Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference (한국조명전기설비학회:학술대회논문집)
The Korean Institute of IIIuminating and Electrical Installation Engineers
- 기타
Domain
- Electricity/Electronics > Home/Electric Appliances
2004.05a
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이탈리아에서 처음 시작된 루미나리에는 조명이 어두움을 밝히는 원시적인 기능에서 유희적 기능을 제공하는 축제의 의미로서의 변화를 나타내는 대표적인 예 중의 하나이다. 오늘날 루미나리에는 이탈리아뿐만 아니라 미국, 스페인, 독일, 일본, 한국 등 전 세계에 걸쳐 개최되고 있으며, 이에 본 논문에서는 루미나리에를 대표하는 이탈리아와 일본, 한국의 3개 나라를 중심으로 2003년 루미나리아를 각각 비교 분석함으로써 앞으로 우리나라에서의 루미나리에의 정착과 발전방향에 대하여 살펴보는데 그 목적을 두고 있다. 2003년 처음으로 개최된 우리나라의 부천 루미나리에는 지방자치단체를 중심으로 문화적 도시이미지구현을 위하여 계획되었으며, 오래된 전통을 바탕으로 계획된 이탈리아의 루미나리에나, 시민들을 중심으로 행사금액을 모금하고 민간 주도로 행사가 진행되는 일본의 루미나리에와 더불어 우리나라를 대표하는 조명축제로서의 그 첫걸음을 내딛었다. 아직 우리나라는 초보적인 단계에 있어 행사 홍보의 미흡 및 입장료의 유료화 등의 많은 문제점을 가지고 있으나 앞으로 이탈리아나 일본의 루미나리에 사례를 바탕으로 문제점을 해결해 나감으로써 더 낳은 조명축제로서 발전해 나갈 것으로 판단된다.
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우리나라의 도시 옥외조명은 1988년 서울올림픽을 전후하여 관심이 확대되었으며, 서울시는 1996년 서울시 경관조명기본방향을 설정하고 숭례문 등 각종 문화재에 옥외조명시설을 설치하기 시작하였다. 최근 옥외조명에 대한 필요성을 인식하고, 설치하고 있는 초기단계에 있어 옥외조명을 계획하는데 반드시 고려해야하는 광공해에 대해서는 아무런 인식 없이 과다한 조명으로 광공해를 유발시키고 있다. 미국과 유럽, 일본 등 선진외국에서는 일찍부터 광공해의 심각성을 인식하고, 이를 방지하기 위해 옥외조명조례의 제정과 가이드라인의 발표로 양호한 조명환경 조성을 위해 노력하고 있다. 이에 본 연구는 광공해가 거주자와 보행자에게 미치는 영향을 고려하여 주거지역의 옥외가로조명의 광공해에 관한 연구를 진행하였다. 외국의 경우 광공해가 발생하는 지역의 조명환경개선사업을 펼쳐 광공해에 따른 악영향을 줄임과 동시에 조명에너지 절약의 효과도 가져왔다. 국내의 경우 전반 확산형(Non-Cutoff) 가로등이 보행자에게는 눈부심을 일으키고, 거주자에게는 프라이버시 침해와 숙면에 방해를 가져오므로 차폐된 조명기구를 사용해 이런 영향을 최소화할 필요가 있다. 따라서 국내의 경우 아직 광공해에 대한 기준이나 가이드라인이 없으므로 이에 대한 대책과 기준안 마련이 시급하다.
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Recently, the eletrodeless lamp is introduced as a new light source of a high efficacy and long life. Although eletrodeless lamp's size is large, most of them is applied to general luminaire for HID lamps. It causes to decrease eletrodeless lamp's efficacy. Therefore, refractor luminaires can be an option to maintain efficacy, so that reflector luminaires are developed for such lamps. The purpose of this study is to develope a optical numerical model of planar prism luminaire that is able to obtain various luminous intensity distributions.
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Light is an environmental element which is essential for a man to live and do creative activities in residential area. Especially, modern people arc used to live under artificial light interior surroundings for much time. Currently, the average illumination level of the present apartment is improving, but it still does not reach the recommended level because the present apartment's luminous environment is only based on the life behavior which puts its priority to clear vision. Therefore, it is necessary that proper standard illumination must be used for various use and purpose. From this point of view, this paper investigated the essence of light in the residential area and the luminous environment for apartments was measured. This paper finally suggested well-coordinated lighting condition, derived from the measurement and analysis of luminous environment in these cases.
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본 연구는 기존에 제안한 방전 AND gate PDP의 결점을 개선한 연구로써 AND gate를 구성하는 DC 방전의 극성을 반대로 설계하여 인접 주사전극에 대한 cross talk를 개선하였다. 또한 기존의 AND gate가 공간전하에 의한 방전의 비선형성에 의존한 것과는 달리 본 연구에서 제안한 AND gate는 방전 경로에 따른 전압의 변화에 의존하는 것으로 AND gate의 동작이 한층 안정해 졌다. 실험 결과 4개의 수평 주사전극에 대해 선택적인 어드레스 방전이 가능하였으며 각각 34V와 70V의 AND 방전 및 Data 방전의 동작마진을 얻을 수가 있었다.
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Son, Hyun-Mok;Ahn, Mi-Kyoung;Heo, Soon-Young;Jeon, Jea-Il;Park, Won-Zoo;Lee, Kwang-Sik;Kim, Jung-Bae;Kim, Min-Soo 29
본 논문에서는 패러데이 효과(Faraday effect)를 이용한 초고압 전력설비에서의 대전류 측정을 위한 광CT의 특성에 대한 기초 연구를 기술하였다. 1310[nm] Laser Diode를 광원으로 사용하고 PIN-Photodiode를 수신부로 사용하였다. 광의 전송로는 파이버 내에서 편광상태를 유지 할 수 있는 30[m]의 싱글모드 파이버를 사용하였다. 전류의 측정은 400[A]에서 1300[A]까지의 범위에서 측정하였으며 온도는$20[^{\circ}C]$ 에서$50[^{\circ}C]$ 까지 측정하였다. 동일한 실험 환경 하에서 출력의 크기는 인가전류가 증가할수록, 온도가 낮을수록 비례하여 증가하였다. 온도가$50[^{\circ}C]$ 의 경우 최대$50[^{\circ}C]$ 의 오차율을 나타냈으며,$40[^{\circ}C],\;30[^{\circ}C],\;20[^{\circ}C]$ 의 경우 각각 최대 오차 0.16[%], 1.24[%], 0.07[%]의 오차율을 보였다. -
Fluorescent lamp operated at high frequency by the electronic ballast provide ballasts like unnoticed flicker effect and higher luminous efficiency. This paper presents analysis of Half-Bridge type resonant inverter for Fluorescent lamp drive for stable characteristic and life improvement of lamp operated at high frequency. Also, it has described an electronic ballast design with the capability of high PF (Power Factor) and low THD (Total Harmonic Distortion). The validity of designed electronic ballast circuit is confirmed by simulation and experimental results. The Designed electronic ballast is implemented successfully on 32W Fluorescent lamp system.
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Most of LV customer has been composed the 3-phase four wire system distribution system which is supplying simultaneously at the 1-phase & 3-phase load. In this system, the composition of the power apparatus system is simple rather than conventional separation mode of the 1-phase & 3-phase, But due to uneven load unbalance or unclean power quality, various kinds such as do-rating or power losses become an issue. In this paper, we measured and analyzed voltage and current waveform in the field, compared with internationally allowable voltage unbalance limits.
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Recently, there are many electricity, electronics, and communication equipment which need to earthing in the building. When electric current flows into a certain earthing system in the same building, the potential of other earthing system rises. This potential interference repuire surface potential of electrodes by electrode shape. In this paper basic formula is deduced on the basis of both electrodes surface potential of earth electrode as a source of the potential interference and earth electrode which receive the potential interference. The degree of potential interference as multiple earth electrode is verified the simulated results by means of the simple model in advance.
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The stabilization of fiber-optic current sensor has been achieved by using a broadband light source and a Faraday Rotator Glass fiber sensor coil. The very low Photo-elastic constant of the fiber suppressed output variations within
${\pm}0.4[%]$ when mechanical disturbance was applied to the sensor coil. Noise characteristics, with different light sources, have also been analyzed, which experimentally proved that the wider bandwidth source showed the better noise performance. -
The PWM inverter drive my cause motor terminals voltage surge and oscillation(ringing), which impose severe electric stresses on inter-turn insulation of motor windings. This paper describes the technique used to simulate the problems associated with the use of PWM ASD's(Adjustable Speed Drive) to drive induction motor. The characteristic of switching surge was analyzed by EMTP(Electromagnetic transient program) model. The effects of switching surge by surge impedance, rise-time and cable lengths are also discussed.
