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This study addresses the issue of carbody hunting in an electric locomotive induced by low wheel-rail contact conicity. The main objective is to mitigate this unstable motion by optimising the location of yaw dampers while ensuring bogie stability under high conicity conditions. A field test was first conducted to observe the carbody hunting behaviour, and a detailed locomotive dynamics model was then developed and validated using experimental data. The impact of yaw damper locations on locomotive stability was investigated, taking into consideration different carbody modes. The findings reveal the mechanism behind the deterioration of carbody stability due to the yaw damper installation angle and two installation layouts were proposed to enhance the carbody stability. Comparisons were then made with traditional solutions using both linear and nonlinear analysis, and experimental validation confirmed the effectiveness of the optimised yaw damper locations in improving carbody stability. This research highlights the importance of optimising the yaw damper's location to suppress carbody hunting, providing valuable insights for railway engineers and offering a promising solution for enhancing stability in high-speed train. [ABSTRACT FROM AUTHOR]

Striving to increase the speed of rail vehicles and thus improve the comfort of traveling passengers at the same time, undertakes activities in the sphere of ensuring an appropriate level of safety of rail, passenger, and freight transport. One of the elements of activities in this area is the training of train drivers. Until recently, this training consisted of a theoretical and practical part on the vehicle, alongside an experienced train driver. Considering the increasing level of automation of railway traffic control systems and locomotive equipment, as well as training costs and requirements related to the introduction of TSI, it is becoming an increasingly common requirement to conduct practical training on railway vehicle traffic simulators, while the conditions in the simulator cabin and the trainee's feelings should correspond to the actual driving conditions. A locomotive driving simulator is a system consisting of a cabin of a suitable type of locomotive or EMU, mapped in 1:1 scale, coupled with a motion excitation system and computer programs connected together forming the software of the cab visualization and dynamics system. The basic program simulating the dynamics and kinematics of the cabin's motion is a program containing a motion dynamics model that generates signals forcing the movement of the exciters on which the cabin's platform is mounted. The correct operation of the simulation model depends on the created mathematical model, which can be built in several ways. This article presents the issue of building a mathematical model describing the dynamics of the rail vehicle motion, which can then be used in the simulation model of the simulator cabin motion. Two ways of proceeding in the process of approaching the construction of a mathematical model of rail vehicle motion dynamics will be presented, with the possibility of later use in creating a simulation model of the motion of the locomotive simulator cabin. One of the possible routes was used in the past in the construction of the EP09 locomotive simulator. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Drive for Locomotives is the property of Electric Drive for Locomotives Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The intelligent monitoring of electric locomotive loading is crucial in unmanned underground systems. A CNN-based monitoring scheme with migration learning was proposed to address efficiency, abnormality, and data acquisition challenges. Locomotive loading datasets are transformed, augmented, and equalized. Our model improves performance and training by modifying the fully connected layer, using optimized learning rate decay and adaptive algorithms. Training in PyTorch, the optimized VGG19-EL migration network achieves 99.85% recognition for 2-classifications, while the optimized RESNET50-EL migration network achieves 97.3% for 10-classifications. Overall, this study proposes a reliable and efficient model for liberating workers and monitoring locomotive loading. [ABSTRACT FROM AUTHOR]

The article presents the results of thermovision tests of the disc brake and the drive system components located in its vicinity on the 111Ed electric locomotive in field conditions. For this locomotive, tests were carried out on a test track to measure the temperature of the disc and the temperature of other devices that were installed close to the brake disc. These tests were performed pointwise, i.e. before and after the test, and continuously throughout the braking process. The article presents the methodology of thermal imaging research and the preparation of the camera for outdoor research with objects with different emissivity. Due to the rotating brake disc, it was decided to measure using an IR camera because measurements using thermocouples were very difficult and complex. In exceptional situations, temperature measurement using thermocouples is used, but it requires an extensive additional measurement system and signal recording, which is more expensive. Correct configuration of the IR camera to real conditions is extremely important because it directly translates into the increase in measurement error. [ABSTRACT FROM AUTHOR]

