• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.401-407
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• 2004

This study proposes a interim development result for the l-㎾ class small wind turbine system, which is applicable to relatively low wind speed regions like Korea and has the variable pitch control mechanism. In the aerodynamic design of the wind turbine blade, parametric studies were carried out to determine an optimum aerodynamic configuration which is not only more efficient at low wind speed but whose diameter is not much larger than similar class other blades. A light composite structure, which can endure effectively various loads, was newly designed. In order to evaluate the structural design of the composite blade, the structural analysis was performed by the finite element method. Moreover both structural safety and stability were verified through the full-scale structural test.

• 한국유체기계학회 논문집
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• 제14권4호
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• pp.64-69
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• 2011

Integrating wind energy systems into building design is a small but growing trend, and high riese with their elevated wind speeds seem particularly suited to the technology. This paper deal with building-integrated wind turbine design. It thus contains two topics: wind energy and building design. Several building-integerated wind turbine design have been categorized and reviewed.

• Journal of Magnetics
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• 제20권2호
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• pp.176-185
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• 2015

We present the design optimization of the magnetic pole and slot design options that minimize the cogging torque of permanent-magnet (PM) brushless generators for small wind turbine generators. Most small wind-turbines use direct-driven PM generators which have the characteristics of low speed and high efficiency. Small wind-turbines are usually self-starting and require very simple controls. The cogging torque is an inherent characteristic of PM generators, and is mainly caused by the generator's geometry. The inherent the cogging torque can cause problems during turbine start-up and cut-in in order to start softly and to run a power generator even when there is little wind power during turbine start-up. Thus, to improve the operation of small turbines, it is important to minimize the cogging torque. To determine the effects of the cogging torque reductions, we adjust the slot opening width, slot skewing, mounting method of magnets, magnet shape, and the opening and combinations of different numbers of slots per pole. Of these different methods, we combine the methods and optimized the design variables for the most significant design options affecting the cogging torque. Finally, we apply to the target design model and compare FEA simulation and measured results to validate the design optimization.

• 산업기술연구
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• 제37권1호
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• pp.37-40
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• 2017

This study was carried out to improve the performance of a vertical-axis micro wind turbine. It is unique in that it has two identical generators on both sides of the main shaft. Also it has a C shape frame to fix the generators and the main shaft firmly and to provide a connection to a tower. Performance analysis of the wind turbine rotor was performed using Qblade, which is an analysis program for vertical axis wind turbines and freeware. Based on the analysis results, the blade airfoil, the chord length, and the rotor size were modified to improve the performance of the rotor. The modification was found to increase the performance of the wind turbine and to reach the targeted rated power.

• International Journal of Fluid Machinery and Systems
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• 제10권1호
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• pp.19-29
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• 2017

An objective of this study is to demonstrate the validity of using a small wind turbine to recover the fluid energy flowing out of an exhaust duct for the generation of power. In these experiments, a butterfly wind turbine of a vertical axis type (D = 0.4 m) is used. The output performance is measured at various locations relative to the exit of a small wind tunnel (W = 0.65 m), representing the performance expected in an exhaust duct flow. Two-dimensional numerical analysis qualitatively agrees with the experimental results for the wind turbine power coefficient and rate of energy recovery. When the turbine is far from the duct exit (more than 2.5 D), an energy recovery rate of approximately 1.3% is obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1005-1007
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• 2005

Small wind turbines are becoming a viable technology option to supply electricity to landowners. These systems provide energy security, product relatively no environmental harm, and in an appropriate setting can be quite cost-competitive with traditional electricity options. This paper is dealing with the methods how to overcome such inconvenience and with the analysis of characteristic and a field test with a prototype of the stand alone wind turbine was performed. The method applies to small systems, equipped with a coreless axial-flux permanent magnet(AFPM) generator in the turbine, a dc-dc converter and batteries. The analysis concentrates on the effect of the load on the power-wind speed curve of the turbine. The system is designed for direct driven, coupled with turbine and generator with a rated power of, 3kW.

• 조명전기설비학회논문지
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• 제27권1호
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• pp.24-34
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• 2013

This paper introduces the study of hood-type wind turbine embedded on highway median strip. Recently, many studies are being made to apply to small wind turbine in city. This study is wind turbine producing electricity generated from the wind by running cars. In order to analyze wind generated by running cars, we measured experiments using running cars and buses. Also, using CFD and interpreter program, we analysis wind turbines performance and applied to the twist-sabonius blade. This wind turbine attached to safety lamp on the road is produced to use electricity generated through the wind tunnel experiment. In this paper results, this wind turbine system is expected to produce the power source installed the heat ray and safety lamps on the road.

• IEIE Transactions on Smart Processing and Computing
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• 제2권4호
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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.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권1호
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• pp.78-83
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• 2005

Currently in Japan, the use of the small wind turbine is an upward trend. There are already many well established small wind turbine generators in use and their various failures have been reported. The most commonly sighted failure is blade damage. Thus the research purpose was set to develop a simple failure diagnostic system, where an Acoustic Emission (AE) signal was produced from the failure part of a blade which was measured by AE sensor. The failure diagnostic technique was thoroughly examined. Concurrently, the damage part of the blade was imitated, the AE signal was measured, and a FFT(Fast Fourier Transform) analysis was carried out, and was compared with the output characteristic. When one sheet of a blade was damaged 40mm or more, the level was computed at which failure could be diagnosed.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.980-992
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• 2019

This paper describes a model test and numerical simulation of a 750-kW-semi-submersible platform wind turbine under several wind and wave conditions for validation of the numerical simulation model. The semi-submersible platform was designed to support the 750-kW-wind turbine class and operate at a water depth of 50 m. The model tests were performed to estimate the performance characteristics of the wind turbine system in the wide tank of the University of Ulsan. Motions and loads of the wind turbine system under the wind and wave conditions were measured and analyzed. The NREL-FAST code was used to simulate the wind turbine system, and the results were compared with those of the test model. The results demonstrate that the numerical simulation captures noticeably the fully coupled floating wind turbine dynamic responses. Also, the model shows a good stability and small responses during waves, wind, and operation of the 750-kW-floating offshore wind turbine.