• 조명전기설비학회논문지
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• 제24권12호
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• pp.78-83
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• 2010

The domestic 30AFs that are currently being produced show many problems due to different instantaneous trip characteristics in case of short-circuit. The troubles may cause explosion by excessive short-circuit capacities and arc emission, which results in a wide range of blackout. The function and safety of the low voltage circuit breakers installed before the end load are very important. This paper presents an idea on the safety improvement of the low voltage circuit-breakers through the analysis of instantaneous trip characteristics of domestic 30AF circuit-breakers.

• 전기학회논문지
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• 제61권6호
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• pp.905-909
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• 2012

Recent WTO/TBT agreement was adopted by the IEC domestic. For this reason, low voltage electrical equipment was many Confusion arises. Low voltage circuit was also one of these. The case of low voltage circuit, existing domestic circuit breakers and circuit breakers IEC curve differs from the behavior of each other. If low voltage circuit breaker wrong facility, circuit breaker malfunction may occur due to the large property damage. In this paper, to solve these problems domestic circuit breakers and circuit breaker operation IEC curves were analyzed. And, through experiments suggested compatible breaker way.

• 전기학회논문지
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• 제56권9호
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• pp.1566-1570
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• 2007

[ $SF_6$ ] gas circuit breakers are widely used for short circuit current interruption in EHV(Extra High Voltage) or UHV(Ultra High Voltage) power systems. To develop $SF_6$ gas circuit breakers, the arc resistance value is necessary to compare experimental results to numerical ones. The arc resistance value can be obtained from a breaking test with a $SF_6$ gas circuit breaker. The direct testing or synthetic testing facility is widely used to verify the breaking ability for $SF_6$ gas circuit breakers. We employed the simplified synthetic testing facility to test a $SF_6$ gas circuit breaker prototype. The arc resistance characteristic was measured and calculated under the various experimental conditions. This arc resistance value can be used for verifying the numerical results from arc simulation in a circuit breakers.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.364-367
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• 2009

현재 국내에서 제조되는 저압 30AF(Ampere Frame) 소형 차단기의 경우 선로 단락사고 시 특성에 따라 순시 (Instantaneous) 동작이 다르게 반응함으로써 정전범위 확대, 정격단락차단용량(Rated short-circuit breaking capacities) 초과로 인한 폭발 및 Trip시 Arc방출 등 많은 문제점을 보이고 있다. 최종부하의 전단에 설치되는 저압차단기(Low voltage circuit-breakers)는 그 기능 및 역할이 큰 만큼 안전성을 중대시키는 것이 매우 중요하다. 본 논문은 국내에서 제조되는 30AF 소형 차단기의 사고유형과 제조사별 순시 Trip 동작속도의 시험 data를 확보하여 이를 분석하였다. 이는 향후 저압차단기의 안전에 관한 규격개정에 활용될 수 있을 것으로 사료된다.

• 한국안전학회지
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• 제37권6호
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• pp.1-8
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• 2022

This study analyzed the characteristics of insulation resistance and operating time based on an accelerated degradation test of a low-voltage circuit breaker. The experimental sample used a molded case circuit breaker (MCCB) and an earth leakage circuit breaker (ELCB). After measuring the insulation resistance of the circuit breakers, the leakage current was affected by an external rather than an internal structure. Furthermore, the insulation resistance of the circuit breakers with accelerated degradation was measured using a Megger insulation tester. In the accelerated degradation test, aging times of five, ten, 15, and 20 years were applied according to a temperature derived using the Arrhenius equation. Circuit breakers with an equivalent life of ten, 15, and 20 years had increased insulation resistance compared to those with less degradation time. In particular, the circuit breaker with an equivalent life of ten years had the highest insulation resistance. Component analysis of the circuit breaker manufactured through an accelerated degradation test confirmed that the timing of the increase in insulation resistance and the time of additive loss were the same. Finally, after analyzing the operating time of the circuit breakers with degradation, it was confirmed that the MCCB did not change, but the ELCB breaker failed.

• 전력전자학회논문지
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• 제25권6호
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• pp.503-510
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• 2020

The importance of DC breakers as key protection equipment is increasing in accordance with growing concerns on MVDC distribution network systems without DC/AC conversion. Different from the situation in AC systems, no natural zero-crossing point exists in DC systems. Thus, DC breaker technology is more difficult than AC breaker technology. The solutions for DC breakers can be divided into three types: mechanical, power electronics, and hybrid. In this study, the operating principles of several topologies of hybrid circuit breakers and that of the proposed DC breaker are analyzed and simulated by sorting two types. The breakers are compared in terms of the type and number of semiconductors, volume, power loss, auxiliary components, isolation, and other aspects. The advantages and disadvantages of the breakers are also analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.926-928
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• 2002

Much progress has been made during the past two decades in numerical analysis of electromagnetic forces in molded case circuit breakers (MCCB) for increasing arc voltage due to the change of the configuration of arc chute and fixed conductor. A review on this topic is given. which mainly covers the past research activities associated with that of our company.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.125-127
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• 2000

Multiple faults are hard to diagnose correctly because the operation of circuit breakers tripped by former fault changes the topology of power systems. The information including operating time of actuated relays and tripped circuit breakers is used for considering changes of the network topology in fault section diagnosis. This paper presents a method for fault section diagnosis using a set of matrices which represent changes of the network topology due to operation of circuit breakers. The proposed method uses fuzzy relation to cope with the unavoidable uncertainties imposed on fault section diagnosis of power systems. The inference executed by the proposed matrices provides the fault section candidates in the form of a matrix made up of the degree of membership. Experimental studies for real power systems reveal usefulness of the proposed technique to diagnose multiple faults.

• 조명전기설비학회논문지
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• 제20권2호
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• pp.68-74
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• 2006

고조파 전류에 의한 배선용 차단기 오동작 및 원인불명 동작이 보고되고 있으나 고조파 전류에 의한 배선용 차단기 동작을 설명할 수 있는 자료가 없는 실정이다. 본 논문에서는 네 가지 형태의 배선용 차단기(열동식, 열동 전자식, 완전 전자식 및 전자식)에 대해 고조파 전류의 영향을 시험하였다. 실험 결과 정격전류 이하의 고조파가 포함된 시험 전류에서는 어떤 종류의 배선용 차단기에서도 오동작은 발생하지 않았다. 그리고 다양한 고조파 부하 조건에서 열동식과 열동 전자식의 경우 제조사의 동작 시간에 별다른 영향을 보이지 않았다. 그러나 완전 전자식 차단기는 과부하 조건에서 고조파 전류가 증가할 수 록 동작 시간이 점차 둔화되었고 이는 케이블 과열을 야기할 수 있을 것이다. 따라서 고조파 전류가 심한 곳에서는 완전 전자식 배선용 차단기의 사용을 피해야 할 것이다.

• 전기의세계
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• 제25권4호
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• pp.59-62
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• 1976

This study on the characteristics of the leakage circuit breakers handles the rolls of each itemized parts of the mentioned apparatus and their influence in determining of the characteristic curve of leakage circuit breaker. Furthermore the differential current transforms in the mentioned apparatus for detecting the fault is handled as a heavy point.