• Proceedings of the KIEE Conference
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• summer
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• pp.1370-1372
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• 2004

At present. distance relay and ${\Delta}I$ current increment relay are used as primary and secondary protection in the AC feeder system. However. electric railway vehicles according to power electronic's development had developed resistance control, thyristor phase control and PWM control system. and operation of train is increasing in a feeder section. Therefore this paper analyzes the load characteristics and situation of relay's maloperation caused by load current increase, harmonics, regenerative braking current and operation of the different vehicles in same feeder section. Based on this analysis. this paper proposes consideration items for relay correction and advanced adaptive relay that can change operation area according to load current.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.694-698
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• 2005

The operation speed improvement of the train in electric railway must pursue continuously and need the investigation of whole railway system whole. The high-speed of the train is related to not only vehicle technique but also the infrastructure, signal system, operation technique, the trolley line and catenary, economical efficiency. Specially, in case of electric railway, we have to consider a technical investigation which is current collection efficiency improvement, voltage drop countermeasure, equipment capacity, track force, signal system. In this paper, we presents the technical investigation of AT feeder system in order to achieve high speed train in exist real railroad. We proved this approach which will use the whole domestic lines in the future.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2213-2214
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• 2011

It is important to consider power stability in case of design and construction of a substation at railroad because a train is operated by electricity and tains are drived simultaneous at the same section. This paper described stability of feeder system considering driving conditions and railroad conditions of train which is drived. Simulation tool, TOM(Train Operations Model) software is used to ensure stability of feeder system. As results of simulation, feeder voltage source is in limits on driving operation dia of trains.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.162-166
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• 2003

Computerized simulation is becoming an indispensable procedure in the stage of planning, design, and operation of railway systems. This paper presents result of simulation technique for describing electrical performance of the power supply system which comprises the substation, catenary, feeder, and rails where multiple trains are running.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1601-1606
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• 2004

Nowadays, the bus system of a metropolitan area is improving very fast. According to the bus, commuter railways increase their competitive power. For this, trains get the mobility increasing, effective transferring system and unified information service. For the mobility increasing, commuting railway must be faster by flexible train diagram and facilities improvement. And finally, optimal commuter train, 'Liner' is needful. And for effective transferring system, it is necessary that railway station and transferring center of a city be merged. And it is needful that direct management bus by railway company and unification fare system on metropolitan region. Next, for information service system improving, the commuting railway station must be regional transportation hub at first. And it is needful that unified line map of trunk line transportation systems and regionally collective transportation system information book. Therefore, metropolitan commuting railways compete with trunk line bus and cooperate with feeder line bus, and can make optimal metropolitan public transportation systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1711-1716
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• 2018

Unlike conventional transmission and distribution lines, catenary system for operating electric railway vehicles are composed of multi-conductor groups (feeder line, contact wire, messenger wire, protection wire) and are used for railway employees, public or passengers in the station yards. Electric shock hazards are exposed and electric shocks such as death or serious injury are occurring in electric railway vehicles, railway high-voltage distribution lines, and catenary system. In order to analyze the types of electric shock accidents on railway by systematic approach method, we modeled 'unsafe behavior classification' method using swiss cheese model. Based on this method, we derived the type of electric shock accidents about railway accidents during the last 5 years by analyzing the frequency of occurrence of human errors and unsafe acts, laws and regulations related to violations, and so on.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.344-351
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• 1999

The safe operation of electro railways is greatly dependant on its protective systems. The system so-called Fault Protection Wire(FW) is now widely adapted to protect in AT feeding systems. It is connected between the feeder and trolley circuit to return the fault current to autotransfonmers at substation. This paper computed the distribution of fault currents at FW in the system and also evaluated the safety from electric shock when ground fault or flashover occur in the feeding system. The results show FW is useful to protect power supply network from fault in electric railways

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.2
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• pp.149-156
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• 1990

In DC electric railway systems, the feeding currrnt is not permitted to flow backward in almost all the substations and the pantograph voltages at the regenerating cars rise extremely by the voltage drop of the resistance of the feeder line. In order to prevent the overrise of the pantograph voltage in power regenerating cars, the squeezing circuits for the regenerative current are equipped and this leads to double losses, which are an extra worn-out of the brake-shoes and an ineffective use of regenerative power. In this study, the insertion of resistors in the feeder line system is proposed as a possible method for the effective utilization of the regenerative power in the electric railways. Also it is investigated how the output voltages of substations affect the effective use of regenertive capability. The investigation results show that the energy savings and the reduction of the worn-out of the brake-shoe can be achieved at the same time by the insertion of resistors in the feeder line system.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1885-1891
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• 2010

Recently metropolitan local governments is actively introducing urban railway's expand and light rail transit as a means of new transport system. DC electricity feeder system operating in the domestic urban railway is typically a feedback circuit consisted of the contact wire and electric railway vehicle via rail. But stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit with respect to a given structure. Stray current is generally results from the leakage of return currents from large DC traction systems that are grounded or have a bad earth-insulated return path. At the place where the current leaves the rail and metallic structures, electrolytic corrosion may take place. This paper presents comparison analysis of field test methods based on criteria of electrolytic corrosion protection of buried metallic structures adjacent to DC traction systems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1618-1625
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• 2015

The reliability of catenary system is very important for uninterrupted train operation as it supplies electric power to train without redundant facilities. This paper provides a systematic approach to the reliability analysis of the catenary system based on FMECA procedures defined by global standards such as MIL Std 1692a and IEC 60812. Field failure data collected from the operation and maintenance of high-speed railway catenary system for 9 years are used to derive critical failure modes and to evaluate the criticality of the failure modes. Evaluation of the criticality are carried out by quantitative procedures defined by MIL Std 1692a and by criticality matrix defined by IEC 60812. FMECA results suggests that three critical failure modes should be checked carefully during maintenance work, which include strand break of dropper and voltage equalizing wire, power supply failure of feeder. Maintenance procedure of catenary system in order of importance is suggested too. These results can be applied to maintenance planning and design of catenary system to improve the reliability of electric railway system.