• Journal of Advanced Marine Engineering and Technology
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• v.26 no.6
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• pp.705-711
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• 2002

디젤기관은 실린더 내경의 크기, 실린더 수 및 회전수에 따라 착화지연, 연소지연 및 디젤기관의 각종 정수가 달라지므로 비선형이 심한 시스템이다. 본 연구에서는 신경회로망을 이용하여 발전기를 구동하는 디젤 기관의 속도를 제어하는 디젤기관 신경회로망 디지털조속기를 제안한다. 이를 위하여 3상 50㎾ 발전기를 구동하는 4행정 4실린더, 1800 rpm ISUTSU 디젤기관의 실제 운전데이터로부터 뉴럴에뮬레이터를 구한다. 최적치 뉴럴에뮬레이터 구성을 위하여 다양한 역전파알고리즘으로 학습을 행하고 결과를 비교한다. 또한 디젤기관의 역으로부터 뉴럴 제어기를 구성하고 뉴럴에뮬레이터로 시뮬레이션을 행한다. 외란이 존재하는 경우에도 효과적인 뉴럴제어기를 구성하기 위하여 선택적 뉴럴제어 기의 사용을 제안한다. 또한 응답성을 향상하고 정확한 목표치추종을 위하여 PI제어기를 보조제어기로 사용하는 하이브리드제어기를 구성하여 시뮬레이션을 통하여 성능이 향상됨을 보인다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.300-302
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• 2003

본 연구에서는 발전기에 적용된 전력계통안정화장치(Power System Stabilizer)의 적용사례를 분석한다. 전력계통안정화장치에 적용된 알고리즘은 Lead-Lag 제어기가 있고, 현대 제어이론에 바탕을 둔 LQR, LQG, $H_{\infty}$, 슬라이딩모드 제어기, 비선형궤환제어기가 있다. 그 외에 퍼지제어기, 뉴럴 제어기, 진화연산제어기등이 있다. 이중에 전력계통안정화장치의 제어알고리즘에 대하여 대표적인 사례를 파악하고져 한다.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.29-32
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• 2006

Recently, many researches of the alternative and renewable energy have introduced due to the increasing oil price, the limited natural resources and the environmental pollution. In case of hydrogen energy, it has some merits, which can be substituted the existing the fossil fuel because of no contaminants from the combustion and the chemical reaction. We have been developing 1kW Hydrogen Linear Generator. In this paper, the thermal characteristic of this prototype linear generator has been investigated and obtained reliable analysis results comparing with experimental measurements. Especially, it is predicted that in case of 1kW, 60Hz test sample, the results satisfy with the temperature standards of H type insulation, which is shown average $69.0^{\circ}C$ temperature distribution at the coil.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.1
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• pp.40-45
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• 2014

This paper suggests the optimal generation dispatch algorithm for ensuring voltage stability margin considering high wind energy injection. Generally, with wind generation being installed into the power system, we would have to consider several factors such as the voltage stability margin because wind turbine generators are mostly induction machines. If the proportion of wind generation increases in the power system increases this would affect the overall stability of the system including the voltage stability. This paper considers a specific system that is composed of two areas: area 1 and area 2. It is assumed that generation cost in area 1 is relatively higher than that in area 2. From an economic point of view generation in area 1 should be decreased, however, in the stability point of view the generation in area 2 should be decreased. Since the power system is a nonlinear system, it is very difficult to find the optimal solution and the genetic algorithm is adopted to solve the objective function that is composed of a cost function and a function concerned with voltage stability constraints. For the simulations, the New England system was selected. The algorithm is implemented and Python 2.5.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.258-264
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• 2018

This paper presents application of a differential search (DS) meta-heuristic optimization algorithm for optimal operation of a micro grid system. The DS algorithm simulates the Brownian-like random-walk movement used by an organism to migrate. The micro grid system consists of a wind turbine, a diesel generator, a fuel cell, and a photovoltaic system. The wind turbine generator is modeled by considering the characteristics of variable output. Optimization is aimed at minimizing the cost function of the system, including fuel costs and maximizing fuel efficiency to generate electric power. The simulation was applied to a micro grid system only. This study applies the DS algorithm with excellence and efficiency in terms of coding simplicity, fast convergence speed, and accuracy in the optimal operation of micro grids based on renewable energy resources, and we compared its optimum value to other algorithms to prove its superiority.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.2
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• pp.125-132
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• 2019

This paper presents a seismic reliability analysis method for an offshore wind turbine with a twisted tripod support structure under earthquake loading. A three dimensional dynamic finite element model is proposed to consider the nonlinearity of the ground-pile interactions and the geometrical characteristics of the twisted tripod support structure where out-of-plane displacement occurs even under in-plane lateral loadings. For the evaluation of seismic reliability, the failure probability was calculated for the maximum horizontal displacement of the pile head, which is calculated from time history analysis using artificial earthquakes for the design return periods. The application of the subset simulation method using the Markov Chain Monte Carlo(MCMC) sampling is proposed for efficient reliability analysis considering the limit state equation evaluation by the nonlinear time history analysis. The proposed method can be applied to the reliability evaluation and design criteria development of the offshore wind turbine with twisted tripod support structure in which two dimensional models and static analysis can not produce accurate results.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.279-280
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• 2011

In order to convert the mechanical movement of a linear generator to electrical power, the amateur current of the generator is controlled in accordance to the mover position. A linear encoder, usually used for direct detection of the mover position, not only is vulnerable to mechanical vibration, but also imposes significant constraint on the mechanical design of the generator system. Thus, this study proposes a method for indirect estimation of the mover position with emfs induced in amateur coils. The estimation algorithm is validated with simulation study.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.50-51
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• 2011

본 논문에서는 영구자석 동기발전기(PMSG)의 전압 및 역률 보상을 위한 기계식 접점을 가지는 조상기의 문제점을 개선하기 위해 전자회로 방식을 채택하여 제어회로에 마이크로프로세서를 사용, 회로를 최소화하고 접점 부분은 전자적인 스위칭소자(MOSFET)를 사용함으로써 조상기의 신뢰성과 특성을 개선할 수 있는 시스템을 제안하고 시뮬레이션을 통해 그 타당성을 검증한다.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.53-57
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• 1989

Until now, method of equivalent circuit is generally used in analyzing the characteristic of the synchronous alternator. But this method can't apply when loads are connected to alternator. In this paper, we analyzed the load characteristic of the synchronous alternator with permanant magnet using 2-dimensional finite element method having voltage source. The loads of a alternator are battary and diodes which are used to rectify. also, we used half periodic boundary condition in the F.E.M calculation

• 전기의세계
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• v.22 no.4
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• pp.11-16
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• 1973

This paper presents an optimum control of the field resistance for the self-excited DC shunt generator to keep a constant terminal voltage in case of the load change or the torque variation in the system. The non-linearity of the system is linearized by applying the small signal technique and the linearized equation is solved by the maximum principle with the digital computer. The optimal control value of the field resistance for the step error of the generator output voltage is obtained and the transient voltage characteristics in the system are investigated.