• Journal of the Korean Society of Systems Engineering
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• v.10 no.1
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• pp.43-48
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• 2014

The door system for railway vehicles is the critical device directly influences on safety and satisfaction of passengers, Recently, electrical type of passenger door system is widely used for EMU type train instead of pneumatic type of passenger door system. The estimation of MTBF and failure rates for electrical type door system is essential. The manufacturor simply provides intrinsic reliability data for the railway operator. But actual reliability data based on operation and maintenance data is not complying with intrinsic reliability. In this study, operation and failure data associated with electrical door system were analyzed in order to determine actual MTBF and failure data. Intrinsic reliability data and service reliability data were studied to finallize much more practical and reliable actual reliability. Relax 2011 was used to predict intrinsic reliability and 217Plus model was also used to estimate of actual reliability data based on field data. Furthermore, it is necessary to keep studying on reliability prediction methodology and applying it in the field and doing research on improvement of reliability through feedback as well.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.2
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• pp.139-148
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• 2014

State-of-charge (SOC) is one of the significant indicators to estimate the driving range of the electric vehicle and to control the alternator of the conventional engine vehicles as well. Therefore its precise estimation is crucial not only for utilizing the energy effectively but also preventing critical situations happening to the power train and lengthening the lifetime of the battery. However, lead-acid battery is time-variant, highly nonlinear, and the hysteresis phenomenon causes large errors in estimation SOC of the battery especially under the frequent discharge/charge. This paper proposes a novel estimation technique for the SOC of the Lead-Acid battery by using a well-known Extended Kalman Filter (EKF) and an electrical equivalent circuit model of the Lead-Acid battery considering diffusion and hysteresis characteristics. The diffusion is considered by the reconstruction of the open circuit voltage decay depending on the rest time and the hysteresis effect is modeled by calculating the normalized integration of the charge throughput during the partial cycle. The validity of the proposed algorithm is verified through the experiments.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.109-112
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• 2015

The Korean electric railway is growing rapidly such as speed of 300km/h in high speed section and 230km/h in the conventional railway section. But, power supply failure occurs because of loss of contact, defective catenary system and high speed vehicle. Therefore preventive maintenance way based reliability has been applied. Typical example is the facility inspection method using trolley inspection system. But it is required differentiated inspection method to prevent problem such as inspection errors. In this paper, a study on the trolley sliding condition inspection system using monitoring techniques is performed for performance enhancement of inspection system. It proposed the efficient maintenance method through monitoring the deviation and height of contact wire after installing inspection system on the top of train which operates in the metropolitan area. Inspection errors were decreased by virtually monitoring the video of faulty facilities. Also those facilities were identified through the impact sound analysis and tests at the main catenary section.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.515-521
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• 2000

This paper describes the field test results of IGBT VVVF inverter for the railway propulsion system. The 1,650kVA IGBT VVVF inverter has been developed. Therefore, the field test is performed in SMG 6 Line to confirm its the reliability and performance. The train consists of 4M4T and the electrical equipment for field test are as follows : VVVF inverter 4 sets, 16 traction motors and 2 SIVs. The propulsion system is composed with 1C4M(1-Controller 4-Motors). The results of propulsion system which have the excellent acceleration/deceleration and the jerk characteristics as well as starting ability on slope are taken through the field test.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.10-12
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• 2009

Electromagnetic Interference(EMI) in electric railway operation has become increasingly important. The components within very high power electronic, and the circuits for treating low-level signals, comprise complex system that must coexist and be highly reliable. To study it, It were included how much the HEMU-400X generates EMI and it has an effect on the power conversion units which resulted from Power Line Disturbance (PLD) phenomenon by contact loss during its running. In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.899-904
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• 2007

