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In this study, the simulation of an electrification system and traction power system of a 25 kV AC feed railway line was performed with all its subcomponents using MATLAB/Simulink. The power ow theory was used while modeling the railway electrification system. The transformer substation, catenary, rail, and vehicle were modeled together with the operational data. This model is used in order to determine the number of transformers, the distance of feeding centers, and the frequency of trips. The optimum design of electrification projects depends on these criteria. A dynamic structure was created with a new algorithm developed for vehicle load characteristics. The simulation of the electrification system and traction power system is performed before the analysis stage, together with the vehicle and other design parameters. This analysis is performed for the best performance of the systems. In this study, the power simulation of the railway was conducted for three different operation scenarios using MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

Based on simulations of passenger transports of two representative types of metro trains in China, this study analyzes efficiencies of energy consumption and passenger transport of a metro train in the effect of its target speed, formation scale (FS) (i.e., length and mass of the formation), relative traction capacity (RTC) (i.e., ratio of the motoring cars to all its cars), and so forth. It is found that increasing energy cost efficiency of ametro train with decreasing its target speed is evidently accelerated with reducing its RTC below 0.50 at the expense of obviously lowering its passenger transport efficiency. Moreover, if the passenger capacity of the train is sufficiently utilized, increasing its FS for the same RTC is easy to have its passenger transport efficiency improved significantly even for a meanwhile much decreased target speed with consuming energy less intensively. Therefore, metro trains in peak hours may take comparatively big FSs, relatively high target speeds, and RTCs over 0.50 tomeet usually urgent and large-scale travel demands in such time. In contrast, trains in nonpeak hours ought to have small FSs, relatively low target speeds, and RTCs smaller than 0.50 for mainly avoiding energy waste. [ABSTRACT FROM AUTHOR]

Abstract: This paper derives the energy efficiencies and CO2 emissions for electric, diesel and hydrogen traction for railway vehicles on a well-to-wheel basis, using the low heating value and high heating value of the enthalpy of oxidation of the fuel. The tank-to-wheel and well-to-tank efficiency are determined. Gaseous hydrogen has a WTW efficiency of 25%low heating value, if produced from methane and used in a fuel cell. This efficiency is similar to diesel and electric traction in the UK, US, and California. A reduction of about 19% in CO2 is achieved when hydrogen gas is used in a fuel cell compared to diesel traction, and a 3% reduction compared to US electricity. [Copyright &y& Elsevier]

In this paper, a new energy storage system (ESS) is developed for an innovative subway without supply rail between two stations. The ESS is composed of a supercapacitor bank and a braking resistor. An inversion-based control of the ESS is deduced from the Energetic Macroscopic Representation of the entire system. This control scheme requires a distribution criterion in order to allow the energy to be shared between the supercapacitors and the braking resistor. Different cases are evaluated via a Hardware-In-the-Loop simulation using a reduced-power ESS. The suggested control enables the energy recovery to be maximal and secure the supercapacitor in real time for different track configurations. [ABSTRACT FROM PUBLISHER]

This paper investigates the procedure for starting a rotation sensorless PMSM under coasting condition for railway vehicle traction. To achieve restarting, the initial rotor position and speed at restart are needed. The existing algorithm for estimation of the initial position and speed cannot be applied to railway vehicle traction because of the greater speed range and the longer current sampling time. We propose a novel method for estimation of the initial speed. The estimation method is verified experimentally to assure that it is suitable for application to the railway vehicle traction system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(2): 56–63, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20764 [ABSTRACT FROM AUTHOR]

Braking or traction torque is regarded as an important source of wheelset skid and a potential source of derailment risk that adversely affects the safety levels of train operations; therefore, this research examines the effect of braking/traction torque to the longitudinal and lateral dynamics of wagons. This paper reports how train operations safety could be adversely affected due to various braking strategies. Sensitivity of wagon dynamics to braking severity is illustrated through numerical examples. The influence of wheel/rail interface friction coefficient and the effects of two types of track geometry defects on wheel unloading ratio and wagon pitch are also discussed in the paper. [ABSTRACT FROM AUTHOR]

Ventilated-type traction motors are widely used for railway vehicles. However, they require overhauls to clean inside them. In addition, they are a major noise source in railway vehicles. To solve these problems, we propose a totally enclosed-type traction motor using a permanent magnet synchronous motor that has the same weight power ratio as that of a conventional ventilated-type traction motor. In this paper, we report the test results of the proposed motor. The test results demonstrate that the temperature rise values are within its limit and the noise level is decreased by 10 dB compared to conventional motors. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(3): 71–80, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20079 [ABSTRACT FROM AUTHOR]

A comprehensive analysis of published experimental data and formulae for the determination of the electrical parameters of railway traction lines is performed. Several results from different authors are presented with particular attention to different assumptions and environmental conditions. Additional measurements were performed over the S Hz-200 kHz frequency range on a line section purposely prepared at La Spezia Railway Station (Italian State Railways). Theoretical formulae are considered and their validity is checked against experimental data. There is general accordance within common variations of the most critical parameters; calculations and measurements agree over the entire frequency range and are very accurate in the frequency range 50 Hz-50 kHz, where significant conducted disturbance lies. [ABSTRACT FROM AUTHOR]

The electrical behavior of sample steel traction rails is analyzed considering the resistance and the internal inductance. Measurements are performed on a sample rail with circulation of audiofrequency current superimposed on a 50-Hz supply current. [ABSTRACT FROM AUTHOR]

I. K. Brunel took the daring but carefully calculated decision to recommend the adoption of atmospheric propulsion on the South Devon Railway in 1844. The principle had been convincingly demonstrated in models and small-scale operation, and it offered attractive advantages on the heavy gradients between Exeter and Plymouth. However, the installation proved to be a costly failure for the South Devon Railway, and it was abandoned in 1848, when still incomplete. The immediate reasons for the failure were the problems involved in scaling up the atmospheric system for main-line operation, such as the maintenance of the pressure tube and its seal, and the provision of adequate pumping engines. But to some extent the atmospheric system was also overtaken by continuing improvements in steam locomotion, and in the long term any notional advantages the system may have possessed were surpassed by those provided by electric traction, so that there was no opportunity to give atmospheric railways another trial when the technical limitations had been overcome. [ABSTRACT FROM AUTHOR]

The article comments on the use of catenary and pantograph in railway trains. Electric traction are used to transfer electric power to the locomotive by an overhead current supply system, and the power is transmitted down to the motors through a pantograph that is mounted on the roof of the locomotive. Mechanically, the pantograph on the locomotive and the overhead current supply system on the track are two dynamic systems that interact with each other through the contact force acting on a collector strip of the pantograph head.