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Since rotor position information is necessary to drive the SRM, absolute-encoder, resolver and incremental-encoder is used to detect a poor position. But, it is not desirable to use a high priced encoder and high efficient microprocessor under the condition of the simple driving system when precision control is not demanded. In this paper, Only using the reflective type 2 photosensors replace the conventional opto interrupter and slotted disk, which not only remove a slotted disk section but drive 3-phase 6/4 SRM bidirectionally. Moreover, as control circuit only is composed of common analog device economy is maximized.
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본 연구는 무기재료 중 층상형 점토를 사용하고 유기물질로는 수용성고분자를 주재료로 이용하여 제조한 새로운 형태의 접지저감제의 특성에 관한 것이다. 위 접지저감제는 수분을 흡습하게 되면 수용성 고분자가 수분에 용해되어 고분자 체인들이 수분에 분산되며 이 분산된 고분자 체인들이 수분과 함께 층상형 점토의 충으로 삽입되는 과정으로 성능을 발휘하게 된다. 이렇게 제조된 유/무기 복합재료형 접지저감제는 함수율이 매우 우수하고 팽창률도 우수할 뿐 아니라 300wt%의 수분을 공급 후 측정한 전기전도도도 우수하여 접지저감제로서의 장점을 가지고 있다. 접지시스템에 시공시 기존의 저감재보다 적은 양을 사용하여 동일한 접지저항을 얻을 수 있으며 환경적으로나 화학적으로 매우 안전하여 접지봉의 부식이나 전식을 방지할 수 있어 토양의 오염도 방지한다. 또한 부재료로 사용되는 여러 종류의 실리카를 이용하여 주재료와 함께 접지시스템에 작용하여 낮은 접지저항을 얻는데 시너지효과를 발휘하며 염분 및 부식성이 높은 화학이온 성분을 갖는 토양에서도 안정적인 접지저항을 나타내는데 도움을 준다. 실제 시공 비교에서 일반 접지동봉에 적용하였을 때 미사용 시보다 7-8배의 접지저항 저감효과를 보였다.
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This paper describes the testing facility to demonstrate the performance of the distribution class circuit breakers and switchgears and the testing methods. The field-test evaluation system consists of two parts. One is the distribution system for simulation of the condition on interruption mode of switches which are installed in the system and tested by the AFG(Artificial Fault Generator) and the thunderbolt generator just like in the real field. The other is a laboratory for confirmation or the important characteristics regarding to the insulation, gas, environment durability of equipment. For the fatal failure mode, a FMEA(Failure Modes and Effects Analysis) technique which is a kind of a structural analysis to consider a counter-plan was emploved.
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Recently polymer arresters are being used widely but we don't have appropriate long term characteristics test methods. Therefore we need to develop special test facility to evaluate long term reliability of polymer arresters. It's polymeric housing can be degraded by environmental stress and the interface between housing and inner module can be affected by moisture absorption. This moisture absorption can cause leakage current and tracking in the interface. We developed multi stress accelerated ageing test facility to simulate field conditions including UV, temperature, humidity, voltage, salt fog and rain. In addition, we carried out field exposure test at the outdoor test yard and characteristics analysis of field operated specimens to evaluate accelerating factor of this accelerated aging test.
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Among various modern control theories, PID control has been well used for several decades. PID algorithms needs son tuning methods are used for selecting PID parameters. But in some cases various kinds of performance indices are used instead of well-known tuning rules, and so variable type of performance index must be tested so that controllers, output characteristics and disturbance rejection property meets some specifications. In this paper, linear conbinational type of performance using error signal, time, control input and robustness is used to the PID control of air conditioning system. By the 2 DOF PID parmeters minimizing perfromacne index, controllers, output characteristics and robustness properties are analyzed. Simulations are done with MATLAB m file and mdl files.
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A systematic approach of measurement, modeling and analysis of grounding system impedance in the field of lightning protection systems is presented. The measurement and analysis of ground impedance are based on a computer aided technique. The magnitude and phase of ground impedance were measured and analyzed by the modified fall-of-potential method and the proposed computer program algerian using the waveforms of the test current and potential rise. The theoretical analysis of ground impedance were performed with the equivalent circuit models, and the theoretical results were compared with the measured data.
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This paper presents the aspect and distribution of voltage and current harmonics being made at low voltage power systems. The voltage and current harmonics in power systems supplying various loads were monitored and analyzed. We have examined the results compared to advanced countries' harmonics control standards. As a result, the current harmonics were significantly greater than the voltage harmonics. In particular, the harmonics of currents flowing through loads with power switching electronics was pronounced. Also, the contents of current harmonics of street lamp circuits was about 30%, and it was decreased to 12.3% with the installation of series reactor. On the whole, The measured results of voltage and current harmonics exceeds the regulation limits recommended by IEEE 519-1992.
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Recently, when electric traction system used DC 1500[Vdc] runs on decline of rail road track and slows down, dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. Therefore this paper proposes that the extra power is regenerated through regeneration inverter to AC utility in result this system obstruct to go beyond regular voltage and improve the efficiency. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality.
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Examine merits and demerits and obstacle factor that exist to all direction of digital infratechnology that is supplied on industry whole according to development special quality of computer by development of computer and Information Technology and electricity electron information communication facility that basic impulse insulation level does not exist examined scorched earth or an interference problem factor and countermeasure of semiconductor degauss of factor and electricity electron information transmission system that is numbed or causes system down.
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This paper gives a measurement data of the feeder demand factor in small size apartments. The power load measurement data of the feeder shows that the feeders have
$10{\sim}30[%]$ margin in capacity. But this margin is not enough to keep up with the trend of power consumption increase from long term standpoint. So it is necessary to measure the feeder power load periodically for the purpose of optimal feeder capacity estimation -
A new control method of spindle induction motor drive is proposed in this paper. In a conventional control method, the vector control was employed in the low speed range, while the constant V/f(volt-per-hertz) PWM control was employed in the high speed range. The two control modes were automatically selected at an intermediate speed. In a proposed control method, the direct vector-control with an encoder is employed in the low speed range(from 0 to 8,000rpm), and the vector control without an encoder is employed in th high speed(from 8,000 to 15,000rpm) by using flux observer and speed estimator. This paper describes problem of control method in a conventional spindle induction motor drive and proposes contort method as variation of motor speed.
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This paper reviews the dimming technology of the electrodeless lamp. Frequently used three methods are technologically reviewed and the performances are individually compared. Then, a lot of circuit technology for constructing the power supply m also reviewed and circuit characteristics are discussed.
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Characteristics of electrodelss lamp as a load of the ballast is different compared to normal fluorescent lamp because the lamp includes the magnetics for inductive discharging process. So somewhat different modeling is necessary to make a proper power match between the lamp and ballast. Modeling of an electrodeless lamps, Endura of Osram, is presented in this paper. Simulation with a result of experiment is given for a verification of proposed model.
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계속되는 조명의 발달에 의하여 과거의 난방, 취사, 보호, 빛 등의 원시적인 기능을 수행하던 빛은 오늘날 다양한 기능과 사회적 역할을 담당하게 되었으며, 도시의 축제적 요소로서 사람들에게 유희적 기능을 제공하게 되었다. 이러한 축제요소로서의 빛은 종교적 행사로서 의미를 가지고 있을 뿐만 아니라 지역의 이미지 향상 및 홍보효과, 지역주민에게 주는 지역에 대한 자긍심효과, 관광사업 활성화에 따른 경제적 파급효과 둥의 다양한 효과를 가져오고 있다. 유럽의 경우 모닥불이 18세기에 이르러 일루미네이션과 불꽃놀이 등으로 계승되었으며, 우리나라의 경우 신라시대부터 시작된 종교적 행사인 연등제와 정원대보름을 기원으로 한 들불축제가 과거부터 오늘날까지 이어져 내려오고 있다. 유럽에서 시작된 폭죽, 조명을 이용한 빛축제 또한 우리나라의 각 지자체를 중심으로 불꽃놀이와 루미나리에라는 이름으로 개최되고 있다. 또한, 사천시의 창선삼천포대교는 다리의 경관조명을 설치함으로써 지역을 홍보하기 위한 조명축제로 자리매김하고 있다. 이에 본 연구는 우리나라의 다양한 빛축제의 사례를 분석하여 앞으로 빛축제를 활성화하기 위한 기초 자료로 제시하고자 한다.
