• Title/Summary/Keyword: Charge and discharge current

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A Study of the Irradiation Environment Effects on the Electrical Properties of Ethylene Propylene Rubber (방사선 조사 환경에 의한 에칠렌 프로필렌 고무의 전기 특성에 관한 연구)

  • 이성일
    • Journal of the Korea Safety Management & Science
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    • v.2 no.2
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    • pp.187-200
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    • 2000
  • The charge and discharge current in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0~600 [kgy/h], have been measured in order to investigate the influence of the atmosphere (oxygen, air and vacuum) on electrical properties. It has been shown that the charge and discharge current increase as the amount of radiant capacity increases in air and vacuum atmosphere. This electrical property degradation can be speculated due to that the C=O radicals or impurities, which comes from during shaping process, may act as dipoles. On the other hand, the charge and discharge current are shown to be higher in the amount of 1[kgy/h] than these in 10[kgy/h] in air atmosphere, because the charge and discharge current can be increased as the exposure time is extended with slower rate. Under the same amount of irradiation, the charge and discharge current in oxygen atmosphere are shown to be higher than those in vacuum. This is possibly due to that the main chain can be broken by oxidation when it is exposed to the $\gamma$ -rays.

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A Study on Properties of Charge & Discharge Current by Degrade in EPR (EPR의 열화에 의한 충.방전 전류 특성에 관한 연구)

  • Lee, Sung-Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.7
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    • pp.679-685
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    • 2008
  • This paper describes the degraded properties of between the charge and discharge current for ${\gamma}$-ray irradiated in electric power cable rubbers using in nuclear power generating station. The charge and discharge current of degradation in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0.033 Mrad/h, have been measured in order to investigate the influence of the atmosphere(in amount of reinforcing agent, moisture absorption and heat treatment) on electrical properties. When ${\gamma}$-ray were irradiated on the EPR with more reinforcing agent from 4 to 40 Phr, charge and discharge currents was increase due to the amount of reinforcing agent. It was verified that the discharging and charging currents irradiated by ${\gamma}$-ray were higher than those that was not irradiated. The amount of the degraded current was more after moisture absorption than before moisture absorption. The charge and discharge current after heat treatment was similar to that of before heat treatment and it was decreased with the time elapsed. As these properties related with ${\gamma}$-ray irradiation dose, it is suggested that these properties can be utilized as a index of irradiation degradation.

Parameter Design and Power Flow Control of Energy Recovery Power Accumulator Battery Pack Testing System

  • Bo, Long;Chong, Kil To
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.787-798
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    • 2013
  • This paper proposes a special power circuit topology and its corresponding control strategy for an energy recovery power accumulator battery pack testing system (PABPTS), which is particularly used in electric vehicles. Firstly, operation principle and related parameter design for the system are illustrated. Secondly, control strategy of the composite power converter for PABPTS is analyzed in detail. The improved scheme includes a high accuracy charge and discharge current closed loop. active power reference for the grid-side inverter is provided by the result of multiplication between battery pack terminal voltage and test current. Simulation and experimental results demonstrate that the proposed scheme could not only satisfy the requirements for PABPTS with wide-range current test, but also could recover the discharging energy to the power grid with high efficiency.

A Study on Electrical Degradation Properties of Epoxy Resin due to Moisture Absorption (흡습에 의한 에폭시 수지의 전기적 열화 특성에 관한 연구)

  • Lee, Sung Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.9
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    • pp.656-661
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    • 2013
  • In this study, the moisture content, charge discharge current, electrostatic capacity and dielectric loss tangent are measured for the specimen of bisphenol type epoxy resin which is mixed with squared amorphous silica filler and dipped in hot water of $50^{\circ}C$ for 169 days. The results of this study are listed below. The longer of deposition day, the charge and discharge current was increased. It is considered that the reason is because there was water attack through the squared silica surface. The longer of deposition day, the absorption rate of all specimens was increased. It found that the absorption rate reached saturated state after 100 days. The higher frequency and the longer of deposition day, the $tan{\delta}$ was decreased. Also, It found that the $tan{\delta}$ and electrostatic capacity of the specimen which is mixed with squared filler are greater.

The Improvement of Accuracy and Measurement Speed in the Low Current Measurement System (저전류 측정 시스템에서의 정밀도 및 측정 속도 향상)

  • Baek, Wang-Ki;Choi, In-Kyu;Park, Jong-Sik;Lee, Kyung-Ho
    • Proceedings of the KIEE Conference
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    • pp.550-553
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    • 2002
  • A source meter is a basic instrument to perform a measurement of DC characteristic of semiconductor devices. the source meter can be used as variable voltage source, variable current source, voltage meter, or current meter. The accuracy of the low current measurement can be improved with the compensation of leakage current and charge and discharge current. In the low current measurement, the RC time constant is extremely big, so the measurement speed is very low. In this thesis, the analysis of the behavior of the measurement current according to the RC time constant and output capacitance and the method to accelerate the measurement speed.

