Search results

An urgent issue is to increase the power factor of electric rolling stock. One of the ways to increase the power factor in the traction and regenerative braking modes was proposed by the scientists of IrGUPS - this is the use of a rectifier-inverter converter on IGBT with modified control algorithms. This solution allows to significantly reduce the consumption of reactive current from the contact network, increase the capacity of railway sections, increase the technical speed, increase the efficiency of the traction power supply system, and also increase the amount of electricity returned to the contact network in the regenerative braking mode. The study of the performance of this converter is of interest. The transported volumes of goods on the railway lines of the Russian Federation continue to increase. One of the key links in ensuring the specified growth rates of tonne-kilometer work is the availability of powerful traction rolling stock equipped with an appropriate traction drive. A powerful traction drive is characterized by the consumption of significant current. To ensure its flow over the arms of the converter, a parallel connection of power semiconductor devices is used. For modern converters of electric locomotives, 4 parallel branches of power switches are used in the arm. The features of the parallel operation of the arm branches affect the performance of the converter on IGBT transistors. This article proposes to consider one of these features, namely the influence of parasitic inductances on the distribution of currents in the parallel branches of the converter, depending on the connection point of the AC power bus. The study was carried out using the Matlab Simulink software package. The article discusses various options for the topology of connecting power buses and presents diagrams of the distribution of currents in the parallel branches of the arm for each connection method. An assessment was made of such parameters as the spread of the peak current of switching on the branches of the arm, the time of current equalization during the conduction period, and the difference in the magnitude of the current in specific branches. Based on the results of the study, as well as taking into account the existing dimensions for the equipment of AC electric locomotives, a conclusion was made about the most optimal option for connecting power buses.

In the Russian Federation, most railway accidents take place at passive level crossings. The majority of scientific papers on the topic of crossings deal with the improvement of active level crossings operation. At present, there is no effective way to improve safety at passive level crossings. The subject of the study is passive level crossings. The aim of the paper is to develop a set of preventive measures to avoid accidents at passive level crossings. The article describes the cases of traffic accidents at level crossings of the West Siberian railway, studies the scheme of passive level crossings and offers a schematic diagram of the accident prevention system at passive level crossings. The work algorithm of the accident prevention system at passive level crossings and the algorithm of giving the locomotive a notification of an emergency situation at passive level crossings are presented. Using the existing coding scheme of the train protection system as a transmission line for information about an emergency situation at a level crossing allows simplifying significantly the scheme of the developed system. The paper also calculates the maximum permissible time of occupation of the crossing by motor vehicles and the time of coding change in the automatic locomotive signaling system of continuous type. The proposed accident prevention system at passive level crossings does not require additional equipment to organize the communication channel and is cost-neutral. Equipping passive level crossings with this system will improve train safety, reduce the number of accidents and increase the efficiency of the railway transport complex in general.

The article sets forth the procedure for preparation of energy saving programmes for the system of traction electric supply. List of key measures aimed at reduction of losses of electric power in traction network and equipment of traction substations, and also on increase of carrying capacity of railway sections. Presents the results of studies evaluating the potential of energy efficiency of the system of traction electric supply of Railways.

The article describes a method for controlling electrical loads rail consumers using energy storage. Different types of energy storage devices used in rail transport were considered. Performed the optimization problem formulation, selected criteria and the method for its solution. As an optimization method used the method of Hooke-Jeeves. A method is proposed to determine the optimal parameters and the optimal control law of charging and discharging of the energy storage. The criteria and calculation expressions that can be used in the design and feasibility study of the effectiveness of implementation of the stationary energy storage for managing schedules loads rail consumers. The mathematical expression was proposed for the energy storage capacity determination. Two criteria were considered in the optimization problem: a minimum active power losses and minimum reduced costs, and a comparison of results. The form factor used to evaluate the changes in electrical loads. Control of reactive power in the AC mains can realize using semiconductor converters and an energy storage. As a variant the electrochemical cells (lithium-titanate batteries) could be used as energy storage for rail electric consumers. As a result, optimal control of electrical loads allows to get technical and economic effects.

The issue of optimizing the use of lubricants to reduce the in-intensity wear of the wheels of traction rolling stock is considered in the work. The purpose of the work and the test objects are defined. The types of tests, their procedure, short description of tests, and compliance with the technical assignment and technical requirements are presented. Design work was carried out on the development of solid antifriction elements for lubricating the ridges of locomotive wheel pairs (hereinafter referred to as TAEL rods). Bench tests were carried out on a universal friction machine 2168 UMT «Unitrib», which models the contact interaction of the wheel with the rail when applying solid lubricant to the wheel ridge. The linear wear rate of the lubricating element and the friction moment were determined. Explutation tests were carried out on the basis of traction rolling stock of the series VL80, 2TE25KM, ChME3. Such indicators as average intensity of development of cores of TAEL and lubricant cores and average intensity of wear of crests of wheels were defined. The results of laboratory bench-out and operational tests of TAEL rods were obtained in accordance with the order of admission of lubricating materials for wheel-rail contact for use in locomotive combs operated on the railways of the Russian Federation. Operational tests of traction rolling stock were carried out at the landfills of the North Caucasus, South-Eastern and Volga Railways. During the performance test period, the following indicators were monitored: assessment of the impact of TAEL on the wear of co-forest steam ridges, assessment of the actual resource of TAEL production, assessment of the functional capabilities of TAEL rods. According to the test results, the developed TAEL rods received permission to use Russian Railways for the infrastructure. At the same time, the wear rate of the ridges of the wheel pairs of locomotives equipped with TAEL in comparison with the standard rods decreased to 50 %.