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In this paper, we have investigated the inductive voltages, currents, frequencies of output line of electrodeless fluorescent lamp system as an surge is supplied and have analyzed the surge characteristics as an phase alteration of input voltage with an surge suppling. A result os measurement is that the inductive over-voltages(H-PE, N-PE) on output line of electrodeles fluorescent lamp system showed more high than inductive overvoltages of H(hot)-N(neutral) line. Therefore, designer of system will lay emphasis on an protective circuit with considening an overvoltage(H-PE, N-PE) or phase of input voltage.
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In this paper, we observed an electrode structure that is an important element that decide life of compact fluorescent lamp. We measured winding and application type of electron emission material and electrode damage with SEM(Scanning Electron Microscope). From now on, we need to measure rather several difference aging-time sample than analyze a relation electrode between life
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특성화된 조명기구와 향상된 램프의 보급과 적용으로 보다 기술적이고 적절한 조영환경이 형성되어 가고 있다. 이러한 상황에 맞춰서 조명설계 및 계산법도 여러 상황이 충분히 고려되고 보다 근접한 조건을 적용되고 있다. 예전에 비해 다양한 등기구의 도급과 적용이 이루어지고 있는 만큼이나 조명기술자료의 요청이나 필요가 많아지고 있다. 등기구의 특성화로 인해 같은 램프를 사용하더라도 각각의 등기구마다 독특한 배광특성을 나타내기 때문에 앞으로는 컴퓨터 시뮬레이션을 통한 조명계산의 적용이 불가피할 것으로 예상된다. 본 논문에서는 2가지 조명프로그램을 사용하여 같은 램프를 사용하는 2가지 각각의 등기구를 적용하여 시뮬레이션 결과치를 비교하도록 하겠다.
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The aim of this study is to make the technical standards for certificating a high efficiency metal-halide lamps and reflectors using the high intensity discharge lamps, to accomplish the practical energy saving effect. Metal-halide lamps are certificated by stabilzed and restarting time, lamp voltage, current, power and light output efficiency. The high illumination reflectors using HID lamps are certificated by testing reflective index, fading, the melting point, glare and install spacing factor.
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There are lots of merits in the electrodeless lighting. But it is not widely used because the price is too high though it has very good quality and efficiency. So it is necessary to develop a electrodeless lighting which can be widely used with its merit.
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A high light lantern system using LEDs is composed of power supply, flash controller, and daylight controller and proper case considering work condition. The performance of developed LED lantern is better than that of the existing marine lantern using an incandescent electric lamp and that of foreign products(Vega LED lantern made in New Zealand, Tideland system made in America). The electric consumption of our products is 30% compared with that of existing marine lantern using an incandescent electric lamp, and the luminous Intensity of them is 200% to 400% compared with that of existing marine lantern and foreign LED lantern. In addition, our LED lantern system is easy to repairing something wrong and changing the LED module and other controllers on the sea when they are in accident.
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Concerning Korean energy consumption, 20% of the total electrical energy (96% is now exported) is consumed in lighting area. Accordingly, it is one of the most important governmental policies to efficiently utilize electricity due to development and application of high-efficiency lighting equipment. In Korea, widely-built traffic signals employ an incandescent and are of 100W/300 mm, and 280,080set/801,932lamps have been installed and operated by 1999. Of them, 58%(161,181set), 25%(69,655set) and 18%(49,244set) correspond to traffic signals, pedestrian signals and other supplementary signals respectively. It was estimated that electrical energy consumed 28MW instantaneously, 245GWH annually. On the other hand, the LED traffic signal is expected to be a future traffic signal since if traffic signals are replaced by LEDs, energy saving effect of 85% and drop of 75% in maintenance fee will be obtained. In this paper, the performance and characteristics of many LED traffic signals made in Korea are summarized in order to reform Korean standard of LED traffic signals.
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무전극 형광램프의 출력선 연장은 무전극 램프가 가지는 장수명 등의 이점을 최대화할 수 있는 방안이 된다. 하지만 이를 위해서는 연장에 따라 발생하는 요인들 -공진주파수의 변경, 온도변화에 따른 안정성 등을 고려하여 인버터의 설계가 이루어져야 한다. 이를 위해 본 연구에서는 ENDURA 150W 인버터의 출력선을 25m 연장하기 위해서 출력선을 고려한 공진 주파수를 설정하였고 온도변화에 따른 대책들을 제시하였다.
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스포츠 조명의 목적은 스포츠 종목의 특성에 맞는 조명방법과 조절을 통해 경기력을 발휘 할 수 있게 조명환경을 조성하는 것이다. 또한 조명 설계를 통해 경기자는 물론, 관중 그리고 T.V. 시청자들에게도 경기 내용의 정확한 시각정보를 전달 할 수 있어야 한다. 본 논문에서는 골프코스의 KS조도기준을 바탕으로 하여 티잉그라운드, 페어웨이, 그린으로 나누어서 골프코스 조명 모델 설계를 위하여 컴퓨터 시뮬레이션을 실시하였으며, 적절한 광원의 선정, 조명 pole의 위치 및 크기 등을 고려하여 조명등의 에이밍 조정으로 양질의 조도분포를 구하였다. 이러한 모델 설계를 토대로 골프장 현장적용 설계안을 제시코자한다.
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본 내용은 기후적 요인에 의해 발생되는 고속도로 또는 일반도로의 안내표지판 상의 결로 현상으로 인한 안내표지판의 반사율 저하로 유발되는 운전자의 표지판 판독성 저하 문제를 해결하여, 각종 안전성 확보를 위한 검토이다. 이를 위한 대책으로 표지판 외부 조명 시설의 설치 방법을 채택하였으며 유지보수의 용이성, 에너지절감, 광원의 질적 요인을 감안하여 장수명, 고효율, 고연색의 특징을 지닌 무전극램프를 조명 광원으로 선정하고, 이의 적용 적합성을 검증하고자 한다.
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항로표지용 광파표지는 섬광을 통해 관측자에게 정보를 제공하고 있으므로, 부동광도 값을 기준으로 성능(광달거리)를 산출하면 안 된다. 그러나 실제로 유효광도 값은 측정하기 어려우며, 계산식 또한 명확하지 않다. 본 논문에서는 항로표지용 광파표지의 유효광도에 대한 IALA(국제항로표지협회)와 해양수산부의 권고기준에 대하여 알아보고, 국내 항로표지용 점멸식 소형등명기의 배광 및 유효광도를 배광측정기로 측정하고, 이를 비교 분석하였다.
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The most important role of photosensor is to measure on exact workplan illuminance of room when daylight responsive dimming systems are used. The shape of most optimal photosensor must be able to measure exact luminous flux without changing setting position corresponding to the change of room situations. That is, shape and positioning of optimal photosensor should be corresponded to the optimal luminous flux measurement.
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It is a global consent that we should conserve our energy consumption, due to our awareness to the environmental problems and the limitedness of the natural resource. In the country, the level of energy consumption is more than it is needed, according to its living standard and the proportion of resources imported from other countries. Educational program focused on energy conservation is essential to overcome these problems. This paper outlines a basic study on the development of an energy conservation education program for children. This program makes students aware of the importance and difficulties in energy conservation. The students can then make their own contribution and besides circulation of resources and improvement of health problems.
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The metal halide lamps are now widely used in the application and commercial lighting due to their attracting properties such as good color rendering and high efficiency. But they have the serious problem of acoustic resonance for high frequency operation and they need the high voltage to ignite. So, they have not been applied to indoors. Over the past few years, a considerable number of studies have been conducted on the electronic ballast together with hot restarting and resonance phenomenon. But very few attempts have been made with the adaptive ignition method according to the lamp state. In this paper, electronic ballast is proposed for metal halide lamps with an igniter for adaptive ignition. The proposed electronic ballast can generate different ignition voltages according to the arc tube state.
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In this paper, we propose the passive PFC(Power Factor Correction) circuit of an electronic ballast with the constant power the detection circuit for 110 or 220 volt. The proposed PFC circuit is composed with the modified dither circuit and the input voltage detection circuit. We have concluded that the proposed method is the attractive method to improve of power factor for the electronic ballast with the input voltage regulation and it is a similar experimental results with other active power factor correction method using other PWM ICs.
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3차원 홀로그램의 생성에 이용되었던 변형 삼각간섭계를 이용한 비접촉진단 방법에 대하여 논하고자 한다. 변형 삼각간섭계를 이용한 비접촉진단은 측정대상물체의 간섭패턴을 구하고 이로부터 위상지도와 변형량을 계산함으로써 이루어질 수 있다. 본 논문에서는 변형 삼각간섭계를 이용한 간섭패턴 생성과 관련한 몇 가지 실험결과를 제시한다.
