• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1028-1029
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• 2015

본 연구에서는 대전류 구간에서의 아크해석 결과를 이용하여 SLF 차단성능을 예측하기 위하여 과도회복전압 상승률에 따라 전류영점 후 수~수백 마이크로초 동안 $SF_6$ 아크현상 이력과 영점후전류를 계산하여 대전류 구간 마지막 시점에서의 10,000K 이하의 가느다란 잔류아크가 완전히 소호될지 아니면 아크가 다시 재발호될지 판단하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.186-188
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• 2001

Recently, the vacuum interrupters have been most widely used in medium voltage level. In the vacuum circuit breaker the most influential part is vacuum interrupter. By performing the precise electromagnetic analysis of the interrupter, we increase the capability of large current interruption. In this paper, diffuse arc and constricted arc are modeled to perform 3D electromagnetic analysis, and also flux distributions and electromagnetic force is calculated at the contacts' separation. It is expected these results will be used importantly in developing the new vacuum interrupters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1888-1891
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• 1996

Recently, FLIC(Fluid In Cell) method has been widely used for the compressible. flow computation. A program which adopts the FLIC method and can analyze the flow conditions with arc in the interrupter was developed in our team. It was applied to the 800kV class gab circuit breaker for flow conditions with arc, and the results are presented and discussed in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2221-2223
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• 1999

Axial magnetic field($B_z$) generated by special electrode construction in vacuum interrupters(Vl) is used to extinguish electric plasma arcs because that restrains this form expending. So VI applied axial magnetic field has more interruption capacity as compared with other VI. Also, the profile of toroidal field($B_{\theta}$) generated by $B_z$, is important to VI design. In this study, it was represented that the behavior of vacuum arc. In addition, The relationship between $B_z$ and $B_{\theta}$ was represented by using Dynamo theory. I hope that this study will be a good data in design of vacuum interrupters.

• 전자공학회논문지SC
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• 제44권1호
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• pp.12-18
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• 2007

본 연구에서 설계한 AFCI는 Arc 고장 차단기로서 종속된 전기 배선상의 노화, 절연 및 배선 파괴, 연결 고장, 절연과 배선에 과도한 기계적 손상으로 인한 아크고장을 검출하여 차단하는 기능을 가지고 있으며 기존 차단기가 가지고 있던 과전류에 의한 바이메탈의 만곡 특성에 의한 동작으로 차단하는 방식은 차단에 긴 시간이 걸리나 설계한 AFCI는 전자방식으로서 과부하, 과전류에 의한 기계적 , 전기적인 스트레스를 검출하여 차단하는 기능을 가진 제품으로 차단시간이 100% 이상 단축되어 전기 화재의 발생률을 낮추도록 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.96-99
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• 2005

In this study, we build system and techniques of evaluating the interruption performance of the GCB with experimental method. We constructed a simplified synthetic test circuit of which ability is up to 245kV, 50kA BTF test. And We composed a model test circuit breaker with puffer assisted self blasting type GCB. With this circuit breaker, we carried out the experiment of no load and SLF90. During the tests, we measured the several factors such as stroke, pressure, arc temperature, the voltage and current near the current zero and dI/dt, dV/dt. Arc conductivity before 200ns before current zero which is one of the indexes of the thermal recovery of a GCB was measured. With these kinds of measurement, we could estimate the performance of a GCB fundamentally. Futhermore these results were used to adjust the arc modeling with CFD(computational fluid dynamics) and we could increase the plausibility of the analytical method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권4호
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• pp.165-172
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• 2003

Low voltage circuit breakers are widely used in power distribution systems to interrupt fault current rapidly and to assure the reliability of the power supply. This paper is focused on understanding the interrupting capability, more specifically of the contacts and the arc runner, based on the shape of the contact system in the current molded case circuit breaker (hereafter MCCB). Moreover, in order to improve the interrupting capability of the circuit breaker, the estimation and analysis of the interrupting capability, based on the 3-D magnetic flux analysis, were developed. Furthermore, this paper also presents results of the estimation and analysis of the interrupting capability when applied to different model breakers. In addition, this paper analyzes the efficiency of the interrupting tests by forming false current paths consisting of a three-division cascade arc runner in the contact system. With regards to the interrupting test, there is a need to assure that the optimum design required to analyze the electromagnetic forces of the contact system generated by the current and flux density be present. Based on the results of this study, this paper presents both computational analysis and test results for the newly developed MCCB 460V/225A/50㎄ contact system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1559-1561
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• 1994

At present, the principle of puffer action in high current interruption is adopted in almost of the EHV(Extra High Voltage) and UHV(Ultra High Voltage) GCB(Gas Circuit Breakers). The thermal interruption capability of these GCBs critically depends on the pressure rise in the puffer cylinder at current zero. The pressure rise in the puffer cylinder depends on the puffer cylinder volume, flow passage and leakage area in the interrupter, stroke curve etc. Recently commercial CFD(Computational Fluid Dynamics ) packages have been widely adopted to calculate the pressure distribution in the interrupter. However, there are still several problems with it, e.g. very expensive price, moving boundary problem, computation time, difficulty in using the package etc. Thus, the calculation of the puffer cylinder pressure in simple and relatively correct method is essential in early stage of GCB design. In these paper, the model ing technique and computed results for EHV class GCB (HICO, 145kV 40kA and 362kV 40kA GCB) are presented and compared with available measured results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.152-157
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• 2005

Recently, higher speeds have been promoted in old overhead-lines. For high-speed operation in electric railways, increasing contact loss of the pantograph is one of the most important subjects. The contact loss causes power interruption and increases wear of contact strips and contact wires. In order to investigate the causes of contact loss and to work out effective improvement methods, theoretical analyses, experiments have been carried out. First of all, the wave propagating velocity (phase velocity) and characteristics of contact wire are one of the important indices for the current collecting performance. In this paper, mathematical formula arc derived for the prediction of the traveling wave velocity. The measured values in the experiment agree well with the theoretical predictions.

• 전기학회논문지
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• 제62권2호
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• pp.190-195
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• 2013

Vacuum circuit breaker(VCB) has been widely used for interruption of load current and fault current for high voltage motor in the industrial field. Its arc extinguishing capability is excellent compared to other breakers. But it has the potential to cause multi reignition surge by high extinguishing capability. Surge voltage is generated by the opening and closing of VCB. Multi reignition surge of VCB is steep-fronted waveform. It may have a detrimental effect on the motor winding insulation. So, most of users install a protection device to limit steep-front waveform at the motor terminal or breaker side. So, most of users install a protection device at the motor terminal or breaker side. This protective device is surge absorber(SA) such as ZnO and RC type. In this study, we analyzed whether there is any effect when two type SA is applied to the VCB multi reignition surge. We confirmed that ZnO SA is slightly more effective than RC SA for reduction of multi reignition surge.