• Proceedings of the KSR Conference
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• 2008.11b
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• pp.248-254
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• 2008

Electric railway system consists of traction power system, rolling stock, track, and overhead line system. A railway substation transforms the electric power transmitted from a electric power company and supply it to the railway power system for the operation of traction system.. It is very important to prevent a possible accident and keep the security of electric power system. This paper proposes a reliability analysis of AC railway substation by using Fault Tree Analysis(FTA). Failure rates of each equipment of railway substation are used to evaluate the reliability of railway substation. The analyzed results can be used to improve the system reliability. FTA is performed by the commercialized program of Relex(Ver. 7.7).

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1014-1019
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• 2011

The substation automation is a system to remote-monitor and control electric power flow. And in line with electrification of railway, an interest in electric railway substation automation is increasing. IEC standardized IEC 61850, IEC 61968 and IEC 61970 communication protocol for the telecommunication standardization of the electric power automation industry. The recent SCADA systems in managed electric railway substations are have the problem about the compatibility with the products which fit to the international standard specification afterward. In this paper, the model of electric railway substation automation based on IEC 61850 and IEC 61970 is presented. And the method supporting the compatibility between the equipment is proposed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1959-1963
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• 2012

Since electric railway load is variable largely due to starting and braking characteristics as well as various operation patterns, load modeling is not easy but complicated. For this reason, a simple technique for modeling of electric railway load of is required to analyze the AC substation system of electric railway. In this paper, a modeling technique of converter-based electric railway load is proposed and is tested using nonlinear loads on Matlab/Simulink.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.6
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• pp.534-539
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• 2015

The DC overhead line voltage of an electric railway substation swings depending on the accelerating and regenerative-braking energy of trains, and it deteriorates the energy quality of the electric facility in the DC railway substation and restricts the powering and braking performance of subway trains. Recently, an energy storage system or a regenerative inverter has been introduced into railway traction substations to diminish both the variance of the overhead line voltage and the peak power consumption. In this study, the variance of the overhead line voltage in a DC railway substation is modelled by RC parallel circuits in each feeder, and the RC parameters are estimated using the recursive least mean square (RLMS) scheme. The forgetting factor values for the RLMS are selected using simulated annealing optimization, and the modelling scheme of the overhead line voltage variation is evaluated through raw data measured in a downtown railway substation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.315-323
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• 2015

Nowadays, it is expected that mobility loads such as electric railways and electric vehicles will be penetrated gradually and affect on the power system stability by their load characteristics. Various researches have been carried out about electric vehicles for the recent decade though the load of electric railway could be forecasted because of the specified path and timetable, is a field with a long historic background. Some precise 5th polynomial equations are required to analyze the power system stability considering mobility load to be increased in the immediate future while the electric railway dispatching simulator uses load models with constant power and constant impedance for the system analysis. In this paper, seasonal urban railway load models are established as the form of 5th polynomial equations and substation load modeling methods are proposed merging railway station load models and general load models. Additionally, load management effects by the load modeling are confirmed through the case studies, in which seasonal load models are developed for Seoul Subway Line No. 2, Gyeongui Line and Airport Railroad and the substation load change is analyzed according to the railway load change.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1303-1308
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• 2004

This paper proposes a reduction method for the mis-operation analysis of the DC High Speed Circuit Breaker(HSCB) in electric railway substation system. The analysis method is based on present condition of operation which is a method for accuracy level up. There is reason to operation of HSCB that it is mis-operation of fault detection relay(50F), operation of ground fault relay(64P), and trouble of electric car. A countermeasure is relay resetting through field test, induction of GTOCB(Gate Turn Off Thyristor Circuit Breaker), HSVCB(High Speed Vacuum Circuit Breaker), coordination with electric car. The results presented in the paper can be used as a reference for maintenance free in electric railway substation system.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.419-424
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• 2010

Through the process of state estimation in the electric railway substation, this paper presents a new method for improving the reliability of the measurements corrupted by gauge error. Unlike the case of commercial power systems, it has been difficult to perform the state estimation by using the usual methods in the electric railway substation. At some of the monitoring points in the substation, most often, it is hard to define the measurement functions by use of the states or as we set up a new states set with the change of system topology, some of the measurement functions become part of the states themselves, which leads to poor results. To resolve the problems in the existing method caused by the relations between the states and the measurement functions at the monitoring points, the proposed method in this paper exploits the equality constraints. They can be derived numerously and concisely from the current and the voltage attributes of the Scott transformer and the buses connecting conditions, etc. We have proofed the effectiveness of the proposed method by the test on a standard sample substation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.138-143
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• 2004

This paper analyzed harmonics from high speed railway traction to high speed railway substation and provide a reduction method of harmonics using the passive filter. A substation supplies the electric power to a train or can supply the electric power to several trains. According to the number of trains covered by a substation, characteristics of harmonics are investigated. These harmonics affect transformer heating and inductive interference. In order to get rid of the damage from the harmonics, this paper presented minimizing method of harmonics. The proposed method is verified in simulation using the PSCAD/EMTDC.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.893-898
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• 2007

At present, one of the big characteristics in electric power market in korea is unique seller but in the near future competitions are expected in the market. so additional service for the electric power are expected. Also with development of IT technology, remote inspection for power usage are possible so as consumption pattern analysis. KORAIL is one of the biggest consumer in electric power market so it is necessary to investigate power consumption pattern. This paper presents electric load consumption pattern for representative substation like urban subway, high-speed train, industrial line and simulation program for electric power rate definition program based on billing system database. Base on the substation annual power usage DB data, the characteristic of the substation power consumption are investigated and effective electrical billing system are compared each other. Through this program it is verified that we can save more then several hundred million won for a year.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1292-1296
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• 2004

This study is experimented results of running characteristics about electric locomotive. it executed to study a power quality in the substation of Honam electrification line and to promote knowledge, observation and management in electric rail-system. we measured to know the more exactly running characteristics that electric locomotive and electric substation at the same time.