• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1511-1514
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• 2007

KORAIL is one of the biggest consumer in electric power market so it is necessary to investigate power consumption pattern and optimize power rates. This paper presents simulation program for electric power rates define 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. Also electric train air condition power consumption was measured to figure the method how to reduce peak energy consumption.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1479-1481
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• 2007

It is important to evaluate the power quality at a substation when a test train is running. Especially, the Korea Electric Power Company(KEPCO) restrict the power quality generated from the electrical train within limited value. So, this paper represents the results of the power quality test when Hanvit 350 is running at the KTX high speed line and the assessment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.132-139
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• 2008

In an electric railway feeding system, transient over-voltage often appears due to the feeder's direct lightning and induced lightning, while switching over-voltage also frequently occurs during operation of electric feeding in substation facilities. Such over-voltage is several times larger than the regular power, and accordingly leads to the dieletric breakdown of eletric power products such as invasion transformers and circuit breakers. Arresters are installed to protect these machines, while arrester counters are installed to observe the arrester's activation. This thesis aims to explore the status of an arrester counter that is being activated several thousand times, determine whether the arrester has actually been activated in relation to the counter, and investigate the over-heatedness and risks of the arrester.

• 한국전자통신학회논문지
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• 제11권10호
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• pp.963-968
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• 2016

논문에서는 도시철도의 변전소의 최대수요전력을 줄이기 위한 새로운 방법으로 OLTC(:On Load Tap Changer)를 갖는 변압기의 사용을 제안한다. 국내의 대부분의 도시철도는 전동차에 필요한 전력을 다이오드 방식으로 정류하며 DC 1500[V]로 공급한다. 변전소가 병렬로 연결되어 있기 때문에 수전전압이 상승하면 정류기 전압도 상승하게 되고 변전소의 최대전력도 증가하게 된다. 시뮬레이션 결과를 통해 본 논문에서 제안하는 방법이 최대수요전력의 증가를 상당히 제한할 수 있음을 보인다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.255-262
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• 2008

The railway is required to be highly reliable, which carries a lot of passenger and baggage. Presently, the reliability prediction method is based on independent failure. If the common cause failure affecting many components simultaneously in a system occurs, the system has seriously an aptitude to be broken out. Therefore, for raising the reliability of the railway power system, it is introduced that the analysis is conducted to use the common cause failure. The common cause failure is modeled and is combined with independent failure. Furthermore in order to examine the method, it is applied to the railway power substation. If this method is used to the power system, the reliability of the railway power system will be highly improved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1081-1082
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• 2006

The more feeding distance of substation is long and travel vehicle increases in feeding section, power supply leaches the limits. And if it exceeds the limit, it causes a serious trouble for train operation. Therefore, it is designed that the number of train increases constantly until 2030. So consistent power supply according to the increasement of vehicle in power system at present Seoul-Pusan high speed railway, regular operation in case of extended feeding occurring accidents in substation, and the least headway scheduled at relevant section and the effects installing compensation facility in case of impossible extended feeding is examined.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.495-498
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• 2008

PCC(Point of Common Coupling) is measured by waveform in power system. Analyzing their frequency, it is possible to get various indices such as THD(Total Harmonic Distortion), TDD(Total Demand Distortion), and VF(Voltage Flicker), and then the harmonic can be evaluated from them. In this paper, the harmonic effect on the power supply which is generated by the vehicle is presented by comparing harmonics with the substation and the vehicle.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.478-485
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• 2017

Urban DC railways have played an important role in urban transportation, and railway operation and energy management have been emphasized to be important to achieve maximum efficiency from existing infrastructure. Fast, accurate DC railway power flow analysis is required to operate a DC railway efficiently, and this paper proposes a novel methodology to analyze the DC railway power network by implementing the participation factor (PF). The PF concept consists of a correlation between the vehicle and the substation, as explained using zones based on the position of the vehicles running on the route. Then, the DC railway powerflow is calculated using the PF concept. Finally, the usability of the proposed method was validated via case studies with actual railway operation data, and we discuss some of the advantages of the suggested methodology.

• 전기학회논문지
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• 제61권7호
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• pp.1056-1060
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• 2012

Online monitoring system is becoming an essential element of railway traction system for utilized to condition based malignance management and various techniques currently employed in railway traction system. Among the various techniques, it is efficient to detect partial discharge signals by electromagnetic wave detection in order to detect insulation fault of rectifier. Although VHF (Very High Frequency), UHF (Ultra High Frequency) sensors were adopted to detect partial discharge of power facilities, due to characteristics of urban railway, excessive noise occurs from 500 MHz to 1.5 GHz on UHF bandwidth. In this paper a new measurement system able to monitoring the conditions of power facilities on DC substation in metro was studied and set up. The system uses UHF sensors to measure the partial discharge of the rectifier due to electric faulting and dielectric breakdown. Comparison and estimation for performance of SHF sensor which had devised to detect partial discharge signal of urban railway rectifier has conducted. In order to estimate performance of SHF sensor, we have compared the sensor with existing UHF sensor on sensitivity upon frequency bandwidth generated by pulse generator, and also we have verified performance of the SHF sensor by detection results of partial discharge signal from urban railway rectifier.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.705-711
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• 2005

In DC traction substation with 12-pulse diode rectifiers, the DC line voltage tends to rise above noload voltage because it can't absorb the regenerative power caused by electric brakes of train. To solve this problem, an IGBT regenerative inverter should be installed and recycles the surplus regenerative power by delivering it. to the supply grid. In this paper, the DC traction substation equipped with a IGBT regenerative inverter is studied using computer simulation. Matlab/simulink is used to simulate the operation of regenerative inverter which injects the regenerative power into the supply grid and stabilizes the DC line voltage. It is confirmed that the high quality regenerative power is delivered to the supply grid thorough computer simulation.