• Title, Summary, Keyword: arc

Search Result 5,553, Processing Time 0.047 seconds

A Study of Detection Algorithms and Analysis Series Arc of Quasi-arc Load (유사아크부하의 직렬아크신호 분석 및 검출 알고리즘에 관한 연구)

  • Lim, Jong-Ung;Ju, Jae-Yeon;Kang, Kyoung-Pil;Bang, Sun-Bae;Choe, Gyu-Ha
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.28 no.7
    • /
    • pp.81-90
    • /
    • 2014
  • This paper proposes new arc algorithm to detect series quasi-arc. This algorithm analyzes odd and even harmonics until 9th using discrete fourier transform (DFT) and detect series arc comparing RMS values of load current. Resistors, lights, dimmer and vacuum cleaner which can be distinguished linearity load and quasi arc load are adopted to perform experiments. This algorithm is confirmed to emulate arc detecting with measuring current data.

A Series Arc Fault Detection Strategy for Single-Phase Boost PFC Rectifiers

  • Cho, Younghoon;Lim, Jongung;Seo, Hyunuk;Bang, Sun-Bae;Choe, Gyu-Ha
    • Journal of Power Electronics
    • /
    • v.15 no.6
    • /
    • pp.1664-1672
    • /
    • 2015
  • This paper proposes a series arc fault detection algorithm which incorporates peak voltage and harmonic current detectors for single-phase boost power factor correction (PFC) rectifiers. The series arc fault model is also proposed to analyze the phenomenon of the arc fault and detection algorithm. For arc detection, the virtual dq transformation is utilized to detect the peak input voltage. In addition, multiple combinations of low- and high-pass filters are applied to extract the specific harmonic components which show the characteristics of the series arc fault conditions. The proposed model and the arc detection method are experimentally verified through a boost PFC rectifier prototype operating under the grid-tied condition with an artificial arc generator manufactured under the guidelines for the Underwriters Laboratories (UL) 1699 standard.

Technology on Arc Welding Machine of Aluminum by Digital Control (디지털 제어를 이용한 알루미늄 아크 용접기의 기술현황)

  • Lee, Chang-Je;Kim, Yu-Chan;Kim, Jong-Do
    • Journal of Welding and Joining
    • /
    • v.31 no.1
    • /
    • pp.26-32
    • /
    • 2013
  • Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

Development of an Effective Arc Sensing Algorithm for Seam-Tracking in Flux-Cored Arc Welding Process for Horizontal Fillet Joints (FCAW 수평 필릿용접용 용접선추적을 위한 아크센싱 알고리즘 개발)

  • 권순창;최재성;장낙영
    • Journal of Welding and Joining
    • /
    • v.15 no.1
    • /
    • pp.66-80
    • /
    • 1997
  • This paper describes a newly developed arc-sensing algorithm of seam-tracking for FCA W (flux-cored arc welding) horizontal fillet welding. In this algorithm, arc current and the Weighted-Are-Current (WAC) are used to adjust the position of a weld torch in directions of bead throat and weaving, respectively. The WAC, which is newly devised in this study, means that arc current in the vicinity of weaving end is more emphasized than that in the center of weaving. The reason of this is because there usually exists much noise in the center of weaving due to abrupt change of arc length in case some empty gaps exist in a fillet joint Variance analysis was performed in order to check the effect of weld parameters on arc current and the WAC. As a result, the relationships between tip-to-workpiece distance and arc current, and between weaving offset and the WAC were established.To check "the validity of the algorithm, seam-tracking experiments were performed ;mder various welding condition. The result of experiments showed a satisfactory tracking performance in the presence of empty gaps in a horizontal fillet joint.et joint.

  • PDF

Finite Element Analysis of a 3D Moving Vacuum Arc for Transverse Magnetic Field Contacts Based on Gundlach's Formula

  • Kwak, Chang-Seob;Kim, Hong-Kyu;Kim, Tae-Hoon;Lee, Se-Hee
    • Journal of the Korean Physical Society
    • /
    • v.70 no.1
    • /
    • pp.22-27
    • /
    • 2017
  • A systematic numerical method for analyzing a 3D moving vacuum arc was proposed and tested in this research by using a transverse magnetic field (TMF) contact. The analysis was carried out by employing the finite element method and the experimental energy equation defined by Gundlach's formula. In the literature, the vacuum interrupter has been widely applied to medium-voltage switching circuits. TMF-type contacts use the Lorentz force density to move a high-temperature arc so as to prevent the contacts from being melted and damaged. The material erosion caused by the arc on the electrode's surface is an important process that results in the interruptive capabilities of these vacuum interrupters. In a classical arc model, to move the vacuum arc, it is required that the magneto-hydrodynamics be analyzed in the arc region at each step. However, with this approach convergence is difficult, resulting in a very time-consuming. Therefore, we propose a new technique to predict the behaviors of vacuum arc between two electrodes. This new approach adopts the experimental arc voltage equation between two electrodes defined by Gundlach's formula. We verify our proposed model by comparing its results with the arcing behaviors obtained from earlier experiments.

