• Proceedings of the KSR Conference
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• 2003.05a
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• pp.493-498
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• 2003

Harmonic current originating from electric locomotives can be magnified due to the impedance characteristics of power supply circuit and bring about various problems. That is, electromagnetic interference with communication lines, operational trouble in signaling, overheat and/or vibration in power capacitor, mis-operation in protection relay and so on. Therefore, the exact assessment of the harmonic current flow must be undertaken at design and planning stage for the electric traction systems. For these reasons, this study propose a new approach to model and to analyse traction power feeding system focused on system response to current and voltage harmonic(PART I ). Measurements of harmonics are also performed for railway power supply systems under normal operation. Spectrum and distortion analyses in measurement data are variously described in PART II

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.499-504
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• 2003

Harmonic current originating from electric locomotives can be magnified due to the impedance characteristics of power supply circuit and bring about various problems. That is, electromagnetic interference with communication lines, operational trouble in signaling, overheat and/or vibration in power capacitor, mis-operation in protection relay and so on. Therefore, the exact assessment of the harmonic current flow must be undertaken at design and planning stage for the electric traction systems. For these reasons, this study propose a new approach to model and to analyse traction power feeding system focused on system response to current and voltage harmonic(PART I ). Measurements of harmonics are also performed for railway power supply systems under normal operation. Spectrum and distortion analyses in measurement data are variously described in PART II

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.9
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• pp.1249-1256
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• 2018

For the screening factor of the tunnel and overbridge structure in the electrified railway, the ITU-T regulation denotes only a theoretical estimation method, and the actual numeric values are notified differently by the official announcement of each nations. In this study, the factors which can affect the screening factor are investigated and analysed by FEM and a suitable calculation method based on multi-conductor line theory for the current pre-estimation formula for the induction noise voltage in the national notice is presented. The case studies are performed using the real data of the tunnel and the overbridge of the electrified railway, and a satisfactory formula for the determining of screening factor is derived.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.152-158
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• 2010

Generally, the AC electrified railway systems have the power quality problems that are induced from the harmonic currents and the reactive power. This paper presents a single-phase hybrid active filter adopting a SRF(synchronous-reference-frame) control for improving power quality in the AC electrified railway systems. The single-phase hybrid active filter can compensate the harmonic currents and the reactive power through the proposed SRF control algorithm. The proposed control algorithm can extract the third and fifth harmonics through the MSRF(multiple-synchronous-reference-frames) which is used to apply the three-phase systems. Therefore, the hybrid active filter can compensates only the high-frequency harmonic currents whereas the passive filter compensates the low-frequency harmonic currents. Also, the proposed SRF control algorithm can compensate the reactive power by the closed-loop control. The Validity and the effectiveness of the proposed SRF control method for the hybrid active filter are illustrated through the simulation results.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.229-235
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• 2007

The KTX, which have opened the revenue service in April 2004, is operating in Kyoung-Bu high-speed line and electrified conventional Ho-Nam line, and the more the electrification are enlarged, the more the requirement of operating of high speed train would be increased. In this paper, the result of test run and evaluation on the suitability of operating high speed train in electrified conventional line between Dae-jeon and East Dae-gu was reviewed. Evaluation and analysis was executed in specific categories, such as operation & running performance of the train considering vibration characteristics based on UIC 518, ride comfort and current collection, and response sensitivity of ATS device for signalling from track facility. The result of this running test was evaluated and considered as a good practice for revenue operation of high speed train in electrified conventional line between Dae-jeon and Dae-gu.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1342-1346
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• 2004

Recently, the load increasement and regenerative system of electrified railway system make a difficult to distinguish between the load current and fault current and it need a new intelligent protection system. The failure of traction system cause collapse of the other systems from high tension current. The over current from abnormal situation produces high tension current flow, high temperature are, voltage instability and current cutting, and break down railway systems. Protective system of traction system playa role of which detect and isolate failure points. In this paper, we proposed intelligent algorithm for discriminating normal and abnormal situation instead of the system being operated abnormally.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1021-1027
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• 2005

The Diesel Multiple Units (DMU) is a successful mass transportation system, that is being, continuously, on demand by train operators and railway authorities around the globe. One of its advantages is the fact that a diesel engine, along with the correct propulsion and control equipment, could also be used on either Electrified or Non-Electrified Railway Lines. Currently, there are almost 12,000 DM Units being used worldwide and the demand is on the increase. This paper describes the special features as well as the advantages/disadvantages of the different types of the DMUs according to the propulsion systems that are employed, to help establish a trend in the DMU market.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.343-347
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• 2002

This paper analyzed the effect of breakdown electric current and it establishes a countermeasure that objective of the place where it put when with protection method which is applied from the existing electric railroad power supply system and where the protection method which is applied in the newly electrified system. Will reach and in order to attain simulation it did a actual power supply system and it analyzed that result.

• Proceedings of the KIEE Conference
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• summer
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• pp.1406-1408
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• 2004

Recently, the load increasement and regenerative system of electrified railway system make a difficult to distinguish between the load current and fault current and it need a new intelligent protection system. In this paper, we proposed intelligent algorithm for discriminating normal and abnormal situation instead of the system being operated abnormally.

• International Journal of Railway
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• v.2 no.4
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• pp.139-146
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• 2009

Vehicle braking in non-electrified rail systems wastes energy. Advanced flywheel technology presents a way to capture and reuse this braking energy to improve vehicle efficiency and so reduce the operating costs and environmental impact of diesel trains. This paper highlights the suitability of flywheels for rail vehicle applications, and proposes a novel mechanical transmission system to apply regenerative braking using a flywheel energy storage device. A computational model is used to illustrate the operation and potential benefits of the energy storage system.