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사진 측광은 일시에 대량의 데이터를 얻을 수 있으므로 시간에 따라 빛이 변화하는 주광의 측정 수단으로 이용될 수 있다. 이를 위하여 자연광 아래에서 디지털 이미지와 휘도 측정치의 보정실험을 행하였으나 청공광과 백색시료를 제외한 나머지 시료에 대해서는 그리 만족스러운 결과를 가져오지 못하였다. 앞으로 Videophotometry를 실현하기 위해서는 피 계측면의 분광 반사특성에 의한 계측치의 오차를 제거하기 위한 CCD 소자의 시감도 보정, 시야를 정확하게 재현하기 위한 광학적 연구, 인간의 시각 특성에 부합하는 측정 휘도의 보정 등에 대한 연구가 이루어져야 할 것이다.
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물질을 구성하는 분자가 빛을 흡수하면 그 빛의 파장에 따른 복사에너지에 의하여 열적 반응이나 광화학적 반응이 일어난다. 특히 적외선 복사에 의한 열적 반응은 물질의 온도상승이나 온도하강 등의 과정을 통하여 물질의 물리적 손상을 초래한다. 따라서 적외선을 포함하는 복사에너지의 조사에 의하여 전시실, 진열장내의 전시물의 온도 변화를 측정하여 그 온도의 변화 범위보다 적은 온도 변화가 전시물에서 일어나도록 조명을 제한하고 알맞은 광원을 선정하여야 할 필요가 있다. 본 연구에서는 광원에 의한 시료의 온도상승과 적외선 복사량을 측정할 수 있는 측정시스템을 구축하고, 전시조명용으로 많이 사용하는 여러 광원을 대상으로 각 광원의 방사조도를 변화시키면서 시료의 표면온도와 적외선 복사량을 각각 측정하였다. 측정의 결과를 토대로 방사조도와 온도 및 적외선 복사량간의 함수관계를 파악하고, 조도의 변동에 따른 시료의 온도 변화 및 적외선 복사량의 변화를 비교, 분석하였다.
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조명기술의 발전에 따라 현대의 조명환경에는 다양한 종류의 광원이 사용되고, 박물관 등에서는 조명에 의한 다양한 연출 효과를 얻기 위해 같은 전시 공간 내에서도 여러 종류의 광원들을 사용한다. 광원마다 전시물에 유해한 성분의 복사비율이 다르고, 여러 성분의 복사에너지가 복합적으로 전시물에 입사되기 때문에 전시물의 관리에 많은 어려움이 따른다. 따라서 박물관에서 전시물의 손상이 어느 정도 일어날 수 있을지를 예측하고, 그에 대한 적절한 대책을 수립하는 등의 박물관 조명의 효과적인 실시를 위해서는, 전시물에 조사되는 광복사량 및 복사분포를 측정하고, 이를 바탕으로 적절한 조명의 형식과 누적조도로서 각 유물을 체계적으로 관리할 수 있는 유지관리 방안을 설정할 필요가 있다. 본 연구에서는 전시조명용으로 많이 사용되는 인공광원과 자연주광을 대상으로, 이들 광원들이 방출하는 복사조도와 자외선을 포함하는 광복사량, 광원의 분광분포 등을 측정하고 그 결과를 분석하였다.
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테니스장 조명 설치 시 검토 되어야할 여러 가지 조건을 제시하였으며 기존의 옥외, 옥내 테니스장에 설치되어 있는 조명의 수평면조도, 수직면조도, 휘도 등을 측정하여 KS 기준에 명시된 값에 적정한지 비교하고 문제점을 도출하였다.
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기존의 램프(백열등, HID 램프 등)를 사용하여 반사갓을 설계하면 광원중심의 기하학적 위치, 점등 자세, 램프 자체의 크기로 인한 반사갓이 커지는 등 여러 가지 제약조건에 부딪히게 된다. 근래 개발된 PLS 광원은 기존의 램프보다 그 크기가 매우 작아 조명기구의 반사갓 설계에 있어서 보다 효율적인 설계가 가능하게 되었다. 본 논문에서는 900W PLS 광원용 4각 투광기용 반사갓 설계를 위하여 개발한 기법을 소개하고 그 성능을 제시하였다.
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본 연구에서는 새로 고안된 NOT 논리를 포함한 방전 AND gate의 방전특성에 대해 고찰하고 동작 특성을 해석하였다. 새로 고안된 방전 AND gate는 방전 경로에 따른 전극사이의 전압의 변화로 AND 출력을 유도한다. 측정결과 AND 출력은 A전극의 A1전압과 B전극 전압의 상호 관계에 영향을 받는다는 것을 알았다. 또한 AND 출력을 위한 DC priming 방전은 방전 후
$30{\mu}s$ 정도까지 영향을 미치며 방전 강도는 AND gate의 특성에 영향을 주지 않는다는 것을 알았다. 시험결과를 통해 AND gate를 구성하는 각 전극 전압의 최적 값을 얻었으며 기존의 연구 결과보다 안정적인 AND 동작을 확인하였다. -
실내의 조명은 자연채광방식과 인공조명으로 나누어지는데 자연형 채광방식에서도 측창채광과 천창채광, 정 측창채광 그리고 반사 채광방식이 있다. 측창채광은 벽면에 대하여 일반적으로 연직인 창에 의한 채광을 말한다. 측창채광의 방향에 따라 실내조도는 영향을 많이 받는다. 따라서 본 연구는 측창채광의 동서남북의 방향에 따라 봄, 여름, 가을, 겨울의 계절에 따라 아침, 점심, 저녁시간대에 따라 변화되는 실내조도를 알아보았다. 실험방법은, 조명시뮬레이션 프로그램인 Lightscape V3.2를 사용하여 교실공간의 치수와 작업면의 높이를 가로 5.8[m], 세로 10.8[m], 높이 3[m], 작업면의 높이 0.75[m]로 정하였고, 각 시설물의 반사율[p]은 벽 80%, 창문 12%, 출입문 13%, 바닥 20%, 천장 85%로 지정하였으며 창문의 투과율은 88%로 설정하였다. 본 연구에서 측정하고자 하는 변수 값은 계절은 여름을 6월20일, 겨울은 1월20일 기준으로 하고 시간대는 09시, 13시, 18시로 하였으며 창측방위는 동, 서, 남, 북으로 정하였으며 계절과 시간은 가장 차이가 많이 나는 값을 선택하였다. 결론으로 창이 남쪽일 때 평균조도가 9,100[lx]로 가장 높았고, 시간별로는 점심에 19,590[lx]로 조도가 가장 높은 것을 알 수 있었고 조도 균제도는 창이 동쪽일 때 겨울에 가장 높았다. 창이 북쪽일 때는 여름이 겨울보다 평균조도가 약간 높았고, 시간별로는 아침에 조도가 약간 높은 것을 알 수 있었고 전체적으로 북쪽 창에서 실내조도가 현저하게 떨어지는 것을 알 수 있었다. 이와 같은 결과로 측창의 브라인드를 현재 사용하고 있는 수직 브라인드 대신에 수평 브라인드를 사용하여 주광의 범위를 넓게 조절하여 사용하게 하고, 점등제어를 현재 측창면과 수직으로 되어있는 배열을 수평으로 한다면 자연채광의 효과를 배가 할 수 있으리라고 사료된다. 미백 전, 미백후, 재광화 후 미세경도 변화 양상이 미백을 하지 않은 대조군과 차이를 보이지 않았으며 (p > 0.05) 미백 전과 미백 후의 미세경도의 차이 미백후와 재광화 후의 미세경도의 차이도 유의할 만한 차이가 없었다 (p > 0.05). 따라서 시중에 판매되고 있는 whitening strip과 미백 젤은 14일 동안의 통상적인 미백과정 동안 법랑질의 미세경도에 영향을 미치지 않는 것으로 사료된다.able pitch와 helical angle보다는 근본적으로 radial land가 screw-in effect의 예방에 더 큰 역할을 하는 것으로 추정될 수 있다 따라서 NiTi file의 사용 경험이 없는 초심자의 경우 근단부 폭경의 유지능력이 좋은 ProFile
$^{(R)}$ 의 사용이 추천된다.)되었다.였으나 강남콩군 외에는 단백질의 소화 흡수율 및 효율은 크게 향상되지 않아 단백질의 소화 흡수율을 떨어뜨리는 요인에 관한 연구가 집중적 으로 이루어져야 하리라고 생각된다.면 바로 위 지점의 풍속을 측정하였다. 각 Seeding 물질에 대해 팬을 켜지 않았을 때, 즉 바람의 영향이 없을 때 측정한 표면유속을 바람의 세기가 변한 경우의 기준 표면유속으로 이용하였다. 본 연구의 결과 비중이 0.01 내외인 Ecofoam과 white polystyrene에 비해 비중이 0.92인 black polypropylene은 대부분이 물속에 잠겨 있어 흐름과 거의 일치하여 움직임을 알 수 있었다. 또한 흐름의 평균유속이 0.165 m/s의 저유속에서 바람이 tracers에 미치는 영향이 평균유속 0.558m/s인 경우보다 커서, 바람의 세기의 증가에 따라 표면유속 측정값이 급속히 감소되었다. 흐름의 평균유속이 큰 경우에는 바람이 tracer에 마치는 영향이 현격히 줄어듬을 보이고 있다. 결론적으로 유속이 증가함에 따라 바람의 영향은 감소하나, 바 -
교실 내에 빛을 공급하는 두 가지 요소는 인공광원과 주광이다. 일단, 빛이 실내에 방사되면 각 시설물의 표면은 빛을 반사하여 제 2의 광원 역할을 한다. 따라서 교실 내 조도를 높이는 확실한 방법은 광도가 높은 등기구를 설치하고 창을 정남향으로 내면 되겠지만 이것이 여의치 못할 경우에는 제 2의 광원인 시설물의 표면속성을 변화시켜 조도를 높일 수도 있다. 본 논문에서는 일정한 인공광원과 주광 하에서 시설물의 속성을 변화시켜 조도에 미치는 영향을 알아보고 개선사항을 연구해 보았다.
