• Title/Summary/Keyword: Electric charges

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An Analysis on the Charge Distribution on the Spacer Using Dust Figure (Dust Figure를 이용한 스페이서상의 대전전하 분포해석)

  • Choi, Jae-Gu;Seo, Kil-Soo;Kim, Young-Bae;Kim, Ik-Soo
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1681-1683
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    • 1998
  • Unlike AC, DC dielectric characteristics of the spacer are very influenced by the quantity and the distribution of surface charges. A general impression of the distribution of surface charges is obtained if electrostatic powders are sprinkled over the surface. The distribution of surface charge was investigated with dust figures. Mechanism of charge accumulation on the spacer of $SF_6$ GIS has been studied using various types of model spacers which have different depths. As a result, it was found that charge accumulation was dominantly influenced by the normal component of the electric field and the usage of embedded electrodes was an adequate method to lessen field concentration around the triple junction. The guide of the optimum depth of the spacer was proposed.

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On the Electric Fields Produced by Dipolar Coulomb Charges of an Individual Thundercloud in the Ionosphere

  • Kim, Vitaly P.;Hegai, Valery V.
    • Journal of Astronomy and Space Sciences
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    • v.32 no.2
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    • pp.141-144
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    • 2015
  • In this paper we study the transmission of the electrostatic field due to coulomb charges of an individual thundercloud into the midlatitude ionosphere, taking into account the total geomagnetic field integrated Pedersen conductivity of the ionosphere. It is shown that at ionospheric altitudes, a typical thundercloud produces an insignificant electrostatic field whereas a giant thundercloud can drive the horizontal electrostatic field with a magnitude of ${\sim}270{\mu}V/m$ for nighttime conditions.

A Study of Optimum Electromagnetic Field Analysis and Application of the Electret Sensor Using Computer Simulation (컴퓨터 시뮬레이션에 의한 일렉트렛트 센서의 최적 전계 해석과 응용)

  • 정동회;김상걸;김성렬;김용주;김영천;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.435-438
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    • 1998
  • In this paper, Electret is formed to range voltage -5[kV] to -8[kV] by corona charging in PTFE film and sensor is manufactured by method of moments in sensing infra sonic. Charges of charged film are calculated also TSC measurement and induced potential of sensing electrode according to the charges is become aware of computer simulation. Electret Infra Sonic Transducer, which is designed and manufactured according to the potential and electric field simulation in using method of moments, is proved as it is effectively. Because sensitivity that measured under 10[Hz] is that average value of sensitivity rising rate is 6.34 [dB/oct] as average value is $\pm$1 [dB/oct] range -5[kV] to -8[kV] in corona charging film. As a result, it is believed that characteristic of acquired transducer can be application of medical treatment, industry, and animal life researches and the study of noise elimination, what's more, is required.

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The Effect of Additive on the Electric conductivity of Insulating Oil (절연유의 전기전도에 미치는 첨가제의 영향)

  • 정광현;김영봉;김용운;임헌찬;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.158-161
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    • 1996
  • The static charges are generated by streaming electrification phenomena in insulating oil flowing by force for the purpose of cooling at the internal of Ultra-high power transformer. In this thesis, their elimination method was studied. In this paper the effect of Additive on the electric conductivity of Insulating oil is studied. The variation of electric conductivity disappear when Additive is molten in insulating oil BTA(Benzotriazole) appear more variation of electric conductivity than that of SP-S10(Sorbitan mono-stearate). But the variation is not enough to decrease streaming electrification of insulating oil($\sigma$>10$\^$-12/[S/cm]).

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Electric Therapy System Based on Discontinuous Conduction Mode Boost Circuit

  • Chen, Wenhui;Lee, Hyesoo;Jung, Heokyung
    • Journal of information and communication convergence engineering
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    • v.18 no.4
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    • pp.245-253
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    • 2020
  • The human body and nervous system transmit information through electric charges. After the electric charge transmits information to the brain, we can feel pain, numbness, comfort, and other feelings. Electric therapy is currently used widely in clinical practice because the field of examination is more representative of electrocardiogram, and in the field of treatment is more representative of electrotherapy. In this study, we design a system for neurophysiological therapy and conduct parameter calculation and model selection for the components of the system. The system is based on a discontinuous conduction mode (DCM) boost circuit, and controlled and regulated by a single-chip microcomputer. The system does not only have a low cost but also fully considers the safety of use, convenience of the human-computer interface, adjustment sensitivity, and waveform diversity in the design. In future, it will have strong implications in the field of electrotherapy.