The problem of increasing the reliability of transport units during maintenance and repair in the locomotive depot is considered. The transient processes in the power circuit of the DC electric locomotive with traction motors was studied and a calculation scheme of a DC electric locomotive with the series connected traction motors was presented. When considering the magnetization curve linearization, small increments in the form of the system magnetization characteristic were applied. On the base of those results, it was determined that the duration of the transient process in the traction motor windings of the DC electric locomotives equals tt = 3τ. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is a plethora of methods in the global literature that can be used to measure CO2 emissions from electrified transport. But are these methods reliable, and do they offer us a true view of how much exactly of this greenhouse gas is being produced by electric rail transport? We answer this question by proposing an improved CO2 emission estimation model based on cargo transport. Unlike other works, our studies include four crucial steps: (1) estimation of energy consumption in electrified rail cargo transport; (2) estimation of energy losses in the railway traction system and high voltage transmission lines; (3) CO2 emission estimation in traditional powerhouses; and (4) determination of the intensity of the CO2 emissions from electrified rail cargo transport. Based on our method, we concluded that the intensity of CO2 depends not only on the type of fossil fuel used for energy production but also on the parameters of the cargo train, such as its length and weight or the total number of wagon axles (which depend on wagon type). The achieved intensity of CO2 emissions in electrified rail cargo transport slightly varies from those reported in the global literature. Among the most important reasons responsible for this are the conditions under which these tests were conducted. Nevertheless, our results shed new light on how CO2 should be measured. We proved that the decarbonization of electrified rail cargo transport will never be possible without infrastructure modernization. In addition, based on a case study, we also delivered knowledge on how to reduce the environmental impact of electrified rail cargo transport. [ABSTRACT FROM AUTHOR]

To control a single-phase dc electric locomotive with controllable excitation converters, control principles have been formulated that make it possible to implement specified characteristics of independent or sequential excitation of traction motors. The presented control algorithm implements axis-based control of currents and traction force of an electric locomotive without disconnecting the power circuit of traction motors, which provides a constant traction force. The results of mathematical modeling of the operation of a three-unit ac electric locomotive are presented. The proposed control algorithm provides a smooth increase in the traction force of the electric locomotive to the specified values by sequential activation of traction motors. [ABSTRACT FROM AUTHOR]

Purpose of the article is to demonstrate that a high-speed electric locomotive, driven by asynchronous motors in a hollow shaft arrangement and swing-out couplings, can generate corrugation conditions on the surface of new and smooth rails on straight and curved track. Most studies carried out in this area is usually concerned with the response of the power train to kinematic excitation from a track where corrugations are already present. The novelty of the look presented in the article is to establish the influence of the vehicle's driveline and the parameters of a perfectly smooth formation track on the mechanism of corrugation. A four-axle EU11 electric locomotive, produced in Poland in the late 1990s, has been selected for analysis. A complete electro-mechanical model of the locomotive was built using the Vi-Rail software and prepared for simulation on straight and curved track. A non-linear model of wheel-rail contact was included and the contact forces were determined for the locomotive model in motion with the active power system. Unbalanced inertia forces generated by the scattering of stiffness characteristics of the coupling links, have been included to the propulsion system as an additional source of dynamic excitations. The complexity of the obtained results was influenced by the fact that simulation studies were carried out in both the time and frequency domains. The results obtained in the time domain were used to calculate the vertical and torsional vibration frequencies with respect to the driving wheelsets. One of the most important results of the simulation studies carried out is the determination of the effect of locomotive acceleration on the frequency of resonant torsional vibrations of the wheelsets in straight and curved track traffic. [ABSTRACT FROM AUTHOR]

