• 한국화재소방학회논문지
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• 제19권2호
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• pp.63-68
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• 2005

본 논문에서는 고감도형 누전차단기의 스위칭에 따른 접점의 아크 비산 특성을 해석하였다. 누전차단기(RCD) 스위칭에 따른 접점의 비산과정 및 인접가연물로의 착화과정은 고속카메라(High Speed Imaging System)를 이용하여 촬영하였다. 부하는 전등부하 60W와 전열부하 950 W를 병렬로 연결하였다. 정상상태의 RCD의 경우 아크의 생성부터 소멸까지의 시간은 약 2.3[ms]을 알 수 있었으며, 아크가 비산될 때 주변에 인접가연물(탈지면)을 착화시키지 못했다. 염수에 의해 오염된 접점의 경우 아크의 비산범위가 훨씬 컸으며 지속시간도 3.3[ms]동안 더 지속되었다. 그리고 주위에 가연성 물질에 착화가 가능하였다. RCD에 의한 사고를 예방하기 위해서는 수분, 먼지 등의 환경적 요인에 주의해야 하며, RCD소자는 난연성 재료를 사용해야 된다.

• 대한기계학회논문집A
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• 제32권1호
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• pp.7-12
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• 2008

The vacuum interrupter (VI) is used for medium-voltage switching circuits due to its abilities and advantages as a compacted environmental friendly circuit breaker. In general, the application of a sufficiently strong axial magnetic field (AMF) permits the arc to be maintained in a diffused mode to a high-current vacuum arc. A full understanding of the vacuum arc physics is very important since it can aid to improve the performance of vacuum interrupter. In order to closely examine the vacuum arc phenomena, it is necessary to predict the magnetohydrodynamic (MHD) characteristics by the multidisciplinary numerical modeling, which is coupled with the electromagnetic and hydrodynamic fields, simultaneously. In this study, we have investigated the effect of changing geometrical parameters for electromagnetic behaviors of high-current vacuum arcs with two different types of AMP contacts, which are coil-type and cup-type, using a commercial finite element analysis (FEA) package, ANSYS. The present results are compared with those of MAXWELL 3D, a reliable electromagnetic analysis software, for verification.

• 전력전자학회논문지
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• 제27권3호
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• pp.175-179
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• 2022

Magnetic arc extinguishing technology is effective as an extinguishing device for low-voltage direct current (DC) circuit breakers with a resistive load of ≤4 kW. The separation distance between the magnet and the electrical contact must be shortened to increase the magnetic arc extinguishing force. However, if the magnet is installed too close to the electrical contact points, the magnet is exposed to high temperatures due to the arc current generated when the load current is cut off and the magnetism is lost. To solve this problem, the effective magnetic flux density at the electrical contact can be maintained high by placing the arc extinguishing magnet in a tandem structure with the electrical contact point between them, and the proper separation distance between the contact points and the magnet can be maintained. In addition, an electric arc extinguishing technology that emits arc energy using a series circuit of diode and resistor is used to suppress the continuous arc voltage generated by the inductive load. For the proposed circuit breaker, the breaking characteristics are analyzed through the breaking test for the DC load of the 760 V level, the load power of 4 kW, and the time constant of 5 ms, and an appropriate arc extinguishing design guideline is proposed.

• 전기학회논문지
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• 제59권2호
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• pp.328-332
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• 2010

The SLF(Short Line Fault) breaking capability test for high voltage class $SF_6$ GCB(Gas Circuit Breaker) was conducted. Simplified LC resonant circuit test facility was used for SLF breaking test. During test, Test current was measured by Rogwski coil and arc voltage was measured by voltage divider. Arc conductance was calculated by using these test results before 200ns at current zero. Critical arc conductance value at rated voltage 145kV class is about 2.3mS regardless of breaking current magnitude and arc conductance value at rated voltage 170kV class is about 2.6mS.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.61-62
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• 2014

