• 전자공학회논문지
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• 제52권1호
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• pp.135-139
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• 2015

플라즈마 디스플레이 패널의 각 부화면 시간동안 기입 방전의 지연시간을 각각 조사하였고 오방전이 발생하지 않는 범위내에서 추가 주사전압의 높이를 다르게 인가하여 모든 부화면 시간동안 기입방전 지연시간을 단축시키기 위한 수정된 구동방법을 제시한다. AC PDP에서 첫번째 초기화 기간 동안 주사전극에 높은 상승 경사파 전압을 인가하여 약한 플라즈마 방전이 발생하고 셀 내부에서 프라이밍 입자와 벽전하 생성을 유도한다. 생성된 벽전하는 셀 내부 벽전압이 되므로 기입기간 중 기입전압과 더해져서 기입 방전을 일으킨다. 그러나 셀 내부의 벽전하는 시간이 지나면서 점차 소멸되므로 1 TV 프레임 시간 동안 각 부화면 시간동안 기입방전은 늦게 발생한다. 첫 번째 부화면 시간에는 초기화 기간 동안 상승 경사파를 갖는 높은 전압에 의해 벽전하가 많이 남아 있으므로 첫 번째 기입 방전은 다른 부화면 시간보다 빠르게 형성된다. 한편, 두 번째부터 마지막 부화면 시간까지의 기입 방전 생성시간은 셀 내의 벽전하 소멸에 의하여 점차적으로 늦어진다. 본 연구에서는 각 부화면 시간동안 기입방전의 시간지연을 조사하였고, 부화면 시간의 기입기간 마다 추가 주사전압을 다르게 인가하여 전체 기입방전지연시간을 단축시켰다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1653-1655
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• 2003

The purpose of this paper is to evaluate the effects of pre-formed space charge by negative DC voltage on partial discharge(PD) patterns of XLPE. We have suggested a modified pulsed electro-acoustic method and demonstrated that the PD patterns are strongly influenced by the pre-formed space charge distributions, which are hardly disappeared up to AC 8kV in electrode configuration including air gap between XLPE layer and electrode.

• 한국안전학회지
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• 제23권4호
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• pp.42-46
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• 2008

Ionizers are essential in various areas of manufacturing industries to protect electrostatic hazards and to reduce inferior products. For ion sources used in the charge neutralizers, there are corona discharge, soft X-ray, ultraviolet and glow discharge. Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. In this paper, we did an experimental study to trace the mechanism and stabilization of atmospheric pressure glow discharge using the several size and shape of electrodes. As an experimental result, to sustain conditions of atmospheric pressure glow discharge is that discharge voltage is 360V, discharge current is 12mA, apply frequency is 1kHz between electrodes when positive electrode is molybdenum(Mo) and negative electrode is copper(Cu). We confirmed that the mechanism and stabilization of atmospheric glow discharge is deeply concerned with the shape and material of electrode for discharge. Especially, glow discharge in atmospheric pressure was well generated and sustained according with the physical properties used electrode materials, example melting point, thermal conductivity, and etc.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.350-351
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• 2005

The electrochemical behavior of Si-C material synthesized by heating the mixture of silicon and polyvinylidene fluoride (PVDF). Coin cells of the type 2025 were made using the synthesized material and the electrochemical studies were performed. Si-C/Li cells were made by using the developed Si-C material. Charge/discharge test was performed at 0.1C hour rate. Initial charge and discharge capacities at Si-C material derived from 20 wt.% of PVDF was found to be 1,830 and 526 mAh/g respectively. Initial charge/discharge characteristics of the electrode were analyzed. The level of reversible specific capacity was about 216 mAh/g at Si-C material derived from 20 wt.% of PVDF, IIE, intercalation efficiency at initial charge/discharge, was 68 %. Surface irreversible specific capacity was 31 mAh/g, and average specific resistance was 2.6 ohm*g.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1603-1605
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• 1997

$LiNiO_2$ is prepared by heating LiOH $H_2O$ and $Ni(OH)_2$ (mole ratio 1:1). In this study, we investigated X-ray diffraction, and charge/discharge property heat treatment condition and conductive agent sort and volume of $LiNiO_2$ prepared at various temperature and time. All $LiNiO_2$ prepared at this study showed hexagonal structure. In charge/discharge capacities, heated at $O_2$ than air and $750^{\circ}C$ than $700^{\circ}C$, specific capacity is higher. Therefore, when preliminary heat at $650^{\circ}C$ $O_2$ and heat at $750^{\circ}C$ carried out, charge/discharge property is best.

