• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.964-966
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• 2003

The three-phase induction motor is rugged, reliable, long-lived, self-starting, smooth-running. But it is relatively inexpensive and three-phase power in not available everywhere, so if possible we need single-phase motor with the same characteristics. In fact, single-phase induction motors have excellent characteristics and outnumber the three-phase variety. Most of the small electric motors used in home, farm, or office are single-phase induction motors of one type or another. This electric motors application field need most energy saving type drive according to enlargement of electronic goods and to tend high class. The paper is proposed a various phase control methods for energy saving of single- phase induction motor. The controllers that are embodied by each method can use by various usage according to each performance and it is considered that application may help in the electrical energy saving because is possible to other electrical appliances.

• 에너지공학
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• 제8권4호
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• pp.519-524
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• 1999

본 논문에서는 1 MW 에너지저장시스템을 특별 고압 수용가에 설치하여 실 계통과의 계통연계 운전시 대상 수용가의 전기요금의 절감을 위한 운전알고리즘을 제안하였다. 제안된 운전 알고리즘을 이용하여 계통연계 운전시 '97년도의 1년 동안 전기요금과 '98년도에는 '97년도와 똑같이 전기를 사용한다는 가정하에 계절별, 시간대별 및 역률 조정운전을 고려하여 적용하였다. 적용결과 1 년동안 약 4 천만원 정도의 종합 전기요금 절감이 기대되었으며, 이상의 결과로부터 본 논문에서 제안된 알고리즘의 유효성을 입증할 수있었다.

• 한국통신학회논문지
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• 제34권4B호
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• pp.319-328
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• 2009

IEEE 802.16e 표준에서는 이동 단말의 제한된 에너지를 효율적으로 관리하기 위하여 서비스의 종류에 따라 서로 다른 수면모드 작동기법을 정의하고 있다. 기존의 수면모드 작동기법에 대한 연구는 이동 단말이 하나의 서비스를 받는 환경으로 제한되어 있으므로, 여러 서비스를 동시에 받을 경우 서로 다른 수면모드 작동기법을 동시에 적용하여 실제로 에너지를 절약하는 구간을 크게 감소시킨다. 본 논문에서 제안하는 에너지 절약 기법은 이동 단말이 여러 서비스를 동시에 받는 환경에서 실제로 에너지를 절약하는 구간을 증가시킴으로써, 에너지 소모를 최소화하고 기존과 비슷한 수준의 QoS(Quality of Services)를 보장한다. 향후 IEEE 802.16e 시스템에서 이동 단말의 제한된 배터리 수명을 증가시키면서 QoS를 보장하고 싶을 경우, 본 논문에서 제안한 에너지 절약 기법이 유용하게 사용될 수 있을 것이다.

• 해양환경안전학회지
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• 제16권2호
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• pp.235-240
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• 2010

백열전구를 대체하기위한 친환경 에너지 절약형 7w급 LED 램프의 구동을 위한 전원장치를 설계하였다. LED 램프는 칩 LED를 여러개 직 병렬로 연결하여 사용하게 되므로 적합한 직류 전압과 전류를 공급하여야 한다. 그런데 LED 램프는 상용 AC 220V 전원에 직접 연결해 사용하게 되므로 드라이버에는 전압제어와 전류제어가 포함된 AC/DC, DC/DC 전력변환기가 반드시 필요하게 된다. 따라서 본 논문에서는 램프의 LED 열에 따라 출력전압과 전류제어가 가능하며 변압기가 없는 간단한 구조의 LED 램프 드라이버를 설계하였다.

• 수산해양기술연구
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• 제52권4호
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• pp.347-355
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• 2016

In this study, a new designed propeller was applied on 24 ton class squid jigging vessel to reduce of fuel consumption. The selected squid jigging boat was under construction at the shipyard to determine the resistance of the hull through the model experiment. The propeller design was carried out by using the experimental data and ITTC procedures. Sea trials were performed by measuring the speed and the horsepower required by the condition of five power levels of engine load, namely 70%, 80%, 90%, MCR and maximum engine power. The speed and delivered horse power were compared between the conventional propeller and the new design propeller. Delivered horse power by installing the new propeller takes 90% engine load at start-up conducted by decreased 9.06%. The measuring speed is increased up to the 0.6 knots in the low-speed range to high range. This study showed that only the design and installation of a new propeller can improve the propulsion efficiency of the boats; furthermore, reduce fuel costs can be achieved at the same time by improving the increased cruising speed.

