• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.271-272
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• 2010

본 논문에서는 서버용 전원 장치의 고효율 및 고밀도화를 위하여 서버용 전원 장치를 구성하는 PFC단, DC-DC단, Standby단의 전력 손실을 분석하고 효율 개선을 위한 설계 시 고려 사항을 제시한다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.457-460
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• 2003

대부분의 전기전자기기는 주 기능을 사용하지 않고 단지 전기 플러그만 연결된 상태에서도 수 와트 정도의 전력을 소모하는데 이를 대기전력이라고 한다. 대기전력은 전기전자기기의 급속한 보급확대와 사무자동화 및 홈 오토메이션의 가속화로 점점 국가적 차원의 주요 에너지 문제로 대두하게 되었다. 본 발표에서는 대기전력을 절감하기 위한 선진국들의 제도와 정책을 조사하고 대기전력 절감을 위한 일련의 과정에 대하여 기술하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.971-972
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• 2007

에너자를 전적으로 수입에 의존하는 우리나라의 현실과 각 나라와 우리나라의 에너지 절약정책 중 대기전력에 대하여 비교검토하고. 특히 전기기기중 멀티콘센트를 이용한 대기전력에 대하여 검토한 결과 컨트롤 제어부가 부착된 멀티콘센트를 사용하였을 때 연간 약, 연간 약 140,000[MWh]의 전력소비 절감효과를 기대 할 수 있다.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.1
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• pp.62-65
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• 2019

Wireless power transfer systems require an algorithm to determine the presence of the target object for mitigating standby power and safety issues. Although many schemes that sense various external objects have been actively proposed for inductive power transfer systems, not many studies on capacitive power transfer systems have been conducted compared with those on inductive power transfer systems. This study proposes a target object detection algorithm by monitoring the capacitance in transmitter-side electrodes without additional pressure sensors or distance sensors. The proposed algorithm determines the presence of a target object by monitoring the change in capacitance in transmitter-side electrodes using the step pulse of the microcontroller unit. The algorithm is verified by two step processes. First, the performance in capacitance measurement is compared with that of an LCR meter. Then, the verification is conducted in a 5-W capacitive power transfer hardware. Experimental result shows that the interelectrode capacitance increases by 6 times when the target object is fully aligned. Thus, the proposed scheme can successfully detect the presence of the target object.

• Journal of the Korean Institute of Navigation
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• v.17 no.3
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• pp.69-76
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• 1993

In harbour the practical shiphandlers should have a expert knowledge of systematically reducing head-way and keeping ship's positions to the final position with confidence and under control. But now in the practical approaches we do not have any special maneuvers of controlling the ship effi-ciently regarding the headway and approaches except some existing reduction of speeds according to the Weight-to-Power Ratio, use of astern power and Rudder Cycling. Consequently this study put Woo's Super Rudder Controlling originally developed by Captain Woo, Ph. D. to practical use as a special maneuvers in the port approaches. The conclusions of this paper are drawn as follows : 1) Optimum standard and desirable controls in combination of three engine speeds with three yaw ang-les were proposed for the practical shiphandlers, 2) According to simulation of the pilotships the Super advances are 10.5 ship lengths for Full full full maneuvers, and 7.9 ship lengths for Full half maneuvers approximately, 3) Approach maneuvers to anchorages by trying Woo's Super Rudder Controlling saved about 30% of total standby time in comparison with the existing Weight-to-Power Ratio maneuvers in the Pusan and Kwang Yang ports.

• Journal of Power Electronics
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• v.15 no.3
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• pp.695-701
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• 2015

Uninterruptible Power Supplies (UPSs) can be largely divided into the passive-standby, line-interactive and double-conversion methods. This paper proposes a double-conversion UPS with a low cost and high performance. This single phase UPS uses a single-loop robust voltage controller and 1-switch voltage doubler strategy PFC. The proposed UPS is composed of a single phase PFC, a half-bridge inverter, a battery charger and a battery discharger. Finally, the validity of proposed UPS was verified by various experimental tests.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.287-298
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• 2016

This paper proposes an effective smart plug system capable of monitoring power, cutting off standby power and overload current. The key design concept is focused on measurement accuracy, self power consumption and controlling via smart phone application. The system is composed of several plugs and a hub, and adopts a star-topology-styled TDMA wireless protocol for communication between plug and hub. The test result shows that the implemented smart plug system meets K10026 regulation and is worth in electrical safety, energy saving, easy living.

• Journal of Power System Engineering
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• v.13 no.5
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• pp.82-88
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• 2009

The purpose of this paper is to provide technical background, techniques and actual diesel engine signature analysis evaluation result. Engine signature analysis(ESA) is a process for monitoring the material condition of diesel engine using external sensors, eliminating the need to periodically disassemble the engine. ESA is also used to balanced the engine. Engine balancing is the process of tuning the engine so that all cylinders carry equal load. ESA is a useful tool to non-intrusively determine the operability and performance and assessment of the material condition of internal component of a diesel engine.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.168-174
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• 2005

A coreless electronic transformer is proposed. Conventional iron cored transformer is heavy and bulky and it has substantial amount of no load loss. On the other hand, electronic transformer can be made of negligible no load loss and is small size and lightweight. It consists of rectifier and PWM inverter. Electronic transformer is easily modeled to conventional Buck converter; therefore, output voltage is controlled by duty ratio. It is thought to be suitable for applications where the operation duty is low. In this paper, a novel coreless transformer is proposed, then it's detailed analysis, simulative and experimental results are presented

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.11
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• pp.655-662
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• 1999

This paper describes controller design and simulation-model development of a dynamic voltage compensator using series and shunt inverters. The control system was designed using PI controller and vector relationship between the supply voltage and load voltage. A simulation model with EMTP was developed to analyze performance of the controller and the whole system. The simulation and experiment results confirm that the dynamic compensator can restore the load voltage under the fault of the distribution system, such as single-line-ground fault, three-line-to-ground fault, and line-to-line fault.