To evaluate anti-corrosion performance of high-frequency arc metal spray film in accordance with metal type and epoxy sealing coat application status, electrochemical impedance spectroscopy(EIS) method was conducted in this study. As a result, in case of applying Al-Mg alloy metal spray film, it showed the best polarization resistance. In case of applying epoxy sealing coat, it showed increased polarization resistance of arc metal spray film. Through this experiment, it is judged that Al-Mg alloy arc metal spray film with epoxy sealing coat can increase the biggest anti-corrosion performance of high-frequency arc metal spray film on steel.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.170-173
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• 2002

The object of this study is to investigate the effect of compounded welding through the AE (Acoustic Emission) characteristics on static tensile test. This study was carried out a SM 490A, high tension steel using the low hydrogen type E4316 of electronic shield metal arc welding and compound wire of $CO_2$gas arc welding. $CO_2$welding, weak in the intensity of HAZ (Heat Affected Zone), can be improved by being combined with coated arc welding, Coated arc welding, weak in the intensity of the bead, can be improved by being combined with $CO_2$welding. Especially, electronic coated arc welding and $CO_2$welding complement the mechanical intensity of HAZ and the bead with each other. So, compounded welding increases the intensity in the special parts and enhances the quality of goods.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.35-36
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• 2013

Electric arc furnace oxidizing slag from massively produced steel slag has been used in road bases and subbases, hot mix asphalt, and landfill. Electric arc furnace oxidizing slag contains iron (15%~30%) and has a high density of 3.0~3.7 ton/m3. Depending on the type and amount of concrete aggregates, the radiation-shielding characteristics can vary. Therefore, aggregates of electric arc furnace oxidizing slag can be considered for the production of radiation-shielding concrete. The experimental design of this study is experiments on Compressive strength experiments, X-ray irradiation experiments, and experiments related to the unit volume weight were carried out on hardened concrete. This experiment compared the performance evaluation of radiation shielding of concrete using electric arc furnace oxidizing slag.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2109-2111
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• 2005

The effect of arc like streamer discharge is investigated on the hydrogen generation in the plasma reactor with multineedle - plate electrode geometry and SDR (Plasma reactor using the surface discharge). An additive of the two type (the saw type and the pellet type) was placed under the water surface to investigate the effect of the water surface conditions. The experimental results are compared in case of the reactor with and without an additive on the water surface. The generation of arc streamer discharge is more powerful with increasing applied voltage in the saw type. The maximum hydrogen Production concentration is about 4300 ppm at 74W in the SDR with additive of the saw type. Also, the Energy yield of the SDR (28990 g/kWh, 4300ppm, 74W) is higher than of the multineedle - plate electrode geometry (20892g/kWh, 3300ppm, 77W).

• 한국화재소방학회논문지
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• 제27권2호
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• pp.1-5
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• 2013

본 논문은 사고전압 감지형의 아크차단 제어회로에 대한 연구로써, 전기사고 발생 시 선간전압의 순간적인 전압감쇠를 감지하여 기존 차단기를 동작시키는 전압감지형 전기화재 예방장치이다. 현재 저압배전 계통에 사용중인 누전차단기, 배선용차단기 그리고 RCD 등은 전기화재의 주요 요인인 아크사고에 대해 보호능력이 없는 것으로 분석된다. 본 논문에서는 이러한 문제점들을 개선하기위하여 이전의 전류감지에 의한 아크사고 차단방식이 아닌 사고발생 시 전압파형의 왜곡을 이용한 새로운 전압감지형 아크차단 제어회로를 개발하여 전기화재를 예방하고자 한다. 제안한 아크차단 제어회로는 소형 경량으로 제작되는 장점과 다양한 동작분석을 통하여 그 실용성을 검증하였다.

• 전기학회논문지
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• 제62권6호
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• pp.876-880
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• 2013

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The principal factor of the fire is electric arc or spark accompanied with such electric faults. Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB), that is, Residual Current Protective Devices (RCDs) used on low voltage distribution lines cut off earth leakage and overload, but the RCD can not cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied in low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To improve such problems, this paper studies on an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. The proposed voltage sensing type AFCI is an electrical fire prevention apparatus of new conception that operates a circuit breaker with sensing the instantaneous voltage drop of line voltage at electrical faults occurrence. The proposed AFCI is composed of control circuit topology using some semiconductor switching devices. Some experimental tests of the proposed AFCI confirm practicality and the validity of the analytical results.