The experimental testing of a Tension Leg Platform (TLP) floating wind turbine at 1:60 scale in wind and waves with a pitch-regulated 10MW wind turbine is presented. The floating wind turbine was tested with three different control configurations: two closed-loop controllers and one open-loop controller. The experimental setup and program is described in this paper, and system identification and the responses of the floater to hydrodynamic loading are analysed and compared for the different control strategies. It was observed that negative aerodynamic damping for the onshore controller resulted in high oscillations in blade pitch, yielding an increased response in surge for all wave types. It was also observed that the surge motion governed the mooring line tensions, thus the onshore controller yielded the highest tensions in the front mooring line. Further the shutdown cases of the offshore controller led to larger surge displacement when the shutdown was initialized right before the wave impact.

In order to design a small wind turbine, the performance of SG604x airfoil and previously existing 15 airfoils was reviewed at a Reynolds number of 300,000, which suggests the maximum lift-to-drag ratio of the airfoils, corresponding lift coefficient, and the maximum lift coefficient for both free and fixed transition. The SG6043 airfoil provides enhanced lift-to-drag ratio performance as compared with previously existing airfoils at a Reynolds number of 300,000. Only a SG6043 airfoil for small wind turbine performance prediction is applied along the length of the blades. This is why a blade constructed using airfoils of different performance may not exhibit the expected performance. A code based on BEMT(Blade Element/Momentum Theory) was used for performance predictions of small horizontal axis wind turbine. As important input parameter of BEMT, distributions of chord and twist was derived by the optimization method using genetic algorithm. The power performance prediction of airfoil data of SG6043 using BEMT is presented over a wide range of wind speeds. The results of BEMT using SG6043 show that the rated wind speed can be reduced to 10 m/s for a rotor radius of 7.25m and a rating of 32kW. The reduced rated wind speed would increases the annual capacity factor as compared the existing airfoils.

：In order to support various studies for assessment of onshore and offshore wind turbine system including foundations, the land-based version of 2MW PMSG direct drive wind turbine has been analyzed using HAWC2 that account for the coupled dynamics of the wind inflow, elasticity, and controls of the turbine. this work presents the steady-state response of the system and natural frequency of the first thirteen structure turbine modes as a function of wind speed. Rotor, generator speeds, pitch angle, power production, thrust force, deflections of tower and blade are compared for one case below and one case above the rated wind speed.Key Words：Land-and sea-based wind turbines(육해상 풍력발전기), Direct drive(직접 구동형), Rated rotor speed (정격로터 속도), Permanent Magnet Synchronous Generator(영구자석 동기발전기), Pitch angle(피치각도), Peak power coefficient(최고점 출력 파워계수)

A series of coupled time domain simulations considering stochastic waves and wind based on five 1-h time-domain analyses are performed in normal operating conditions. Power performance and tower base Fore-Aft bending moment and pitching motion response of the floating spar-buoy wind turbine with 2 MW direct-drive PMSG have been analyzed by using HAWC2 that account for aero-hydro-servo-elastic time domain simulations. When the floating spar-buoy wind turbine is tilted in the wind direction, maximum of platform pitching motion is close to 4°. Statistical characteristics of tower base Fore-Aft bending moment of floating spar-buoy wind turbine are compared to that of land-based wind turbine. Maximum of tower base Fore-Aft bending moment of floating spar-buoy wind turbine and land-based wind is 94,448 kNm, 40,560 kNm respectively. This results is due to changes in blade pitch angle resulting from relative motion between wave and movement of the floating spar-buoy wind turbine.