Three-Dimensional Magnetotelluric Modeling Using Integral Equations (적분방정식을 이용한 3차원 지자기 지전류 모델링)

  • Kim, Hee Joon;Lee, Dong Sung
    • Economic and Environmental Geology
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    • v.27 no.2
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    • pp.191-199
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    • 1994
  • We have developed an algorithm based on the method of integral equations to simulate the magnetotelluric (MT) responses of three-dimensional (3-D) bodies in a layered half-space. The inhomogeneities are divided into a number of cells and are replaced by an equivalent current distribution which is approximated by pulse basis functions. A matrix equation is constructed using the electric Green's tensor function appropriate to a layered earth, and is solved for the vector current in each cell. Subsequently, scattered fields are found by integrating electric and magnetic Green's tensor functions over the scattering current About a 3-D conductive body near the earth's surface, interpretation using 2-D transverse electric modeling schemes can imply highly erratic low resistivities at depth. This is why these routines do not account for the effect of boundary charges. However, centrally located profiles across elongate 3-D prisms may be modeled accurately with a 2-D transverse magnetic algorithm, which implicitly includes boundary charges in its formulation. Multifrequency calculations show that apparent resistivity and impedance phase are really two complementary parameters. Hence, they should be treated simultaneously in broadband MT interpretation.

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Smart Panel Board for EV Standard Chargers and Its Control Method (전기자동차 완속충전기용 스마트 분전반 및 그 제어방법)

  • Kim, Myeong-Soo;Hong, Soon-Chan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.6
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    • pp.511-521
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    • 2014
  • This study proposes an electric vehicle (EV) smart panel board and its control method on the basis of charging scheduling. The proposed system consists of batteries, a three-phase battery charger, three single-phase inverters, transfer switches for electric power distribution, and a controller. The three-phase battery charger usually charges the batteries at midnight when electric rates are cheap and in light load. When the electric power consumption of the EV standard chargers connected to one phase of the power line is relatively large or when a blackout occurs, the electric power stored in the battery is supplied by discharging through the inverters to the EV standard chargers. As a result, the value of peak load and the charging electric power quantity supplied from a utility grid are reduced, and the current unbalance is improved. The usefulness of the proposed system is confirmed through simulations, experiments, and case studies.

Study and Recovery on the Capacity Loss after the Long Charge-discharge Operation of VRFB-ESS (장시간 충방전에 따른 VRFB-ESS의 용량 손실 회복에 대한 연구)

  • Hai-Kyung, Seo;Wonshik, Park;Jae-woo, Park;Kangsan, Kim;Hansol, Choi
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.181-187
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    • 2022
  • As the charges/discharges of VRFB-ESS were repeated during 150cycles or more, the capacity of electrolyte in VRFB-ESS was decreased little by little. It results from the decreasing of the level of anolyte and the increasing of the valance value of the catholyte. Then, we tried to recover the capacity loss with 3 different ways. The first way was that the levels of anolyte and catholyte were allowed to be evenly equalized when the difference in the levels of two different electrolytes were severe. The second one was to lessen the valance value of the catholyte through the reduction reaction to 4-valant ions of 5-valant ions in the catholyte with the reductant, oxalic acid. The last one was that the all electrolytes of analyte and catholyte were allowed to be electro-chemically reduced to 3.5 of the valance value by oxidizing new electrolyte with 3.5 valance ions. The last way was the most effective to recover the capacity loss.

Studies of Electric Double Layer Capacitors Used For a Storage Battery of Dye Sensitized Solar Cell Energy

  • Kim Hee-Je;Jeon Jin-An;Sung Youl-Moon;Yun Mun-Soo;Choi Jin-Young
    • Journal of Electrical Engineering and Technology
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    • v.1 no.2
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    • pp.251-256
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    • 2006
  • To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell (DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results, the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on the central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.

Studies of electric double layer capacitors used for a storage battery of dye sensitized solar cell energy (염료감응형 태양전지의 축전지로 사용되는 전기이중층콘덴서에 대한 연구)

  • Choi, Jin-Young;Lee, Im-Geun;Hong, Ji-Tae;Kim, Hee-Je
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.673-676
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    • 2005
  • To design the effective usage of electric double layer capacitors (EDLCs) used for a storage device of dye sensitized solar cell(DSC) energy, we first investigated the accumulation state of electrical charges and the charge behavior in the EDLCs. Based on the results. the voltage characteristics of EDLCs connected to DSC energy were evaluated. The results showed that the charge accumulation region concentrated on central part of the carbonaceous electrode in EDLCs and the required times for charging and discharging were almost the same.

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