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The visual environment in an educational building, apart from providing the comfortable seeing conditions needed for the performance of a wide variety of work tasks, must also satisfy the psychological and emotional needs of learners. This paper presents study on actual illumination environment of college and comparison of economical efficiency in order to figure out illumination problems. Furthermore, it attempts to suggest an optimum design of lecture room illumination through computer simulation. We try to evaluate economical efficiency of lighting design in lecture room under the illumination plan which is based on illumination maintenance and uniformity ratio that KS. illumination standard sets.
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As electric shock accident take place frequently, electrical safety is extremely important to prevent them. This paper describes the characteristics of electric shock. In order to examine it, an experimental apparatus including a model of a human body is fabricated and the magnitude of the voltage held by the model is measured under several conditions as follows;(1) the model is not contacted to an electric pole and a step voltage does not exist. (2) the model is not contacted to an electric pole and a step voltage exists. (3) the model is contacted to an electric pole and a step voltage does not exist (4) the model is contacted to an electric pole and a step voltage exists. As a result of the experiment it is found that the voltage held by the model depends on the step voltage as well as the voltages applied to the electric pole.
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Mean energy of electrons in
$SF_6-Ar$ Mixtures Gas used by MCS-BEq algorithm has been analysed over the E/N range$30{\sim}300[Td]$ by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%]$SF_6-Ar$ , 0.1[%] and 5.0[%],$SF_6-Ar$ mixtures were measured by time-of-flight(TOF) method. The transport Coefficients for electrons in (100[%])$SF_6$ . (100[%])Ar, (0.2[%])$SF_6-Ar$ and (0.5[%])$SF_6-Ar$ , (5.0[%])$SF_6-Ar$ , (0.1[%])$SF_6-Ar$ mixtures were measured by time-of-flight method, and the electron energy distribution function and the parameters of the velocity and the diffusion were determined by the variation of the collision cross-sections with energy. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules. -
In this research, we used discharge tube without dielectric bead or with dielectric beads
$(SiO_2,\;Al_2O_3,\;or\;ZrO_2)$ for removal of Escherichia coli. At the result of experiments, the removal characteristics of Escherichia coli appeared relation ratio to input voltage. Because, the electric field of discharge tube is increased when input voltage is increased. And, discharge tube used dielectric$bead(ZrO_2)$ , the removal characteristics of Escherichia coli was better than cases of else. -
A number of guard lamps are utilized to ensure to safe walking during nighttime. Due to the lack of legal regulations, however, many guard lamps are not installed in organized ways, resulting in the increase of electric shock hazard. In order to establish the legal regulations which can be specifically applied to guard lamps, a research on the actual state of them is performed in this paper. As a result of the research, three regulations are addressed and suggested on equipment installation, management and development.
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The overvoltage generated by the lightning strokes has been doing considerable damage to the distribution network as well as the consumer facility until now. Because most of the lightning strokes are accompanied by a storm, the aftermath of damage to the consumer is so serious. Therefore it is very important to survey the optimal operation plan by the field test of distribution lightning facilities. In this paper we have accomplished the field test to verify the impulse characteristic of Secondary Arrester(SA), and analyzed the effect of the SA in power distribution system.
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It is well known that a discharge in oil is the source of various physical phenomena. Ultrasonic-wave detection is a useful method to the diagnosis of the transformer-insulation condition. Conventionally, ultrasonic waves are detected by Piezo-electric transducer, and we use optical method that has many advantages. In this paper, we constructed a Mach-Zehnder interferometer with optical fiber and investigated the principle of operation. Test arrangement is based rut the needle-plane electrode system in oil and applied AC high voltage Ultrasonic waves were detected and showed signal- analysis results with wavelet transform.
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This paper simulated partial discharge caused by 22.9[kV] power cable using XLPE(Peroxide Crosslinkable Polyethylene) insulation having the outside damage. As one of the insulation diagnostic method a radiated electromagnetic waves were measured by an UHF method using a BiconiLog antenna(EMCO-3142) and a spectrum analyzer used to measure EMI, EMC. From results of this study, It was confirmed that discharge progress were possible to be estimated by the proposed method.
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Lee, Chang-Ho;Chun, Byung-Joon;Song, Hyun-Jig;Lim, Chang-Ho;Choi, Sang-Tae;Yoon, Byung-Han;Park, Won-Joo;Lee, Kang-Sik 308
In this paper, a silent discharge type ozonizer has been designed and fabricated for environment improvement. After that discharge and ozone generation characteristics in accordance with frequency of power supply and input voltage were investigated Consumed discharge un of silent discharge type ozonizer was calculated by computer program designed in "Sigma Hot 2000" program. The data needed for calculation was stored as ASCII file type from oscilloscope. -
This paper shows the structure of a control System for Fluorescent fin Dimming Ballasts. The control system is composed of phase angle controller, a transducer, many dimmable ballasts. For the implementation of the control system, We made a controller and the transducer that transform the phase angle controlled signal into the DC level. we used the conventional dimmable ballast In this ballast, dimming control is achieved by varying the switching frequency that is controlled by the external DC level. This has non-linear illumination characteristics as the dimming control. Therefore we compensate characteristics using the transducer proposed in this paper. We measured the illumination of two FL-28 lamps with dimming controller.
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We investigated the basic properties of a superconductive current limiting fuse (SCLF) based on YBCO/Au films. The SCLF consists of meander type YBCO stripes covered with an Au layer for current shunt. The fault current was first limited to a designed value in less than 0.4 msec by resistance development in YBCO/Au upon quenching. This enables the SCLF to transfer small fault power and the suppressed current was sustained for more than 0.5 msec while Au layer melting and arcing. The arcing time was less than 2.5 msec, that is short enough to do self-interruption.
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Electrical facilities of entertainment spaces become more complicate and bigger due to growing industry and economy. Therefore using only Technical standards for Electrical facilities of internal standard, we have some difficulty for management and installation of electrical facilities of entertainment spaces. So this paper gives a information which is applied to install the electrical facilities of entertainment space by analysing and comparing of internal and external standard.
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The electric train is a kind of amusement ride and it is installed in a lot of amusement parks. The object of this study was to analyze and to find out of problem about electrical facilities of amusement electric train. For the purpose of this study, we give careful consideration to the technical standard to be Notification of the Ministry of Commerce, Industry and Energy and foreign electrical codes and we carried out an actual condition investigation on twelve amusement electric trains from among domestic amusement parks. As a result, we could how that there is discrepancy between the electrical regulations and the actual condition.
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In this paper, we studied on the fire dispersive patterns and the fire progress at the power cord sets for low voltage appliances in the wall-model. For the experiment, we manufactured a wall-model and applied the external flame at the power cord sets. From the results, short-circuit of the power cord sets was haunted by the external flame it was disconnected with the flashing and the scattering. The fire progress on the polyvinyl chloride insulated flexibel cords is not observed because the ignition energy decreases. In case of rubber insulated flexible cords, however, the fire was progressed continuously. Molten marks were formed at a two electric wire by continuous electric discharge in power source part. A large molten mark was formed in load part. And the columnar structure and voids were observed in molten wire.
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To analyze risk factors of temporary power installations, the investigation was carried out for power receiving system and pack and panel boards at construction sites. The subject was variable such as an airport, an apartment, a municipal playground. There are many risk factors caused by inadequate working environments and the deterioration of temporary power installations using equipment with minimum safety devices at construction sites. There, it is intended to present problems and preventive measures against electrical shock accidents, through analyzing risk factors of real field condition and investigating temporary power installations all over the country.
