• Title/Summary/Keyword: charge distribution

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Charge Distribution Characteristics of Polystyrene/Polyaniline Conducting Blends (폴리스타이렌/폴리아닐린 전도성 블렌드의 전하분포 특성)

  • Kim, Won-Jung;Ko, Jung-Woo;Park, Chang-Mo;Suh, Kwang-S.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1457-1459
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    • 2003
  • Space charge distributions and behaviors of polystyrene/polyaniline conducting blends were investigated using a pulsed electroacoustic(PEA) method. It was found that positive charges were accumulated near the cathode with increasing polyaniline content in polystyrene/polyaniline when electric field was applied. Breakdown phenomena was investigated by breakdown test and it was observed that dielectric strength was diminished as polyaniline content was increased. By Scanning Electron Microscopy, corss-sectional views of polystyrene/polyaniline conducting blends were observed that the particles of polyaniline were well distributed in polystyrene.

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Statistics on the Present Status of Installations of Non-conventional Lightning Rods (일반형이 아닌 피뢰침의 설치 실태에 대한 통계적 조사)

  • Lee, Bok-Hee;Lee, Seok-Yeon;Lee, Su-Bong;Baek, Young-Hwan;Lee, Kyu-Sun;Kim, Dong-Sung
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.347-350
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    • 2006
  • The conception of early streamers is in sufficient and inadequate as a parameter for the determination of any advantage of early streamer emission(ESE) lightning rods versus ordinary lightning rods. Thus, standards for many other national and international lightning protection as well as KS C IEC 61024-1 do not take ESE lightning rods, charge dissipation systems or non-conventional lightning rods. Unfortunately, many non-conventional lightning rods such as ESE lightning rods and charge dissipation systems in Korea are increasingly used in lightning protection of structures including explosive manufacturing buildings, electric generating, transmission and distribution systems. This study attempts to make aware of no advantage of ESE rods and other non-conventional lightning protection systems and to investigate the present status of installations of ESE lightning rods.

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A investigation for Local Trapped Charge Distribution and Multi-bit Operation of CSL-NOR type SONOS Flash Memory (CSL-NOR형 SONOS 플래시 메모리의 Multi-bit 적용과 국소 트랩 전하 분포 조사)

  • Kim, Joo-Yeon;An, Ho-Myoung;Han, Tae-Hyeon;Kim, Byung-Cheul;Seo, Kwang-Yell
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.37-40
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    • 2004
  • SONOS를 이용한 전하트랩형 플래시 메모리를 통상의 0.35um CMOS 공정을 이용하여 제작하였으며 그 구조는 소스를 공통(CSL. Common Source Line)으로 사용하는 NOR형으로 하였다. 기존의 공정을 그대로 이용하면서 멀티 비트 동작을 통한 실질적 집적도 향상을 얻을 수 있다면 그 의미가 크다고 하겠다. 따라서 본 연구에서는CSL-NOR형 플래시 구조에서 멀티 비트을 구현하기위한 최적의 프로그램/소거/읽기 전압 조건을 구하여 국소적으로 트랩된 전하의 분포를 전하펌핑 방법을 이용하여 조사하였다. 또한 이 방법을 이용하여 멀티 비트 동작 시 문제점으로 제시된 전하의 측면확산을 측정하였다.

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Characteistics of Charge Traps and Poling Behavior of Poly (Vinylidene Fluoride)

  • Seo Jeong Won;Ryoo Kun Sang;Lee Hoo Sung
    • Bulletin of the Korean Chemical Society
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    • v.6 no.4
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    • pp.218-221
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    • 1985
  • Transient charging and discharging currents as well as space charge limited currents have been measured in biaxially stretched poly(vinylidene fluoride) film under various poling fields and temperatures. At low temperatures and short poling times, the I-V characteristics showed shallow trap behavior. When the current values extrapolated to the infinite time, the I-V characteristics indicate that the distribution of the trap energy levels is uniform or very broad. The abnormal suppression of current at higher poling voltages and the high discharge rate observed also in the same voltage range are attributed to the morphological changes due to dipole reorientation.

