• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.883-887
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• 2016

The power supply system in Korean electrified railway has adopted AT feeding. If a fault occurs in some substation for any reason, the vicinity substation must feed electric power on the outage substation through catenary. So, the feeding distance grows twice of the normal state at extended feeding condition. If substation's feeding distance is longer than normal condition, the catenary impedance and train to supply electric power from the substation. Therefore, the severe voltage drop can occur and power supply shall be not allowed. This paper presents the model of compensator against voltage drop using multi-port network algorithm. Whole traction power supply system can be analyzed with this model. Computer simulation including this model is performed based on real train schedule and increased schedule in case studies.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.145-155
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• 2006

High level of reliability in facility operation is specifically required these days. The goal of this study is to secure a methodology for reliability analysis of hydro-power plant so that an appropriate decision for operation and investment can be made. Fault tree analysis of water supply system within hydro-power plant has been performed in this study. We briefly examined the electric power generation facility and water supply system. We then developed fault tree for the water supply system based on failure modes and effects analysis. We conclude this study and provided future research areas.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.101-107
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• 2018

In wireless sensor network technology, which has been applied to various fields, the power supply and the power management of sensors are the most important issues. For this reason, a new concept of power supply and power management device is required. In this paper, we developed an autonomous independent power supply system that supplies the stable power to a sensor node without an additional external input by applying the energy harvesting technology using the electromagnetic induction principle by utilizing the current flowing in the transmission line. The proposed autonomous independent power supply system consists of a power supply using Power CT and a power management system including a charging circuit. The power management device uses a voltage limiter circuit and a monitoring circuit of charging voltage and current to ensure the safety of charging of the battery. In order to verify the performance of the proposed system, we applied it to the SVL diagnostic system and confirmed that it operates stably.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.135-144
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• 2006

The significance of hydro-power plant is increasing in its public roles such as flood control and water supply as well as electric power production. Even if high level of reliability in facility operation is required, no specific reliability research has been made. This specifically stems from the lack of technology and research investments. The eventual goal of this study is to secure a methodology for reliability analysis of hydro-power plant so that an appropriate decision for operation and investment can be made. Specific effort was put to develop a reliability model for water supply system within hydro-power plant. For this study, we briefly examined the overview of the hydro-power plant including the electric power generation facility system. We then discussed the facility reliability analysis methodology for hydro-power plant. Based on rigorous examination of the water supply system and components roles, we drew major failure modes for each component and examined their effects.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.735-737
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• 2004

This paper proposes a method of fault diagnostics on switching mode power supply. When the error of switching mode power supply cannot be found when the conventional diagnostics is performed, this proposed method first performs diagnosis on the switching mode power supply strictly to judge the operating condition. This method analyzes the PWM wave which depends on the load change, to make sure the feedback control of the power supply to diagnosis the operation of the power supply system.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.216-218
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• 2017

The imbalance at the 3-phase side at the railway power supply substation has been a well-known issue. Due to the difference in status of loads at each phase at any given moment, it is difficult to maintain the balance in the 2-phase side of the transformer. Consequently, the 3-phase side also presents a certain level of imbalance as well. A co-phase power supply was proposed as a solution. The real application of such system is gradually expanding, proving the effectiveness of the system. In this paper, the application of the single phase D-Q rotating frame theory was applied to the control of the co-phase power supply system. In addition, the power stack of the system was composed of MMC valves, which offers superior operational characteristics. The effectiveness of the system was verified with a real-time simulation, and the results are presented.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.696-703
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• 2000

This paper describes the capacity calculation of power supply system for light Rail Transit Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we considered all of them for capacity calculation of power supply system for LRT. At first DC-fed-traction system is introduced on an outline, a characteristics of train and fed network, and design method of substation arrangements. Optimal design procedures are described, and program for capacity calculation of the system is presented. In addition, the computer simulated results are computed with the conventional simple calculation method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1919-1924
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• 2016

In general, Diode rectifier has been applied to DC traction power supply system. Diode has some characteristics which is voltage drop in inverse proportion of load because of non-controlled switch, and cannot flow a current in reverse bias. So, voltage drop occurs frequently, and regenerated power cannot use in substation. The PWM rectifier is able to control output voltage constantly to reduce voltage drop and to use regeneration power without additional inverter. This paper proposes analysis algorithm for DC traction power supply system with PWM rectifier.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.421-423
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• 2003

To prevent fault effect in supply of electric power distribution system and plan stable operation of electric power system, must control magnitude of fault current. Although there are various kinds of method to solvethis, approached from super conductivity Fault Current Limiter application viewpoint among them. High Temperature Superconductor-Fault Current Limiter (HTS-FCL) development is progressing according to HTS technology development, and system application is tried. For actual system application of such super conductivity FCL, so that can reflect special quality of actuality supply of electric power distribution system just as it is in this treatise supply of electric power system by two modelling do. Also, by simulation of HTS-FCL action and protection coordination with another equipment appliances, verified the effectiveness in supply of electric power system applying itself super conductivity FCL EMTDC dynamic characteristic model that is develope.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.278-282
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• 2010

Since a power supply substation of the magnetic levitation train system includes a inverter which is necessary to change the frequency of power, it has a different characteristic comparing to any other railway system. Nowaday a study for determining rating of facilities constituting a power supply system and modeling that system is undergoing. In this paper, a analysis model for the power supply system of the magnetic levitation train using the 3-level inverter is proposed. And the analysis for output characteristic is performed using the PSCAD/EMTDC program. The control method about the output of 3-level inverter for supplying power to loads in magnetic levitation train system is also described.