• Proceedings of the KSR Conference
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• 2004.06a
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• pp.290-295
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• 2004

Electrification of existing railroad as well as extension of double track, need a large amount of electric energy. Especially, increase in energy consumption of high cost causes much problems in domestic economy. It is neccessary to save energy for the crisis of exhaust of fossil energy. About $20{\~}25\%$ of regenerated energy of an electric railcar is lost on down slope run or on braking. In order to save energy in electric railway system, Therefor, application of energy regeneration system is proposed and introduced in the present paper.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.498-506
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• 2010

The neutral section was installed in order to prevent conflict with different phase angle source in electric railway catenary system. The speed of electric train reduced due to coasting operation by notch off when it passed the neutral section. And, the catenary wire was damaged and the accident might be happened because of the arc generation when the electric train passed the neutral section with notch on condition. This project has a goal to develop the automatic changeover system using by noncontactless semiconductor device in neutral section of catenary system so that the train pass as notch-on condition. In this first year, we obtain as following results such as domestic and international systems applications and completion requirements, development and analysis of stability for automatic changeover system, design of static switching device on automatic changeover system in neutral section and drawing up interface design and specifications according to equipment.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.505-511
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• 2008

when electric traction system used DC 1500V runs on decline of rail road track and slows down, dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. This paper described a DC electric railway system, which can generate the excessive DC power form DC bus line to AC source in substation for traction system. The purpose of this study was the development of the regenerative inverter system which suppress extra DC-line voltage and regenerate the energy instead of using a resister. That is Developed regenerative inverter system returns the regenerative energy from the DC line voltage to the utility. In addition, the inverter can be compensate the harmonics caused by the power conversion devices used in the DC traction system.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.287-292
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• 2005

Safety of Station electric equipment is not analysed yet. this paper try the safety first times on the basis of hazards which railway stations contain. The stations use many electric equipment such as lights, escalator and elevator for facilitating for passengers and public moving, HVAC system making good environment and so on. The electric equipments could be changed to harmful systems to passengers and publics resulting from abnormal operation condition. To ensure safeties in the station, we need to identify and analyse the hazards in the station and to provide risk mitigation methods. In this paper, we shows processes and methods to ensure the safety, how to identify and analyse the hazards. Finally, we demonstrate how to mitigate the potential risks in the stations.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.676-681
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• 2005

The regenerative braked cars are being introduced in DC electric railway for energy saving. There has been a recent tendency for DC traction substation with regenerative inverter to increase in number. This is strongly related to the desire for effective utilization of electric power regenerated by DC electric cars and to the aim ensuring stable operation of regenerative braking system. The regenerative inverters DC power feed back from a generative car into AC power at a substation and supplies it to distribution lines. This paper suggest the result of characteristic analysis and capacity simulation. economical analysis in the regenerative inverter system.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1488-1494
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI(Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• Journal of Power Electronics
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• v.17 no.3
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• pp.788-797
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• 2017

The power quality of AC electric railways has become an issue worthy of more and more concern. Many active compensators based on power converters have been proposed, but with complex transformers or coupled branches. This paper presents a single-phase cascaded H-bridge multilevel active power filter (APF), which can directly connect to the 27.5-kV power supplies to deal with power quality problems. According to field measured data, the load characteristics are analyzed, and the system configuration and control system are designed based on the load characteristic analysis. Finally, simulation and experimental results verify the effectiveness of the proposed APF system, considering some problems such as the supply voltage fluctuations and transient inrush currents in AC electric railway systems.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1849-1854
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• 2010

Energy Storage System(ESS) is installed at feeding line of railway substation. ESS will absorb regenerative energy when train braking and also charge electric energy when feeding line is no load condition. Absorbed and charged energy will be supplied when train is accelerating condition. Due to ESS the energy variation will be minimized and this effect is estimated.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1396-1401
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• 2004

This paper proposes analysis on new equipment for power quality in electric railway. The Proposed equipment consists of series inverter and parallel inverter. Each inverter is connected by capacitor as de link. This structure can be compensated for active and reactive power in catenary through transformer.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1519-1525
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• 2016