• 전기화학회지
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• 제1권1호
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• pp.8-13
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• 1998

This work presents the way how to evaluate the degree of reversibility of the discharging process undergone by the nickel hydroxide film cathodically deposited on pure nickel as a positive electrode for electrochemical capacitor using the combined cyclic voltammetry and potential drop method, supplemented by galvanostatic discharge and open-circuit potential transient methods. The time interval necessary just to establish the current reversal of anodic to cathodic direction from the moment just after applying the potential inversion of anodic to cathodic direction, was obtained on cyclic voltammogram. The cathodic charge density passed upon dropping the applied potential, was calculated on potentiostatic current density-time curve. Both the time interval and the cathodic charge density in magnitude can be regarded as being measures of the degree of reversibility of the discharging process undergone by the positive active material for supercapacitor, i.e. , the longer the time interval is, the lower is the degree of reversibility and the greater the cathodic charge density is, the higher is the degree of reversibility. From the applied potential dependences of the time interval and cathodic charge density, discharge at $0.42 V_{SCE}$ was determined to be the most reversible.

• 전력전자학회논문지
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• 제15권6호
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• pp.441-450
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• 2010

리튬전지는 다양한 전자기기의 구동전원으로 널리 사용되고 있으며, 충전과 방전 동작을 수차례 반복하는 화성공정은 이러한 리튬전지의 생산에 필수적이다. 본 논문에서는 충전동작과 방전동작을 하나의 장치로 수행할 수 있는 리튬전지 충방전용 직류-직류 변환기를 제안하고 설계한다. 제안한 변환기는 리튬전지의 충방전 특성을 고려하여 설계하였으며, 충전모드에서는 포워드 변환기로 동작하고 방전모드에서는 절연된 부스트 변환기로 동작한다. 해석을 바탕으로 설계조건에 부합하는 변압기의 권선 수, 인덕터, 커패시터 및 스위칭 소자를 설계하였다. 끝으로 설계한 변수를 적용한 시뮬레이션과 실험을 통하여 본 논문에서 제안한 변환기 설계의 타당성을 입증하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.275-278
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• 1997

We investigated effectness of sort and volume of conductive agent to charge/discharge capacity of LiMn$_2$O$_4$. LiMn$_2$O$_4$is prepared by reacting stoichiometric mixture of LiOH . $H_2O$ and MnO$_2$(mole ratio 1 : 2) and heating at 80$0^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. All LiMn$_2$O$_4$cathode active materials show spinel structure. Cathode active materials calcined at 80$0^{\circ}C$ for 36h, charge/discharge characteristics and cycle stability have remarkable advantages. Used that super-s-black and 20wt% as conductive agent in LiMn$_2$O$_4$, it is excellent than property of cathode used Acetylene black or mixture of Super-s-black and acetylene black at charge/discharge capacity and cycle stability. Also, specific efficiency of cathode is excellent as over 98% and that of first cycle is excellent as 92%.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.13-15
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• 2008

Charging or discharging secondary batteries such as a lithium-ion battery is essential in the stage of production and takes long time over two hours. And the charge/discharge system is operated with high switching frequency over several tens kHz. Therefore, to simulate such a system in the conventional way takes very long time and huge files are produced. Finally, the simulation would be unable with general PC class. In this paper, the lithium-ion battery charge/discharge system is analyzed by using state space averaging method. As a result, the simulation time is reduced dramatically and the charge/- discharge characteristics of the lithium-ion battery can be observed.

• 한국진공학회지
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• 제9권1호
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• pp.36-41
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• 2000

$SnO-2$ thin films for thin film secondary battery anode were deposited n glass substrate with stain-less steel collector and charge/discharge experiments were conducted to investigate feasibility of $SnO-2$ thin film as a new anode material. The as-deposited films were pure $SnO-2$ phase which is not related to deposition condition. The grain size on the surface of as-deposited films increased with increase of oxygen partial pressure. However, the grain size did not show any change above oxygen partial pressure of 80:20. The surface roughness of the as-deposited films increased after decreasing because of resputtering effect of oxygen negative ion in plasma. All films showed typical $SnO-2$ anode characteristics which has a side effect at the first cycle, which is not related to the deposition condition. The charge/discharge experiments of 200cycles indicated that capacity of $SnO-2$ films depended on oxygen contents and surface roughness. The cycle characteristics was determined by initial charge/discharge reaction. The $SnO-2$ film with low initial capacity showed more stable cycle characteristics than film with high initial capacity.