• Title/Summary/Keyword: AC arc

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A Study on Sinewave Air Gap Flux Density of Surface Type Magnet Motor (표면부착형 영구자석 전동기의 정현파 공극자속밀도 연구)

  • Kim, Hyun-Cheol;Kim, Jang-Mok;Kim, Cheul-U
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1571-1576
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    • 2007
  • This report describes the analytical characteristic of sinewave air gap flux density for the brushless AC motor with surface permanent magnet. The analysis of sinewave air gap flux density is the key to expect the performance of back EMF for the design of brushless AC motor. The numerical analysis and FEM analysis are performed to adopt radial and parallel flux magnetization of magnet on the rotor. And it is also executed to vary the magnet arc angle and arc radius for the condition of constant and non constant air gap. This report is focused on the characteristic of sinewave air gap flux density for permanent magnet of surface brushless AC motor. This results also have more reliable data against the previous paper which had the representative numerical analysis of air gap flux density[1][2].

Electrical Breakdown Strength of Insulation under Combined DC-AC Voltages

  • Grzybowski, S.
    • Electrical & Electronic Materials
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    • v.11 no.10
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    • pp.32-39
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    • 1998
  • Electrical breakdown strength of paper-oil and polypropylene/film-oil insulation samples was measured under dc, ac and pulsating voltages. The latter was obtained by superimposing ac upon dc volate and provides an attractive method for a simultaneous testing and assessment of the state of insulation of the various parts of HV apparatus in service. The measurements were carried out over a wide range of the pulsation ratio defined as p=Eac/Edc. The results obtained under pulsating voltages follow colsely an experssion which relates the breakdown strength to the sum of arc tangent and arc cotangent function of the parameter p. The study was carried out using dry paper as well as paper containing various degrees of moisture. The presence of moisture showed a pronounced effect upon the breakdown strength which varied with the pulsation parameter p.

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Investigation of Arc Breaking Characteristic for Arc Chamber in Molded Case Circuit Breakerg (배선용차단기의 소호구조에 의한 한류 특성 연구)

  • Kim, Yong-Gi;Song, Jung-Chun;Ryu, Man-Jong
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.708-710
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    • 2001
  • In this paper, back commutation phenomena for iron chute chamber in AC low testing. For this experimental we used high speed camera and carried out with same prospective currents up to 10kA RMS. Hybrid arc quenching chambers which are composed with iron plate and insulating materials tested for reducing back commutation phenomena in interrupting process. It is shows that hybrid chambers which are various narrow slot path width reduces back commutation. As a result, a new type arc quenching chamber is to force the arc rapidly into a narrow insulating slot with iron plate. By this means the arc is lengthened and squeezed between insulating walls. Using this model, the behavior of the arc squeezed in the hybrid chamber and characteristics of arc voltage are also investigated.

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CAE Analysis of $SF_6$ Arc Plasma for a Gas Circuit Breaker Design (가스차단기 최적설계를 위한 $SF_6$ 아크 플라즈마 CAE 해석)

  • Lee Jong C.;Ahn Heui-Sub;Kim Youn J.
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.365-368
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    • 2002
  • The design of industrial arc plasma systems is still largely based on trial and error although the situation is rapidly improving because of the available computational power at a cost which is still fast coming down. The desire to predict the behavior of arc plasma system, thus reducing the development cost, has been the motivation of arc research. To interrupt fault current, the most enormous duty of a circuit breaker, is achieved by separating two contacts in a interruption medium, $SF_{6}$ gas or air etc., and arc plasma is inevitably established between the contacts. The arc must be controlled and interrupted at an appropriate current zero. In order to analyze arc behavior in $SF_{6}$ gas circuit breakers, a numerical calculation method combined with flow field and electromagnetic field has been developed. The method has been applied to model arc generated in the Aachen nozzle and compared the results with the experimental results. Next, we have simulated the unsteady flow characteristics to be induced by arcing of AC cycle, and conformed that the method can predict arc behavior in account of thermal transport to $SF_{6}$ gas around the arc, such as increase of arc voltage near current zero and dependency of arc radius on arc current to maintain constant arc current density.

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Decomposition Characteristics of Perfluorocompounds(PFCs) Gas through Gliding Arc Plasma with Hydrogen Gas (수소 가스를 첨가한 글라이딩 아크 플라즈마의 과불화화합물(PFCs) 가스 분해 특성)

  • Song, Chang-Ho;Park, Dong-Wha;Shin, Paik-Kyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.4
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    • pp.65-70
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    • 2011
  • Perfluorocompounds (PFCs) gases were decomposed by gliding arc plasma generated by AC pulse power. $N_2$ gas of 10 LPM flow rate and $H_2$ gas of 0.5 LPM were introduced into the gliding arc plasma generated between a pair of electrodes with SUS 303 material, and the PFCs gases were injected in the plasma and thereby were decomposed. The PFCs gas-decomposition-characteristics through the gliding arc plasma were analyzed by FT-IR, where pure $N_2$ and $H_2$-added $N_2$ environment were used to generate the gliding arc plasma. The PFCs gas-decomposition-properties were changed by electric power for gliding arc plasma generation and the H2 gas addition was effective to enhance the PFCs decomposition rate.