• 수산해양기술연구
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• 제53권4호
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• pp.446-455
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• 2017

The improvement of resistance performance for the 4.99 ton class fishing boats was shown. The 4.99 ton fishing boats are the most commonly used one in the Korean coastal region. The evaluation of resistance performance was estimated by the Computational Fluid Dynamics (CFD) analysis. The CFD simulation was performed by the validation for various types of bow shapes on the hull. The optimized hull form from the simulation was selected and showed the best resistance performance. This hull type was tested on the towing tank in the National Institute of Fisheries Science (NIFS). The effective horsepower (EHP) was estimated by the resistance test on the towing tank with the bare hull condition. The drag force on the three service speed conditions was obtained for the resistance analysis to power prediction. The measured drag forces are compared with the results from the CFD simulation with one another. As results of the model tests, it was confirmed that the shape of the bow is an important factor in the resistance performance. The effective horsepower decreased about 30% in comparison with the conventional hull form. Also, the resistance performance improved the reduction of required horsepower, which especially contributed to the energy-saving for the fisheries industry. In the CFD analysis, the resistance performance improved slightly. In this case, the ratio of the residual resistance ($C_R$) in the total resistance ($C_T$) was high. Therefore, the CFD analysis was not enough to satisfy with reflection for the free surface and wave form in the CFD procedure. Both model test and CFD calculation in this study can be applied to the initial design process for the coastal fishing vessel.

• 수산해양기술연구
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• 제50권4호
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• pp.487-494
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• 2014

This study describes the result on PV system for evaluating the performance of small fishing boats. Photovoltaic system with 200 watts power generation facilities on the 3-ton fishing boat was carried. Load test was performed on the condition that the work lamps lit during night operations. As a result the performance can be used for more than two hours at 60 watt work lamps. The load test was performed on the condition that fishing vessels are on the cruising condition at sea. The solar power systems have been investigated as a power generation efficiency of about 36.55%. Additional tests show that the power generation efficiency is difficult to expect a maximum of 50% or more. Fuel consumption of fishing boats by installing a solar power system is reduced. Also the PV system is useful for the verification of their availability for fishing vessels as well as the satisfaction of the fishermen. The results for the durability of the photovoltaic device is acceptable, including a solar panel, controller and the performance exhibited no breakage in the harsh marine environment or failure so far. The installed PV system was confirmed that the durability with at least 2 years.

• Journal of Power Electronics
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• 제4권3호
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• pp.138-151
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• 2004

In this paper, a constant frequency phase shifting PWM-controlled voltage source full bridge-type series load resonant high-frequency inverter using the $4^{th}$ generation IGBT power modules is presented for innovative consumer electromagnetic induction heating applications, such as a hot water producer, steamer and super heated steamer. The bridge arm side link passive capacitive snubbers in parallel with each power semiconductor device and AC load side linked active edge inductive snubber-assisted series load resonant tank soft switching inverter with a constant frequency phase shifted PWM control scheme is evaluated and discussed on the basis of the simulation and experimental results. It is proved from a practical point of view that the series load resonant and edge resonant hybrid high-frequency inverter topology, what is called, DE class type, including the variable-power variable-frequency regulation function can expand zero voltage soft switching commutation area even under low output power setting ranges, which is more suitable and acceptable for newly developed induction heated dual pack fluid heaters. Furthermore, even the lower output power regulation mode of this high-frequency load resonant tank inverter circuit is verified so that this inverter can achieve ZVS with the aid of the single auxiliary inductor snubber.

• 한국태양에너지학회 논문집
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• 제29권1호
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• pp.1-10
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• 2009

This study was carried out to evaluate the Life Cycle Cost(LCC) of three types of RTPV(Building Integrated Photovoltaic) systems-Glass plus Granite. Crystalline BIPV and See through Amorphous BIPV-which were vertically installed to generate the same power output(76 kW level). Initial investment costs. cost. savings and maintenance costs had been predicted during the period of analysing the LCC of three types of BIPV(Building Integrated Photovoltaic) systems installed for the purpose of evaluating the LCC. In case of cost savings, it had been analyzed by measuring the amount of electric power generated, reduction in lighting load and heat & cooling loads through simulation. From this analysis, it was predicted that the See-through amorphous BIPV offering cost saving advantages demonstrated the economical efficiency similar to the Class plus Granite when it is backed by more than 20 years of durability.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.1917-1926
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• 2018

In view of the current state of the reserves of electric energy generated resources and the share of electric motors in electricity consumption, many researches and studies related to efficiency in electric motors are being made. The presented work is related to the Axial Flux Permanent Magnet Synchronous Motor (AF-PMSM), which has recently undergone significant work based on the development of magnet and motor technology. In this study, a novel AF-PMSM was designed analytically through Finite Element Method (FEM) which can be started by connecting to a line such as an asynchronous motor in a transient state and can operate with high efficiency and power factor after synchronization in steady state without the need for an expensive motor drive. According to the obtained FEM results, a design with an efficiency class of IE4 of 5.5 kW shaft power, a 4 poles motor was obtained. As a result, economic calculations indicate that the extra cost of the designed Line start AF-PMSM with respect to the asynchronous motor is rapidly compensated by energy saving due to a more efficient operation, especially constant speed operations. As a result of the analysis obtained, the targeted values are reached. For induction motors and radial flux permanent magnet synchronous motors, a good alternative motor that can operate with high efficiency and power factor has been obtained.