• 한국안전학회지
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• 제11권3호
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• pp.89-96
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• 1996

This paper presents a study on the analysis and evaluation for ELF( Extremely Low Frequency) electric and magnetic fields under the transmission line according to the power system states. The power system states are classified into two types, normal state resulting from normal operation and alert state from outages. The current in a system is changed continually owing to the load fluctuations even in a normal operation. To calculate the current of the concerned line in a normal state, the system load level is devided into light, base and heavy load level. In case of contingency, an efficient algorithm based on matrix inversion lemma is developed to figure out the current changes. In order to analyze the variations of ELF field caused by the current fluctuations the electrostatic field approach which is far simpler than the electromagnetic field one based on Maxwell equation is introduced in this paper. The suggested method is applied to the IEEE 14 bus system to demonstrate the usefulness.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권4호
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• pp.473-477
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• 2013

The railway developed countries in Europe, Japan such as ERTMS Regional, FFB, COMBAT, it is the stage of development or testing the train control system for the signal system of branch interval of low density. Similar to the signal system used by the mainline and branch sections of low density domestic portions not suitable in terms of maintenance operational efficiency in accordance with the installation and operation in many cases. Therefore these low-density branch railway lines required that oriented train control system of wireless communication to improve the operation efficiency and line side equipment controlled on board the train. In this paper, We was published a route on setting is the operation of the new on-board oriented train control system for controlling a line converter of the train so that it is possible to improve the operational efficiency of the branch of the low density.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.459-464
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• 1996

The 3-D power distribution synthesis scheme was implemented in Totally Integrated Core Operation Monitoring System (TICOMS), which is under development as the next generation core monitoring system. The on-line 3-D core power distribution obtained from the measured fixed incore detector readings is used to construct the hot pin power as well as the core average axial power distribution. The core average axial power distribution and the hot pin power of TICOMS were compared with those of the current digital on-line core monitoring system, COLSS, which construct the core average axial power distribution and the pseudo hot pin power. The comparison shows that TICOMS results in the slightly more accurate core average axial power distribution and the less conservative hot pin power. Therefore, these results increased the core operating margins. In addition, the on-line 3-D power distribution is expected to be very useful for the core operation in the future.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1247-1252
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• 2004

ATC(Automatic Train Control) system employed in Bundang urban transit is operated in accordance with automatic blocking equipment. Using AF(Audio Frequency) track circuits installed at a block section, the block signal is automatically controlled and the safety of train operation is supported. In this paper, we investigate the operation mode of bundang urban transit and analyze the operation algorithm of ATC on-board system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 특별세미나.특별세션
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• pp.27-41
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• 2008

Construction of metro transportation infra is a large-scale project requiring tremendous financial resources. This study suggests operation method to use for rapid transit line existing infra such as Gyeongbu line and spare line capacity following second phase KTX construction. Reviewing various constraints of metro rapid transit operation, we found that the conditions for metro rapid transit operation are already satisfied in Daegu area, just like the case of Gyeongbu line in Seoul Metro area. Also, the evaluation of the economic feasibility of metro rapid transit operation in Daegu area shows that B/C is about 2.4, which implies that there is sufficient economic feasibility. According to the result of sensitivity analysis, the project is economically feasible unless the passenger demand decreases 15% and construction costs increases more than 70%. B/C is evaluated large because the utilization of already exiting infra lowers the initial cost. As one of mass transportation system of large capacity, metro rapid transit can generate significant spillover effect: It will strengthen competitiveness of metro area by connecting cities within the area and by extending one-day life zone of the area, to say nothing of the benefit of improving traffic condition. The construction of metro rapid transit network is necessary for the mass transportation system of Yeongnam area as well as Daegu area, and it may work as a starting point for uniting Daegu and Gyeongbuk and strengthening regional competitiveness.