The mechanical sensor of electric locomotive is easy to lose, leading to position measurement error, which deteriorates the performance of permanent magnet synchronous motor (PMSM) drive system. Therefore, a limp-home mode based on high-frequency injection sensorless strategy is proposed. The signal processing of conventional high-frequency rotating injection needs several filters, and the delay has an impact on estimated position, which is phase-based demodulation. In this paper, an amplitude-based demodulation strategy is proposed, which needs only one low-pass filter, meanwhile the digital control delay can be canceled automatically. Accordingly, the position estimation precision and robustness can be enhanced with the aid of proposed method. The feasibility and effectiveness of theoretical analysis is verified on an 18-kW PMSM drive system experimental platform. [ABSTRACT FROM AUTHOR]

Copyright of Smart Rail Transit is the property of Smart Rail Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper deals with the detection process of energy loss in electric railway hauling vehicles. The importance of efficient energy use in railways and cost-effective rail transport tendency toward regenerative braking energy are considered. In addition, the current situation and improvement opportunities to achieve efficient energy use are examined. Seven measurement series were performed with scheduled Railjet trains between Hegyeshalom and Győr railway stations in Hungary. This railway section is related to the Hungarian State Railways' No. 1 main railway line (between Budapest-Kelenföld and Hegyeshalom state board), which is a part of the international railway line between Budapest and Vienna (capitals of Hungary and Austria, respectively). This double-track, electrified railway line with traditional ballasted superstructures and continuously welded rail tracks is important due to the international passenger and freight transport between Germany, Austria, and Hungary. The value of the regenerative braking energy can be even 20-30% of the total consumed energy. This quite enormous untapped energy can be used for several aims, e.g., for comfort energy demand (air conditioning, heating-cooling, lighting, etc.) or energy-intensive starts. The article also investigates the optimization of regenerative braking energy by seeking the energy-waste locations and the reasons for the significant consumption. The train operator's driving style and habit have been identified as one of the main reasons. Furthermore, train driver assistance systems are recommended to save energy, which is planned for future research. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Operation modes of rolling stock at mining enterprises are considered and analyzed. The justification of the need to replace it with a modern specialized electric locomotive for quarry railway transport, equipped with an asynchronous traction electric drive and an on-board energy storage system, is presented. The determination of the parameters and structure of the on-board energy storage system, based on the condition of power compensation with limited power consumption from the traction network and ensuring the autonomous movement of the electric locomotive, is considered. This study was carried out by modeling the processes of energy exchange in the traction system of an electric locomotive. The use of lithium cells and supercapacitors in energy storage is considered. Variants of the hybridization of energy storage were studied from the standpoint of minimizing the weight, size, and cost indicators. It was established that reducing the mass of the energy storage device, which includes lithium cells and supercapacitors, leads to an increase in the cost of one kilowatt-hour of energy storage capacity, which reduces the attractiveness of capital expenditures for the creation of such an energy storage device. Hybridization of the energy storage device by combining lithium cells of different types practically does not improve its weight, size, and cost indicators. The recommended option is a storage capacity of energy based on LTO elements, for which it is necessary to select elements in order to minimize weight, size, and cost indicators. [ABSTRACT FROM AUTHOR]

