• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.373-375
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• 2008

In this paper the arc behavior in spiral type vacuum interrupter was analyzed by observing taken photographs from high-speed digital camera(10000frame/second) and current-voltage waveform from oscilloscope. As a result, the influence of twisting angle between contacts on arc behavior could be analyzed by matching and comparing arc voltage and photographs simultaneously.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.959-964
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• 2012

Internal pressure of vacuum interrupter (VI) is one of the most important parameters in VI operation and may increase due to the outgassing from the materials inside VI or gas permeation through metal flange or ceramic vessel. The increase of the pressure above a certain level leads to the failures of switching or insulation. Therefore, an effective pressure check of VI is essential and an analysis of partial discharge (PD) characteristics is an effective monitoring method to identify the degree of the internal pressure of VI. This paper introduces a research work on monitoring the internal pressure of VI by analyzing PDs which were measured using a capacitive PD coupler. The authors have developed cost effective capacitive coupler based on the ceramic material that has an excellent insulation properties and the main component of the capacitive coupler is made by SrTiO3. Detectable internal pressure range and distinguishability of the internal pressure of VI were investigated. From the PD tests results, the internal pressure range, from $10^{-2}$ torr to 500 torr, can be monitored by PD measurements using the capacitive coupler and PD inception voltage (PDIV) follows the Paschen's law. In addition, rise time of PD pulse at 13.2kV decreases with the increase of the internal pressure of VI.

• 한국전기전자재료학회논문지
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• 제16권10호
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• pp.952-957
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• 2003

The purpose of this paper is analyses about in 12kV/50kA vacuum interrupter with an axial magnetic field type electrode system through the studies of electromagnetic phenomena. Vacuum interrupter is important in electric safety part. In this paper, we performed analysis of electric field, magnetic field, current density in AMF electrode using the Maxwell 3D simulation. The current distribution and magnetic field in simple models are analyzed to verify its efficiency and accuracy. In addition the validity of FEM is confirmed by performing the analyses of distribution in current density and magnetic flux density.

• Progress in Superconductivity
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• 제12권1호
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• pp.23-26
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• 2010

A double line commutation (DLC) type SFCL with first peak limiting function has been proposed for ideal fault current limiting operation. Very fast switching (commutation) without any arc or high voltage problems for any kind of switching device is needed for the first peak current limiting. We've tried to find suitable conditions for a successful switching of a Vacuum Interrupter (VI) with HTS elements as a Peak Current limiting Resistance (PCR).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2500-2505
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• 2007

The vacuum interrupter (VI) is used for medium-voltage switching circuits due to its abilities and advantages as a compact and 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 electromagnetic behaviors of high-current vacuum arcs for two different types of AMF 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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2515-2518
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• 2008

The vacuum interrupter (VI) is widely used in medium-voltage switching circuits due to its abilities and advantages as an environmental friendly circuit breaker. An understanding of the vacuum arc flow phenomena is very important for improving 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 the thermal flow fields, simultaneously. In this study, we have investigated arc plasma constriction phenomena and an effect of AMF on the arc plasma with the high-current vacuum arcs for the cup-type AMF electrode by using a commercial finite element analysis (FEA) package, ANSYS. The simulation results applied with various AMFs and constant Joule heat generation show that strong axial magnetic field (AMF) permits the arc to be maintained in a diffused mode to a high-current vacuum arc. However, further studies are required on the two-way coupling method and radiation model for arc plasma in order to accomplish the advanced analysis method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1863-1865
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• 2004

As rise the demands for the protcetion of environment and the compactness of equipments, the movement brisks for replacing the circuit breaker of GIS(Gas Insulated Switchgear) to VI(Vacuum Interrupter). For these reason an increase in the interruption capability of VI is required. To satisfy these requirement, the academic and industrial worlds have been studying extensively for AMF(Axial Magnetic Field) contact, which is effective in interrupting large current over tens of kA, and introduced many kind of AMF contacts. However there are little effort to compare these contacts comprehensively, so it is difficult to choose most suitable shape for user's needs. In this paper, focusing unipolar type contact among various type of AMF contacts, we performed magnetic field analysis for several models designed in same dimension and compared the result and characteristics of each model in order to help deciding the direction for developing profitable VIs for interrupting large current.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권2호
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• pp.141-148
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• 2015

본 연구에서는 진공 차단기(Vacuum circuit breaker)의 동적 특성을 모사하기 위해 리커다인을 이용한 다물체 동역학 해석 모델이 개발 되었다. 진공 차단기는 VI(Vacuum interrupter)를 포함한 3 개의 주회로 부와, 구동 메커니즘을 포함한 기구부로 구성된다. 이 해석적 모델의 검증을 위해, 해석 결과와 실측을 통한 실험적 결과를 비교 하였다. 일반적으로, 원활한 사고 전류 차단을 위해서는 0.9~1.1m/s 의 차단속도(Opening velocity)가 필요하다. 차단 속도의 향상을 위해, 다구찌 기법을 이용하여 진공 차단기의 설계 변수 최적화를 수행하였다. 또한 향상된 차단기의 동적 특성을 검증하기 위해, 해석 결과와 개선된 샘플의 실험적 결과를 비교 분석 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.247-248
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• 2008

This paper describes the influence of shield(Arc shield) on the electric fields in a vacuum interrupter(VI). The equipotential line and electric field in a VI are analysed by a finite element method at various shield length. in result, The electric potentials of Arc shield edge was increased because the length too short or long approach the source. it confirmed that equipotential line was influenced that shape and length by end shield. finally this pater proposed to optimal length and shape by arc shield.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.184-190
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• 2009

One of the purposes of arc control is to change its state to the diffuse state before current zero as soon as possible. This can provide optimal conditions for full extinction of arc by minimizing the quantity of residual plasma between contacts near current zero. TRV(transient recovery voltage) occurs at current zero at the same time with current interruption. If there is substantial residual plasma near current zero it can cause 'post arc current' by the interaction of its conductance with TRV. In this paper, arc control ability as a function of configuration of spiral type VI contacts was compared on the criteria of the time taken for arc to reach to the diffuse state.