• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.26-32
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• 2011

The object of this paper is to optimize the battery system for supplying stably power in separate house in which a PV-wind hybrid power generation system is applied. In a power system to be used in a stand alone, it is very important to build optimize the electrical storage system and to utilize it for supplying stably output voltage when there is a shortage of the power generation capacity or there is no sunshine, or when power is to be supplied with a load. This paper provides an optimized method to evaluate capacity of battery by analyzing advantages and disadvantages of the existing battery evaluating method being used in each company for supplying stably power in separate house utilizing the new renewable energy such as a light of the sun.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.65-69
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.349-352
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• 2010

본 논문에서는 소규모의 태양전지를 전원으로 사용하며 LED 부하를 이용하는 소형 사인보드 시스템의 설계방법에 대해 제안한다. 소형 PVLED 시스템의 최적 설계를 위해 고려해야 하는 LED 부하의 운전 전력소비량에 대한 계산과 더불어 축전지, PV모듈 등과 같은 시스템 용량을 주변 환경을 고려하여 설계한다. 시스템 설계를 위해 LabView를 사용하였으며, 실제 사용현장에서 PVLED시스템의 효과적인 유지관리를 위한 고장 검출기능을 추가하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1237-1241
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the characteristics of charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle. An analysis performed in this paper indicates that supercapacitor storage system may be cost effective for high cycle applications.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.59-60
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• 2013

슈퍼캐패시터(Super Capacitor) 또는 울트라 캐패시터(Ultra Capacitor) 등으로 불리우는 전기 이중층 캐패시터(EDLC, Electric Double Layer Capacitor)는 기존 콘덴서보다 월등한 용량 특성을 가지며, 전극과 전해질의 화학반응을 이용하던 이차전지들과 달리 주로 계면반응을 사용한 축전원리를 이용하여 높은 출력밀도와 충방전 효율, 무제한에 가까운 사이클 특성을 가지고 있다. 또한 전류변화에 안정적이어서 기존의 이차전지와는 달리 보호회로를 생략할 수 있기 때문에 단순한 회로 구성이 가능하고 전극활물질로서 탄소재를 사용하여 환경 친화적인 특성을 가진 차세대 에너지저장장치라고 할 수 있다. 특히 50만 사이클이라는 우수한 수명특성으로 인해 기존의 이차전지가 사용되기 어려운 다양한 분야에 적용이 늘어가고 있는 추세에 있다.

• 한국해양학회지
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• v.23 no.2
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• pp.53-61
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• 1988

A capacitance wavestaff system was devised, which is suitable for the wave measurement near to surf zone. Laboratory tests show that the performance of the wavestaff is not significantly affected by the sea water characteristics such as temperature and salinity, and output signals of the wavestaff are linearly proportional to sea surface elevations. The major error source of the wavestaff system is the improper setting of the wavestaff in field experiment.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.217-222
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• 2006

Polyimides have been investigated extensively and used widely over the past three decades because of their high performance properties such as excellent thermal, mechanical, and electrical properties. Polyimides are difficult to be processed because of the aromatic moieties, imide group, and insoluble nature in most organic solvents. The soluble polyimides were synthesized from 2,2,-bis(3-amino-4-hydroxyphenyl) hexafluoropropane (BAPAF) and 3,3,-diamino-4,4-dihydroxybyphenyl (HAB) as aromatic diamines and 4,4-(hexafluoroisopropylidene)diphthalic dianhydride (6FDA), pyromellitic dianhydride (PMDA), 4,4-oxydiphthalic dianhydride (OPDA), 3,3,4,4-benzophenone tetracarboxylic dianhydride (BTDA) and 3,3,4,4-diphenylsulfone tetracarboxylic dianhydride (DSDA) as aromatic dianhydrides. The polyimides were characterized by NMR, FR-IR, TGA and the dielectric constant of the obtained polyimides was calculated from storage of electro-capacity. A novel photosensitive polyimide was synthesized by the reaction of polyimide, containing hydroxyl group and methacryloyl chloride using triethylamine. The good micro-pattern was obtained with photosensitive polyimide from the photolithographic technique.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.689-693
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• 2010

When natural rubber dissolved in toluene comes into use as a binder of carbon powder, the volatilization of solvent just after the construction of biosensor brought the mechanical robustness on the paste. This characteristic satisfied the pre-requisite condition for the practical use of carbon paste electrode and a biosensor for the determination of hydrogen peroxide was designed. In order to evaluate its electrochemical qualitative and quantitative behaviors, various electrochemical kinetic parameters of the electrode, e.g. the symmetry factor (${\alpha}$, 0.37), the exchange current density ($i_0$, $0.075mAcm^{-2}$), the capacitance of double layer ($C_d$, $9.7{\times}10^{-3}F$), the time constant (${\tau}_A$, 0.92 s), the maximum current ($i_{max}$, $5.92{\times}10^{-7}Acm^{-2}$), the Michaelis constant ($K_M$, $1.99{\times}10^{-3}M$) and others were investigated. Results show that natural rubber is a promising binder of carbon powder.

• Journal of the Korean Chemical Society
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• v.43 no.1
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• pp.23-29
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• 1999

The Al oxide layer formed in 1M $H_2SO_4$ solution and the influence of applied frequency for electrodeposition of Mn on Al oxide layer were characterized using by impedance spectroscopy. Mn compounds were electrodeposited at the base of pores during deposition with applied low frequency voltage. For the Mn deposited oxide layer at 6OHz and 5Hz in 1 g/L $KMnO_4$ solution, in equivalent circuit for interpretation, the resistance ($R_2$) and capacitance ($C_2$) were considered to be due to deposition of Mn on base of pore. The electrochemical behavior of barrier layer and porous oxide layer on Al have been characterized by capacitance ($C_b$) and Young capacitance ($C_Y$) in equivalent circuit model.

• Membrane Journal
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• v.26 no.1
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• pp.62-69
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• 2016

In this study, sulfonated poly(ether ether ketone) (SPEEK) as cation exchange membrane and blended and crosslinked poly(vinyl amine) (PVAm) with poly(vinyl alcohol) (PVA) membrane as anion exchange membrane were used and then the performance experiments of the membrane capacitive deionization (MCDI) installed with both membranes were carried out. The newly prepared anion exchange membrane were characterized through water content, ion exchange capacity and FT-IR. The crosslinking time of 3 h to 5 h indicated that the salt removal was reduced from 81.3, 65.7% to 53.8%. The effect of PVAm contents from 40, 60, to 80% on the salt removal was shown 81.3, 75.2 and 37.7%, respectively. As a result, it was concluded that the crosslinking time and the content of PVAm had an influence on the salt removal efficiency.