• Title, Summary, Keyword: arc

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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.

An Integrated Environmental Impact Assessment Model using FEMWASP and ArcView (FEMWASP 모형 및 ArcView를 결합한 통합적 환경영향평가 모형의 개발 및 적용)

  • Kim, Joon Hyun;Han, Young-Han;Choi, Yoon-Jung
    • Journal of Environmental Impact Assessment
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    • v.7 no.2
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    • pp.65-70
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    • 1998
  • An integrated EIA tool was developed to analyze present and future environmental quality status of Youngwol Basin using ArcView and FEMWASP. All the input data and computational results were prepared and graphically displayed on the basis of ArcView. FEMWASP and ArcView were integrated using the command "system.execute" in script of Avenue. Modeling items were inserted in the GUI of ArcView. The modeling result showed that the water quality of the proposed Yougwol Lake would be at the stage of eutrophication. The developed system can be applied to the water quality management of drinking water resources to set up the regulatory acts and project plan of governmental policy.

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Analysis of Ignition Time/Current Characteristics and Energy when Series Arc-Fault Occurs at Rated 220 V (220 V 직렬 아크고장발생 시 점화 시간/전류 특성 및 에너지 분석)

  • Ko, Won-Sik;Moon, Won-Sik;Bang, Sun-Bae;Kim, Jae-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.8
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    • pp.1184-1191
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    • 2013
  • Probability of ignition due to arc-fault and energy of the arc-fault for the case of applying serial arc-fault interruption time of 120 V defined in UL 1699 to the voltage of 220 V of domestic condition and also for the case of applying it to the HIV wire type are analyzed. It has been confirmed that when the arc-fault occurs under 5 A, 10 A, and 20 A. Probability of ignition for the three different current conditions is 0.74(74%), 0.48(48%), and 0.32(32%) respectively for respective interruption time within 1 sec, 0.4 sec, and 0.2 sec. We discover that when we apply the same arc interruption time for 120 V defined in UL 1699 to the domestic environment of 220 V. The probability of ignition increases from 1.5% for 120 V condition to as much as 74% for 220 V condition. Conclusively, if we apply the standard for the serial arc-fault interruption time defined in UL 1699 for 120 V to the domestic condition of 220 V, the fire prevention effect of electric fire due to arc-fault equal to that of UL standard of 120 V can not be achieved.

A simple approach for circular Arc detection using a least squares fitting and preprocessing (최소자승법과 전 처리를 이용한 원호 검출의 간단한 접근)

  • Nkurunziza, Armel;Kim, Jong-nam
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.840-843
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    • 2016
  • The circular arc is a very useful feature for object detection and recognition in industrial environments. In this paper, a new method to detect circular arcs is proposed. The detection of the circular arc includes the estimation of the center, the radius and the two ending points of the arc. This new method is based on determining the best part of the circular arc (part which does not contains outliers points) using 3 points designated along the arc. A least square method is applied to the best part of the arc and the center and the radius of the arc are obtained. The distance between the remaining edge's points (points which are not lying on the best part of the arc) and the radius is used to the two ending points of the arc.

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A Study of Arc Detection at DC Power System (직류 시스템에서의 아크 검출에 관한 연구)

  • Ban, Gi-Jong;Kim, Jin-Woo;Won, Young-Jin;Lim, Sung-Ha
    • Proceedings of the IEEK Conference
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    • pp.461-462
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    • 2007
  • DC Arc is an electric discharge which is occurred in two oppolsite electrode when system operating with DC current appliance. In this paper, DC arc detection system is designed for the display of DC arc fault current which is occurred in the local electric network with DC Power. This DC arc is one of the main causes of electric fire of dc system. Arc fault in electrical network has the characteristics of low current, high impedance and low frequency. DC Arc current detection device is designed for the display of arc fault current which has the modified arc characteristics.

