• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3632-3637
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• 2009

In this paper, we describe the performance results of the field installation test which is required to practicalize the single-phase MJ81 Switch Point Machine. This product has passed the certified test through performance improvement of driving parts in order to use 3 phase MJ81 Switch Point Machine, which is localized by taking over technology from Alstom and Cogifer when constructing Seoul-Busan rapid-transit railway, without change of the electrical equipment at track-side in domestic existing lines which single-phase 220V is used. KRRI and Samsung SDS have localized the single-phase MJ81 Switch Point Machine to improve the speed and safety of the conventional lines through the existing railway technology development project. For practicalization of this, we should, however, verify the performance through not only field installation test in real lines but also interface test with the interlocking. In this paper we verify the practicality of the domestic single-phase MJ81 Switch Point Machine through analysis on the performance result of the field installation test as well as the research contents for this test. Thereby, in Feb 2009 we have received an order from the Korea Rail Network Authority and are currently installing the single-phase MJ81 Switch Point Machine.

• Journal of Power Electronics
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• v.16 no.2
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• pp.542-552
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• 2016

Central 60° synchronous modulation is an easy pulse-width modulation (PWM) method to implement for the traction inverters of urban rail trains at a very low switching frequency. Unfortunately, its switching patterns are determined by a Fourier analysis of assumed steady-state voltages. As a result, its transient responses are not very good with over-currents and high instantaneous torque pulses. In the proposed solution, the switching patterns of the conventional central 60° modulation are modified according to the dynamic error between the target and actual stator flux. Then, the specific trajectory of the stator flux and current vector can be guaranteed, which leads to better system transients. In addition, stator flux control is introduced to get smooth mode switching between the central 60° modulation and the other PWMs in this paper. A detailed flow chart of the control signal transmission is given. The target flux is obtained by an integral of the target voltage. The actual PMSM flux is estimated by a minimum order flux state observer based on the extended flux model. Based on a two-level inverter model, improved rules in the α-β stationary coordinate system and equations of the switching patterns amendment are proposed. The proposed method is verified by simulation and experimental results.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.724-730
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• 2011

A turnout serves to switch train from one line to another. The turnout consists of a Point which is switchs the rail to induce direction, and a Crossing which is cross over two line on the plane surface, and a Lead where is middle section in Point to Crossing. Point machine, consists of a turnout, is important facilities in railway signal, that is safety issue relates in derailment of the train. Recently, train delay and accident frequently occurred because of the turnout include in a point machine trouble of electrical and mechanical. So in order to prevent train accident the research is advanced, install of normal and reverse indication lamp in a point machine, development of adherence detector for sensing the status of adhesion between the stock rails and tongue rails etc. In this paper investigates the problem which is connected with a turnout trouble, include in a point machine, occurrence at the time of train accident, and then proposed to the safety system model in order to prevent the train accident in turnout.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.26-30
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• 2007

The total control system of main engine and transmission will be designed specially for use in drive systems in rail vehicles. The domestic diesel train was controlled by the relay control circuit. But the exportation to Europe and the Middle East was controlled by total control system. When the driver operates the train, the operating signals are sent to Voith Controller. The VTIC controls the main engine and transmission. The system communicates with TMS, and the data are displayed by TMS when the function switch at the display unit is operated. The this driving control system which is applied to reduce the maintenace load and cost at Turkey diesel multiple unit train is proposed.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.880-885
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• 2003

Using a Assistance Power Sources of the Railroad Vehicles Three-Level ZVZCS DC/DC Converter is presented in this paper. The proposed three-Level DC/DC Converter Is to achieved zero voltage and zero current switching for the two Main switches. phase shift method is used a parastic capacitance by reverse recovery characteritics in a inner diode of the switching device. Also. using a diode second part of the Transformer by the simple auxiliary circuit for the achieved zero current switching of the Auxiliary switch. For the ZVZCS movement of the all switching devices is analyzed and verified under a 5kW, in the 100kHz switching frequency.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.569-574
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• 2011