Carbody hunting stability has attracted more and more attention due to its great influence on the dynamic performance of a railway vehicle. To fully understand the correlation between the wheel–rail contact relationship and the carbody hunting stability of an electric locomotive, the wheel–rail contact geometry analysis and the multi-body dynamics simulation are carried out in this work. The focus is on the influences of track parameters (including rail profile, rail cant and track gauge) on wheel–rail contact relationships and carbody hunting stability. A group of rail profiles are obtained by interpolating between the standard CHN60 profile and the worn rail profiles. The nominal equivalent conicity, the effective equivalent conicity and the wheel–rail contact bandwidth for a wheelset lateral displacement of ±6 mm are used to evaluate the wheel–rail contact relationship, while the lateral continuous comfort index is used to evaluate the carbody hunting stability. The simulation results show that keeping the rail cant at about 1/40 and reducing the track gauge and the wear depth at the gauge corner of rail can improve the carbody hunting stability of the electric locomotive. Furthermore, the effective equivalent conicity is a good choice to establish the relationship between the wheel–rail contact geometry and the carbody hunting stability. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve the conditions of coupling of the wheels of electric locomotives with rails it is proposed to use traction motors with independent excitation. For this purpose, it is proposed to use controlled excitation converters shunting each excitation winding in the power circuit of a single-phase dc electric locomotive. The power scheme of an electric locomotive and a mathematical model of the electric locomotive power circuit, which allows performing research on the operation of a controlled excitation converter, are given. The results of mathematical modeling of electromagnetic processes during operation of a controlled excitation converter in the normal excitation mode and in recharge and discharge modes are presented. The proposed solution provides smooth continuous control of the excitation currents of traction motors in independent and sequential excitation modes without breaking the power circuit and losing the traction. [ABSTRACT FROM AUTHOR]

This article presents a new method for the estimation of active power losses based on a "field" approach, i.e., on the theory of the electromagnetic field and the theory of propagation of electromagnetic waves in a dielectric medium. Electromagnetic waves are assumed to transmit energy from the traction substation to electric rolling stock through the airspace of the inter-substation zone (i.e., not through the wires of the traction network) and meet electrically conductive surfaces on their way. The waves are partially reflected from the surfaces and partially penetrate them, thus creating thermal losses, the determination of which is the main task of this article. The analytical expressions for specific losses of active power are obtained by solving the system of Maxwell's equations. Calculations of specific power losses in the catenary, rails, roofs, and bottoms of carriages and electric locomotives are performed. Power losses in carriages and electric locomotives are found to be at least 7%. A comparative assessment of the magnitude of total power losses of different types obtained by the "field" and "circuit" approaches is provided, which has established that "conditional" losses correspond to losses in rails, train carriages, and electric locomotives. [ABSTRACT FROM AUTHOR]

Copyright of Smart Rail Transit is the property of Smart Rail Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Buletinul AGIR is the property of Asociatia Generala a Inginerilor din Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In particular locations of the railway track, the excessively polished rail in the inner corner and the large rail cant will lead to an extremely low wheel–rail contact conicity. Consequently, the carbody hunting instability arises and deteriorates the ride comfort of passengers. In this paper, the carbody hunting instability of an electric locomotive is observed and tested. Combined with the analysis of wheel–rail contact and track condition, the ride comfort and running stability indices are evaluated. The dynamic model for the locomotive is established. The measured wheel and rail profiles as well as the curve radius and superelevation are integrated into the simulation model to reproduce the phenomenon that the carbody hunting displayed violent in the straight line while the abnormal vibration disappeared in the curve segment. The linearised and non-linear study on the optimisation of suspension parameters are carried out to solve the carbody hunting instability. Finally, the optimised measures that decreasing the series stiffness and damping of the yaw damper as well as the primary longitudinal stiffness are put forward, and verified by the on-track test. The investigation enriches the study of carbody hunting instability and gives some ideas to probably solve the abnormal vibration. [ABSTRACT FROM AUTHOR]

Severe vibrations and an increase in structural component fatigue failures have been observed on a freight locomotive class operating in South Africa. The cause of the severe vibration was linked to polygonal wheel wear dominated by the 20th order. This locomotive is powered by an alternating current traction system, which is controlled by a variable frequency drive. The variable frequency drive generates interharmonics that produce torque pulsations in the torque output from the motors. Interharmonics are determined by the alternating current supply frequency ( f g ) and the fundamental frequency ( f m ) of the variable frequency drive. The interference of the torque pulsations with a coupled resonance mode is reaffirmed as the root cause of the polygonal wheel wear. An experimental investigation of this phenomenon was performed by means of on-track testing. It was found that the 5 f g - 7 f m interharmonic excited the coupled resonance mode at approximately 42 km/h, which fixes the 20th-order polygon on the wheel. Two approaches that may eliminate the polygonal wheel wear were introduced and discussed. It was found that the forced excitation of the coupled mode by the 5 f g - 7 f m interharmonic could be avoided by postponing the speed where the alternating current traction motor's pulse mode changed. [ABSTRACT FROM AUTHOR]