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A Study on the Accelerated Life Test for Evaluating the Reliability of Nickel-Cadmium Batteries

  • Kwon, Soo-Ho;Huh, Yang-Hyun;Lim, Tae-Jin
    • International Journal of Reliability and Applications
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    • v.1 no.1
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    • pp.89-104
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    • 2000
  • Accelerated testing consists of a variety of test methods for shortening the life of products or hastening the degradation of their performance. This paper presents practical, modern statistical methods for evaluating the reliability of Nickel-Cadmium batteries at their design temperature of 2$0^{\circ}C$ by accelerated life test. Batteries have been life tested at three high temperature conditions, 50, 60, 7$0^{\circ}C$, respectively to yield failures quickly. The failures have been observed and judged by means of charge and discharge current integration. Analyses of life data from those conditions resulted in the Weibull distribution, which has been verified on the ground of the Kolmogorov-smirnov test and the pairwise t-test. Life data are modeled according to the Arrhenius life-temperature relationship. The mean life of tested batteries is assessed at about 590 cycles, and the activation energy of this chemical reaction is concluded to be 0.39eV as results. This study provides procedures for estimating the reliability of batteries in a short period, which has little been possible in domestic industries. The results can be applied in many fields such as proof testing, acceptance testing, and estimating assurance periods.

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Analysis of Effects of Space Charge in Removal efficiency of Pollutant using Dielectric Barrier Discharges (유전체장벽방전효과를 이용한 공해물질 제거 효율에 미치는 공간전하의 영향 분석)

  • Nam, S.H.;Jeon, S.I.;Lee, D.Y.;Lee, J.H.;Han, M.K.
    • Proceedings of the KIEE Conference
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    • pp.1441-1443
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    • 1998
  • In this work, the effects of space charge was analyzed in removal efficiency of pollutant using dielectric barrier discharges. In order to investigate effects of space charge, two dielectrics(XLPE and TR-XLPE) was chosen which are different in space charge distribution. The simultaneously measurement of space charge and discharge current was carried out in XLPE and TR-XLPE with air gap by Pulsed-Electro-Acoustic Method in ac. Also, the removal efficiency is measured by classical ozone generator(von Siemens 1875). From the experimental results, we knew that the space charge distribution affects the discharge patterns. The more space charge is in surface, the quickly discharge initiates and the magnitude of discharge is increased when polarity changes. And these affect the removal efficiency of pollutant.

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Modified Single-Phase SRM Drive for Low Torque Ripple and Power Factor Improvement (저토크리플 및 역률개선을 위한 수정된 단상 SRM 구동시스템)

  • An, Young-Joo
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.8
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    • pp.975-982
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    • 2007
  • The single-phase switched reluctance motor(SRM) drive requires DC source which is generally supplied through a rectifier connected with a commercial source. The rectifier is consist of a diode full bridge and a filter circuit. Usually the filter circuit uses capacitor with large value capacitance to reduce ripple component of DC power. Although the peak torque ripple of SRM is small, the short charge and discharge current of the filter capacitor draws the low power factor and system efficiency. A modified single phase SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor. In the proposed drive circuit, one switching part and diode which can separate the output of AC/DC rectifier from the filter capacitor is added. Also, a upper switch of drive circuit is exchanged a diode in order to reduce power switching device. Therefore the number of power switch device is not changed, two diodes are only added in the SRM drive. To verify the proposed system, some simulation and experimental results are presented.

A study on control of generators based on SMPS (SMPS 기반 발전기 제어 시스템에 관한 연구)

  • Jeong, Yang-Kwon;Um, Tae-Hyoun;Kim, Gi-Hoon;Choi, Hyung-Ju
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.1
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    • pp.107-115
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    • 2012
  • This study incorporates welders and generators needed to use it and welder generators to be used as is to configure the system. Thus in order to propose an integrated system to prevent the rapid charging process to manage the power state information, system configuration is the most important. Therefore, the battery charging output port, the main input and output control ports, the generator control port, a warning alarm buzzer, UI switch input, EXT power output, check the battery status input, battery charge and discharge current, UI input control switch, generator status, the main power input and output, the output voltage, EXT warning output, DEBUG communication, UI display unit, an external input ADC units with a focus on generator control system was implemented.

The structural and dielectric polarization characteristics of composite oxide material in $(Ba Ca)TiO_3$-Zn (복합산화물 $(Ba Ca)TiO_3$-ZnO의 구조적 및 유전분극 특성)

  • 홍경진;임장섭;정우성;민용기;김용주;김태성
    • Electrical & Electronic Materials
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    • v.10 no.3
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    • pp.239-246
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    • 1997
  • The ZnO is stabilize dielectric constant over a broad temperature range because its addition makes the relaxation time short. In this study, the composite oxide material (B $a_{0.85}$ $Ca_{0.15}$)Ti $O_{3}$ was mixed by ZnO additive material and the dielectric polarization characteristics was studied. The relative density was over 90[%] at all specimen in the structural characteristics. Among of the specimen, the relative density of (B $a_{0.85}$ $Ca_{0.15}$)Ti $O_{3}$ with ZnO (0.4mol) has a 95[%]. The grain size of composite oxide material with an increasing ZnO increased and it was 1.0[.mu.m]-1.22[.mu.m]. In the electrical characteristics, the charge and discharge current was increased by ZnO addition. The dielectric relaxation time was increased by space charge polarization at above 110[.deg. C] and the dielectric relaxation time was fixed by space charge polarization of para-dielectric layer at below 110[.deg. C]. The dielectric relaxation time was maximum when the grain size was small. The dielectric relaxation time is decreased with an additive material ZnO and interface polarization, existing void at the grain and grain boundary. The remnant polarization is increased and the coercive electric field is decreased by ZnO.

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