• Journal of the korean veterinary medical association
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• v.25 no.3
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• pp.152-160
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• 1989

• Bulletin of the Korean Chemical Society
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• v.20 no.11
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• pp.1371-1372
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• 1999

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.906-908
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• 2002

The technical improvement of servo system, it is required to study on robust control method in company. It needs to study on brake system that has constant torque-speed performance as load variation. In this paper, braking torque characteristics of eddy current braker between electromagnet stator and rotating disk are analyzed. The torque-speed characteristics and proper disk construction are presented. From the computer simulation results, it was found that eddy current braking torque is linear or approximately constant over the desired speed range depending on the rotor material, disk construction, pole number and pole displacement of stator. The relationship of these parameters are confirmed by experimental result.

• Journal of Aerospace System Engineering
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• v.1 no.2
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• pp.21-26
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• 2007

DMFC(Direct Methanol Fuel Cell) has been considered as an attractive option to produce electric power in many application. In this study, in order to estimate the effects of the methanol concentration, wind velocity and temperature on the performance of DMFC, a physical prototype of DMFC was designed and manufactured, and the stack voltage of DMFC was measured during the operation of DMFC. Expecially, the experimental results showed that a low stack temperature, a low wind velocity and an excess methanol concentration lead to the increase of the time to reach the maximum stack voltage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.61-70
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• 2012

Recently due to the increasing of the importance on the green energy is getting higher by implementing EERS(Energy Efficiency Resource Standards) and NA(Negotiated Agreement) such as lacks of natural resources and The United Nations Framework Convention on Climate Change. And the most practical solution is CHP(Combined Heat and Power) which performs the best energy efficiency. This paper developed optimal operation mechanism of CES(Community Energy System) for enhancement of energy efficiency using CHP(Combined Heat and Power), PLB(Peak Load Boiler) and ACC(ACCumulator) capacities. This method optimally operated these capacities calculated the maximum profits by Dynamic Programing. Through the case studies, it is verified that the proposed algorithm of can evaluate availability.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.59-62
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• 1991

This paper describes an effective algorithm for evaluating the reliability indices and calculating the production cost for generation system with thermal, hydro and pumped storage plants. Using the Energy Invariance property, this algorithm doesn't need deconvolution process which gives large burden in computing time. In order to consider an adaptable load model, we consider the system load with forecasting uncertainty. The proposed algorithm is applied to the KEPCO system and its result shows high accuracy and less computing time.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.244-246
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• 1990

This paper describes the Large Deviation Method for computing the loss-of-load-probability (L.O.L.P.) index for a generating system. Also, we introduce a rule to prevent the initial value from diverging in Newton-Raphson method which we have to use to determine the value of t. By applying the Large Deviation Method to computing the L.O.L.P. index for some representative reliability test systems, it is verified that the Large Deviation Method is generally very accurate and very fast.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.1-9
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• 1991

This paper describes a new method of calculating expected energy generation and loss of load probability (L.O.L.P) for electric power system operation and expansion planning. The method represents an equivalent load duration curve (E.L.D.C) as a mixture of cumulants approximation (M.O.N.A). By regarding a load distribution as many normal distributions-rather than one normal distribution-and representing each of them in terms of Gram-Charlier expansion, we could improve the accuracy of results. We developed an algorithm which automatically determines the number of distribution and demarcation points. In modeling of a supply system, we made subsets of generators according to the number of generator outage: since the calculation of each subset's moment needs to be processed rapidly, we further developed specific recursive formulae. The method is applied to the test systems and the results are compared with those of cumulant, M.O.N.A. and Booth-Baleriaux method. It is verified that the M.O.C.A. method is faster and more accure than any other method.

• Journal of Energy Engineering
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• v.4 no.3
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• pp.344-353
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• 1995

화력발전기의 주간운용계획을 수립함에 있어 여러 에너지사용에 관련된 제약조건의 지배를 받는 발전기를 효율적으로 고려할 수 있는 새로운 방법을 개발하였다. 우선 이를 위하여 에너지제약을 고려한 운용계획문제를 Lagrangian Relaxation법에 의해 모델링하였다. 또한 에너지제약을 만족하는 최적의 화력발전기의 기동정지계획 및 발전출력을 원문제 내에서 구할 수 있도록 하였으며, 쌍대문제를 효율적으로 풀 수 있는 알고리즘을 개발하여 보다 빠르고 정확한 해를 구할 수 있도록 하였다. 제안한 방법을 시험계통 및 대규모 실계통에 적용하여 유용성을 검증하였다.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.128-132
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• 2004

This paper presents a new methodology to get pareto-optimal solution for generation planning. First, we apply dynamic programming, and we can get an optimal economic dispatch considering total quantity of contamination for the specified term. Second, we developed a method which can get pareto-optimal solution. This solution is consisted of a set of optimal generation planning. As a result, decision maker can get pareto-optimal solutions, and can choose a solution. We applied this method to the test system, and showed the usefulness.