• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.134-137
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• 1998

In this paper, a hybrid maximum power tracker for a photovoltaic/wind hybrid power system is proposed. In the hybrid system, a direct interfacing the wind power system to the photovoltaic system gives the problems of voltage fluctuations, poor maximum power tracking, and harmonics generation associated with the random wind speed, the random solar irradiation and the pulsating torque came from the wind turbine synchronous generator and photovoltaic. To overcome these problems, a wind side DC/DC converter are proposed employing a star/delta transformer interconnected between the wind turbine side and the photovoltaic side. The control objective for each dc/dc converter is to extract maximum power from each different photovoltaic system and wind system, and transfer two different powers to the inverter and load.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.698-704
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• 2012

This paper proposes a new methodology for evaluating the probabilistic reliability based grid expansion planning of composite power system including the Wind Turbine Generators. The proposed model includes capacity limitations and uncertainties of the generators and transmission lines. It proposes to handle the uncertainties of system elements (generators, lines, transformers and wind resources of WTG, etc.) by a Composite power system Equivalent Load Duration Curve (CMELDC)-based model considering wind turbine generators (WTG). The model is derived from a nodal equivalent load duration curve based on an effective nodal load model including WTGs. Several scenarios are used to choose the optimal solution among various scenarios featuring new candidate lines. The characteristics and effectiveness of this simulation model are illustrated by case study using Jeju power system in South Korea.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1123-1129
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• 2009

The main goal of this paper is to simulate a Doubly-Fed Induction Generator (DFIG), which is similar to a real system. Wind velocity data is applied to a 2D Lookup table as a speed reference for a turbine model. A real electric machine's parameters are put in the simulator to get some results of the real system. The Matlab have been generally used to simulate DFIG, but it has some differences from the real system and is difficult to implement. A Simplorer simulator, however, simplifies DFIG simulation. The turbine is directly connected with the DFIG to be close to the real system. The machine's rotor is excited and controlled by the discrete carrier modulated matrix converter. It is possible to retrieve important information, like a generated power and wind quality etc., from the simulator without a huge wind turbine.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.201-203
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• 2002

In recent years there has been a growing interest in renewable energy systems due to the environmental problem and the economic benefits of fuel savings. Such systems are usually connected to the existing power grid for "fuel displacement" purpose as well as of earning some "capacity credit". Wind power generation system(WPGS) is one of the most useful energy resource using natural environment. So far, it was very difficult to simulate the dispersed generation system including WPGS using EMTP or EMTDC because the source of the dispersed generation system has a particular wind power characteristic equation. In this paper, a novel simulation method of WPGS has proposed and a new wind turbine component for EMTDC is also developed. The wind power characteristic equation of wind turbine is used in order to realize the WPGS in EMTDC simulation. And the real field data of weather conditions is interfaced to EMTDC using Fortran program interface method. Consequently the simulation of WPGS using field data is realized in this paper and shows acceptable results.

• Journal of Ocean Engineering and Technology
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• v.23 no.5
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• pp.25-31
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• 2009

The most important component of wind turbine is rotor blades. The developing method of wind turbine was focused on design of rotor blade. By the way, the design of a rotating body is more decisive process in order to adjust the performance of wind turbine. For instance, the design allows the designer to specify the wind characteristics derived by topographical map. The iterative solver is then used to adjust one of the selected inputs so that the desired rotating performance which is directly related to power generating capacity and efficiency is achieved. Furthermore, in order to save the money for manufacturing the rotor blades and to decrease the maintenance fee of wind power generation plant, while decelerating the cut-in speed of rotor. Therefore, the design and manufacturing of rotating body is understood as a substantial technology of wind power generation plant development. The aiming of this study is building-up the profitable approach to designing of rotating body as a system for the wind power generation plant. The process was conducted in two steps. Firstly, general designing and it’s serial testing of rotating body for voltage measurement. Secondly, the serial test results above were examined with the CFD code. Then, the analysis is made on the basis of amount of electricity generated by rotor-blades and of cut-in speed of generator.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.211-212
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• 2008

As a result of environmental concerns, the production of electricity through renewable energy resources is rapidly increasing. Wind energy is among the fastest growing renewable energy resources now being integrated in the power system, and the penetration rate of wind generation has been gradually increased. For power flow analysis of the recent systems, thus, steady-state modeling of wind turbines and their application are of great importance. This paper presents the procedure we applied for implementation of a steady-state wind turbine model in power flow.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.62-68
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• 2009

There has been a continuous increase in the utilization and utility value of renewable energy such as wind power generation in modem society. Wind condition is the absolute variable to the energy volume in the case of a wind power generation system. For this reason, wind power generators have already been installed in areas where wind velocity is high and the possibility of danger is very low. In other words, instability is likely if the wind velocity in an area is high and where a wind power generation system can be built. On the contrary, low wind velocity is possible in an area with high stability. Therefore, the design and manufacture of a wind power generation system should be carried out in a more complicated topography in order to secure a bigger market. This study examines and suggest how topography affects wind shear by analyzing the measured data in order to predict wind power generation more reliably.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.375-378
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• 2003

This paper presents a study on the power factor improvement of the Wind turbine Generation System(WTGS) at Haeng-won wind farm in Jeju Island. Vestas WTGS named V47 as a model system is selected in this paper, and has 660 kW Power ratings. In this system, power factor correction is controlled by the conventional method with power condenor bank. So, model system at Haeng-won wind farm has very low power factor in the area of low wind speed, which is from 4 m/s to 6 m/s. This is caused by the power factor correction using power condenser bank To improve the power factor in the area of low wind speed, we used the static var compensator(SVC) using current controlled PWM power converter by IGBT switching device. finally, to verify the profosed method, the results of computer simulation using Psim program are presented to support the discussion.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1040-1048
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• 2013

In this paper, a sensorless pitch angle control method for a wind generation system is suggested. One-step-ahead prediction control law is adopted to control the pitch angle of a wind turbine in order for electric output power to track target values. And it is shown that this control scheme using the inverse dynamics of the controlled system enables us to predict current wind speed without an anemometer, to a considerable precision. The inverse input-output of the controlled system is realized by use of an artificial neural network. The proposed control and wind speed prediction method is applied to a Double-Feed Induction Generation system connected to a simple power system through computer simulation to show its effectiveness. The simulation results demonstrate that the suggested method shows better control performances with less control efforts than a conventional Proportional-Integral controller.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2402-2409
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• 2009

This paper proposed a simple and helpful analysis model of voltage variation in order to predict the voltage variation at PCC (Point of Common Coupling), when a wind turbine is connected in an isolated grid. The PCC voltage flucuates when the wind turbine outputs active power to an isolated grid. This voltage variation is proportional to the product of the line impedance from the ideal generator to the PCC and the wind turbine output current. And It is different according as where wind turbine is connected. To solve the problem of voltage variation, this paper proposed the reactive power control. To verify the proposed analysis model, this paper utilized PSCAD/EMTDC Simulation and the field measurement data of the voltage variation during the wind power generation.