• 조명전기설비학회논문지
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• 제29권8호
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• pp.40-48
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• 2015

In this paper, battery charging and discharging circuit with a single voltage power supply is proposed. The proposed circuit has the separated current path and charging-monitoring sequence control scheme. In the charging sequence, the proposed 2-level comparator combined with control signal of the micro-processor can control the constant charging current to protect the over current of the battery. Furthermore, the proposed circuit uses a periodic main power switch control to detect the discharging characteristics to estimate the approximated battery life-time. In the experiments, the proposed emergency power supply for emergency call system has 89% efficiency with 98% power factor. And the proposed sequence control scheme is well operated in the designed emergency power system.

• 전력전자학회논문지
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• 제24권5호
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• pp.342-348
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• 2019

The emergency power supplies (EPSs) are required to increase battery sizing for protecting power source loss above designed criteria. This study proposes a sizing method for lithium-based batteries for EPSs in nuclear power plants on the basis of the calculation method for the required energy under variable conditions. The variable conditions are related with the characteristics of lithium-based batteries, such as the temperature of the location of EPS installation, aging, and design margin. The usage of lithium-based battery reduces the cost and installation space and enables the safe and long-term supply of power compared with the use of lead-acid battery.

• 전기전자학회논문지
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• 제23권2호
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• pp.667-674
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• 2019

최근 발생한 원전 사고는 소외전원 및 비상전원의 기능이 상실되어 발전소 전체 정전이 발생한 사례를 계기로 원전의 비상전원공급용 배터리의 중요성이 부각되고 있다. 현재 원전의 비상전원공급용 배터리는 기존의 납축전지를 대신하여 리튬계열 배터리로 교체가 고려되고 있는 상황이다. 이에 따라 원통형 리튬 배터리의 적용성을 판단하기 위해 여러 가지 리튬 계열 배터리의 전기적 특성 실험을 진행하여 결과를 분석해야 한다. 본 논문은 현재 ESS(Energy Storage Systems)에 많이 사용되는 세 가지 타입의 리튬 배터리의 전기적 특성실험을 통해 적절한 배터리 타입을 선정하고, 선정된 배터리가 비상전원공급용 배터리로 사용될 때 최적의 C-rate를 제안한다. 또 배터리 모델링을 통해 배터리의 상태를 추정하며 문제점을 제시한다.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2268-2275
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• 2018

This paper presents a high-efficiency low-power permanent magnet (PM) generator for the power supply of the generator exciter. In the conventional generator system, the power for the exciter is fed by the generator output power or an emergency battery for the starting. The proposed low-power PM generator can generate the proper power and voltage to excite the exciter field winding. According to the starting of the generator, the designed PM generator can supply the constant voltage to the Automatic Voltage Regulator (AVR), then it can be used to control of exciter field current for the generator. Because of the designed PM generator which is placed inside the conventional generator system, the emergency battery and Potential Transducer(PT) for AVR can be removed. Thus, the total efficiency can be improved. The proposed generator system is tested in the practical system. And the efficiency characteristic is analyzed.

• 전력전자학회논문지
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• 제21권4호
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• pp.302-311
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• 2016

This paper proposes a hybrid ESS that integrates an energy storage system (ESS) with an uninterruptible power supply (UPS). The hybrid ESS has a demand management and emergency power supply function while increasing the battery utilization of the UPS, which has just been used in a power failure. In addition to the critical load, the proposed system augments the capacity of emergency generation using an additional load, which has voltage and frequency-dependent characteristics to the grid side. The control algorithm of the AC-DC converter and bidirectional DC-DC converter is proposed for demand management and emergency power supply. Furthermore, seamless and autonomous transfer methods to alleviate the transient during mode transfer are proposed. To validate the proposed control scheme, experimental results from a 5 kW prototype are provided.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.392-401
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• 2020

연구목적: 본 연구는 비상시의 예비전원장치로 사용 가능한 리튬이온커패시터의 동작 특성을 분석하고, 충·방전시의 선형비례특성을 이용하여 전압을 측정하는 것으로도 예비전원장치의 동작 이상 유무를 판단 할 수 있는 실험근거의 제공을 목적으로 한다. 연구방법: 본 연구를 위한 방법으로 먼저 기존 예비전원장치와 리튬이온커패시터에 대한 동작원리 및 특성을 분석하고, 다음으로 실험에 사용한 유도등의 구성도와 시스템 블록도에 따라 리튬이온커패시터의 전압 측정을 통해 배터리의 보유 전력량을 확인하는 전압대역별 방전전력량 측정 값 테스트와 유도등을 이용한 동작 테스트 실험으로 진행한다. 연구결과: 리튬이온커패시터의 선형비례특성을 이용한 충전전압을 확인하는 것만으로도 정확하게 유도등 램프의 유효동작 시간을 추론 할 수 있는 근거를 제시하고 있다. 결론: 재난 상황 시 리튬이온커패시터를 비상유도등의 예비전원장치로 사용함으로써 비상유도등의 완전 방전을 미연에 방지하고, 예비전원장치의 정상 작동 수행의 문제가 발생하지 않게 하며, 간단한 전압측정만으로도 예비전원장치의 이상 유무를 확인 할 수 있게 하여 향후 피난설비 적용에 많은 활용도를 제시하고자 하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.207-210
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• 2005

This paper describes a design of several ship's emergency lighting system(SELS) that power factor is improved and power is controlled extensively, and techniques to control and monitor this system in remote distance by PC serial communication. The remote monitoring control system is composed of emergency power supply system (EPSS), half bridge(HB)inverter, fluorescent lamp(FL), microprocessor, multi communication interface. EPSS checks the voltage of the emergency backup battery in real time. In case that the voltage of 13[V] or less has been detected for 5[msec] or longer for 3 times in a row, charger circuit is connected for battery charging. Experimental works using proposed system confirm that speedy and stable power to be supplied when main power source cut-off, compared with conventional analog type, and input power up to 35.0[%] by adjusting of pulse frequency of the HB inverter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2668-2670
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• 2002

The generators of a small size below 100Kw are often used as power suppliers for emergency only in most domestic telecommunication companies. Serious twisted waves occur due to the inflow of harmonies from the generator into a S-type rectifier. And the increasing by stages of load upon the rectifier end up a stoppage of power supply during the serious hunting, which makes it difficult to supply power securely on the other part as well as that of communications. In case of long time of power failure the generators of a small size will be essential because the battery for emergency has a limit in capacity. Therefore it is necessary to solve the problems concerning the generators. This study is focused on the identifying and solving the problem including use of SCR elements connected to the generators.

• 대한전기학회논문지:전력기술부문A
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• 제49권4호
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• pp.152-160
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• 2000

This paper presents an efficient evaluation method on the role of new energy storage systems, especially the secondary Battery Energy Storage (BES) systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a synthetical and quantitative manner, because they are very costly in the early stage of their development and commercialization. In this paper, the multiple functions of BES systems, which are operated at distribution systems, such as load levelling, effective utilization of power distribution systems and uninterruptible power supply at the emergency conditions are classified and analyzed. And then the quantitative evaluation methods of the multiple functions for BES systems are proposed using the mathematical modelling.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.600-605
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• 2003

Battery of rolling stock is a very important device as power supply at starting and emergency control. This paper analyzes the quality of Ni-Cd battery by means of performance test. Ni-Cd battery have suitable and stable properties. That is very stable to discharge on low temperature state and very easy to manage and repair. This paper confirm the performance and property of Ni-Cd battery on low temperature environment by the performance test and estimate the life-cycle of Ni-Cd battery on board at rolling-stock by the life-test and the using-test.