220Vrms Series Arc Characterization Depending on load capacity For Arc Fault Detection (아크사고 검출을 위한 부하용량별 220Vrms 직렬아크특성)

  • Choi, Su-Kyung;Kwon, Wan-Sung;Kim, Chong-Min;Bang, Sun-Bae;Choe, Gyu-Ha
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.213-214
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    • 2010
  • The Arc fault is primary reason of electric fire. so we must detect. the purpose of this study is to extend our knowledge of AC-arc characteristics and detect. The Arcs are produced by separating two electrodes made with graphite and copper. A very low separation speed allows arcs to reinitiate, as in arc fault in wires. Power is 220Vrms-60Hz and the load is light bulbs and capacities are 220W, 660W and 1100W. I measured Arc voltage and current. and defined voltage and current Max level, voltage plateau and Arc-power at each cycle.

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Study on Characteristic of Methane Reforming and Production of Hydrogen using GlidArc Plasma (GlidArc 플라즈마를 이용한 메탄의 개질 특성 및 수소 생산에 관한 연구)

  • Kim, Seong-Cheon;Chun, Young-Nam
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.11
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    • pp.942-948
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    • 2007
  • Popular techniques for producing hydrogen by converting methane include steam reforming and catalyst reforming. However, these are high temperature and high pressure processes limited by equipment, cost and difficulty of operation. Low temperature plasma is projected to be a technique that can be used to produce high concentration hydrogen from methane. It is suitable for miniaturization and fur application in other technologies. In this research, the effect of changing each of the following variables was studied using an AC GlidArc system that was conceived by the research team: the gas components ratio, the gas flow rate, the catalyst reactor temperature and voltage. Results were obtained for methane and hydrogen yields and intermediate products. The system used in this research consisted of 3 electrodes and an AC power source. In this study, air was added fur the partial oxidation reaction of methane. The result showed that as the gas flow rate, the catalyst reactor temperature and the electric power increased, the methane conversion rate and the hydrogen concentration also increased. With $O_2/C$ ratio of 0.45, input flow rate of 4.9 l/min and power supply of 1 kW as the reference condition, the methane conversion rate, the high hydrogen selectivity and the reformer energy density were 69.2%, 32.6% and 35.2% respectively.

PROCESS OPTIMIZATION OF METHANE REFORMING IN ARC JET (아크젯 플라즈마에서의 메탄개질의 최적화)

  • Hwang, Na-Kyung;Lee, Dae-Hoon;Song, Young-Hoon
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.266-271
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    • 2006
  • Characteristic of partial oxidation of methane using arc-jet plasma by AC power is investigated. Arc-jet reactor used in this work is slightly modified from typical arc jet reactor so that it can make and sustain stable state of plasma. Methane conversion, selectivity of chemicals such as hydrogen and hydrocarbon materials in the product are analyzed. Parametric approach on the performance of the reactor or detail on the partial oxidation process is carried with $O_2/C$ ratio as parameter. In addition to the results, SED and arc length is changed to understand the effect of current-voltage correlation on the reforming performance and relative role of thermal process.

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Extraction of Series Arc Signals Based on Wavelet Transform in an Indoor Wiring System

  • Ji, Hong-Keun;Cho, Young-Jin;Wang, Guoming;Hwang, Seong-Cheol;Kil, Gyung-Suk
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.4
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    • pp.221-224
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    • 2017
  • This paper dealt with the extraction of series arc signals based on wavelet transform in order to improve the accuracy of arc detection in indoor wiring systems. Three types of arc sources including a cord-cord, a terminal-cord, and an outlet-plug were fabricated to simulate typical arc defects. An arc generator fabricated according to UL 1699 was used to generate arcs. The optimal mother wavelet was selected as bior1.5 by calculating the correlation coefficients between the detected single current pulse and the wavelet. The detected arc current signals were then decomposed into eight levels using the discrete wavelet transform that implements the multi-resolution analysis method. By analyzing the decomposed components, the detail components D6, D7, and D8 were associated with arc signals, which were used for signal reconstruction. From the result, it was verified that the proposed method can be used for the extraction of the series arc signal from the AC mains, which is expected to be applied to further analysis of arc signals in indoor wiring systems.

AC/DC Resonant Converter to Control for DC Arc furnace (직류 전기아크로를 제어하기 위한 전원장치로서의 AC/DC 공진형 컨버터)

  • Ryu Byoung-woo;Choi Jae-ho;Jarvik Jaan
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.769-772
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    • 2002
  • 본 논문에서는 직류 전기아크로의 전원장치로서 AC/DC 공진형 컨버터가 묘사된다. 또한 무효전력을 보상하기 위한 커패시터와 인덕터를 각각 직렬과 병렬로 연결되어 있다. 그러므로 무부하부터 단락회로까지의 범위에서 역률이 매우 높다. 이 컨버터는 직류 아크로의 전원장치로서 매우 적당하다.

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