• Proceedings of the KSME Conference
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• 2003.04a
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• pp.729-733
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• 2003

Hybrid RMU is a kind of power circuit breaker and protects electric devices from over-current. In this paper we built a dynamic model of RMU driving mechanism using ADAMS and performed a optimal design of several design parameters. Finally we developed a prototype of RMU driving mechanism through results of analysis and confirmed it to satisfy design requisitions.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.455-457
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• 2003

In the present IEC 60427(2000), reduced applied voltage can be used for synthetic short-circuit making current tests if the maximum pre-arcing time of the test circuit breaker is less than $1/{\omega}$. But in the near future IEC, only the making tests with full test voltage shall be allowed. To meet this trend, KERI is preparing synthetic making test facilities using step-up transformer, ITMC and plasma making switch. This paper presents analytical characteristics of KERI's synthetic short-circuit making test circuits. The results of this paper can be useful for effective and adequate tests.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.719-724
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• 2016

This paper describes the performance improvement of an inrush current limiter to prevent damage or malfunctions in power converters due to the inrush current. When the power converter of military radar is operated, the circuit breaker of the power converter is often activated because the overcurrent flows through the circuit breaker of the power converter. Therefore, this study performed a cause analysis of the problem, which is a larger current flow than the intended current(250A). The operation principle of an inrush current limiter and SCR (Silicon Controlled Rectifier) used in the inrush current limiter was analyzed. As a result, the overcurrent flow through the circuit breaker was found to be due to dv/dt triggering of SCR. Based on cause analysis, this paper proposes a technique by adding the resistor in front of the SCR to prevent an unnecessary inrush current. Finally, the effectiveness of the improvement was verified by measuring the output current in the inrush current limiter. The power converter equipped with the improved inrush current limiter operated for more than 1 year without the circuit breaker of the power converter being activated.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.6
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• pp.233-241
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• 2005

The present model of a SF6 arc accounts for the copper vapour contamination from the electrodes inside a Laval nozzle of a circuit breaker. Steady state simulations have been done for the arc with electrode gap of 60mm and DC electric current of 500A, 1000A and 1500A for both cases with and without copper contamination. The effects of electrode polarity are considered for the arc current of 1000A. It was found out that evaporation of copper from the anode results in a cooling of the arc in a region close to the electrodes. The electrical potential across the electrodes is not sensitive to the presence of copper vapour, typically less than $4\%$ difference. Transient analysis has been done in order to obtain the arc properties at current zero. The arc current is increased linearly from -1000 to 0A when the upstream electrode is cathode with constant dI/dt of $27.0A/{\mu}s$ (or decreased linearly from 1000 to 0A when upstream electrode is anode). It has been predicted that the presence of copper vapour reduces the interruption capability of the breaker.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.170-172
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• 1998

In the future, it is expected that a fault-current of 345kV power system is beyond 60kA and stability and reliability in transmission system will be more important. From these points of view, we needed a development of a circuit breaker having ability of breaking a large fault current, more than 60kA. This paper describe the specification and history of a development on 362kV 63kA 8000A GCB(Gas insulated Circuit Breaker) of which we completed a development. A development of this GCB will contribute to improve the technique to design and make GCB, and the stability and reliability of power system in our country.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.357-359
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• 2003

This paper is for the transient analysis of instant short-circuit test equipment according to the test of tripping limits and characteristics under IEC 60947-2. The in-rush current is harmful to almost equipments and the exact testing is not made because of it. LGIS has a instant short-circuit test equipment, but it is not suitable for carrying out instant short-circuit test on ELB(Earth Leakage Circuit breaker) by reason of that. Now, I am going to show a solution for that problem. After applying this method, manufacturer is going to acquire the exact testing result according to the IEC standard. Moreover, Testing laboratory will be trusted by clients.

• 전기의세계
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• v.25 no.4
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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.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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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.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.38-42
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• 2012

This paper describes electrical fire on residential environment such as apartment and detached house caused by defect of interior wiring. We carried out experimental study on short circuit characteristics by the interior wiring length. We were measured arc current, arc energy and interrupting time of earth leakage current circuit breaker(ELB), when an interior wiring break out short circuit in residential environment. From the experiment results, the longer of the interior wiring, the magnitude of arc current decreased and the interrupting time of ELB increased. When applied the A maker's ELB, the strength of arc current and interrupting time of ELB was 254 A and 245 ms respectively at 30 m interior wiring length. In 3 m interior wiring length, arc current and interrupting time was 716 A and 4.24 ms respectively. Arc energy was dependent on the magnitude of arc current and the interrupting time of ELB, the longer the interrupting time, arc energy increasing. In this paper, minimum arc energy was 277 J using C maker's ELB and 3 m interior wiring length(arc current 283 A, interrupting time of breaker 6.28 ms). Therefore in the residential environment, short circuit caused by defect of the interior wiring lead to electrical fire.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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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.