• 전기전자학회논문지
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• 제13권2호
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• pp.175-180
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• 2009

본 논문에서는 3[kW]급 태양광 발전시스템의 환경 조건 및 시스템 파라미터들을 고려하여 태양광어레이와 태양광인버터를 시뮬레이션 하고 태양광어레이의 설치에 따른 최적 조건과 성능을 분석을 하여 태양광 발전시스템의 최적 설계를 구현할 수 있도록 한다.

• Journal of Power Electronics
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• 제17권2호
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• pp.323-333
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• 2017

This paper proposes a model-based optimal control algorithm for the clamp switch of a zero-voltage switching (ZVS) bidirectional DC-DC converter. The bidirectional DC-DC converter (BDC) can accomplish the ZVS operation using the clamp switch. The minimum current for the ZVS operation is maintained, and the inductor current is separated from the input and output voltages by the clamp switch in this topology. The clamp switch can decrease the inductor current ripple, switching loss, and conduction loss of the system. Therefore, the optimal control of the clamp switch is significant to improve the efficiency of the system. This paper proposes a model-based optimal control algorithm using phase shift in a micro-controller unit. The proposed control algorithm is demonstrated by the results of PSIM simulations and an experiment conducted in a 1-kW ZVS BDC system.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.511-515
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• 2012

At the moment, with an interest in renewable energy sources (RES) that continue to grow its penetration will be expected to considerably increase in the future power system. However, this penetration of RES leads to new challenges to be solved in electric power systems. In this paper, optimal configuration of renewable energy resources and operation strategy is presented. By using this methodology for allocation of the optimal sizes and types, system operational efficiency and stability of the microgrid will be maximized.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.113-116
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• 2007

The fuel cell which converts directly chemical energy of fuel into electric energy has higher efficiency than the conventional power generation which involves several additional processes. Especially, polymer electrolyte membrane fuel cell (PEMFC) of which the electrolyte is a thin proton conductive polymer membrane is affordable for portable power applications and small-scale distributed power generation including household and small building. It is very important to not only increase the efficiency of FC itself but determine the optimal operation mode. The optimal operational planning of lkW household PEMFC system based on the daily electricity and heat demand patterns was performed. The estimated economic gain was up to 20% by adoption of PEMFC system.

• 한국항해항만학회지
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• 제33권2호
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• pp.127-134
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• 2009

If the research on double cycle is revitalized, crane productivity will be rapidly improved bemuse double cycle is an operational technique that can maximize equipments efficiency (Quay crane, RMG/RTG, Yard tractor). Unfortunately, it is very difficult for terminal operators to find out the starting point of double cycle bemuse the loading & unloading pattern and conditions are various. Therefore, terminal operators are apt to fail to find out the optimal starting point of double cycle to maximize its frequency. Experiencing the same mistakes in the process we made efforts to find out the optimal starting point, finally we found out the formula for it. And we verified its precision is perfect through a lot of testing. This paper on double cycling focused on making the formula to find out optimal starting point of double cycle to maximize its frequency. And it can be applied to various ships' stowages in common.

• 한국시뮬레이션학회논문지
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• 제25권4호
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• pp.93-108
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• 2016

전기차 카셰어링은 친환경차량인 전기차를 여러 사용자들이 함께 이용함으로써 교통부문의 온실가스 발생량을 감소시키고, 동시에 자가용 증가로 인한 공간 및 환경문제를 해결할 수 있는 방안으로 주목받고 있다. 그러나 아직 도입단계에 불과하기 때문에 전기차 카셰어링 시스템의 효율성이나 사업가능성에 대한 연구나 분석이 필요한 실정이다. 이러한 배경하에 본 연구에서는 전기차 카셰어링 시스템의 운영상태와 결과를 분석이 가능한 모형을 개발하였으며, 현재 실시되고 있는 시범사업 내용을 반영하여 시뮬레이션을 실시하였다. 시뮬레이션 결과 전기차 카셰어링 시스템 운영과 관련된 변수들 사이의 관계와 운영효율을 최대화 할 수 있는 최적용량 등을 분석하였다. 시뮬레이션 분석에서는 차량대수와 충전기수가 증가할수록 서비스 제공율은 계속 증가하다가 일정수준에 도달하면 증가폭과 그 효율이 감소하는 것으로 나타났다. 또한 카셰어링 시스템 운영에 따른 수익과 비용을 분석하여 연간 운영 이익을 최대화 할 수 있는 최적 차량대수 및 최적 충전기 수를 도출하였다.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권4호
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• pp.491-497
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• 2013

This paper introduces the high efficiency operation of switched reluctance generator (SRG). The proposed SRG operates under the rated speed. The high efficiency can be obtained by the optimal current shape which can make the total losses minimum. For this purpose, theoretical analysis of the copper and core loss is done. In addition, a modified angle position control (MAPC) method which can get the optimal current shape over wide speed condition is presented. In order to verity the theory, the experimental platform is set up. The feasibility of the theory is verified by the simulation and experimental results. The proposed method is simple, reliable and easy to achieve.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.21-23
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• 2007

In this paper a high efficiency bi-directional DC-DC converter for hybrid vehicles is proposed. The proposed converter a three-phase half-bridge interleaved ZVS converter, is designed to have high efficiency in the main operation range. The component ratings are calculated, the actual devices are selected, and the efficiency analysis has been performed to determine optimal ZVS range. The input and output current ripples are significantly reduced due to the interleaved operation. The dual loop control for the interleaved three-phase converter is also presented. To confirm the proposed convert ter, The simulation and experimental results are presented.

• 전기학회논문지
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• 제57권9호
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• pp.1536-1545
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• 2008

In this paper, we research a new method for efficiency improvement of a single-phase Induction motor by minimization of the stator loss. To make this, we perform winding design which is based on balanced and quasi-balanced operation condition. It gives efficiency improvement greatly but poor starting torque simultaneously. To obtain the best efficiency improvement maintaining the maximum and starting torque, the optimal winding specification and rotor dimension is determined with variation of secondary resistance, running capacitor and turn ratio. Finally, this paper gives the comparison between the simulation results and experimental results.

• KIEAE Journal
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• 제14권6호
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• pp.105-110
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• 2014

The basic factors determining the amount of energy used in hospital buildings are weather conditions and building factors. But the real energy consumer is central plant equipment such as boilers and chillers that produce thermal energy for heating and cooling. Inaccurate decision of the primary equipment's size can cause a high initial-cost, an excessive equipment space, a wasted energy by low operation-efficiency and shortening of the machine's life. In this reason, the decision of optimal size for central plant equipment is very important. There are several factors for the decision such as an operation factor, a factor (equipment factor), piping losses and a simultaneous usage factor applied in the sizing process except a basic cooling load. But there is no standard method for applying those factors. Usually, factors are applied individually by an experience or custom of each engineer. In this study, the authors emphasize the meaning and the problem of those factors, examine them by analyzing factors which were applied to actual practices, and propose the recommendation value of safety, load, operation factors and application methods.