• 전기의세계
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• 제28권10호
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• pp.48-54
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• 1979

The electrification phenomena of polymerized materials is governed by the competitive processes of the charge generation and the charge dissipation. In this paper, The charged particles were supplied on the naked upper surface of the polyethylene film from a point corona discharge with a screen electrode which controls the potential difference across the film. The charging current with the corona charging was found to be larger than that obtained with the electric charging on the MIM structure and the discharge current was found to flow in the same direction as that of the charging current. these results can suggest that the charge injection occurs from the interface between the polethylene surface and the accumulated charge layer, the injected charge are trapped and the space charge is established.

• 대한안전경영과학회지
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• 제3권3호
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• pp.231-241
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• 2001

The epoxy resin materials used in outdoor high voltage equipments are required to have the high electric performance because of the miniaturization. The frequence dependence of the permittivity and the loss tangent have important information. In this paper we describe the frequency dependence of the permittivity and the loss tangent for epoxy resin filled with silica and the influence of filler shapes on the dielectric properties. The increment of tan $\delta$ in the low frequency region is caused by the increment of both the electrical conductivity and the polarization due to the shape of filler and the water absorbed in and near the interface between fillers and resins. The result of charge current and discharge measure, electric conduction is increased according to voltage.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.172-176
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• 1997

It is likely that the corona discharge appears due to the motion and the multiplication of electron and ion under the nonuniform electric field. Because the motion and the multiplication of electron and ion are the function of electric field, for the simulation of the corona discharge, we have to calculate the electric field, before the calculation of the motion and the multiplication of electron and ion. In this paper, the electric field is calculated on the assumption that the gap between a hyperboloidal needle and a plane is 1-dimension, and the motion and the multiplication of electron and ion are determined by Flux-Corrected Transport method. For this purpose, we solve the electron and ion continuity equation together with Poisson equation. We calculated the current density and the electron and ion density distributions between electrodes as well as electric field distortion due to the space charge assuming that the discharge channel radius is 100${\mu}{\textrm}{m}$. In this simulation, it is found that the current density has one peak as observed by experiment, and electric field distortion is important to the formation and the stability of the corona discharge.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권4호
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• pp.226-231
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• 2000

In this paper, we present new method to analyze the space charge effect on the electrical characteristics in polymer. It is new measurement system and analysis method that have not reported yet. By using this measurement system, we make observation to space charge accumulated on the surface of polymer at AC voltage, so it is examined to verify the correlation of space charge and partial discharge(PD). In the result of experiment, it can be known that PD pattern is related more closely to space charge accumulated on the surface of polymer than in the inner part, and applied voltage in the air is ruled by this dynamic partial discharge. Also, above critical voltage, the space charge accumulated on the surface of polymer have no effect to the magnitude of PD and the applied voltage in the air. It has been known that the electric power of the dissolution system is proportioned to the frequency and the magnitude of applied voltage, but we can know by this result of the experiment that the efficiency of the dissolution is not related to the rise of voltage above critical voltage.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.423-426
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• 1996

The conditions to be satisfied with SOC(State-of-Charge) indicator installed on the electric vehicle were that it should be used under frequent loading conditions and that it should enable the monitor to adjust to the aging effect. But, the state-of-charge test requires a lengthy stabilization period after discharge cycles and the ampere-hour test requires the knowledge of the battery capacity in terms of amp-hours. However, a monitoring technique combining the state-of-charge test to enable the monitor to adjust to the aging effect with the ampere-hour test to use under frequent loading condition is studied and implemented on a microcontroller-based circuit in this paper. Specially, optical fiber is used to realize hydrometer which is immune to electromagnetic interference and toxic environment and makes it possible to be used in a wide temperature range.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.318-323
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• 2005

This paper introduces the mechanism of the ESD (Electrostatic discharge) in the HDD spindle system using FDBs (Fluid Dynamic Bearings). When a HDD (Hard Disk Drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction of the lubricant between the rotating shaft and stationary sleeve. And this electrostatic charge is accumulated in the rotating part of the HDD spindle system because it is insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic charge and discharge of the FDB spindle system due to the chanse of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.474-477
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• 2001

The properties of LiMnO$_2$ was studied as a cathode active material for lithium polymer batteries. LiMnO$_2$ cathode active materials were synthesized by the reaction of LiOH . $H_2O$ and Mn$_2$O$_3$at various temperature under argon atmosphere. For lithium polymer battery applications, the LiMnO$_2$cell was characterized electrochemically by charge-discharge experiments and a.c. impedance spectroscopy. And the relationship between the characteristics of powders and electrochemical properties was studied in this research. A maximum discharge capacity of 160-170 mAh/g for ο-LiMnO$_2$ cell was achieved. Used that SP270 as electric active material in LiMnO$_2$, it is excellent than property of electric active material used Acetylene black or KS6 at charge/discharge capacity.

• 한국기계가공학회지
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• 제18권1호
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• pp.78-84
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• 2019

Design of an electric power system on the solar-electric vehicle is very important because sunlight intensity is changed by weather conditions and road environments. Power output of solar module on the vehicle being changed by unsteady sunlight intensity. In this paper, design method of an electric power system are proposed to generate steady electric power output. The test results shows the electric power system are effective because the solar-electric vehicle have steady driving speed under unsteady sunlight conditions.

• 조명전기설비학회논문지
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• 제16권4호
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• pp.101-107
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• 2002

본 논문은 종래형 전해수 발생장치의 평판전극을 슬릿형 평행평판전극 구조로 함으로써 고효율의 강전해수 발생장치를 제안하였다. 염화나트륨이 용해된 수도수와 일반 수도수를 본 강전해수 발생장치에 인입하였을 때 전해수 생성공간내의 공간전하제한작용을 크게 감소시키면서 또한 이 전해수 생성공간내의 전계분포를 집중시킬 수 있는 슬릿형 평행평판전극을 설정하고, 이러한 슬릿의 형태와 개수증가가 수중 이온분리집속성능에 미치는 영향과 산화성물질 생성에 미치는 영향을 연구 검토하였다. 실험결과 수중 강전해수 발생장치내에 슬릿을 형성함으로써 전해수 발생공간내의 전계를 집중시키고 분리집속된 고농도의 이온들에 의한 공간전하 제한작용을 크게 감소시켜 저전력에서 기존의 전해수 발생장치보다 훨씬 고농도의 강전해수와 산화성물질 용존수를 얻을 수 있었다.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.171-178
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• 2013

This paper discusses to conduct experimental verification of two types of micro electric vehicles (EV) in order to realize improvement in electric mileage and shorten a charging time of the battery. First, electric double layer capacitor (EDLC) systems to use as a secondary battery are proposed. The internal resistance of EDLC is small compared with a rechargeable battery, and it is suitable for momentary charge-discharge of EV. Next, control circuits of the capacitors to increase the regenerative electric power are utilized. Then, a novel method to charge a main battery of the EV is introduced. Finally, experimental results demonstrate the validity of the proposed method.