The parameter perturbation of grid‐side equivalent inductance is a significant feature of the uncertainty in the single‐phase pulse‐width modulation rectifiers system for the electric locomotive. This characteristic tends to reduce the robustness of the rectifier system. This study handles these problems in the framework of the structured singular value, which helps to reduce the influence of model parameter perturbation, caused by measurement error and operation condition change, on the robustness. However, the conventional μ‐synthesis robust controls only reflect tracking and anti‐disturbance performance by weighting functions and ignoring the dynamic response performance. Herein, a direct current control (DCC) scheme based on improved μ‐synthesis is proposed. A desired closed‐loop transfer function is introduced to the conventional μ‐synthesis control structure to ameliorate the performance of the dynamic response. Furthermore, considering the external disturbances on the system control output, a suitable weighting function is used to restrict the external disturbance. The input–output relationship of the generalised open‐loop plant can thus be constructed accordingly. The proposed control scheme is compared with the widely applied proportional–integral‐based DCC scheme and the conventional μ‐synthesis DCC scheme. Hardware‐in‐the‐loop experiment results show promising dynamic performance as well as stronger robustness against parameter perturbation and external disturbances. [ABSTRACT FROM AUTHOR]

A locomotive is usually powered by the electromagnetic torque which is transmitted from the traction motor to the wheelset by gear transmission. In order to investigate the dynamic coupling effects from the gear transmission subsystems on the entire locomotive dynamics system, a comprehensive spatial locomotive dynamics model that considers the dynamic coupling effect of the gear transmissions is developed based on the multibody dynamics theory. In this model, the moved Marker technique is employed to calculate the dynamic mesh force of the gear pairs through which more accurate time-varying gear mesh stiffness excitations could be imported, which is the core of this dynamic model. Then, the established locomotive dynamics model is validated by comparing with the experimental test results. Finally, the dynamic effects of the gear transmissions are revealed by comparing with the results from the traditional locomotive dynamics model without considering the dynamic excitations from the gear transmissions. The results indicate that the gear transmissions have negligible effects on the vibrations of the carbody and the bogie frame, and on the lateral vibrations of the motor and the wheelset. However, the gear transmissions have significant effects on the vertical and, in particular, the longitudinal vibrations of the motor and the wheelset. Thus, it is suggested that the dynamic effects of the gear transmissions are considered in the locomotive dynamics modeling, especially when the vibrations of the motors and the wheelsets are taken into account. [ABSTRACT FROM AUTHOR]

In recent years, the AC‐DC‐AC electric locomotives have been wildly applied in electrified railways, deteriorating the current quality of network. Therefore, filters in electrified railways are essential. However, considering the volume and weight of filters, it is inappropriate to install them on locomotives. And resonance accident caused by high‐frequency harmonics is hard to suppress because of the low switching speed of high‐power Si‐based devices. In this article, a novel locomotive auxiliary converter control strategy with harmonic suppression function is proposed to filter harmonic currents injected into the traction supply network. By controlling the auxiliary converter, the strategy could complete the function of rectification and filtering, converting power for auxiliary equipment, filtering the harmonic current, and suppressing resonance accidents with the high‐frequency characteristics of SiC devices. For compensating high‐frequency harmonics, the parameters of main circuit and control scheme are analyzed to ensure a stable system. The feasibility of the scheme is verified by simulation and RT‐LAB hardware‐in‐loop experiment. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