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국민의 생활수준 향상에 따른 서비스산업의 발달로 화재위험 건물로 분류되는 나이트클럽과 같은 유흥장은 전국적으로 늘어나고 있는 추세이며, 규모가 대형화되고 화려해짐에 따라 전기설비도 복잡하고 다양해지고 있다. 특히 수많은 조명과 음향설비 등이 한정된 장소에 집중되어 시공되는 유흥장의 특성상 전원선이나 신호선의 배선이나 접속 방식에 있어서 많은 문제점이 상존하고 있는 실정이다. 본 논문에서는 유흥장 특성에 적합한 배선이나 접속에 관련된 국내 외 규정을 간략히 소개하고 유흥장의 현장실태조사를 통한 문제점을 파악하여 시공이나 유지 관리에 있어서의 착안점을 제공하고자 한다.
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Chung, Choon-Byung;Cho, Ju-Hyun;Jho, Jung-Min;Jeon, Kee-Young;Lee, Sang-Chip;Oh, Bong-Hwan;Lee, Hoon-Gu;Han, Kyung-Hee 347
The author present a modified multi-loop algorithm including feedforward for controlling a 55kW step down chopper in the power supply of Maglev. The control law for the duty cycle consists of three terms. The first is the feedforward term which compensates for variations in the input voltage. The second term consists of the difference between the slowly moving inductor current and output current. The third term consists of proportional and integral terms involving the perturbation in the output voltage. This perturvation is derived by subtracting the desired output voltage from the actual output voltage. The proportional and integral action stabilizes the system and minimizes output voltage error. In order to verify the validity of the proposed multi-loop controller, simulation study was tried using Matlab simulink. -
This paper presents the result of survey of case study for harmonics in electrical installations of buildings. Recently, many power electronic equipments(power converter, computers, air conditioners electronic ballasts for fluorescent lamps and so on) are used in office buildings, and harmonic current from them influence the other equipments in a distribution line. Notably, voltage distortion or voltage harmonics may approach or exceed is allowable level in power distribution system. Individual electric power consumers and end-users and responsible for reducing current harmonics while companies or utilities are responsible for reducing voltage harmonics at the point of common coupling in distribution system. As for harmonics, which one of the electric power qualities, it becomes important to obtain harmonic voltage/current distribution of the power system precisely because the use of power electronic apparatus in increasing. To suppress harmonics in electrical ins tallations of buildings, one of many methods suggest that resonance frequencies are controlled by modulating the capacities of high-voltage customer's capacitors.
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To reduce the earth resistance, earth electrode are installed horizontally or vertically in the earth. There are two kinds of vertical earth electrode methods, one is a deep-driven rod and another is slight-driven parallel rods. Bibliography have so far analyzed the earth resistance calcalation of a rod type electrode and parallel rods type for the multi-layered earth. Befor long, We are going to study earth resistance of deep-driven rod and slight-driven parallel rods in the multi-layered earth with reference to bibliography.
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This paper describes the various characteristics of voltage sags which can affect the functions of three-phase induction motors that are mostly used in the power distribution systems. These assorted characteristics include motor speed losses, voltage recovery, motor reacceleration, and transient characteristics. An experimental study on the induction motor behaviors was also carried out to confirm these impacts. In addition sequential voltage sags with short durations were considered and investigated. The results show that the occurrence of the second voltage sag after the first one may affects the induction motor adversely.
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Arc-furnace is one of the large loads in the electric power system. When the arc-furnace operates, it may cause a bus voltage fluctuation in the power system, because it consumes a lot of reactive power. In this paper, we simulated this phenomenon by using a PSAF program with on-site measured arc-furnace load. The simulated results show that the fluctuation of bus voltage adjacent the arc-furnace was varied from
$4.3%{\sim}7.8%$ the normal voltage because of reactive power consumption by arc-furnace. Therefore, we expect this study will come into use as the basic information on the probability of the demand control -
The inside and outside of the country utilities considered that they focused energy and economic aspect for short-term in new environment change of restructure. but it need service reliability preservation and improvement countermeasure, that is no to use existent estimation method for reliability preservation. therefore, analyze the equipment failure rate for suitable reliability preservation through equipment failure rate analysis of power distribution r system and evaluated equipment that is composing power distribution system by the failure rate. This paper estimated failure causes and the TVFR(Time Varying Failure Rate) for main equipment that is composing power distribution system using Weibull distribution.
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We present a detailed design study of high power large diameter backward wave oscillator operating at 24 GHz for a beam energy of 100 keV. The ratio of the mean diameter of the slow wave structure to the wavelength of output microwaves is increased to be 4.8. Analysis is made within the scope of linear theory of absolute instability.
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This paper gives information which is applied to install the electrical equipment of amusement park and ride. For analyzing the standard of electrical equipment installation, we research the related regulation of National Electrical Code(2002), IEC 60364-series and Technical standards for Electrical facilities of internal standard. Among electrical equipments of amusement park and ride, especially we study the transformer vaults, overcurrent protection and ground protection of electrical equipment. So we the furnished the installation information of transformer vaults, overcurrent and ground protection at amusement park and ride.
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As we have advanced in culture the consumption trend of main industrial energy source, electric energy has been increased in correspond with it. This increment is not only causing depletion of fossil energy since long times ago, but issuing the environmental problem nowadays. So considering a point of this view, it is necessary that we adapt the photovoltaic solar system as a new electric energy source. In this paper, we have to design that Chlorine injector. This system uses photovoltaic Power generation system. Therefore, we obtained low-price and stability system.
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To find out the reason of accident by being stained of insulators, this paper researched and analyzed the result of electrical characteristic test and field test of EHV insulator through artificial contaminated method. The best way to evaluate contaminated level of insulator surface is getting a contamination data by regional groups continually. But it is needed a lot of time and manpower. To overcome those difficulties, this research introduced ESDD(equivalent salt deposit density) measurement method which is adapted to the international codes of IEC and compared the relation between experimental test results which contaminated insulators by going through stain procedure and electrical measurement results.
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Experimental equipments for long-term outdoor tests of EHV insulators in outdoor were constructed. The testing insulators have been energized with 89 [kV] phase-to-ground AC voltage under identical condition at station, and the investigation was carried out for leakage current and various environments such as temperature, relative humidity and wind velocity. The test results of leakage current wave trends have forms on distorted waves including harmonics. The porcelain and glass insulators have low leakage current in case of daytime because moisture and humidity have relative low values. In comparison with these conditions, high leakage current was shown at dawn and rainy day due to high humidity. However, leakage current of polymer insulators was shown approximately
$129[{\mu}m]$ without relation to the weather due to hydrophobicity on their surface. -
The controller area network(CAN) was originally developed to support cheap and rather simple automative applications, However, because of the its performance and low cost, it is also being considered in automated manufacturing and process control environments to interconnect intelligent devices, such as modem sensors and actuators. This paper presents a new application technology of the developed CAN control modules for the automated doors in building automation system. Key pad and RF methods are used to open and close the automated door by the slave CAN module with CAN protocol. BAS application technology of CAN field bus modules is also presented firstly in our nation.
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With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with CPLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.
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In this paper, a new distributed intelligent control module based on LonWorks fieldbus for air handling unit(AHU) of heating, ventilating and air-conditioning(HVAC) is proposed to replace with a conventional direct digital control(DDC) with 32 bit microprocessor. This article also addresses an Internet-based HVAC system architecture that combines Web technology and networking. The proposed control architecture has a excellent features such as highly compact and flexible function design, a low priced smart front-end and reliable performance with various functions. This also addresses issues in control network configuration, logical design of field devices by S/W tool, Internet networking and electronic element installation. Experimental results showing the system performance are also included in this paper.
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This paper shows a new concept of digital power meter based on the optical sensing technique. The digital power meter with isolate IC so called Photocoupler is designed and implemented. The system composed of power and analong interface circuits, micro-controller and LCD display circuits. The most errors in power meter happen on measurement and calculation process for load voltages and currents. The suggested method on this paper is to use no noise sensor and PIC microprocessor. The results of simple test for power meter prototype are showed a nearly similar date to commercial product.
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A wind turbine system converts wind energy into electric energy, the system operated under normal environmental conditions. In case of particular turbulent wind flow such as typhoon, hurricane etc, the control of a blade used to a yaw control and a pitch control method. A small wind turbine has not a speed control system to only a manual tail safety brake. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The controller composed of wired motor, relay system, steel wired motor him down a perpendicular to wind flow and then the blade speed reduced high to zero. The operation of automatic tail safety controller verified by manual test.
