• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.75-80
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• 2014

The small wind turbines 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 big range systems, and the developing of it is continuously proceeding. The objective of this paper is to provide the design characteristics analysis of a permanent magnet synchronous generator(PMSG) skewed for magnet of rotor, the main advantage to be explored with the use of a split core design is the reduction in manufacturing costs and its simplicity in manufacture, compared to the manufacturing costs of a core skew PM machine. This thesis is aiming mainly analyzing the characteristics of the prototype to verify through Finite Element Method(FEM) and tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.2
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• pp.136-142
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• 2007

A small supersonic wind tunnel was designed and built to study the flow characteristics of a supersonic impulse turbine cascade. The supersonic cascade with a 2-dimensional supersonic nozzle was tested for the axial gap ratio (${\delta}$) of the supersonic turbine that is the one of the turbine design parameter. Firstly, the flow was visualized by a single pass Schlieren system. Next, total and static pressure of the cascade were measured by a pressure scanning system. Highly complicated flow patterns including shocks, nozzle-cascade interaction and shock boundary layer interactions, flow characteristics of the supersonic turbine were observed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1281-1289
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• 2011

This paper deals with several statistical distribution functions for the analysis of fatigue life data of composite laminates for small wind-turbine blades. A series of tensile tests was performed on triaxial glass/epoxy laminates for loading directions of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. Then, fatigue tests were carried out to determine the fatigue life at the aforementioned loading directions and the fatigue stresses at four levels. Two-parameter Weibull, three-parameter Weibull, normal, and log-normal distributions were used to fit the fatigue life data of the triaxial composite laminates. The three-parameter Weibull distribution most accurately described the fatigue life data measured experimentally for all the cases considered. Furthermore, the variation of fatigue life was simultaneously affected by the loading direction and fatigue stress level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.663-667
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• 2017

Fuel depletion and environmental problems due to the use of fossil fuels have been worsening of late, and the development of alternative energy sources is urgently required to address these problems. Among the alternative energy sources, wind energy is attracting much attention as a clean energy source, because it can be used unlimitedly without any pollutant emissions. In wind power generation, wind energy is converted to kinetic energy through rotor blades and this kinetic energy is converted to electric energy through generators. The design and manufacturing of the blades, which are the major parts of wind power generators, are very important, but South Korea still lacks the requisite basic data and key technologies and, therefore, has to import the blades from overseas. In this study, multi-layered blades capable of generating power at low wind speeds were applied to a small wind power generator and the output characteristics of the generator according to the wind speed and the number of blades were analyzed. As a result, at the maximum wind speed of 8m/s, the application of three blades achieved up to 33% and 18% higher generator output voltage, up to 33% and 15% higher generator output current, and up to 23% and 13% higher generator RPM than the application of one or two blades, respectively. In this study, the application of multi-layered blades to a small wind power generator was shown to improve the output characteristics of the generator and make the collection of electric energy possible even at low wind speeds.

• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.70-76
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• 2013

Recently industrial control systems have been required to ensure intelligent, high tech automation, interconnection and interoperability demands. Therefore, there is a need to redefine the structure concepts of SCADA system for wind power. Also, at this time, the integrated management system is required for the distributed development of wind farms where are needed often interoperability features and exchange information between different wind farms, wind turbines or SCADA systems. In this paper, an integrated structural concepts for SCADA system are defined. Based on this definition of an integrated SCADA system, the basic designs are analyzed on physical layer, system layer and application layer which are corresponded to wind turbine controller, the SCADA server and the SCADA client, and implement HMI. Between the implementation SCADA server and the client, their normal functions were verified at the small scale wind energy test facilities.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.513-516
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• 2011

The dynamic behavior of a small wind-turbine blade was analyzed experimentally. Arrays of fiber Bragg-Grating (FBG) sensors attached along the blade were used to measure the strains of the blade surface. An impact test was performed to estimate the resonance frequencies of the fundamental and higher modes of the cantilever blade system developed for this study. The results were similar to the results for conventional strain gages. However, FBG sensors could sense modes that strain gauges could not sense. The strains obtained from the FBG sensor array were used to estimate displacement-mode shapes of the blade.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1407-1413
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• 2011

In this paper, the structural design for composite blade was performed and full scale structural test was conducted to verify the structural design and integrity of composite blade. Firstly, FE analysis was performed using commercial software ABAQUS under conditions of rated wind speed and Case H in IEC 61400-2. Lay-up sequence and ply thickness were designed based on FE results. And to verify the structural design, full scale structural test was conducted according to IEC 61400-2 under identical loading conditions of FE analysis. Finally, the force-deflection and local strain behavior of composite blade were evaluated.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.121-123
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• 2002

This paper presents the finite-element (FE) analysis results of a permanent-magnet (PM) generator for wind-power applications under different operating conditions. Finite-element method is applied to analyze generator performance at no-load and load with variable resistance and inductance. The results of FE analysis show that proposed PM generator is a useful solution for small-scale wind-turbine systems.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.301-304
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• 2001

Wind power generation system is one of the most useful energy resource using natural environment. One of the biggest problem we encountered is toot the wind speed is fluctuating sharply according to the weather conditions rather than it is stable. In this paper we do the equivalent modeling the mechanical energy of wind power turbine according to wind speed into the synchronous generator. We analyse the equivalent modeling output part of rectifier into DC/DC converter input part theoretically. We analyse a battery charging characteristics for power storage enabling the supply of stable power to the load. We design a system and do the modeling of it analytically so that it supplies a stable power to the load by constructing a DC-AC inverter point. Also we make a small size model usable in actual wind power generation system of 30kw and make an experiment and confirm its validity.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.4
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• pp.141-147
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• 2016

A direct PM generator has the effect of reducing the mechanical noise and ease of maintenance by eliminating a number of power transmission components. In addition, wind turbines operating at low speed with the advantages of high output, high efficiency, and small size. The generator was designed as a small direct-drive PM generator that can be applied to a kite even at low wind speeds. The RPM (Revolutions Per Minute) of the reel was measured in two ways using a cadence/speedometer sensor and a tachometer while the actual kite. The RPM derived from the experiment was applied to the simulation on the designed generator. The no-load characteristic analysis for the magnetic fields produced for the permanent magnet generator by a permanent magnet and stator winding currents is achieved using a 2D coordinate system. A commercial electromagnetic analysis program, ANSYS Maxwell, was used to model the electromagnetic dynamics.