• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1066_1067
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• 2009

Wind power is one of most promising renewable energy. The output capacity of large wind turbine has been increased for off-shore application. Number of installation of small wind turbine also has been increased for the stand-alone and off-grid application of remote area and recently small wind turbine equipped with lamp on the pole is used for street lamp. Maximum wind energy must be extracted by wind turbine within rated wind speed. Power must be controlled to protect the system such as blade, generator, and power system above the rated wind speed. In this paper, small wind power system of 800W rating for battery charging is implemented and output power control by furling system is verified at wind tunnel test.

• Journal of Power Electronics
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• v.9 no.1
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• pp.85-92
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• 2009

This paper studies the method to predict voltage variation that can be presented in the case of operating a small-sized wind turbine in grid connection to the isolated small-sized power system. In order to do this, it makes up the simplified simulation model of the existing power plant connected to the isolated system, load, transformer, and wind turbine on the basis of PSCAD/EMTDC and compares them with the operating characteristics of the actual established wind turbine. In particular, it suggests a simplified model formed with equivalent impedance of the power system network including the load to analytically predict voltage variation at the connected point. It also confirms that the voltage variation amount calculated by the suggested method accords well with both simulation and actually measured data. The results can be utilized as a tool to ensure security and reliability in the stage of system design and preliminary investigation of a small-sized grid connected wind turbine.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.959-960
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• 2007

The wind power has been used steadily since long ago, but the importance of it has been faded because of the abundant and convenient fossil energy. Now, due to the energy crisis, experiencing the environmental problems etc, the necessity of using it growing bigger. Because the small wind turbines under a few kW grade has the merits of setting up with low costs by individuals, and get the energy saving effects that, it has the secured, separate markets from the range systems, and the developing of it is continuously proceeding. The small wind turbine system must have the output power regulating system for the over wind speed, to run steadily in the various wind speed environment. In case of the small wind turbine system, to prevent the breaking and for safety, at the over wind speed, additional system is required, and in most cases, output power is restricted by mechanical means. In this paper, the furling system makes the tail and the head move to make the blades to the wind in slanted angle, restrict the output power at the over wind speed. In thesis, small prototype wind turbine is made, and analyzing the output power characteristics at the over wind speed, and to verify, through the logical study and tests.

• International Journal of Aerospace System Engineering
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• v.10 no.2
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• pp.1-4
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• 2023

Even though the recent development trend of wind turbine systems has been focused on larger MW Classes, the small-scale wind turbine system has been continuously developed because it has some advantages due to easy personnel establishment and use with low cost and energy saving effect. This work is to propose a specific structural design and analysis procedure for development of a low noise 500W class small wind turbine system which will be applicable to relatively low wind speed region like Korea. The proposed structural feature has a skin-spar-foam sandwich composite structure with the E-glass/Epoxy face sheets and the Urethane foam core for lightness, structural stability, low manufacturing cost and easy manufacturing process. Moreover this type of structure has good behaviors for reduction of vibration and noise. Structural analysis including load cases, stress, deformation, buckling and vibration was performed using the Finite Element Method. In order to evaluate the designed blade structure the structural tests were done, and their test results were compared with the estimated results.

• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.48-52
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• 2017

Small-scale motor-generator sets have been used in laboratories for verification of real large wind turbines whose rated power are more than 1 MW. In this paper, a result of designing a small-scale motor-generator system, which is composed of motor, gear box, flywheel, and generator, is presented in the aspect of speed response. Design objective is to make a small-scale motor-generator system have the same time constant and optimal tip speed ratio region as a real MW wind turbine. A small-scale 3.5 kW motor-generator system for emulating response of a 2 MW wind turbine is considered and designed.