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Most utiltity systems are subject to frequent changes, often due to increased loads and demand to up-grade quality of service provided. Urban renewal, expressway construction and suburban growth have also caused significant changes in urban utility distribution systems. Recently, it is required that a guideline for planning of a complete system, the reasonable design and construction methods for the efficient installation common utility tunnels must be estabilished. It prompts drastic measures to guard cities and their inhabitants against the horror of massive fires in the future. Preparedness holds the key to safety.
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Load forecasting is essential in the electricity market for the participants to manage the market efficiently and stably. The percentage errors of 24 hourly load forecasting for holidays is relatively large. In this paper, we propose the maximum and minimum load forecasting method for holidays using a fuzz linear regression algorithm. 24 hourly loads are forecasted from the maximum and minimum loads and the 24 hourly normalized values. The proposed algorithm is tested for 24 hourly load forecasting in 1996. The test results show the proposed algorithm improves the accuracy of the load forecasting.
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Recently, as the power capability of satellites increase, we need to develop a new SAR(Solar Array Regulator) with much higher power capacity whenever we design a power system of a new satelite. In this case, modular design method could be a good solution for this kind of problem. But when we use a modular method in the design of the parallelled converter, it is very important to share current equally between each module connected in paralled. In this paper, we study how to design the optimum current control-loop and voltage control-loop when we apply average current-mode control method to the parallel SAR. With the design results, we make a protype of the 3-module paralleling SAR and verify its performances.
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KOMPSAT series use software-controlled unregulated bus system in which the main bus is directly connected to a battery and the duty-ratio for PWM switch is controlled by the on-board satellite software. This paper proposes a new power-stage circuit that can be available for modularization of the power regulator which is used at the software-controlled unregulated bus system satellite. And we analyze the proposed power-stage operation according to its operating modes and verify it by performing software simulation and hardware experiment using prototype. We constructs a parallel-module converter which is composed of proposed power-stages and perform experiment to verify modular characteristics of the proposed power-stage. Finally, we verify the usefulness of the proposed power-stage by comparing above results with those of a parallel-module converter made of conventional power-stages.
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This paper presents the basic application idea of superconductor cable for voltage stability limited power system. In bulk power system, the transfer capability of transmission line is often limited by the voltage stability, and superconductor cable could be on of the countermeasure to enhance heat transfer limit as well as voltage stability limit. Steady state voltage stability approach by P-V curve is used to calculate the maximum transfer capability of initial system and superconductor applied system IEEE-14 bus system is used to demonstrate its applicability.
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Although DC ground resistance is a good index of performance for a grounding system, it does not reflect the grounding performance during the transient states. Besides, impulse ground impedance, which is defined by a ratio of the peak value of transient ground potential rise to the peak value of impulse current, cannot be an absolute performance index due to its dependence on impulse current shape. In this paper, a grounding performance of needle-typed ground rod has been compared with simple ground rod.
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Generally, instrument transformer of the core type have been used for measuring current. Because instrument transformer has defects, electronic instrument was appeared. Electronic instrument has many merit-linearity, small size, low cost, etc. Rogowski coil is typical electronic CT and R-divider is typical electronic VT. This paper is introduced a basic concept and theory of electronic current transformer, electronic voltage transformer.
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This paper gives a basic data of improving the performance of railroad signalling equipment by adopting GPS and wireless telecommunication technologies. These approach enable the moving block control of train, which can optimize train operation by reducing the distance between trains and maximize the railroad capacity. These method of detecting train position and controling train movement can also improve the train route control at stations.
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The digital motor protection, measuring and control equipment, as called "The digital motor control equipment", for applying to single/three phase motors designed an integrated one unit and manufactured a compact size which will be installed on the motor control center. It performs serveral protection functions and motor starting function, and measures and indicates a serveral measurement. This paper proposes the design concept and functionality of new digital motor control equipment to improve control performance and integrate several equipments for the control and protection of the motor.
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본 논문에서는 직선형 피스톤 액추에이터의 응용모델을 제안하고 이를 구현하였다. 구성된 액추에이터의 해석을 위해서 패러데이 법칙으로부터 기본 방정식을 유도하였고, 이를 바탕으로 소형, 경량, 고속 응답을 요구하는 시스템에 적용 가능한 실험적 자료를 얻었다. 또한 본 논문에서는 자계로부터 일반적으로 구할 수 있는 전자기력을 에너지 변환 이론적 관점에서 기계 방정식과 결합하고 전원 공급부의 인가 전압의 변화로부터 액추에이터에 나타나는 현상을 Matlab 프로그램을 활용하여 간접적 방법으로 고찰하였다. 그 결과는 실제적인 설계에 적용할 경우 설계 프로그램의 자료나 부분적 변경시 참조 할 수 있으리라 사료된다. 이 결과를 바탕으로 Linear Actuator MfdBl 시스템과 구현된 직선형 피스톤 액추에이터의 동작이 실제 시스템에 활용될 수 있는 방법으로 가능함을 검증할 수 있었다.
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인버터는 주로 커패시터 입력형 정류기를 사용하고 있다. 이로 인해 인버터는 역률이 나쁘고 고조파가 발생하며 화학적, 열적 특성의 열화로 인버터 고장율을 증가시킨다. 따라서 평활용 커패시터를 제거하면 불완전한 특성을 갖는 커패시터로 인한 문제점을 해결할 수 있다. 그러나 다시 이로 인하여 발생되는 리플전압으로 인한 문제가 발생하게 된다. 본 연구에서는 이러한 리플을 순시추종 보상형 PWM 제어기를 사용하여 해결하므로 우수한 특성을 갖는 인버터 시스템을 설계할 수 있었다.
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we studied the effect of the type of non-thermal plasma on the decomposition of
$CF_4$ . 3 types of reactors were manufactured to generate different types of plasma respectively, and went into the experiments. As the results, we found that high density of the energy of non-thermal plasma and the minimization of non-discharged area should be met in order to elevate decomposition rate of$CF_4$ . Among the reactors used in the study, the hole-type reactor was such one that satisfying that requirement. Using the hole-type reactor, treatment efficiency for high concentration of$CF_4$ was excellent. We got decomposition rate of more than 95[%] between 500[ppm] around and less than 400[ppm], and up to 85[%] at 900[ppm]. -
The purpose of this study is to develop a practical image inspection system that could recognize it correctly, endowing flexibility to the productive field, although the same object for work will be changed in the size and rotated. In this experiment, it selected a fighter, rotating the direction from
$30^{\circ}\;to\;45^{\circ}$ simultaneously while changing the size from 1/4 to 1/16, as an object inspection without using another hardware for exclusive image processing. The invariant moments, Hu has suggested, was used as feature vector moment descriptor. As a result of the experiment the image inspection system developed from this research was operated in real-time regardless of the chance of size and rotation for the object inspection, and it maintained the correspondent rates steadily above from 94% to 96%. Accordingly, it is considered as the flexibility can be considerably endowed to the factory automation when the image inspection system developed from this research is applied to the productive field. -
대용량의 직류 전원을 연속적으로 얻기 위한 가장 손쉬운 방법은 상용 교류전력을 정류하여 사용하는 것이다. 이렇게 얻어진 직류 전압 원은 리플을 포함하는 문제와 허용된 법위에 있지만 전압 변동율이 존재하게 된다. DC-DC 컨버터나 인버터 제어에서 이러한 문제를 해결하기 위하여 많은 연구가 행해지고 있다. 그러나 보상제어시간이 길거나 제어나 제어 이론이 복잡하여 시스템이 복잡하게 되는 등 각각의 문제점을 가지고 있다. 본 연구에서는 아나로그 적분기의 적분시간이 적분기 입력전압의 크기에 반비례하는 원리를 이용하여 이 펄스 변조 스위칭 컨버터를 순시 추종 제어하는 방법을 제시한다. 제안된 제어방법의 주요 특징은 정주촉수로 동작한다. 보상제어시간은 스위칭 주기를 기본단위로 추종제어 한다. 제어결과는 한 주기의 평균치로 추종 제어한다. 정상상태는 물론 과도 상태에서도 정확하게 지령치에 추종하여 제어됨을 알 수 있다.
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Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve. Hence, it is imperative to develop practically applicable solution algorithms for this problem. Several efficient algorithms have been developed for finding approximate solutions to such problems. these algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.
