• 대한기계학회논문집
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• 제6권2호
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• pp.133-139
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• 1982

One of factors that affect combustion in the cylinder of the engine is to keep a greater energy in the ignition system to minimize pollutant emissions and to increase its performance of the low temperature. This paper reviews theoretically the state and input variables of the ignition system from the state transition equation. Effects on characteristics of the system such as primary current, secondary available voltage and spark duration by reducing the pre-resistance from 3.5 to 0 ohm in 12V system is experimentally investigated when the ignition coil has a primary resistance of 1.5 ohms ad the dwell angle of the breaker point is 43.2 degrees (0.75 radian). Advantages and limitations for using the low resistance of the primary circuit are also presented to optimize the performance of the ignition system with the breaker point.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1998년도 추계 학술논문발표회 논문집
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• pp.335-340
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• 1998

This paper presents a study on the electrical fire hazards of leakage current in a distribution circuit simulating a domestic circuit for low voltage. In this simulated circuits, total charges and energy of leakage current are calculated by a theoretical approach and compared with the results obtained from experiments, The approach and results become a cornerstone for studying and analyzing causes of electrical fires.

• 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.

• 전기의세계
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• 제28권7호
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• pp.49-55
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• 1979

본논문은 Thyristor를 이용하여 교류회로의 고장전류를 차단하는 기구에 대한 것이다. 즉 Thyristor 한류차단회로를 설정하고 게이트제어회로 과전류검출기를 설계하고 동작과정을 확인하였다. 결과에 있어서 (1) 고속차단이 가능하다(60Hz 교류에서 4ms이내) (2) 이 방식에 의하면 차단용량을 감소시킬 수 있다. (3) 적은 신호로 지체없이 동작한다. (4) 기계적부분이 없으므로 반영구시 수명을 가진다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.327-331
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• 2008

This paper dealt with high speed breaking method to parallel arcing in low-voltage systems. The proposed high speed breaking circuit consists of a Rogowski coil and an integrator, and operates with an earth leakage circuit breaker (ELCB). A parallel arcing state was simulated by a short circuit using stripped wires. In this test, we analyzed tripping characteristics of the circuit breaker by the length of wires from 5m to 30m. From the experimental results, we confirmed that the proposed method can break the parallel arcing within a few millisecond.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.56-62
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• 2010

본 논문에서는 IEC 60364에서 제시하고 있는 접지계통(TT접지계통, TN-S 접지계통 및 TN-C)의 누전차단기 동작특성 및 보호도체의 임피던스변화에 따른 Loop Impedance 특성분석을 실시하였다. 분석결과 Loop Impedance의 경우 저항성분과 인턱턴스성분에 영향을 받는 것으로 나타났다. 접지계통별 전류 전압특성은 TN-S 접지계통 및 TN-C 접지계통의 경우 사고전류가 높고 접촉전압이 낮은 특성을 나타낸 반면 TT 접지계통의 경우 사고전류는 낮고 접촉전압이 높게 나타남을 확인하였다.

• 한국화재소방학회논문지
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• 제17권2호
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• pp.1-5
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• 2003

현재 고감도의 누전차단기(RCD)와 배선용차단기(WCCB)및 퓨즈(Fuse)설치를 통하여 누전·단락사고와 과전류 발생시 차단기능을 부여함으로써, 전기화재의 발생을 억제하고 있으나, 매우 미흡한 실정이다. 특히 소손사고와 접속·접촉불량사고 및 순간단락사고 발생시는 구조적으로 차단이 불가능할 것으로 사료되며, 이에 대한 연구가 필요하다. 따라서 본 논문에서는 상기의 상황에 기초해서 가장 일반적으로 사용되고 있는 열동형 누전차단기(단락보호, 과부하 겸용)의 동작원리와 시험항목 및 기준분석을 통하여 문제점을 제시하고자 한다. 또한 저압 배선선로의 소손사고와 접속·접촉불량사고 및 순간단락사고 발생시 전등(R)부하 및 전동기(R-L)부하에 따른 누전차단기의 동작특성을 실제 실험을 통하여 검토하고자 한다.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.109-113
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• 2007

In this paper, an arc current controller was designed for the interruption of arc fault currents occurred in a low voltage network. Arc in an electrical network represents the characteristics of low current, high impedance, and high frequency. Conventional controllers do not have arc current interrupt functions. Thus, an arc current controller was designed for the interruption of arc fault currents.

• 조명전기설비학회논문지
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• 제28권12호
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• pp.124-129
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• 2014

This paper describes the analysis of the effect on personnel computer in case of turning off power supply of main breaker in general electrical installation. In order to analyze the effect on personnel computer in case of turning off the power supply of main breaker, the switching impulse generator has been designed and fabricated which makes it possible to evaluate the effect on electrical product by switching impulse. The switching impulse tests were carried out for personnel computer according to applied voltage and number of switching impulse. As a consequence, switching impulse had not a significant influence on personnel computer in this study. The varistor of power input section functions as a protection of switching impulse as well as lightning impulse. The results will be used to related organization, and electrical product manufacturer, and residents.

• 조명전기설비학회논문지
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• 제29권8호
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• pp.49-54
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• 2015

Molded Circucit Breaker(MCCB) is a most widely used device to protect loads from the over-current in low power level distribution system. When the MCCB interrupts the over-current, the arc discharge occurred between fixed contact and moving contact to create hot gas. By the Lorentz force due to arc current, the occurred arc is bent to the grids. The grids extend and cool and divide it for arc extinguish. In the majority cases, the MCCB protects loads by interrupting the over-current successfully but in some cases the re-ignition is occurred by hot-gas created during process of interruption. The re-ignition arises when the recovery voltage(RV) is more higher than the recovery strength between contacts and it leads to interruption fault. Therefore to find out the dielectric recovery characteristics of protecting device has a great importance for preventing interruption fault. In this paper, we studies measurement method of the dielectric recovery characteristics considering inherent attribute of the MCCB. To measure the dielectric recovery characteristic of MCCB, we makes an experiment circuit for applying the over-current and the randomly recovery voltage. The measurement methode to find out the dielectric recovery voltage of the MCCB was established and the result was based on experiment results.