Improvement projects has been progressed for railway electrification and double track line in the conventional line as well as high speed line for the high speed and large transportation capability of railway. Especially, many variable operation plans are possible such as interaction between high speed line and conventional line and operation of tilting train due to the electrification of the conventional line. Railway electrification is more energy efficient and environmentally-friendly, but it has some problems such as an enormous initial construction and maintenance costs and electrical accidents. Therefore, the more intensive research will be progressed about railway electrification effectiveness for the continuous electrification project. So, we analyzed railway electrification effectiveness about the energy side using annual operation data of electric car and diesel car. The energy side was divided into energy costs and national energy consumption for analyzing electrification effectiveness about entire line and specific line. We verified advantage of energy costs and national energy consumption in this paper and this result will contribute to the progress of the continuous electrification project and the more efficient operation ways in electrification line

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1168-1173
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• 2007

The Seoul Subway is one of the most heavily used Subway System in the world. It provides reliable transportation services, conveys nearly 4 million Passengers across 117 subway stations with a length of 134.9 Km. Over the years the safety for the Subway has been a major concern, trains going off the track, equipment failure, careless operation, Signal failure are increasing day by day. In a Recent Public opinion 40% said the causes to above facts are Vehicle breakdown because of Operators, Old rail defect, Quality of material. 20% of the opinion said the obstacles were because of Operation, crew carelessness, negligence in signal operation. In case of any accident the crew members cannot resolve the issue on site (Aid insufficiency), because of lack of knowledge and carelessness. The main obstacles for Subway are vehicle breakdown, Electric equipment failure, Signal Equipment failure, and Crew carelessness. This paper aims to provide major problems which are needed to be solved as quickly as possible for citizen's safety for a comfortable subway system making a comfortable ride and providing better service gradually.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.133-138
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• 2010

This paper describes on aerodynamic characteristics of pantograph system for Next generation high speed train(HEMU-400). The pantograph which supports electric power is located on the roof. Because of this, it generate high drag, severe acoustic noise and vibration which induced unstable flow due to complex configuration. Therefore, the design of high efficient pantograph needs to increase operational speed. In this research, wind tunnel tests were performed to design a high efficient pantograph system using 1/4 scaled model which were KTX-II pantograph, single arm pantograph and periscope type pantograph with square cylinder shape panhead and optimized shape panhead. For real operational condition, flow directions were adapted by rotation of pantograph. From this results of wind tunnel, it is checked that the pantograph with optimized panhead and single arm type or periscope type has better aerodynamic performance. In addition, lift control device and spoiler in pantograph were tested to investigate the validity of application.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.775-783
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• 2010

The Yong-san rolling stock depot in which KORAIL does the maintenance of PP was required to move to the other place, so there are some disputes how to treat PP rolling stock, that is, early scraping, extending life-span or introduction of intercity EMU, but introducing a new train are very expensive and also very risky, so executed economical analysis for the precision political decision. For the specific analysis, set some scenario, first uses PP to their life span, second, introduces new intercity EMU, third, extends the life-span of PP by rolling stock precision diagnosis. Largely, maintenance cost, operation cost, rolling stock value are used for the economical analysis. This research is the specific case of KORAIL, but this result can be a valuable data in the perspective of operation cost between diesel rolling stock and electric rolling stock.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.3
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• pp.205-212
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• 2008

This paper describes the application of an inverse building model to a calibrated forward building model using EnergyPlus program. Typically, inverse models are trained using measured data. However, in this study, an inverse building model was trained using data generated by an EnergyPlus model for an actual office building. The EnergyPlus model was calibrated using field data for the building. A training data set for a month of July was generated from the EnergyPlus model to train the inverse model. Cooling load prediction of the trained inverse model was tested using another data set from the EnergyPlus model for a month of August. Predicted cooling loads showed good agreement with cooling loads from the EnergyPlus model with root-mean square errors of 4.11%. In addition, different control strategies with dynamic cooling setpoint variation were simulated using the inverse model. Peak cooling loads and daily cooling loads were compared for the dynamic simulation.