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When using a conventional power factor correction circuit, a comparatively huge capacitor is used to boost-up output voltage. It has a large amount of harmonic distortion in the input current waveform. To improve the input current waveform of diode rectifiers, we propose a new operating principle for the power factor correction circuit. Due to the fact that the proposed circuit uses smaller ones and a smaller reactor, the output voltage increases and obtains higher input current waveforms. These are suitable for the harmonics guidelines. The proposed circuit is able to obtain higher power factor and efficiency. Also, it has reduced switching loss and held over-shooting by using an inverter of eliminated dead-time HPWM that has non-linear impedance circuits to make up diodes, capacitance and a reactor. We compared the conventional PWM inverter and proposed HPWM inverters and found that a high input power factor of 97[%] and an efficiency of 98[%] were also obtained.
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The primary failure causes of underground distribution power cables are water penetration in insulation layer and stress enhancement at inner semi-conductive layer. Accordingly, it is needed to improve the materials and the structure of power cables for extending lifetime and preventing failure. We uses non-flaming PE materials instead of PVC as a covering material and encapsulating structure. We also use super smooth class material as a inner semi-conductive layer. The newly developed cables are improved in AC breakdown voltage after ageing tests.
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The purpose of this experiment is to modify diagnosis criterion of isothermal relaxation current(IRC) measurement equipment which is using for distribution cable diagnosis. We're using this system for several years in the field instead of DC leakage current measurement and lots of cables were replaced. But we have to investigate on the reliability of this equipment for our cables because we didn't carried out condition assessment of extracted cables after field diagnosis by this equipment. It is important thing for cable maintenance. If the replacement criterion is improper we can not prevent failures or will waste budget on account of replacement of the sound cables. In this papar we selected field installed cables and injected silicone fluid to the cables for insulation rehabilitation. In order to prove reliability of the diagnosis equipment we compared diagnosis results and AC breakdown strength according to operating time after silicone treatment. This is the results of the field test for 1 year.
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A multi-phase interleaved buck converter is used to reduce current ripples and filter size of a power supply. This paper addresses the modelling and steady-state analysis of the multi-phase interleaved buck converter operated in discontinuous inductor current mode. The model is derived using an averaging technique in steady state. The do voltage ratio and the range of the discontinuous inductor current mode(DICM) and the continuous output current mode(COCM) are derived from the averaged state-space model. In addition, the efficiency is investigated according to the number of phase.
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In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.
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This paper describes a new 3 phase Sag-Swell generator for the test of custom power devices such as UPS, DVR, DSTATCOM, SSTS, etc. The proposed scheme has good features of simple structure, high reliability wide range of sag and swell variation, It can also generate voltage outage. The control scheme for the generation is simple. The operation principle of the proposed scheme is described and verified through simulations.
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This paper describes a dynamic UPS system with flywheel energy storage element. There are three operating modes of charging, voltage compensation, and UPS. The operating principle of each mode is analyzed and simulated. The simulation results show the validity of the operation of the proposed scheme.
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This paper describes a new method of detecting rotor position in switched reluctance motor(SRM). Some strategies of position sensorless control methods for the motor include the measurement of phase current and applied pulse voltage in an unexcited phase. The principle of the estimation of a rotor position is based on the detection of inductance by pulse currents. Suggested method is verified by some experimental tests.
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A new SEPIC-Flyback convater is proposed. The proposed converter is the superposition of SEPIC and Flyback converter. Not only SEPIC output but also Flyback output could be fully regulated by constant frequency PWM control. Merged SEPIC and Flyback topology could share the transformer and power MOSFET. When the switch turns of one topology operates via capacitive energy transfer. Another topology acts as powering mode while the switch is off. So, it could increase power falsify per one cycle. The operating principle of the proposed converter is described below. Prototype featuring 24V input 48V output, 100kHz switching frequency, and 100W output is simulated under the proposed topology.
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We propose a phase stabilisation and control system for the use in fiber-optic ESPI. The fast phase stabilisation against environmental perturbations has been achieved by using Fuzzy PI control. Combined with closed-loop switching, the system showed accurate and fast
${\pi}/2$ phase stepping capability. -
Lee, Bok-Hui;Gang, Seong-Man;Choe, Hwi-Seong;Park, Geon-Yeong;O, Seong-Gyun;Kim, Byeong-Geun 535
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Conventional SVPWM method has null switching vectors. Null switching vectors cause common-mode voltage making high in induction motor drive system. New SVPWM method without using null switching vectors are proposed in the paper. So, new SVPWM method reduces the common mode voltage for induction motor drive system. It is realized by changing software without adding hardware to induction motor drive system. Simulation results show that common-mode voltage adapting proposed method are reduced regarding conventional method.
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This paper describes the electrical characteristics of the polymer lightning arresters(L.As) used to protect distribution lines and power facilities from surge. For the relative comparison, the characteristics assessment was done for 2 states of L.As before and after water immersion treatment. The L.As for the comparative test were immersed with water of
$95[^{\circ}C]$ considered a severe condition. After the immersion treatment, the assessment was carried out for material analyses in chemical structure(FTIR : fourier transform infrared spectrophotometer). Electrical performance measured insulation resistance measurement, leakage current measurement, critical operation voltage measurement etc.. In addition to, the results were compared with those for the L.As deteriorated in the field. Thus, the accelerative deterioration degree of polymer materials by immersion treatment was evaluated, by which the structural defects of the polymer L.As could be inferred. -
This paper describes the performance improvement of switchgear. G/S(Gas Switch) is a common and very important facility in distribution system. In this paper We analyze the cause of trouble with operating switches. Using the conclusion through the investigation We propose the countermeasure of a malfunction in switching equipment.
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Due to the asymptotic property, deadbeat control can hardly applied to the continuous time system control. But some delay element method can deal such a problem. Except delay element method, well-known digital deadbeat control can br used with the aid of som smoothing elements. In this paper, and order smoothing element is used for the smoothing of the digital deadbeat controller. And this element is argumented to the plant, and so control problem is to control digitally the argumented system. We simulated this control system using Matlab language and finally apply this algorithm to the rotary inverted pendulum system.
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This paper deals with the device for measuring the time-varying magnetic fields and induced voltages caused by lightning discharges. The two magnetic field measuring systems were designed and made. One consists of the loop-type magnetic field sensor with the active integrator operated by a differential amplifier. The other consists of the loop-type magnetic field sensor and Labview software. The loop-type magnetic field sensor detects the time derivative of the magnetic field being measured, and the signal detected is integrated by the Labview software. As a consequence, from the calibration experiments, the frequency bandwidth of the full measuring system ranges from 400 [Hz] to 1 (MHz) and the response sensitivity are 0.98 (mV/nT) and 22 (mV/nT) for the magnetic field sensor of 2 turns and 6 turns, respectively. Also, the results obtained by the two measuring devices well agreed with each other.
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This paper deals with the characteristics of potential rise and effective impulse impedance of deep-driven ground rods that are used in high resistivity soil or in confined places such as downtown. Also the effects of the impulse and fault currents on the deep-driven ground rods combined with different type grounding electrodes like as mesh grids and counterpoises are described. The
$8/20{\mu}s$ impulse current and other wave currents with different rise times are injected into the test ground rod and the effective impedances are examined. The most effective way to obtain the fine transient impedance behaviors of deep-driven ground rods is to reduce the inductive component of grounding electrode systems combined with other ground electrodes. -
Technical supply reason of digital base and important color reappearance of WEB base that is diffused rapidly on industry whole. Examined my outside factor investigation and revision method of inaccurate color reproduction and color reappearance valuation method influencing in color reappearance of monitor for last reception using in on-line shopping as well as end consumers in graphic age
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The latest equipment automatic Intelligence of digital base done large size equipment appear in succession. That run by voltage electric current(mA, mV,
${\mu}A,\;{\mu}V$ ) that outline is microscopic of action of accuracy large size equipment of this digital base is bulk. Have received influence that is great in river electric field by installment that use computer. Most of domestic working voltage from service entrance extra-high voltage and working voltage of commercial frequency 60Hz working voltage 220V that use our country outside 1 country in interior of 22.900V for semiconductor use computer use digital installment of appliance as well as various smalls of digital base, middle, large size that safety is these fine voltage electric current that is not enough direct admonition hundred vast damage give can. Also, already act in surge circle and impulse transient phenomena such as several thousands, myriads, strong bit error more than billions time to digital fine electronic circuit by mistake use of using electric facility system of system electric power. -
The wave shapes of electromagnetic pulses radiated from lightning discharges are significantly changeable one of the topics concerning on EMI/EMC of modern electronic systems is the efficient and economic protection of electronic circuits against transient voltages caused by not only by cloud-to-ground lightning but also by intracloud lightning discharges. In this work, in order to obtain the detailed information about lightning electromagenetic pulses, the electromagnetic pulses radiated from intracloud lightning discharge processes were measured and analyzed statistically.