 실험을 통한 분석을 실시하였다.