• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.261-264
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• 2006

In this paper, doubly-fed induction-type wind power generation system simulation model for grid connection is developed. The simulation model is based on PSCAD/EMTDC and consists of rotor-blade, blade controller, generator power converter and generator controller Blade controller controls the blade pitch angle for starting, peak power limiting and emergency condition. Generator controller controls the generator output power to maximize the system efficiency. Simulation results are shown for the variable wind speed conditions. The simulation model can be utilized for study of actual interaction between wind turbine and grid for reliable operation and protection of power system.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2015년도 자성 및 자성재료 국제학술대회
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• pp.38-38
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• 2015

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.93-94
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• 2005

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.528-529
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• 2005

• Journal of Power Electronics
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• 제10권5호
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• pp.548-554
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• 2010

In this paper, a 1.5 kW Interior Permanent Magnet Synchronous Generator (IPMSG) with a power conditioner for the grid integration of a variable-speed wind turbine is developed. The power-conditioning system consists of a series-type 12-pulse diode rectifier powered by a phase shifting transformer and then cascaded to a PWM voltage source inverter. The PWM inverter is utilized to supply sinusoidal currents to the utility line by controlling the active and reactive current components in the q-d rotating reference frame. While the q-axis active current of the PWM inverter is regulated to follow an optimized active current reference so as to track the maximum power of the wind turbine. The d-axis reactive current can be adjusted to control the reactive power and voltage. In order to track the maximum power of the wind turbine, the optimal active current reference is determined by using a simple MPPT algorithm which requires only three sensors. Moreover, the phase angle of the utility voltage is detected using a simple electronic circuit consisting of both a zero-crossing voltage detecting circuit and a counter circuit employed with a crystal oscillator. At the generator terminals, a passive filter is designed not only to decrease the harmonic voltages and currents observed at the terminals of the IPMSG but also to improve the generator efficiency. The laboratory results indicate that the losses in the IPMSG can be effectively reduced by setting a passive filter at the generator terminals.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.146-152
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• 2012

To install a wind power generator, the survey on the wind environment resources must be conducted in advance. The survey on the wind environment resources is to collect and analyze data regarding the wind speed and direction on a data logger. The data logger consists of a sensor, signal processing circuit and storage device. According to the analysis of the stored data, the amount of power generation by the types of generators can be predicted and the most optimal generator including safety grade can be selected, and in case of installing a generator in the future, it can be utilized as basic data regarding supporting base and foundation construction method of survey points. Data logger was developed for a small wind power generator that is suitable for the international standard(IEC 61400) by using DSP-F28335 micro controller in this paper. It was developed to measure the wind speed of 1 [m/s]~17 [m/s], the wind direction of 0 [$^{\circ}$]~359 [$^{\circ}$], and temperature of -30 [$^{\circ}C$]~50 [$^{\circ}C$], and the comparative experiment with other companies' data loggers was conducted, and an error was measured to be less than ${\pm}0.1$ [m/s] for wind speed and less than +1 [$^{\circ}$] for wind direction.

• 신재생에너지
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• 제10권3호
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• pp.22-30
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• 2014

The isolated self-generating electricity with diesel engine generator has been used in islands far away from main land. It costs high because of increasing oil price, and unsafe to have supplying oil and its related components by ship due to unexpectable marine conditions. Therefore there is the need for the hybrid system of renewable energy like wind or solar energy systems with oil engine generator, which can reduce oil use and extend oil supplying period. In this study, the feasibility of such hybrid system with smart micro grid on the eight islands of Jeon-nam province is surveyed to find good place for the demonstration test of the hybrid system. In each island, 3 wind turbine systems of 10 kW and photovoltaic of 20 kW are tested with already installed diesel engine. The performance and costs of the hybrid system in each island are compared in the given conditions of solar and wind energy potential. As a result of the study, Jung-ma island is recommended for the optimum place to make real field demonstration test of isolated hybrid generating and smart grid systems.

• 한국정보통신학회논문지
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• 제16권11호
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• pp.2487-2494
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• 2012

본 논문에서는 MPPT 제어 기능을 갖는 열에너지 하베스팅 회로를 설계하였다. MPPT(Maximum Power Point Tracking) 제어는 열전소자의 개방회로전압과 MPP 전압간의 관계를 이용하였으며 열전소자의 개방회로전압을 주기적으로 샘플링 함으로써 이를 이용해 MPPT 기준전압을 생성하여 이를 기준으로 부하로의 에너지 공급을 제어한다. 모의실험 결과 94%의 최대 전력 효율을 보였다. 제안된 열에너지 하베스팅 회로는 $0.35{\mu}m$ CMOS 공정으로 설계하였으며 설계된 칩 면적은 PAD를 제외하고 $1168.7{\mu}m{\times}541.3{\mu}m$이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1885-1886
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• 2006

The thermal energy from nuclear fission is transferred to the steam generator which is a kind of a large heat exchanger. After the feedwater is injected into the steam generator and absorbs the thermal energy, it is converted into the steam. This steam goes into the turbine. The balance between the generated energy and the consumed energy is required for the nuclear power plant to be stable. For the purpose of which, the feed water, a parameter for energy transfer, should be controlled in stability. Usually, the nuclear power plants are operated in base load in the view of power system for the stability of fission system. Therefore, though there will be almost no unbalance, there can be some instability from unbalance in case of startup/shutdown or disturbance. In this case, the controllability of feedwater pump is very important for the quick recover of stability.

• 한국수소및신에너지학회논문집
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• 제29권4호
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• pp.363-369
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• 2018

This paper considers the alternative way to mitigate cost for REC instead of Photovoltaic (PV) panels with Energy Storage System (ESS). This study starts from an economic analysis of a 1 megawatt PV system without ESS. Several assumptions have been applied in consideration of the current domestic situation. Based on this result, the economic efficiency of PV with ESS improved. However, the reliance on government subsidies was very high. The alternative way to cover the fluctuation power from renewable energy was reviewed with economical and technical way. In case the natural gas engine applied to PV, the IRR and Levelized Cost of Electricity (LCOE) can be improved without ESS. And if small amount of additional REC, the IRR can be improved up to investment level.