A mathematical model of the "traction network–ac electric locomotive with four-quadrant converter" electrical system is proposed. Analysis of electromagnetic processes is carried out. Calculation formulas of the system parameters are derived, and the results are presented in graphs. A mathematical model of the electrical system is proposed. Software implementation of the proposed mathematical model and numerical studies of reproducible electromagnetic processes are carried out in the Simulink package of the MATLAB computing environment. Conclusions about the electromagnetic compatibility of electric locomotives with different traction converter structures are drawn. [ABSTRACT FROM AUTHOR]

The objective of this study is to develop a new online model for wheel wear that takes into account the track flexibility. The proposed model consists of two parts that interact with each other, namely, (a) a locomotive/track coupled dynamics model considering the track flexibility, which is validated by field measurement results, and (b) a model for the wear estimation. The wheel wear prediction model can be employed in online solutions rather than in post-processing. The effect of including the track flexibility on the wear estimation is investigated by comparing the results with those obtained for a rigid track. Moreover, the effect of the wheel profile updating strategy on the wheel wear is also examined. The simulation results indicate that the track flexibility cannot be neglected for the wheel wear prediction. The wear predicted with the rigid track model is generally larger than that predicted with the flexible track model. The strategy of maintaining unchanged wheel profiles during the dynamic simulation coincides with the online updating strategy in terms of the predicted wear. [ABSTRACT FROM AUTHOR]

Experiments were conducted at field sites to investigate the mechanism of the polygonal wear of electric locomotive wheels. The polygonal wear rule of electric locomotive wheels was obtained. Moreover, two on-track tests have been carried out to investigate the vibration characteristics of the electric locomotive's key components. The measurement results of wheels out-of-round show that most electric locomotive wheels exhibit polygonal wear. The main centre wavelength in the 1/3 octave bands is 200 mm and/or 160 mm. The test results of vibration characteristics indicate that the dominating frequency of the vertical acceleration measured on the axle box is approximately equal to the passing frequency of a polygonal wheel, and does not vary with the locomotive speed during the acceleration course. The wheelset modal analysis using the finite element method (FEM) indicates that the first bending resonant frequency of the wheelset is quite close to the main vibration frequency of the axle box. The FEM results are verified by the experimental modal analysis of the wheelset. Moreover, different plans were designed to verify whether the braking system and the locomotive's adhesion control have significant influence on the wheel polygon or not. The test results indicate that they are not responsible for the initiation of the wheel polygon. The first bending resonance of the wheelset is easy to be excited in the locomotive operation and it is the root cause of wheel polygon with centre wavelength of 200 mm in the 1/3 octave bands. [ABSTRACT FROM AUTHOR]

At the beginning of the paper, the analysis of energy efficiency indicators for freight electric locomotive with asynchronous traction drive feeding from AC network under various operating conditions including when working with trains of various masses is made. The movement on different railway sections is considered. The graphs of locomotive's speed, traction force, consumed power, and power for the traction obtained by on-board recorder are shown. In addition, the dependence of the locomotive's energy efficiency from the degree of using of its available traction capacity has been experimentally obtained, the greater is the using of the locomotive's capacity, the greater will be its efficiency. On the basis of the performed analysis of energy efficiency indicators for various operating conditions, the proposals for their improvement are formulated. The algorithm ensuring the stabilization of the instantaneous value of efficiency at partial load to its nominal level at full load is presented. This algorithm is the implementation of Scalable Power Control Technology with respect to the problem of reducing electricity consumption for electric locomotive traction. The direct the experimental confirmation of energy consumption reduction for freight electric locomotive due to the application of our proposals (under the same operating conditions of the locomotive) is obtained. [ABSTRACT FROM AUTHOR]

