• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1519-1520
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• 2006

This paper describes a selection and application recommendations of ZnO arresters on DC electric traction vehicles. We measured and analyzed the system voltages applied to arresters and the surge currents flowing arresters on DC electric traction vehicles under operation to decide the Continuous Operating Voltage($U_C$), the Rated Voltage($U_R$), and the Nominal Discharge Current($I_n$). System voltages measured up to 1,800 V during anti-breaking in 1,500 V-system, and surge currents were recorded up to 3 times per running-service-route and their magnitudes were ranges of $150A{\sim}2kA$. From these results and the standard EN50163, we proposed the Continuous Operating Voltage($U_C$) the Rated Voltage($U_R$) for the $1,500V_{dc}$ electric traction vehicles.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.439-442
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• 2004

This paper described a dc power system, which can generate the excessive do power form do 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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.104-109
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• 2004

Recently, when electric traction system used DC 1500[Vdc] 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. Therefore this paper proposes that the extra power is regenerated through regeneration inverter to AC utility in result this system obstruct to go beyond regular voltage and improve the efficiency. 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.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.78-85
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• 2000

Computer algorithms for the loadflow of the DC traction power supply system are examined. Algorithms to solve the nodal equation are reviewed and the two iterative methods to solve the nonlinear nature of the loadflow are analyzed and tested, which are so called conductance matrix method and current vector iterative mettled. The result of the analysis tells that the current vector iterative method makes faster convergency and needs less computing time, and it is verified by the test running of the programs based on each of the iterative methods.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.886-890
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• 2003

This paper introduces the combined test results of the traction system for KHST(Korean High Speed Train: hereafter refer to KHST). The main purpose of this combined test is to verify the performance of the traction system that is designed to operate up to maximum 350km/h speed. Combined test system consists of a traction transformer, two AC-DC PWM converters, a PWM Inverter, two traction motors and flywheel system. Flywheel system represents equivalent model of the train inertia. Also traction control system and MASCON Interfaces are included. Various kinds of experiments are performed to prove total traction system performance and detail waveforms are described

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.196-201
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• 2008

In DC traction systems, a part of feedback current returning through rails becomes leakage current, illumination on a metal laid underground results from the leakage current to ground. To prevent the leakage current on rails, feedback rails almost have insulated with the ground. Insulation between rails and the ground causes that the earth method changes a isolated method in DC traction systems. the rail potential rise results in the isolated method. the rail potential rise causes an electric shock when a person touches the ground and rolling stock. To decrease the rail potential rise and leakage current, there are methods for reducing the feedback resistance and current of rails, increasing the leakage resistance, decreasing the distance between substations. But it are necessary to forecast and analyze the rail potential and amplitude of leakage current. In this paper, we modeled DC traction systems and feedback circuit to simulate the rail potential and amplitude of leakage current using PSCAD/EMTDC that is power analysis program, forecasted the rail potential and amplitude of leakage current about changing various parameters in the electric circuit. By using the simulation model, we easily will forecast the rail potential and amplitude of leakage current in case of a level of basic design and maintenance in electric railway systems, valuably use basic data in case of system selection.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.1-6
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• 2009

With respect to a given structure, a stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit. Most often DC-powered traction systems like railroads and tramlines are responsible for large dynamic stray currents. This type of 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 investigates the domestic conditions on the electrolytic corrosion protection of buried metallic structures adjacent to DC traction systems by survey.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1405-1407
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• 2000

This paper is on optimal design for DC substation capacity for Mass Transit System. Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we discussed substation power capacity only. At first, DC-fed-traction system is introduced on an outline, a characteristics of train and fed network. Optimal design procedures is described, and modelling for DC-fed-traction system are presented. The circuit-solution method is presented by matrix formula. In order to simulate DC substation power capacity more closely to actual situations, we proposed the program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.96-104
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• 2004

This paper proposes a dc power regenerating systems, which can generate the excessive dc power from dc bus line to ac supply in substations 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 an 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. 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.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.463-465
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• 2005

This paper proposes a regeneration inverter system, which can regenerate the excessive power form the DC bus line to the AC source for traction systems. The proposed regeneration inverter system for DC traction can reduce harmonics which is a characteristic of the AC current source. The simulation was composed as a prototype model[3.7kW]. Finally, it is shown that the inverter can successfully operate in regeneration mode.