Flux Density Distribution of the Dish Solar Concentrator (KIERDISH II) (KIERDISH II 태양열 집광시스템의 플럭스밀도 분포)

  • Kang, Myeong-Cheol;Kang, Yong-Heack;Yoo, Seong-Yeon
    • Journal of the Korean Solar Energy Society
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    • v.24 no.4
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    • pp.11-18
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    • 2004
  • A solar concentrator, named KIERDISH II, was built at KIER in order to investigate the feasibility of high temperature solar energy application system. The constructed concentrator is a dish type solar concentrator with a focal length of 4.68m and a diameter of 7.9m. To successfully operate KIERDISH II, optimal design of the absorber is very important and flux density distribution has to be known. The focal flux density distribution on the receiver was measured. We have observed the shape and size of flux images and evaluated percent power within radius. Flux density distribution is usually measured by a CCD(charge coupled device) camera and a radiometer. In this paper we present a flux mapping method to estimate the characteristic features of the flux density distribution in the focal region of solar concentrator. The minimum radius of receiver is found to be 0.15m and approximately 90% of the incident radiation is intercepted by receiver aperture.

Evaluation of Insulating Reliability in Epoxy Composites by DC Dielectric Breakdown Properties (DC 절연파괴 특성을 이용한 Epoxy 복합체의 절연 신뢰도 평가)

  • 임중관;박용필;김정호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.92-95
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    • 2001
  • The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher Finally, from the analysis of weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5 [Mv/cm].

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Calculation of ion distribution in an RF plasma etching system using monte carlo methods (몬테카를로 계산 방식에 의한 RF 플라즈마 에칭 시스템에서의 이온 분포 계산)

  • 반용찬;이제희;윤상호;권오섭;김윤태;원태영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.5
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    • pp.54-62
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    • 1998
  • In a plasma etching system, ions become an important parameter in determining the wafer topography which depends on both the physical sputtering mechanism and the chemically enhanced reaction. this paper reports the energy and angular distributions of ions across the plasma sheath using a monte carlo method. The ion distribution is mainly affected by the magnitude of the sheath voltage and by the collision in the sheath. Furthemore, the local potential distribution in a plamsa sheath has been determined by solving the poisson's equation. In th is work, ionic collisions were cosidered in terms of both charge exchange and momentum transfer. The three-dimensional distributions of ions were calculated with varying the input process conditions in the plasma reactor.

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Analysis of Electrical Degradation in Epoxy Composites by Dielectric Breakdown Properties (절연파괴 특성을 이용한 Epoxy 복합체의 전기적 열화 분석)

  • 최철호;박용필;임중관
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.414-419
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    • 2002
  • The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of (idled specimens with treating silane, the breakdown strength become much higher Finally, from the analysis of weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5 MV/cm.

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Evaluation of Insulating Reliability in Epoxy Composites

  • Park, No-Bong;Yang, Dong-Bok;Lim, Jung-Kwan;Park, Yong-Pil;Lee, Hee-Kab;Kim, Gui-Yeul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1200-1203
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    • 2003
  • The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, according to Weibull distribution analysis, reducing breakdown probability of equipment insulation lower than 0.1% level requires the allowable field allowable field intensity values to be kept under 21.5 MV/cm.

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Development of EV Charging Scheme Considering Distributed Generation and Energy Storage System (분산전원과 ESS를 고려한 전기 자동차 충전 기법 개발)

  • Sim, Bo-Seok;Kim, Jun-Hyeok;Lee, Soon-Jeong;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.521-522
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    • 2015
  • Many countries concern about environmental problems. Therefore, they have made regulation for mandatory reduction of greenhouse gases. Electric Vehicles(EVs) are one of the most effective counterproposals for it. EVs are usually charging for it by using actual distribution system of the Korea Electric Power Corporation(KEPCO). However, it could cause adverse effects such as increase of the power demand and voltage variation on the distribution system. To reduce adverse effects for demand power side, in this paper, charging for EVs by using PV(Photovolatic Power Generation) connected with ESS(Energy Storage System) are modeled by using Electro Magnetic Transient Program(EMTP). And then, the simulation results are compared with EVs that are connected to the distribution system of KEPCO for using charge.

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