This paper presents a detailed investigation of out-of-round electric locomotive wheels through extensive measurement conducted at field sites. More than 2000 wheels, of seven types of locomotives widely used in China, have been measured since April 2013. The measurement results indicate that two types of freight traffic locomotives suffer serious polygonal wear problems with center wavelengths ranging from 160 to 315 mm. The dominating wavelength is 200 mm. Therefore, the investigations are mainly focused on the two locomotive types. The other types, which are taken for comparison, do not exhibit obvious polygonal wear. However, they exhibited more or less eccentricity. The effect of wheel re-profiling on the wheel polygon is also investigated and discussed. The dominating harmonic orders and center wavelengths after re-profiling are consistent with those before re-profiling at the correct circumstances, if the center wavelength of the polygonal wear is about 200 mm. [ABSTRACT FROM AUTHOR]

An assessment of the overall performance of 3ES5K alternating-current electric locomotives with a collector drive in the regimes of traction and recuperative braking using the concrete example of a staged route between the Khabarovsk-2 and Bikin stations of the Far East Railroad is given in this article. Real traction and brake characteristics of a 3ES5H electric locomotive in the case of a cargo train of large weight and length are shown. Analysis is carried out of all the characteristics of a 3ES5H electric locomotive, and they are compared with the movement of a 2ES5 electric locomotive with an asynchronous drive. It is determined why 3ES5K electric locomotives are more power efficient than 2ES5 ones. [ABSTRACT FROM AUTHOR]

Abstract-'The Technical Maintenance Regulations of Russian Federation Railways' and 'The Arrangement Regulations of the Russian Federation Railways Traction Power Supply System (TsE-462)' set out clear requirements to ensure minimum voltage in the aerial contact wire for freight and high-speed passenger train movement. These requirements are confirmed by the Norms of the European Electrotechnical Standard EN 50163 (1995). However, the voltage norms at traction substations (TsE-462) are in contradiction to the maximum continuous voltage in the aerial contact wire demanded by Railway Research Institute (VNIIZhT) and accepted by EN 50163 Standard. This paper proposes using continuous voltage at traction substations in the normal operating mode in the range of from 3600 (the minimum value) to 3700 V. The maximum voltage (3700 V) was obtained as a result of electrical calculation of the traction power supply system at the track sections with hard mountainous track profile while running trains with an increased weight of 6300-9000 t or two combined trains with a combined weight of 12000 t with powerful electric locomotives of 2ES6, 2ES10, and 3ES10 series. This voltage value was confirmed by long-term operation on a Tyumen-Yekaterinburg-Perm-Balezino track section of 923-km length with voltage stabilization at the level of 3650 V at the traction substations. The voltage levels at the traction substation buses are provided by a contactless automatic control system (CACS) with ±0.6% inaccuracy. The maximum voltage in the traction substation buses is acceptable and equal to maximum aerial contact wire voltage (4000 V) under the recuperation mode. [ABSTRACT FROM AUTHOR]

A device for improving the power factor for ac electric locomotives that are based on an adjustable passive reactive-power compensator is described. This compensator configuration allows an increase in the power factor of an electric locomotive in all its operating modes. The control of the compensator unit is based on the method of extremal voltage control at the output of an autonomous voltage inverter (AVI). The voltage is chosen on the basis of the numerical differentiation of the dependence of the power factor on the AVI voltage. The mathematical simulation of the operation of the compensator with an extremal regulator, which was performed in the MATLAB package, showed that the proposed device is highly efficient. [ABSTRACT FROM AUTHOR]

