• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.349-354
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• 1998

The grid reference system (GRS) has been useful for identifying the geographical location of satellite images. In this study we derive a GRS for the KOMPSAT Electro-Optical Camera (EOC) images. The derivation substantially follows the way that SPOT defines for its GRS, but incorporates the KOMPSAT orbital characteristics. The KOMPSAT EOC GRS (KEGRS) is designed to be a (K,J) coordinate system. The K coordinate parallel to the KOMPSAT ground track denotes the relative longitudinal position and the J coordinate represents the relative latitudinal position. The numbering of K begins with the prime meridian of K=1 with K increasing eastward, and the numbering of J uses a fixed value of J=500 at all center points on the equator with J increasing northward. The lateral and vertical intervals of grids are determined to be 12.5 km about at the 38$^{\circ}$ latitude to allow some margins for the value-added processing. The above design factors are being implemented in a satellite programming module of the KOMPSAT Receiving and Processing System (KRPS) to facilitate the EOC data collection planning over the Korean peninsula.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.223-226
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• 2011

건축이나 조선소에서는 도면 설계를 위하여 캐드 프로그램을 활용하여 작업을 수행하고 있다. 그리고 작업 현장에서 설계를 참조하기 위하여 출력된 도면을 휴대하고 있다. 그러나 현장 환경이 열악하기 때문에 출력 도면은 훼손되기 쉽고 관리가 어려운 단점이 있다. 이 논문에서는 스마트 운영체제를 사용하고 있는 스마트 기기에서 캐드 도면을 출력하고 관리하기 위한 시스템 설계를 제안한다. 제안한 시스템에서는 화면 출력 속도를 개선하기 위하여 고정 그리드 파일 색인에 기반한 색인 파일을 사용하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권1호
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• pp.111-119
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• 2013

This paper present stabilization control of fixed speed wind generator by using variable speed permanent magnet wind generator in a wind farm connected with multi-machine power system. A novel direct-current based d-q vector control technique of back to back converter integrated with Fuzzy Logic Controller for optimal control configuration is proposed, in which both active and reactive powers delivered to a power grid system are controlled effectively. Simulation analyses have been performed using PSCAD/EMTDC. Simulation results show that the proposed control scheme is very effective to enhance the voltage stability of the wind farm during fault condition.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권8호
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• pp.413-419
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• 2003

The paper presents a simulation model and analysis of a grid-connected variable speed wind energy conversion scheme (VSWECS) using the PSCAD/EMTDC software. The modeled system uses a variable speed drive, a fixed pitch angle, a synchronous generator as a wind generator and an AC-DC-AC conversion scheme, which facilitates the wind generation to efficiently operate under varying wind speed while connected to the distribution network. The power output of the WECS is controlled by the AC-DC-AC conversion scheme, the objective of which is to capture the maximum active power under varying wind conditions and to keep the voltage magnitude of the terminal bus at a specific level. Aerodynamic models are applied for a wind turbine model. An simulation analysis of the scheme in terms of its responding to wind variations is also presented.

• 전기학회논문지
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• 제58권7호
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• pp.1313-1320
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• 2009

This paper analyzes the steady-state operating characteristics of doubly-fed induction generator(DFIG) and fixed-speed induction generator(FSIG) in wind turbine system. It also presents a modeling and simulation of a grid-connected wind turbine generation system for dynamics analysis on MATLAB/Simulink, and compares the responses between DFIG and FSIG wind turbine systems with respect to wind speed variation, 3-phase fault and 1-phase ground fault of the network. Simulation results show the variations of generator's active/reactive output, rotor speed, terminal voltage, fault current, etc. Case studies demonstrate that DFIG illustrates better performance compared to FSIG.

• 대한조선학회논문집
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• 제54권6호
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• pp.492-500
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• 2017

In the study, numerical simulation on the greenwater impact load of free surface offshore structure in the regular waves using fixed cartesian grid system and Modified Marker-Density (MMD) method were carried out and the results were reviewed. In order to compare numerical simulation and experimental results, the FPSO with the scale ratio of 1/100 model ship with fixed rectangular deck was selected and turbulence characteristic of the flow was considered by applying the Sub-Grid Scale (SGS) in laminar flow. As a result, it is reviewed how the greenwater impact load inflowed from bow in regular headsea wave influence the flow on the deck and the flow characteristic by numerical simulation and the experiment results were compared and reviewed. Based on this study, it would be useful to numerically study the effect of greenwater on offshore structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.704-705
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• 2011

At present, the widely used wind power generators in the whole world are fixed speed induction generator (FSIG) and doubly fed induction generator (DFIG). The models of FSIG and DFIG wind power generation system connected with the grid are built, and their steady-state and transient characteristics are studied. A new coordinated control strategy using both the grid and rotor side converters of DFIG for voltage regultation and reactive power support is put forword to improve the steady-state and transient performance of the FSIG in the case of DFIG in parallel with FSIG.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.320-322
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• 2002

The paper presents an electrical model of a grid-connected wind energy conversion system (WECS) with a variable speed drive, a fixed pitch angle, a synchronous generator as a wind generator and AC-DC-AC conversion scheme for simulating dynamic behaviors and performance responding to varying wind speed input. The electric output of the WECS is controlled by the AC-DC-AC conversion scheme, the objective of which is to capture the maximum active power under varying wind conditions and to keep the voltage of WECS terminal bus at a specific level. Aerodynamic models are used to incorporate the power characteristics to wind speed. The modeling and simulation of the WECS are realized on PSCAD/EMTDC environment.

• 한국산학기술학회논문지
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• 제20권3호
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• pp.470-475
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• 2019

본 논문에서는 진동수주형(OWC: Oscillating Water Column) 파력발전시스템을 위한 30kW 급 계통연계형 PCS(Power Conversion System)을 다룬다. 해양에너지 중 파력 발전은 삼면이 바다인 반도의 특성을 지닌 한국에 적용하기 적합하고 연안재해 시 파력 발전기가 방파제 역할을 하여 피해를 감소시킬 수 있고, 다른 해상 발전과 개발 대상 적지가 일치하므로 통합하여 효율을 증대 시킬 수 있다. 파력발전 방식은 작동 원리에 따라 가동 물체형과 진동수주형, 월파형 등 여러 형태로 구분하며, 설치 형태에 따라 고정식과 부유식으로 구분된다. 본 논문에서는 구조적으로 안정되고 터빈과 발전기의 유지 보수가 비교적 쉬운 진동수주형을 채택하여, 파력발전용 30kW 계통연계형 PCS 토폴로지 및 모델을 제안하고 계통에 안정적으로 전압을 공급할 수 있는 DC link 전압 제어 등 계통연계 시 필요한 제어방법에 대해 설명하였다. 또한 이를 검증하기 위해 시뮬레이션을 수행하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.469-471
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• 2005

Wind farms employs induction generators which are two type, one is Squirrel cage for fixed speed wind turbines and the other is Wound induction generator (doubly fed induction generator DFIG) for variable speed wind turbines. this paper describes grid connection scheme of wind power system using two type induction generators and simulation results show the characteristics of two type induction generators.