• Proceedings of the KSR Conference
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• 2002.10a
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• pp.553-558
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• 2002

The harmonics in railway high voltage system is due to common use of 3 phase incoming bus and doing the power converter for traction system on the electric car(or electric locomotive). This paper, we analyze the harmonics mechanism and characteristics of railway high voltage system, also we analyze the problem according to the actual measurement about influence of harmonicsontherailwayhighvoltagesystem. And we proved the countermeasure device(passive filter or L-C filter) of harmonics applies in the field. The test result, we have know that the filter is not fit. Consequently, The countermeasure of harmonics for the railway high voltage system be able to resolve by another filter.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.65-69
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• 2004

In reference to this study, Part Ⅰ showed how the system respond to the harmonics originated from electric locomotives. That is, the system response to the harmonics was derived by computational algorithm with numerical formulas in theoretical aspects. However, Real catenary system has complex configuration of conductors and it is an important point that if we can consider the circuit element of catenary conductors as an uniformly distributed RLC element. Moreover, harmonic characteristics in electric locomotive depend on its operational modes. From these point of view, measurements of harmonics are performed for real railway power supply systems under the various operational modes, and spectrum and distortion analyses in measurement data are described.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.60-64
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• 2004

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.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.52-59
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• 2014

Operator training simulator, within a training environment designed to understand the principles and behavior of the railway system with respect to operator's entries and predefined scenario, can provide a very strong benefit in facilitating operators' handling undesired operations. This simulator consists of computer system and applications, and the purpose of applications is to generate the power and voltage and analyze the AC substation and DC railway, respectively. This paper describes a novel approach to the new techniques for AC/DC hybrid simulation for the operator training simulator in the railway system. We first propose the structure the database of railway system. Then, topology processing and power flow using a linked-list method based on the proposed database, full or decoupled newton-rapshon methods are presented. Finally, the interface between the analysis for AC substation using a newton-rapshon method and the analysis for DC railway system using a time-interval power flow method is described. We have verified and tested the developed algorithm through the extensive testing for the proposed test system. To demonstrate the validity of the developed algorithm, comparative simulations between the proposed algorithm and PSS/E for the test system were conducted.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.713-718
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• 2014

DC urban railway power system consists of DC power network and AC power network. The DC power network supplies electric power to railway vehicles and the AC power network supplies electric power to station electric equipment. Recently, because of power consumption reduction and peak load shaving, intelligent measurement of regenerative energy and renewable energy adapted on DC urban railway is required. For this reason, DC smart metering system for DC power network shall be developed. Therefore, in this paper, DC voltage sensor, current sensor, and DC smart meter were developed and evaluated by performance test. DC voltage sensor was developed for measuring standard voltage range of DC urban railway, and DC current sensor was developed as hall effect split core type in order to install in existing system. DC smart meter possesses function of general intelligent electric power meter, such as measuring electricity and wireless communication etc. And, DC voltage sensor showed average 0.17% of measuring error for 2,000V/50mA, and current sensor showed average 0.21% of measuring error for ${\pm}2,000V/{\pm}4V$ in performance test. Also DC smart meter showed maximum 0.92% of measuring error for output of voltage sensor and current sensor. In similar environment for real DC power network, measuring error rate was under 0.5%. In conclusion, accuracy of DC smart metering system was confirmed by performance test, and more detailed performance will be verified by further real operation DC urban railway line test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1431-1436
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• 2017

The high-speed railway of catenary system, supplies a stable electric power supply to the train by satisfying the special conditions between pantograph and trolley wire, which operates more than 250km/h mutually sliding and feeding electric lines. According to Korean Railway Standard KRS PW 0026-13 (R), the standard for the grip strength of the dropper clamp in conventional line is established, but the high-speed railway line is not yet. When the grip strength of the dropper clamp is detached from the catenary line of the high-speed railway line, various problems may occur, such as damage to the pantograph due to the collision and arcing. In this paper, it is expected to be used as a basic data for establishing the durability criteria of the high-speed railway dropper clamp by verifying the dropper clamp on the Gyeong-bu and Honam high-speed line.

• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.772-777
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• 2009

The development of fuel cell hybrid power system, as a next generation power system to promote clean energy which will mitigate the continued global warming, has demonstratd a significant progress in passenger vehicle applications. Also, in case of railway vehicles in non-electrified railway lines, the adoption of fuel cell hybrid power system is being studied among well-known manufacturers. This paper introduces both the configuration and the control strategy of fuel cell hybrid power system to apply to a light electronic railway vehicle having a repeated driving pattern of acceleration, coasting and deceleration. The simulation results demonstrate the viability of the proposed power system design and its control strategy.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.804-808
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• 2007

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 proposed regeneration inverter system for DC traction can be used as both an inverter and an active power filter(APF). As a regeneration inverter mode, it can recycle regenerative energy caused by decelerating tractions and as an active power filter mode, it can compensate for harmonic distortion produced by the rectifier substation. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality. From the viewpoint of both power capacity and switching losses, the system is designed on the basis of three phase PWM inverters and composed of parallel inverters, output transformers, and an LCL filter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.812-816
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• 2015

Recently, various monitoring systems have been proposed to detect interaction performance between trains and infrastructure, as well as, various techniques to improve the accuracy and performance of such inspection equipment in high speeds. Especially, it is important to predict electric noise of high speed trains due to its effect on detection system accuracy. In this paper, we analyze various types of electrical noise in electric vehicles to improve the accuracy of the detection module of the inspection car. In detail, analysis of electric noise of high speed railway is performed as a function of speed based on field tests that were carried out by HEMU-430X (Highspeed Eletric Multiple Unit - 430 km/h eXperiment).

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.92-94
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• 2005

In this paper, when electric train is in dead-section the effect on electric train system was dealt. The feeding system of electrical railway is AC or DC. When the electric train is passed AC feeding system to DC, vice versa or phase is changed in between AC feeding systems, there is a dead section. A dead section usually makes the electrical system complex md may have an adverse effect on the electrical system inside the train. Accordingly, it is important to analyze the effect on trains in dead-section. Modeling an electric train and simulation using PSCAD/EMTDC was accomplished to analyze how power quality problem such as inverter switching surge is propagated to electric train through the feeding line, railway, pantograph.