Failures of reversible converters (RCs) in ac electric locomotives can cause failures of ac locomotive power equipment. Depending on their severity, the electric locomotive can be placed in one of several different modes, from partial loss of function to complete halting. With this in mind, it becomes important to develop (upgrade) diagnostic support of RCs and decide on a procedure of diagnostics that would make it possible to identify defects of RCs not only in the running mode, but also in the stationary mode, during scheduled and unscheduled repairs of an electric locomotive. To provide a more reliable evaluation of the technical condition of the RC functional control, is necessary to check the connections between the converter parts. It is also important that the diagnostics allows modifications of input signals supplied to the converter inlet, depending on the results of a scheduled check for specifying the diagnosis and troubleshooting. The stationary automated diagnostics system makes it possible to determine the technical condition of an RC in the rectifier mode in stationary conditions and is intended for use in testing an RC exposed to simulated operational effects. In the current phase of development, the diagnostics system allows evaluation of the capacity and correctness of implementing the RC control algorithm in all four adjustment zones, as well as identification of RC leg interruptions. Together with the algorithm for RC diagnostics, the suggested method makes it possible to conduct functional tests and identify a particular defect, as well as check the operation of the RC by monitoring the work of the converter as a single diagnosed object before the RC is installed on the locomotive. This will ensure faster and more reliable diagnostics and make it possible to almost completely avoid the use of RCs with unidentified defects. [ABSTRACT FROM AUTHOR]

In an electric locomotive, the failure of any element or unit of the control system does not have to cause damage to power circuits or emergency operation. A control strategy for a four-zone ac-dc power converter with a discharge diode branch, which is connected in parallel to the rectified current circuit, is proposed. Such control improves the switching conditions of thyristors and allows reduction in the switching time and a decrease in the equivalent inductive reactance of the ac circuit; in addition, it provides reservation due to simultaneous switching of paralleled thyristor branches and skipping of control pulses in any control zone. [ABSTRACT FROM AUTHOR]

Comparative analysis of results of modeling the motion of two 2ES5K electric locomotives on a standard railway section with a hilly profile (type III), which is regulated by the normative documents, is carried out in this paper. These electric locomotives are equipped with controllable reactive power compensating devices. As a result, we obtained consumption graphs of active, reactive, and apparent energy for the electric locomotives, as well as their recoil by the traction substations. We calculated the specific energy consumption for traction based on these data, as well as the average factors of power and reactive power. Comparison of the simulation results for electric locomotives with the standard power scheme and electric locomotives equipped with the onboard reactive power compensating devices is carried out using this data. It is shown that the use of controlled reactive power compensators leads to a significant reduction in the consumption of reactive power by the electric locomotives and losses of active energy in the traction network. [ABSTRACT FROM AUTHOR]

Copyright of Transport Problems: an International Scientific Journal is the property of Silesian University of Technology, Faculty of Transport and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Monitoring the wheel-rail adhesion state and maintaining the stability are the key issues to ensure the safety of locomotives with increasing running speed nowadays. In this paper, a novel methodology is proposed to determine the wheel-rail adhesion stability. It is proved that when the adhesion state is in the unstable region, the transmitting factor which is defined as the ratio of the adhesion force in the wheel drive force is negative. Based on this principle, we propose a novel adhesion stability detector via measuring the wheel drive torque and the wheel rotational speed. It is free from measuring or determining the chassis speed, creep ratio, and optimal creep ratio, which are usually difficult to obtain in practical applications. In addition, the proposed methodology can evaluate the adhesion state dynamically regardless of the specific wheel-rail conditions. Numerical simulations are carried out to validate its effectiveness. [ABSTRACT FROM AUTHOR]

Copyright of Transport Problems: an International Scientific Journal is the property of Silesian University of Technology, Faculty of Transport and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A method of improving the power factor of single-phase valve rectifiers for ac electric locomotives is considered. This paper is important because of the need to design and improve technological means of ensuring energy efficiency of electric transport and solve the important problem of conserving energy. A previously proposed circuit design of the four-zone ladderlike valve rectifier made it possible to improve the power factor by 4-5% by modifying the topology of valve gates and the algorithms of their control. The considered rectifier was further improved by changing the principle of regulation by average rectified voltage in the domain of the lowest power factor values corresponding to zone 1. The shares of reactive power and levels of higher harmonics determined by the shift and distortion factors were calculated for sectoral regulation. The efficiency of sectoral regulation as a method of improving the power factor of the four-zone ladder-type rectifier for ac electric locomotives was evaluated. [ABSTRACT FROM AUTHOR]