• 한국화재소방학회논문지
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• 제34권4호
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• pp.1-6
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• 2020

본 논문은 직렬 아크 방전이 진행될 때의 전압 및 전류 파형을 실시간 측정하였다. 아크 방전의 방사 패턴을 분석한 결과 간헐적인 방전, 아크의 성장, 발열부의 생성, 플룸의 발생, 적열부 형성 순서로 진행되는 것을 알 수 있었다. 직렬 아크 방진이 진행될 때 전류 및 전압 파형은 정현파와 같은 주기성을 나타냈다. 그리고 + 파형에서 - 파형으로 바뀔 때와 - 파형에서 + 파형으로 바뀔 때 파형의 재기전압이 발생하는 것이 확인되었다. 방전이 진행될 때 1 s 동안에 발생하는 열량은 약 0.317 mJ이고, 600 s 동안에 약 190 mJ의 열이 발생하는 것으로 해석되었다. 그리고 단락 지속시간은 약 1.66 ms인 것으로 해석되었으며, 동일한 주기에서 전압 파형은 49.9 V까지 전위가 상승하는 것을 알 수 있었다. 또한, 방전이 진행될 때 전류의 실효치는 약 1.72 A이고, 최대치는 약 2.53 A로 분석되었다. 그리고 전압의 실효치는 약 42.8 V로 계산되었고, 최대치는 약 208 V로 측정되었다.

• 한국전기전자재료학회논문지
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• 제25권2호
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• pp.147-152
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• 2012

This paper dealt with the frequency component analysis of acoustic signals produced by corona and series-arc discharges as a diagnostic technique for closed-switchboards. Corona and series-arc discharge were simulated by a needle-plane electrode and an arc generator specified in UL1699, respectively. Acoustic signal was detected by a wideband acoustic sensor with a frequency bandwidth of 4 Hz~100 kHz (-3 dB). We analyzed frequency spectrums of the acoustic signals detected in various discharge conditions. The results showed that acoustic signals mainly exist in ranges from 30 kHz to 60 kHz. From the experimental results, an acoustic detection system which consists of a constant current power supply (CCP), a low noise amplifier (LNA) and a band pass filter was designed and fabricated. The CCP separates the signal component from the DC source of acoustic sensor, and the LNA has a gain of 40 dB in ranges of 280 Hz~320 kHz. The high and the low cut-off frequency are 30 kHz and 60 kHz, respectively. We could detect corona and series-arc discharges without any interference by the acoustic detection system, and the best frequency is considered in ranges of 30 kHz~60 kHz.

• Carbon letters
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• 제3권3호
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• pp.142-145
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• 2002

Multiwall carbon nanotubes (MWNT) were produced using the arc-discharge graphite evaporation technique. Composite films were developed using MWNT dispersed in polystirol polymer. In the present work, various properties of the polymeric thin film containing carbon nanotubes were investigated by optical absorption, electrical resistivity and the same have been discussed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1283-1286
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• 2005

Arc Fault Current is an electric discharge which is occurred in two opposite electrode. In this paper, arc current control algorithm is designed for the interruption of arc fault current which is occurred in the local electric network. This arc is one of the main causes of electric fire. Arc fault in electrical network has the characteristics of low current, high impedance and high frequency. Conventional arc current controller does not have the arc current interrupt function. Hence, Controller of arc current is designed for the interruption of arc fault current which has the modified arc characteristics.

• Tribology and Lubricants
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• 제38권6호
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• pp.274-280
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• 2022

There is a problem that semiconductor probe pin has a short lifespan. In order to solve this problem, Ti having excellent conductivity was doped to tetrahedral amorphous carbon (ta-C) having excellent hardness and abrasion resistance. This experiment was planned through the Taguchi robust design to determine the effect of the control factor of the ta-C:Ti coating film. The effect and contribution of control factors such as Unbalanced Magnetron Sputter(UBM) discharge current, arc discharge current, temperature, and bias voltage on ta-C:Ti characteristics were analyzed from the perspective of electrical and mechanical characteristics. The UBM discharge current was set to 4, 6, and 8 A. The main control factor of thickness and resistance is the UBM discharge current, and the thickness increased and the resistance decreased as the current increased. The decrease in resistance is due to the increase in the Ti content of the ta-C:Ti coating film. The arc discharge current was set to 60, 80, and 100 A. The main control factor of hardness and wear is the arc discharge current, and as the current rises, the hardness increases and the wear area decreases. This is due to the increased ta-C content of the ta-C:Ti coating film. Since resistance and wear are important for Probe Pin, the optimal level is set from the perspective of resistance and wear and a confirmation experiment is conducted.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.918-921
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• 1992

A basic study on the discharge phenomenum of rod-to-rod microgap in the deionized water has been investigated with emphasis on the microgap spacing. The I-V charateristics for the case of ac and dc applied voltages had 3 different regions, a low conduction ohmic region, a medium conduction corona discharge region, and a high conduction arc discharge region. The corona discharge in the deionized water for the case of ac and de applied voltages had no different from the those in the air. But the arc discharge in the water occurred pulsative with sound which, however it is not clear, would be encounted due to the influences from the low temperature of the ambient water, vast of electrolytic generated electronegative gases(e.g. $O_2$, OH, O) and water molecules($H_2O$), and the space charge effects near the rod in the microgap from the ions of $H^+$, $OH^-$, $O_2^-$, etc, whose mobilities in the water are originally very low.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1769-1770
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• 2006

Arc Fault is an electric discharge which is occurred in two opposite electrode. In this paper, AFCI(arc fault circuit interrupter) is designed for the interruption of arc fault current which is occurred in the local electric network. This arc is one of the main causes of electric fire. Arc fault in electrical network has the characteristics of low current, high impedance and high frequency. Conventional interrupter does not have the arc current interrupt function. Hence, Arc fault circuit interrupter controller is designed for the interruption of arc fault current which has the modified arc characteristics.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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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.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권1호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.699-701
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• 2003

This paper compare the Townsend theory with the Molten metal bridge theory of Holm for the arc discharge at opening contacts. And we measured the arc voltage at opening contacts of the 3 types arc extinction unit used in DC magnetic contactor. So, we sure that the molten metal bridge contributes to form the arc. By the experiment of the 3 types arc extinction unit, we know that the magnetic force acting on the arc doesn't effect forming arc but contribut the arc extinction.