• New & Renewable Energy
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• v.10 no.3
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• pp.14-21
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• 2014

As the world supply of fossil fuel sources decreases, the need for efficient energy consevation and develping green energy technologies becomes critical. Because of the high cost of the foundation for large turbines and optional high wind speed (over 12 m/s), it is very difficult to be located at inland city. For the solution above mentioned problem, we have been experimented about that not only using the adaption of wind power system on buildings for improving turbine efficiency, but also applying a wound rotor type induction generator for a small wind turbine.In this research, we try to find out the wind direction and wind speed those were measured every 1 min., during operation period, using the anemometers which consist of horizontally spinning cups on a vertical post. Performance testing for small wind turbine generating system was carried out by using the induction motor and invertor. Finally, we measured the power of 1 kW wind turbine system with the clamp meter and a voltmeter.

• Journal of the Korean Solar Energy Society
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• v.26 no.4
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• pp.25-30
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• 2006

10kW wind turbine has been successfully commissioned at the King Sejong station in April, 2006. The wind turbine installed is a part of the R&D program for developing a solid wind/diesel hybrid power control system for a remote area such as Antarctica. At the same time, the current research aims to develop an anti-icing and de-icing technologies for a small wind turbine rated under 50kW. Since its commissioning, the turbine has generated about 500kWh for 47days without any system faults. Although sufficient data have not been obtained yet, any trouble has not occurred in the wind/diesel hybrid system based on the current analysis. Concerning on the environmental impact by the wind turbine operation, the turbine is installed within the station boundary in order to meet the Madrid protocol. Therefore, wind turbine operation meets the international requirements for preservation of antarctic ecosystem.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.473-473
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• 2009

There have been many academic researches on the aerodynamic design of wind turbine based on blade element method (BEM) and momentum theory (MT, or actuating disk theory). However, in the real world, the turbine blade design requires many additional constraints more than theoretical analysis. The standard procedure is studied in the present paper to design new blades for the wind turbine system ranged from the small size from 1 to 10 kW. From the experience of full design of a 10 kW blade, the authors tried to set up a standard procedure for the aerodynamic design based on IEC 61400-2. Wind-turbine scale, rotating speed, and geometrical chord/twist distribution at the segmented span positions are calculated with a suitable BEM/MT code, and the geometrical shape of tip and root should be modified after considering various parameters: wing-tip vortex, aerodynamic noise, turbine efficiency, structural safety, convenience of fabrication, and even economic factor likes price, etc. The evaluated data is passed to the next procedure of structural design, but some of them should still be corresponded with each other: the fluid-structure interaction is one of those problems not yet solved, for example. Consequently, the design procedure of small wind-turbine blades is set up for the mass production of commercial products in this research.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.240-247
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• 2013

The main aim of this study was to suppress the angular velocity against strong winds during storms and analyze the stability and performance of the phase plane method. The utilization of small-scale wind turbine system has become common in agriculture, houses, etc. Therefore, it is considered to be a scheme for preserving the natural energy or avoiding the use of fossil fuels. Moreover, settling small-scaled wind turbines is simpler and more acceptable compared to ordinary huge wind turbines. In addition, after converting the energy there is no requirement for distribution. Therefore, a much lower cost can be expected for small-scaled wind turbines. On the other hand, this system cannot be operated continuously because the small-scaled wind turbine consists of a small blade that has low inertia momentum. Therefore, it may exceed the boundary of angular velocity, which may cause a fault in the system due to the centrifugal force. The aim of this study was to reduce the angular velocity by controlling the stall factor. Stall factor control consists of two control methods. One is a shock absorber that is loaded in the junction of the axis of the blade of the wind turbine gear wheel and the other is pitch angle control. Basically, the stall factor itself exhibits nonlinear behavior. Therefore, this paper confirmed the feasibility of stall factor control in producing desirable performance whilst maintaining stability.

• The KSFM Journal of Fluid Machinery
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• v.15 no.2
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• pp.63-68
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• 2012

This paper deals with the aerodynamic analysis and structural test under estimated loading condition for small composite blade, which is utilized in dual rotor wind turbine system. Firstly, the front and rear blades of dual rotor wind turbine system were modeled using reverse engineering method. And using finite volume method, the aerodynamic forces were analyzed at the rated and cutout wind speed to identify the pressure distribution on blades. And then, the full scale structural tests were conducted according to load and strength based methodology in IEC 61400-2 to identify the structural integrity of composite blade.