• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.6-8
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• 2001

차단기 내에 위치하는 이동부에서 작용하는 힘은 외부 조작력 외에도 여러 가지가 존재하며 이들 힘의 상호작용으로 인해 이동부의 스트로크 곡선이 결정된다. 또한, 이 힘들에 따라 차단기에서의 아크 소호시간, 차단기의 성능 등이 영향을 받으므로 이동부에서 작용하는 힘들의 해석이 필요하다. 이 힘들은 유체의 밀도와 압력, 이동부의 기계적 구조 등을 고려하여 해석이 되며, 이 힘들을 해석함으로써 결과적으로는 차단기의 동작특성을 파악할 수 있다. 본 논문에서는 이러한 힘들을 정의하고 이들 각각에 대하여 해석한다. 이동부에서 작용하는 힘들을 해석하기 위해서 먼저 이동부에서의 운동방정식을 세우고 이를 시뮬레이션하여 스트로크 곡선과 이동부에서의 힘들을 얻는다. 이렇게 얻어진 결과를 실험 값과 비교하고 이동부에서 작용하는 힘들에 대해 논의한다.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.88-92
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• 2017

As the considerable request of the fast and accurate way of the selection of circuit breaker is increased, we introduce the development of software of circuit breaker selection for the marine use. Originally, the selection of circuit breaker has been carried out by manual in the marine project. It is not the easy work to select the proper type of circuit breaker to check the time-current characteristic curves of each type of circuit breakers for the various type of loads. In this regards, we developed the software to select the proper type of circuit breaker to confirm fast and accurately. And, we introduce the course of the development of the software for the selection of circuit breaker.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.768-776
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• 2021

Current protection-coordination methods use the reverse time characteristics of the T-C curve, which is not effective for a LVDC distribution system because the protective operation time of converters and DC circuit breakers is much faster than AC protection devices. Therefore, an algorithm is proposed for fault-section isolation using the fault current slope to minimize the blackout region and coordinate between converters and protection devices in a rapid and accurate manner. The method deals with the slope characteristics of a fault current, which may depend on the fault location in an LVDC distribution system. Thus, an LVDC distribution system can be operated in a stable manner by isolating the fault section selectively before the shutdown of the main converter using slope characteristics, which change in proportion to the line impedance and fault location. A 1.5-kV LVDC distribution system was modeled to verify the effectiveness of the proposed algorithm using PSCAD/EMTDC. The system is composed of a distribution substation, LVDC converter, and distribution lines. The simulation results confirm that the proposed algorithm is a useful tool for minimizing the fault section in an LVDC distribution system.