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Measurements of the rotating arc speed in Rotary Arc Gap switch (Rotary Arc Gap 스위치에서의 아크 회전속도 측정)

  • Cho, Chu-Hyun;Rim, Geun-Hie;Lee, Hong-Sik;Pavlov, E.P.
    • Proceedings of the KIEE Conference
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    • pp.2135-2137
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    • 2000
  • Usually arc phenomena are not easily characterized due to unstable behavior very short existence-times, high temperature and the required isolation of measurement instruments. This paper presents some arc-behaviors in a rotary arc gap-switch(RAG) using a 500kJ capacitor bank. It includes the speed variations of the rotating arc, the impacts of the oscillating current on the arc initiations and re-ignitions. Changes in the arc-dimension with respect to time and current magnitudes are also analyzed.

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A Study on Rotating Arc Using Hollow Shaft Motor (중공축 모터를 이용한 회전아크에 관한 연구)

  • 김철희;나석주
    • Journal of Welding and Joining
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    • v.18 no.5
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    • pp.49-54
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    • 2000
  • High speed rotating arc process, forming a flat bead surface with shallow penetration depth, can be applied to the automatic seam tracking, because the amplitude of current waveform increases at high rotation speed. Two high speed arc rotation mechanisms have been developed in Japan and Germany b rotating the electrode nozzle using an external motor, which are used prevalently for narrow gap and conventional seam welding. In this study, a new rotation mechanism was developed by using a hallow shaft motor designed to be installed in the electrode nozzle. By rotating the welding arc, the amplitude of current waveform increases remarkably since the self-regulation of arc is not fully performed. Experiments show that the arc sensor with high-speed rotation arc has improved its responsiveness and sensitivity.

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Design and Test of Vacuum Rotary Arc Gap Switch (Vacuum Rotary Arc Gap Switch의 설계 및 시험)

  • 서길수;황동원;이태호;황리호;김희진;이홍식;임근희
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.1
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    • pp.19-24
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    • 2003
  • Design and test results of a VRAG(Vacuum Rotary Arc Gap) switch were presented. To control the damage of electrodes caused by the vacuum arc, Lorentz's force by the radial magnetic field between spiral electrodes was used to rotate the vacuum uc. VRAG switch electrodes were made of the material of CuCr and OFHC. Gap distance between two spiral type electrodes for the rotation of the arc discharge is 8, 10, 12mm. In the cathode, one trigger electrode was inserted into each spiral wing. Normal operation of the VRAG switch was confirmed with 10.6[$mutextrm{s}$]of trigger delay and 2~3[$mutextrm{s}$] of the jitter time. The speed of the vacuum arc was measured to be 0.6 ~ 1[km/s] by a motion analyzer.

Influence of Contact and Wall Material on Arc Interruption in Air (기중 아크 차단에 대한 접점 및 소호 재료의 영향)

  • Lee, S.Y.;Park, H.T.;Oh, I.S.;Lee, K.H.
    • Proceedings of the KIEE Conference
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    • pp.1637-1639
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    • 2001
  • Air arc interruption used in low rated voltage breaker, ACB and MCCB, have used the arc chamber composed of metal plates and insulating laminates which supposed these mechanically. and geometry and materials of arc chamber are very different by breaker manufacturer. These breakers have required to be smaller and to interrupt higher current by user. therefore the arc chamber geometry and material in breaker have been small, complex and various. The purpose of this study is to examine the effects of insulating laminates and contact materials on air arc interruption. Contacts were surrounded by a rectangle chamber of insulating laminates. Contact concoctions were composed of AgW, AgCdO that have used in low rated voltage breaker, and insulating laminates were polyester, epoxy. We found strong dependance of arc voltage on insulating material. The ablated vapor on polyester increased arc voltage that was useful in air arc interruption.

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Analysis of Magnetic Arc Reduction of Relay Contacts (릴레이 접점의 자기적 아크 저감 분석)

  • Choi, Sun-Ho;Huh, Chang-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.3
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    • pp.234-240
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    • 2019
  • In this work, the magnetic arc reduction phenomena encountered in AC relay contacts were analyzed. To this end, arc duration, instantaneous voltage, and current changes due to changes in the magnetic field were observed. The arc generated at the contact point was affected by the magnitude of the applied magnetic field; the voltage and current waveforms rapidly intersected, resulting in a decrease in arc duration and arc energy. Furthermore, the orientation of the N pole of the magnetic field was found to play a role in the effectiveness of potential arc prevention.