• 전기학회논문지
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• 제65권9호
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• pp.1610-1617
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• 2016

To execute load curtailment efficiently for Urban Railway Load, the load patterns of the Urban Railway Load and available amount of load curtailment over the Urban Railway Load are analyzed through comparing the load to the common power loads. In addition, the current policies of the load curtailment for the Urban Railway Load are investigated and the problems of those are presented. Based on the researches, the optimal load curtailment strategies for the Urban Railway Load are proposed to minimize the consumer's utility diminishment and the costs of the use of energies. Finally, the optimal load curtailment strategies are applied to the real Urban Railway Load, the results shows that proposed methods are efficient and cost effective while the amount of load curtailment is minimized.

• 전기학회논문지
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• 제64권2호
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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.

• Structural Engineering and Mechanics
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• 제46권4호
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• pp.571-594
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• 2013

Railway truss bridges are amongst the essential structures in railway transportation. Minimization of the construction and maintenance costs of these trusses can effectively reduce investments in railway industries. In case of railway bridges, due to high ratio of the live load to the dead load, the moving load has considerable influence on the bridge dynamics. In this paper, optimization of the railway truss bridges under moving load is taken into consideration. The appropriate algorithm namely Hyper-sphere algorithm is used for this multifaceted problem. Through optimization the efficiency of the method successfully raised about 5 percent, compared with similar algorithms. The proposed optimization carried out on several typical railway trusses. The influences of buckling, deformation constraints, and the optimum height of each type of truss, assessed using a simple approximation method.

• 전기학회논문지
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• 제61권12호
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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.

• 한국철도학회논문집
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• 제13권3호
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• pp.290-297
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• 2010

현재 국내 표준열차하중은 일반철도와 고속철도로 나뉘어져 있으며, 일반철도의 경우 미국의 표준열차하중 혹은 과거 일본의 K하중을 기반으로 하는 L22, 고속철도의 경우 Eurocode의 LM71를 기반으로 하는 HL25 하중 모델을 적용하고 있다. 표준열차하중의 구조물 설계의 출발점이 되는 것으로 매우 중요한데 반하여 국내에서는 표준열차하중 개발과 관련한 연구가 진행된 바가 전무한 상황이다. 반면, 유럽과 일본에서는 선진 설계법 도입과 병행하여 합리적 표준열차하중에 대한 연구가 지속적으로 수행되고 있다. 최근 유럽에서는 새로운 표준열차하중인 LM2000 모델 개발 시 결정론적, 확률론적, 비용효과 분석 등 종합적이고 합리적인 방법에 의해 표준열차하중을 개발한 사례가 있다. 본 논문에서는 국내 표준열차하중 개발을 위한 단계적 접근 중 하나로서 결정론적 분석에 의한 표준열차하중 결정 과정을 분석하였다. 현재 국내 운행 중인 실열차를 기반으로 교량 단면력에 대한 여유도를 평가하여 합리적인 표준열차하중을 제시하고자 하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2814-2820
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• 2011

Railway bridge, contact of vehicle needs to design considering the running safety about the running train load of the railway bridge, ride comfort and dynamic safety. Also, upper structure of the railway bridge has to satisfy design standard about moving load(train). So, the railway bridge has to satisfy the requirement for vertical acceleration of the bridge deck, vertical displacement of the bridge and face distortion, which is suggested railway design standard in Korea(2011.5.). In this study, it was investigated and evaluated to the running safety about the running train load of the railway bridge, ride comfort and dynamic safety with railway design standard for steel composite(Steel Box Girder) railway bridge considering KTX, freight train and standard train load.

• 한국철도학회논문집
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• 제9권6호
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• pp.753-760
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• 2006

This paper presents the procedure and results of the numerical modelling that was carried out to investigate the stability of reinforced soil slopes under dynamic railway load. The two-dimensional explicit dynamic finite element method (ABACUS) was used to carry out the numerical analyses. To simulate the railway load, the top surface of the embankment was excited by the uniform distributed load whose frequency and magnitude was estimated by the measured railway acceleration during train passing. The embankment displacements and geogrid axial forces were analyzed to evaluate the stability of reinforced soil slopes under the dynamic train load.

• 산업기술연구
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• 제19권
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• pp.313-320
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• 1999

Steel railway bridge gets vibration from moving load ; additionally, this kind of moving load is going to be a sufficient reason, which causes fatigue damage to steel railway bridge. Fatigue damage and stress curve were raised by moving load depends on span length in steel railway bridge. In other words, stress curve appears index regarding every axial load in short span, but self weight lets stress curve's change decrease in proportion to increasing span length. Thereby, we have studied that how the steel railway bridge appear fatigue damage in proportion to span length of steel railway bridge. Dynamic strain was measured in 4 steel plate-girder railway bridge during the trains was passing, which is located on the line of Kyoung-chun railway. And time history response analysis has been done in order to ensure actual survey. The results of this study show the decreased of the fatigue damage in steel railway bridge according to length of span. This paper ends is bases research of fatigue design in steel railway bridges according to span length.

• 전기학회논문지
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• 제63권6호
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• pp.860-865
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• 2014

This paper proposes the method for determination of the capacities of ESS (Energy Storage System) and PCS (Power Conditioning System) for the peak load shaving based on the load data in the substation of urban railway. In addition, this paper analyze the actual measurement of loads in the substation of urban railway. The load of a weekday in the substation of urban railway is high around rush hours in the morning and evening, which is different from that of a normal substation. The required capacities of ESS and PCS become larger as the amount of peak load shaving is higher, and are affected from the patterns of daily load in the substation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1229-1234
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• 2005

Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a now pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.