• 한국통신학회논문지
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• 제42권5호
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• pp.975-981
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• 2017

본 논문에서는 WSN 환경에서 플래시 장치를 사용할 때 에너지를 효율적으로 사용하기 위한 방법을 제안한다. 전형적인 플래시 장치는 높은 대기 에너지로 인해 에너지가 제한된 WSN에서 비효율적인 에너지 소모 저장 매체라는 단점을 가지고 있다. 플래시 장치를 WSN 환경에서 에너지 효율적으로 사용하기 가장 쉬운 방법은 유휴 상태일 때 플래시 장치를 끄는 것이다. 이와 관련하여 우리는 비휘발성 및 바이트 주소 지정 기능을 제공하는 새로운 메모리 기술인 NVRAM (Nonvolatile RAM)을 활용하여 높은 대기 에너지 소모 그리고 시작 지연시간을 제거함으로써 간단하지만 이상적인 접근 방식을 현실적으로 제안한다. 특히 NVRAM을 메타 데이터 저장소의 확장으로 사용하여 FTL 메타 데이터 검색 프로세스를 제거하여 앞의 두 가지 장애 요소를 해결 하고자 한다. 실험을 통해 제안하는 방법이 기존 저장장치 비해 약 1.087% 에너지 만을 사용함을 알 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.879-884
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• 2007

Flywheel energy storage systems have advantages over other types of energy storage devices in such aspects as unlimited charge/discharge cycles and environmental friendliness. In this paper we propose a millimeter scale flywheel energy storage device. The flywheel is supported by a pair of passive magnetic bearings and rotated by a toroidally wound electric motor/generator. The geometry of the bearings is optimized for the maximum dynamic performance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.212-214
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• 2007

Regenerative energy which is generated during brake periods of DC traction might cause malfunction or destruction of rectifier or any other power conversion devices caused the increment of DC line voltage. Regenerative energy storage system using super-capacitor is one of the method to control the DC line voltage safely. And super-capacitor is very important device as energy storage device. Therefore, In this paper, we designed the regenerative energy storage system using super-capacitor and propose the method about predicting the lifetime of super-capacitor established in storage system. According to the this research, we can estimate the proper replacement moment for the existed super-capacitor due to the safety of the system. And improve the reliability of regenerative energy storage system using super-capacitor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.231-232
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• 2011

It is very important thing to efficiently utilize the solar power. The conventional solar power system has no energy storage device. So the conventional system cannot cut the peak load. In this paper, the solar power system with the energy storage device and the operation algorithm of peak cut function was proposed to cut the peak load. The algorithm principle is proposed based on the insolation curve and load curve. The simulation and experiment was performed to demonstrate the validity of the peak cut algorithm.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.689-692
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• 2000

This paper presents a designing for the Off-line UPS usig SMB Flywheel Energy Storage System. This described flywheel energy storage system is designed to replace of the conventional EMB(Electro Mechanical Battery) system. To realize the high efficiency and to minimize the torque ripple the waveform of the inverter output current is controlled to be sinusoidal. The actual performance of the Off-line UPS using flywheel energy storage system is described. The prototype device was manufactured, The experimental result has good characteristics at a time of power transition region and regeneration modes,

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.735-736
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• 2012

• 한국수소및신에너지학회논문집
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• 제22권2호
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• pp.178-183
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• 2011

Metal hydride alloys are a promising type of material in hydrogen storage applications, allowing for low-pressure, high-density storage. However, while many studies are being performed on enhancing the hydrogen storage properties of such alloys, there has been little research on large-scale storage vessels which make use of the alloys. In particular, large-scale, high-density storage devices must make allowances for the inevitable generation or absorption of heat during use, which may negatively impact functioning properties of the alloys. In this study, we develop a numerical model of the discharge properties of a high-density MH hydrogen storage device. Discharge behavior for a pilot system is observed in terms of temperature and hydrogen flow rates. These results are then used to build a numerical model and verify its calculated predictions. The proposed model may be applied to scaled-up applications of the device, as well as for analyses to enhance future device designs.

• ETRI Journal
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• 제39권6호
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• pp.874-879
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• 2017

This paper challenges the fabrication of a thin film energy storage device on a flexible polymer substrate specifically by replacing most commonly used metal foil current collectors with coated current collectors. Mass-manufacturable spray-coating technology enables the fabrication of two different half-cell electric double layer capacitors (EDLC) with a spray-coated silver paste current collector and a Ni foil current collector. The larger specific capacitances of the half-cell EDLC with the spray-coated silver current collector are obtained as 103.86 F/g and 76.8 F/g for scan rates of 10 mV/s and 500 mV/s, respectively. Further, even though the half-cell EDLC with the spray-coated current collector is heavier than that with the Ni foil current collector, smaller Warburg impedance and contact resistance are characterized from Nyquist plots. For the applied voltages ranging from -0.5 V to 0.5 V, the spray-coated thin film energy storage device exhibits a better performance.

• 전력전자학회논문지
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• 제17권6호
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• pp.523-531
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• 2012

This paper proposes a high efficiency power conversion system for battery-ultracapacitor hybrid energy storages. The proposed system has only one bidirectional dc-dc converter for hybrid power source with batteries and ultracapacitors. The hybrid power source has bidirectional switching circuits for selecting one energy storage device. Bidirectional power flow between the energy storage device and high voltage capacitor can be controlled by one bidirectional converter. An asymmetrical switching method is applied to the bidirectional converter for high power efficiency. Switching power losses are reduced by zero-voltage switching of power switches. System operation and design considerations are presented. The experimental results are provided to verify the performance of the proposed system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.51.2-51.2
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• 2010

Efficient and durable electrical energy storage is one of the major factors limiting the wide-spread adoption of renewable energy. Since lithium-ion batteries (LIBs) were first commercialized in the early 1990s, LIBs have emerged as an important energy storage device for portable electronics. LIBs are very desirable because of their high energy storage per volume and per mass. However, LIBs with high energy and power as well as higher stability are needed for their use in a variety of energy storage applications such as MEMS devices, PDA, plug-in hybrids, all-electric vehicles and large scale utility systems. In this talk, I will discuss present energy perspective, especially energy storage and its role in renewable energy. After that I will discuss the recent advances in nanostructured materials and interface engineering that have led to the achievement of improved Li-ion batteries. Finally I will talk aboutcritical issues that need to be addressed to obtain further improvements in Li-ion batteries.