Optimization of Total Arc Degree for Stereotactic Radiotherapy by Using Integral Biologically Effective Dose and Irradiated Volume (정위방사선치료 시 적분 생물학적 유효선량 및 방사선조사용적을 이용한 Total Arc Degree의 최적화)

  • Lim Do Hoon;Lee Myung Za;Chun Ha Chung;Kim Dae Yong
    • Radiation Oncology Journal
    • /
    • v.19 no.2
    • /
    • pp.199-204
    • /
    • 2001
  • Purpoe : To find the optimal values of total arc degree to protect the normal brain tissue from high dose radiation in stereotactic radiotherapy planning. Methods and Materials : With Xknife-3 planning system & 4 MV linear accelerator, the authors planned under various values of parameters. One isocenter, 12, 20, 30, 40, 50, and 60 mm of collimator diameters, $100^{\circ},\;200^{\circ},\;300^{\circ},\;400^{\circ}C,\;500^{\circ},\;600^{\circ}$ or total arc degrees, and $30^{\circ}\;or\;45^{\circ}$ or arc intervals were used. After the completion of planning, the plans were compared each other using $V_{50}$ (the volume of normal brain that is delivered high dose radiation) and integral biologically effective dose. Results : At $30^{\circ}$ of arc interval, the values of $V_{50}$ had the decreased pattern with the increase of total arc degree in any collimator diameter. At 45 arc interval, up to $400^{\circ}$ of total arc degree, the values of $ V_{50}$ decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. At $30^{\circ}$ of arc interval, integral biologically effective dose showed the decreased pattern with the increase of total arc degree in any collimator diameter. At $45^{\circ}$ arc interval with less than 40 mm collimator diameter, the integral biologically effective dose decreased with the increase of total arc degree, but with n and n mm or collimator diameters, up to $400^{\circ}$ or total arc degree, integral biologically effective dose decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. Conclusion : In the stereotactic radiotherapy planning for brain lesions, planning with $400^{\circ}$ of total arc degree is optimal. Especially, when the larger collimator more than 50 mm diameter should be used, the uses of $500^{\circ}\;and\;600^{\circ}$ of total arc degrees make the increase of$V_{50}$ and integral biologically effective dose. Therefore stereotactic radiotherapy planning using $400^{\circ}$ of total arc degree can increase the therapeutic ratio and produce the effective outcome in the management of personal and mechanical sources in radiotherapy department.

  • PDF

수은정유기 아아크관경크기에 대한 정량적 고찰

  • 천희영
    • 전기의세계
    • /
    • v.16 no.4
    • /
    • pp.6-10
    • /
    • 1967
  • The deionization behavior in plasma during arc discharge of mercury arc rectifier depends on ambipolar diffusion. It is shown here in the quantitative analysis that a diameter of arc path which affects the mercury arc rectifier characteristics is related with the density of charged particles in plasma, the particle number of extruguish ion, the deionizing time and the recovering time of grid controlled ability. The conclusion would he useful for designing a diameter of arc path of mercury arc rectifier by quantitative method. And it could be applied to the designing of electrical apparatus using arc discharge phenomena.

  • PDF

Modeling of Arc Blow for FCAW (FCA 용접의 아크 블로우 모델링)

  • Go Seong Hun
    • Proceedings of the KWS Conference
    • /
    • v.43
    • /
    • pp.202-204
    • /
    • 2004
  • The purpose of this study is to evaluate the effects of welding conditions on the shape of arc of FCAW using high speed camera system. Length and deflection of arc were evaluated from images of arc which were transformed by threshold processing. Based on the experimental results, a regression model for the length of arc was established. A major factor affecting deflection of arc was the length of arc.

  • PDF

A Study on the Effective Arc Sensing by the Use of the Weighted-Arc-Current in Flux-Cored Arc Welding for Fillet Joints (가중용접전류를 이용한 FCAW 필릿용접용 아크센싱 알고리즘 연구)

  • 권순창;최재성
    • Journal of Welding and Joining
    • /
    • v.18 no.1
    • /
    • pp.83-90
    • /
    • 2000
  • It was attempted to improve seam-tracking performance by applying a new arc-sensing algorithm for FCAW(flux-cored arc welding) process in fillet joints. For this study the authors have introduced three different weight factors: $\circled1$ arc currents at the weaving end are more weighted, $\circled2$ arc currents are evenly weighted along the weaving, and $\circled3$ arc currents at the weaving center are more weighted. To evaluate the 3 factors the values of signal-to-noise(S/N) ratio has been measured. The values were obtained for various welding conditions with different gaps in horizontal and vertical fillet joints. The test results showed that the S/N ratio of the 1st case was highest which resulted in the best of seam tracking performance. In addition, the comparison between the seam tracking performance in horizontal fillet joints and that in vertical ones has been done, and the result showed that tracking performance in vertical joints was relatively better than that in horizontal joints.

  • PDF