An effective approach to distributing budget to railway line facility improvement is to use investment priorities of railway line segments based on their deterioration. In this paper we present an evaluation method of railway line segment deterioration which can be used to distribute limited budget. Railway line facilities include rail track, railroad switch, subgrade, bridge, tunnel. These facilities and line shape can affect line segment deterioration. Deterioration evaluation method we present is a weighted sum of each component deterioration scores. The component weight can be obtained from experts using analytic hierarchy process.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.288-295
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• 2018

Purpose: The paper aims to compare the effectiveness of the two types of transport demand management measures, namely pull measures and push measures. Method: Case studies of two metropolitan areas in the developing world assess the extent to which increases in fuel prices can contribute to reducing automobile use and increasing the public transport use and the potential of urban rail transit to cause mode shift from automobiles. Within the case studies, a stated response survey of current car users has been conducted for Cairo and an on-line survey of rail transit users in Algiers. Results: There was a major proportion of car drivers who intend to switch to public transport, depending on the range of fuel prices in Cairo and a considerable proportion of rail users who have switched from automobiles resulting in a measurable reduction in CO2 emissions in Algiers. Conclusion: Investments in urban rail can be highly effective where there are demands for better public transport, but this type of pull measures can be much more effective if combined with push measures which significantly raise driving costs.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.232-240
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• 2015

Two types of track circuits are used in high speed railway car depots: one is High Voltage Impulse Track Circuit(HVITC); the other is AF track circuit. HVITC detects train occupation of blocks and broken rail; the AF track circuit is used for train onboard control system pretesting before departure. This testing is used to transmit train control information through the AF track circuit. The two systems are switched in turns for testing. We propose a system in which the AF track circuit is replaced by a loop cable that is installed on the inside rail; as such, engineers do not need to switch the systems. In cases in which the two systems run simultaneously, mutual interference may occur. In this paper, we identified this mutual interference by modeling of the two circuits.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.8
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• pp.1210-1215
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• 2012

Traction motors for driving and power conversion devices using semiconductor switch are equipped with a transportation systems such as an electrical railway system. Power conversion devices have the possibility of malfunction by external electromagnetic waves. As a result, these could affect the safe operation of the railway. Moreover, the electromagnetic waves above safe limits will be harmful to the passengers inside the railway vehicles or anyone working around the rail-track. For this reason, the importance and need about the reliability check and complement of electromagnetic waves generated from the IPT(Inductive Power Transfer) system have been suggested for the safe application of the IPT system to the railway system. In this study, prediction for the electromagnetic wave properties was conducted through FEM(Finite Element Method) analysis of 5kW-class IPT system design model. Next, the 5kW IPT system prototype was made and then the small-scaled railway vehicle was made to mount the IPT system and the energy management system. Finally, the electromagnetic waves generated from the real small-scaled IPT system were measured and analyzed, and then the reliability check of predictions by FEM analysis were carried out.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.377-382
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• 2005

This paper presents two new circuit topologies of DC bus lineside active edge resonant snubber assisted soft-switching PWM full-bridge DC-DC converter acceptable for either utility AC 200V-rms or AC 400V-rms input voltage source. One topology of proposed DC-DC converters is composed of a typical voltage source-fed full-bridge high frequency PWM inverter using DC busline side series power semiconductor switching devices with the aid of a parallel capacitive lossless snubber. All the active power switches in the full-bridge arms and DC busline can achieve ZCS turn-on and ZVS turn-off commutations and the total turn-off switching power losses of all active switches can be reduced for high-frequency switching action. It is proved that the more the switching frequency of full-bridge soft switching inverter increases, the more soft-switching PWM DC-DC converter with a hish frequency transformer link has remarkable advantages for its efficiency and power density as compared with the conventional hard-switching PWM inverter type DC-DC converter