• 전기학회논문지
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• 제58권11호
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• pp.2185-2191
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• 2009

Wind power and photovoltaic(PV) generation systems are the fastest growing sources of renewable energy. The nonlinear devices, such as power electronic converter or inverter, of wind power and PV generation systems are the source of harmonics in power systems. The harmonic-related problems can have significant detrimental effects in the power system, such as capacitor heating, data communication interference, rotating equipment heating, transformer heating, relay misoperation and switchgear failure. There is a greater need for harmonic analysis that can properly maintain the power quality. By measuring harmonics of existing wind power and PV generation systems as harmonics modeling, the studies were made to see the harmonic impact of grid-connected wind power and PV generation systems.

• 대기
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• 제28권1호
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• pp.1-13
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• 2018

Characteristics of wind resources of offshore and coastal regions were compared using wind data obtained from HeMOSU-1 (Herald of Meteorological and Oceanographic Special Unit-1) meteorological mast located at Southwestern Sea, and ground-based LiDAR (Light Detection And Ranging) at Gochang observation site near it. The analysis includes comparison of basic wind statistics such as mean wind speed, wind direction, power law exponent and their temporal variability as well as site assessment items for the wind power plant such as turbulence intensity and wind power density at the two observation sites. It was found that the wind at HeMOSU-1 site has lower diurnal and seasonal variability than that at Gochang site, which lead to smaller turbulence intensity. Overall, the results of the comparative analysis show that the wind resource at HeMOSU-1 site located offshore has more favorable condition for wind power generation than the wind resource at Gochang which shows nature of coastal area.

• 신재생에너지
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• 제7권2호
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• pp.51-58
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• 2011

Saemankeum is well known for its high speed wind, and it is known that the blueprint of a future city around Saemankeum, including new industrial complex, has been planned. As a result, large-scale offshore wind farm, on the basis of the measurement of wind resource for a long time, can be considered, so that generated electricity can be used to meet the energy demand near the wind farm. Wind speed in Kokunsando of Saemankeum is measured and analyzed with its statistical distribution and wind directions. The probability of wind power resource over Kokunsando of Saemangeum is reviewed with the measured data in one island of Kokunsando. According to measured data, the shape and scale factor of Weibull distribution of wind speed are obtained, and then power density is analyzed as well. Through this study, it is clear that the Saemangeum area has a fluent and abundant wind power source to develop the wind farm in Korea.

• 설비공학논문집
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• 제23권8호
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• pp.543-548
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• 2011

New concept of wind energy conversion system is proposed to increase the energy density at a given working space. The quality of wind for wind power generation is depend on its direction and speed. However, the quality is not good on land because wind direction is changeable all the time and the speed as well. The most popularly operated wind turbine system is an axial-flow free turbine. But its conversion efficiency is less than 30% and even less than 20% considering the operating time. In this research, a cross-flow type wind turbine system is proposed with a convergent-divergent duct system to accelerate the low speed wind at the inlet of the wind turbine. Inlet guide vane is also introduced to the wind turbine system to have continuous power generation under the change of wind direction. In here, the availability of wind energy generation is evaluated with the change of the size of the inlet guide vane and the optimum geometry of the turbine impeller blade was found for the innovative wind power generation system.

• 풍력에너지저널
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• 제14권3호
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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.

• 전기학회논문지
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• 제62권4호
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• pp.451-456
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• 2013

Development of the technologies for offshore wind power is proceeding actively and the installation capacity is continuously increasing because of its many advantages in comparison with the land wind power. Accordingly, project for Southwestern 2.5GW offshore wind power plant is in progress in Korea. Design of electric power systems for offshore wind power plant is very important due to its high investment and operational costs. Hence, it needs to be designed in order to minimize costs. This way can be employed in determining the installation location of offshore substation for HVAC wind power plant. According to the offshore substation site, MV inter-array cable and HV export cable lengths vary and they change a total cost regarding submarine cable. This paper represents cost models with variables which are MV inter-array cable and HV export cable lengths to locate the offshore substation for HVAC wind power plant. It is classified into submarine cable installation cost, reactive power compensator installation cost, ohmic losses, and unsupplied energy cost. By minimizing a total cost, an appropriate installation site of the offshore substation is determined.

• 전기학회논문지
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• 제64권7호
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• pp.984-991
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• 2015

This paper presents the methodology for optimal design of power grid for offshore wind power plant (OWPP) and optimum location of offshore substation. The proposed optimization process is based on a genetic algorithm, where the objective cost model is composed of investment, power loss, repair, and reliability cost using the net present value during the whole OWPP life cycle. A probability wind power output is modeled to reflect the characteristics of a wind power plant that produces electricity through wind and to calculate the reliability cost called expected energy not supplied. The main objective is to find the minimum cost for grid connection topology by submarine cables which cannot cross each other. Cable crossing was set as a constraint in the optimization algorithm of grid topology of the wind power plant. On the basis of this method, a case study is conducted to validate the model by simulating a 100-MW OWF.

• 전기학회논문지
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• 제59권9호
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• pp.1560-1565
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• 2010

The renewable resource are getting more attentions with increased concerns on the depletion of fossil fuels and several environmental issues like emission problem. Wind power is a representative option among several renewable sources and the generation capacity using wind power is being increased. However, the wind generation is so volatile on its output characteristic, so it is required to assess the grid impact of wind power generation by measuring the fluctuation effect more precisely. This paper proposes the method for measuring the generation output according to IEC 61400-21(Measurement and assessment of power quality characteristics of grid connected wind turbines) to assess the power quality of wind turbine generation. In addition, it shows an application case to a small-scale wind power generator. In the case study, it suggests a structure design of the proposed measurement instrument both on hardware and software aspects, which is composed of a remote monitoring & data analysis program and an FPGA based real-time signal processing device.

• 전력전자학회논문지
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• 제19권2호
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• pp.149-156
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• 2014

This paper proposes the battery charging algorithm for small-scale wind power generator using three phase PWM converter. it is impossible to control output power of the converter in over wind speed region since back EMF of PMSG is higer than battery voltage. Therefore, battery charging algorithm is proposed to expand battery charging over wind speed region. The suggested method is using the q-axis current for battery charging in the rated wind speed region. In the over wind speed region after it lower back EMF of PMSG using d-axis current it can control output power of the converter. The validity of the proposed algorithm are verified by experiments.

• 한국태양에너지학회 논문집
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• 제37권6호
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• pp.59-68
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• 2017

In accordance with the policy of local government, the large scale of wind farms have been installed in Jeju power system. However, The intermittent characteristics of wind power output may cause grid voltage and frequency variation, especially in weak power system. One of the solution to solve this problem is installation of Energy storage system (ESS). In this case, the ESS will regulate the active power generated from wind farm to mitigate fluctuation. Actually, the local government of Jeju island constructed ESS connected to Hangwon wind turbine in 2016. From this point, this paper analyzes requirement capacity of ESS to mitigate wind power fluctuation based on measured data from Hangwon wind turbine and ESS. The simulation results will be carried out by Matlab program.