• Electric Engineers Magazine
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• v.177 no.5
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• pp.48-53
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• 1997

전력전자기술 발전에 따라 최근의 전기설비에서는 FA 및 OA용 전원은 정보통신용 전원으로 무정전 전원장치가 필수적으로 시설되고 있다. 또한 성에너지를 위한 전동기 가변속 구동장치가 많이 채택되고 있다.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.317-321
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• 2002

• KIPE Magazine
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• v.19 no.5
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• pp.47-52
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• 2014

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.236-238
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• 2012

본 논문은 저전력 데이터센터에 사용되는 DC 서버를 위한 고효율 DC UPS 결합형 전원분배장치의 구현과 설계에 관한 내용이다. 본 논문이 제안한 노드 준위 UPS 결합형 전원분배장치의 전력효율은 96%에 이르며 저전력 볼륨 서버의 전원공급장치(PSU)와 UPS를 대체할 수 있는 기술이다.

• Journal of IKEEE
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• v.23 no.2
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• pp.495-501
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• 2019

This paper proposes a variable passive harmonic filter for reduction and improvement of harmonics and power factor of single-phase uninterruptible power supply(UPS) with full bridge rectifier. Recently, UPSs have excellent harmonic and power factor operation characteristics by applying 2-level or more levels of power conversion methods. On the other hand, the single-phase UPS of the full bridge rectifier seriously causes the third, fifth, and seventh harmonics, and the power factor reduction on the grid side. Therefore, we present a variable passive harmonic filter for eliminating (2n+1) order harmonics and improving the power factor generated by the full bridge rectifier operation. In order to evaluate the performance of the proposed variable harmonic filter, the its validity is verified by various simulations and experiments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.100-105
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• 1998

This paper proposes a new control strategy of bidirectional uninterruptible power supply (UPS) with the performance of active power filter which compensates the harmonics and reactive power. With only one power stage, it is working simultaneously as the AC/DC rectifier/battery charger and DC/AC inverter to the operation of battery charging or back-up power supplying. Therefore the operation of the proposed system can be divided into the modes, such as the active power filter mode and the battery back-up power mode. And a novel closed-loop control strategy is used to calculate the reference current. The performance of the proposed 5[kVA] system is verified by the simulation and experimental results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.602-604
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• 2006

한국천문연구원(KASI)은 국제 GNSS 관측망(IGS)의 글로벌 데이터 센터(GDC)를 설립하였다. KASI GDC는 공식적으로 IGS GDC이고 세계 4번째로 설립되었으며, 아시아 및 오세아니아 지역에서는 최초이다. KASI GDC는 IGS GNSS 데이터를 기록하고, IGS GPS 데이터와 IGS 산출물을 인터넷을 통해 제공한다. GDC에서 다루는 데이터의 양은 매우 빠르게 증가한다. GDC 데이터의 대용량을 처리하기 위해서는 시스템의 높은 효율성과 신뢰성이 요구된다. 그래서 KASI GDC는 높은 신뢰성과 대용량 저장 장치를 필요로 하는 저장 시스템을 구성하기 위해 RAID와 LVM을 적용했다. KASI GDC의 공식 출범 이후 데이터 이용 현황을 확인하고, 항상 시스템이 Active 상태로 유지하기 위한 무정전 시스템 구성에 대해 기술한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.5
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• pp.18-24
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• 2006

This paper proposed UPS system parallel connected in battery and ultracapacitor to compensate instantaneous voltage drop. Ultracapacitor parallel connected with battery compensate instantaneous voltage drop at failure and it's reduced the voltage regulation of output voltage. We are produced for fast instantaneous voltage drop compensation of ultracapacitor at UPS system and experiments are achieved. Experimental result was verified that the ultracapacitor indicated the fast compensation characteristics and regulation of the output voltage satisfied within 5[%] by using ultracapacitor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.685-688
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• 2006

A single-phase uninterruptible power supply system suitable for a SMES unit is proposed to achieve a simple circuit configuration and higher system reliability. It reduces the number of switching devices by applying a common-arm scheme. Operational principles to normal, stored-energy, and bypass mode are discussed in detail. Eliminating some of the switches or substituting passive components for active switches generally increases the sophistication and reduces degree of freedom in control strategy. However, the high-performance digital controller ran execute the complicated control task with no additional cost. The validity of the proposed UPS system will be verified by a computer-aided simulation.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.273-278
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• 2014

Recent use of electricity during peak hours electricity supply-demand imbalance is inevitable that limit power use force. Therefore, in this paper, a circuit of parallel power operation equipment for peak power reduction which saves the power to electricity storage device during the non-peak power time and supply from the storage power during the expected power shortages time is designed Through this circuitry, the peak power of the commercial power supply with the parallel operation and connection of the commercial power supply and the power supply of the inverter from electricity storage that is a key feature of PRS(Peak power Reduction System) can be controlled. In addition, in order to increase the efficiency, a Transless Power Circuit DC-AC inverter is developed. Moreover, a variable impedance control is applied to the storage of electric power of an Uninterruptible Power Supply associated with a commercial power source.