• 대한전기학회논문지:전력기술부문A
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• 제52권3호
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• pp.165-172
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• 2003

This paper presents an operation scheme to enhance the power system security by applying FACTS on Power systems. Three main generic types of FACTS devices are suggested an illustrated. Flow congestions over lines have been solved by controlling active power of series-compensated FACTS devices and low voltages at buses have been solved by controlling reactive power of shunt-compensated FACTS devices. Especially, Especially, UPFC has been applied in both line congestion and low voltages. Two kinds of indices which indicate the power system security level related to line flow and bus voltage are utilized in this paper. They have been minimized to enhance the power system security level through the iterative method and the sensitivity vector of security index is derived to determine the direction to minimum. The proposed algorithm has been tested on the IEEE 57-bus system with FACTS devices in a normal condition and a line-faulted contingency.

• 한국전기전자재료학회논문지
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• 제23권2호
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• pp.148-152
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• 2010

The superconducting fault current limiter (SFCL) applied into the neural line of a power system, which can limit the unsymmetrical fault current from the single-line ground fault or the double-line ground fault, was reported to be the effective application location of the SFCL in a power system. However, the limiting operation for the symmetrical fault current like the triple line-ground fault is not effective because of properties of the balanced three-phase system. In this paper, the limiting method of the symmetrical fault current in a power system with a SFCL applied into neutral line was suggested. Through the short-circuit experiments of the three-phase fault types for the suggested method, the fault current limiting and recovery characteristics of the SFCL in the neutral line were analyzed and the effectiveness of the suggested method was described.

• 한국철도학회논문집
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• 제12권5호
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• pp.623-630
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• 2009

한국철도시스템은 일반열차(각종 여객열차, 화물열차), 고속열차(KTX), 광역전철 급행열차(EMU) 등 다양한 종류의 열차가 사용되는 대중교통시스템이다. 철도시스템의 특징은 공시된 시간표에 의하여 열차가 운행되며, 안전, 정확, 신속, 쾌적한 서비스를 제곱한다는 것이다. 본 연구의 목적은 기존 열차의 속도향상과 다양화를 반영하여 보다 현실적인 선로용량 산정방식을 제시하고 검증하는 것이다. 본 논문은 이론식에 근거한 선로용량과 철도운영기관의 실용용량과의 차이를 최소화 하는데 역점을 두었다. 이를 위해 노선선형에 대한 TPS 시행, 운전방식과 열차제어방식 및 신호시스템 등을 고려한 새로운 철도용량 개념을 도입하였다. 실용Dia예시를 통해 새로운 선로용량산정방식의 결과를 검증하였다.

• 조명전기설비학회논문지
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• 제19권8호
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• pp.40-47
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• 2005

본 논문에서는 대표적인 유연송전기기인 UPFC(Unified Power flow Controller)를 대상으로 UPFC 운전이 송전계통에 미치는 영향을 분석하여 송전선 보호를 위한 전류차동방식을 개선하였다. UPFC가 포함된 송전계통을 대상으로 UPFC의 여러 운전 모드에 대한 동적 해석을 통하여 UPFC 동적 특성이 송전선 보호를 위한 전류차동 계전방식에 미치는 영향을 분석하였다. 이를 바탕으로 UPFC가 운전하고 있을 때의 고장을 효과적으로 판단할 수 있도록 개선된 전류차동 보호방법을 제안하였고, 제안된 방법의 타당성을 시뮬레이션으로 입증하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제19권4호
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• pp.47-60
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• 2013

Purpose: This study examines construction core plans for the users of vertical-typed general hospitals to effectivly use the flow line. Methods: The study sampled representative 9 hospitals, calculated the depth value through Convex Map of Space Syntax and Justified Graph according to the determination of form of construction cire, and analyzed its functional connectivity. Results: The analysis of the connectivity between operation core part and emergency part of core space with high importance in the hospitals showed that the types of hospital and hospital have the lowest depth value in the spatial phase diagram, where central treatment part and outpatient part are arranged well vertically. Elevators for patients at these hospitals are close to operation and emergency parts actually separated from the elevators for passengers. For shortening of flow line of patients and private movement environment, however, it is desirable to arrange the elevators for patients to be adjacent to the operation parts and to arrange the emergent patient entrances more effectively to separate them from the flow line of visitors and guardians. Implications: Consideration should be taken into account for the effective flow line design. This study hopefully may serve as a stepping stone for the standard design of horizontal/vertical flow line.