• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1110-1122
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• 2018

This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

• Journal of Wind Energy
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• v.14 no.3
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• pp.14-24
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• 2023

The significance of renewable energy has been on the rise, as evidenced by the 3020 renewable energy plan and the 2050 carbon neutrality strategy, which seek to advance a low-carbon economy by implementing a power supply strategy centered around renewable energy sources. This study examines the wind resources on the west coast of South Korea and confirms the potential for wind power generation in the area. Wind speed data was collected from 22 automatic weather system stations and four light house automatic weather system stations provided by the Korea Meteorological Administration to evaluate potential sites for wind farms. Weibull distribution was used to analyze the wind data and calculate wind power density. Annual energy production and capacity factors were estimated for 15-20 MW-class large wind turbines through the height correction of observed wind speeds. These findings offer valuable information for selecting wind power generation sites, predicting economic feasibility, and determining optimal equipment capacity for future wind power generation sites in the region.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1571-1577
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• 2012

This paper presents a method for assessing the voltage sag performance of power system involving wind power generation. Wind power generation is considered as one of the most desirable renewable energy sources. However, wind power generation have uncertain energy output and it is difficult to control the output. The existing methods of voltage sag assessment are not reflected the characteristics of wind power generation. Therefore, in order to more accurately assess the voltage sag performance, the probability of wind power operation is evaluated. In this paper, the probability is determined by combining the wind speed model with the output curve of wind turbine. The probability of wind power operation is reflected as a parameter in voltage sag assessment. The proposed method can provide more accurate results of voltage sag assessment for the case involving the wind power generation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.

• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.19-25
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• 2013

Energy generation from an instrumented Skystream 3.7 small wind turbine was used to investigate the effect of ambient turbulence levels on wind turbine power output performance. It is widely known that elevated ambient turbulence level results in decreased energy production, especially for large sized wind turbine. However, over the entire wind speed range from cut in to the rated wind speed, the measured energy generation increased as ambient turbulence levels elevated. The impact degree of turbulence levels on power generation was reduced as measured wind speed approached to the rated wind speed of 13m/s.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.146-154
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• 2015

This paper proposes a control method for maintaining the energy level for a supercapacitor energy storage system coupled with a wind generator to stabilize wind power output. Although wind power is green and clean energy source, disadvantage of the renewable energy output power is fluctuation. In order to mitigate the fluctuating output power, supercapacitor energy storage system (SCESS) and wind power simulator is developed. A remaining energy supercapacitor (RESC) control is introduced and analyzed to smooth for short-term fluctuating power and maintain the supercapacitor voltage within the designed operating range in the steady as well as transient state. When the average and fluctuating component of power increases instantaneously, the RESC compensates fluctuating power and the variation of fluctuating power is reduced 100% to 30% at 5kW power. Furthermore, supercapacitor voltage is maintained within the operating voltage range and near 50% of total energy. Feasibility of SCESS with RESC control is verified through simulation and experiment.

• Journal of Environmental Impact Assessment
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• v.23 no.1
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• pp.11-17
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• 2014

Since the Renewable Portfolio Standard (RPS) would be started in 2012, the use of renewable energy should be 11% of total energy use including bio-fuel in 2030. The economic efficiency for renewable energy in B power plant was considered with the bio-diesel, wind power and solar power. The Net Present Value (NPV) and Benefit/Cost Ratio(BC) were used for the economic efficiency with the cost and benefit analysis. In case of bio-diesel, the cost resulted from the fuel conversion and the benefit would be created with trade and environmental improvement. With regard to wind power and solar power, the construction cost would be required and benefit factors would be same as the bio-diesel. The wind power was the best of economic efficiency of renewable energy as the results of NPV and BC ratio. Whereas, the market of wind power was very popular and the techniques of wind power has been developing rapidly.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.498-500
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• 2009

When we urgently need to develop and supply an alternative energy, wind power is growing with much interest because it has relative low cost for generating power and small area for wind turbine. To estimate the wind power resource, it is necessary to make an observation first. Although the large wind farm and resources are near coast and mountain area, the wind energy in urban area has the strong thing of direct access to power generator. In this study, we estimate the probability of wind energy in urban mountain area using A2C (Atmospheric to CFD) model, which is used for horizontally urban scale phenomena. In the steady state results, the site C is most suitable for wind power in the point of the only wind speed. But, estimating the TKE and vertical wind shear, the site B is showing the better results than the site C.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.3
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• pp.9-16
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• 2016

This study had the purpose on feasibility judgment through performance forecast of wind power generation system using the cross flow vertical type wind power turbine for the situation of domestic small size wind power technology development. Wind power generation system uses the principle of venturi tube that gathers the wind through the first guide vane, and second guide vein changes the angle of the wind simultaneously by playing the role of venturi tube. After this, wind got out from the second guide vane spins the wind power turbine and has the meaning of judging on the aspect of numerical interpretation the feasibility for the small size wind power generation through wind power generation system that comes out from the back.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.1-10
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• 2012

This paper proposes a modeling and controller design approach for a wind-diesel hybrid system including dump load. Wind turbine depends on nature such as wind speed. It causes power fluctuations of wind turbine. Excessive power fluctuation at stand-alone power grid is even worse than large-scale power grid. The proposed control scheme for power quality is fuzzy PI controller. This controller has advantages of PI and fuzzy controller. The proposed model is carried out by using Matlab/Simulink simulation program. In the simulation study, the proposed controller is compared with a conventional PI controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PI controller, and thus it contributes to a better quality wind-diesel hybrid power system.