The results of field researches of the oscillatory process subgrade erected with sand dunes. The analysis of the oscillations records of particle of sand dunes at the main field, in the frame and be-hind of the subgrade. Given findings change of the value of oscillation amplitudes of dunes sand depending on the speed of trains. Analytical dependence of definition of attenuation of fluctuations in a body of subgrade from sand dunes and behind its limits is revealed.

The article is devoted to the experimental study of the force interaction of the working elements of a disc brake in order to establish the dependence of the coefficient of static friction, taken as a criterion for the potential frictional properties of the friction unit, on the pressing force of the brake linings to the brake disc and the coefficient of mutual overlap. The experiments were performed on a full-scale stand, the basis of which is an electric drive with a power of 75.0 kW and a full-scale disc brake of the LT-10 tram. The stand allows to measure the static friction force under conditions of real forces, pressures, geometry of the contact area, as well as the coefficient of mutual overlap. TR119 and UT22-B were taken as friction materials for brake linings, in the first of which, according to the characteristics declared by the manufacturer, the coefficient of friction decreases with increasing temperature, in the second it increases. During the experiments, these materials worked in a pair of friction with the material steel 35, from which the brake disc is made. The experimental results were processed using the methods of mathematical statistics and presented in graphical form. It is shown that in the range of loads realized during braking, the stress-strain state of the contact area of the working elements of the disc brake according to the criterion of microstrains corresponds to an unsaturated elastic contact. This type of contact is typical for the studied overlap coefficients (0,33; 0,66; 0,98). It was found that with an increase in the pressing force of the brake linings to the brake disc, the static friction coefficient tends to decrease, and with an increase in the overlap coefficient, an increase in the static friction coefficient is observed for all specified values of the pressing force. At the same time, the UT22-V material is characterized by lower values of the coefficient of static friction compared to the TR119 material. Field of application of the results: development and design of advanced designs of disc brakes.

With the advent of new series of locomotives, the development of heavy freight trains, the increasing speeds of passenger trains, the introduction of innovative technical means and technologies, the degree of influence of various indicators on energy consumption is redistributed. The aim of the article is to develop a methodology for monitoring the efficiency of locomotives when changing the set of operational factors. This will make it possible to more accurately determine the estimated change in specific energy consumption, which in turn will increase the objectivity of the assessment of the causes of changes in the energy intensity of transport and will help to reduce energy losses.

The subject of consideration of this article is the traction electric motor of a diesel locomotive. Traction electric motor (TED) is the main element of power transmission, therefore, the reliability of the locomotive as a whole depends on its reliability. The main causes of failures of traction motors in operation are considered. Based on the analysis of statistical data, it can be argued that the most damaged part of the traction motor is its armature. In the context of the introduction of new classes of insulation heat resistance by the new standard - GOST 2582-2013 - ensuring the reliability of the anchor is especially important. The causes of the most common failures of TED in operation have been established: violation of the integrity of the insulation of the winding by the sharp edges of the extreme sheets of the anchor core iron package when laying the winding in the grooves of the core, vibration of the extreme sheets of the anchor core iron package when exposed to electromagnetic forces with a frequency multiple of the number of poles of the electric motor, imperfection of the fastening system of the frontal parts of the armature winding, mismatch of the coefficients of temperature linear elongations copper windings, insulating materials and steel core of the armature. The result of the analysis of the design of serial TED were proposals to improve the design of the nodes most prone to failures. To eliminate breaks in the insulation of anchors in operation, a new design of pressure washers and an improved technology for impregnating anchors of commercially produced traction electric motors of locomotives are proposed. The proposed design solutions can be used both when creating new TED designs for promising locomotives and when upgrading serial designs. Thus, the application of the proposed design and technological solutions will increase the reliability of the diesel locomotives.

The technique of a prediction of coefficient of Hurst on the basis of various ways of a prediction is offered. For a choice of a method of a prediction errors of underestimation and revaluation are entered. It is shown that if not to consider fluctuation of value of coefficient of Hurst, the demanded parameters of a multiservice network, the allocated resources of a network used for calculation or will be insufficiently for high-quality service of the arriving traffic (that is QoS indicators will worsen), or resources of a network will be inefficiently used.

The work is devoted to the consideration of the possibility of using composite materials with an aluminum matrix in the design of electric transport pantographs. Currently, there is a tendency to increase the speeds of electric transport. This fact requires reliable and high-quality current collection, which can be achieved by reducing the mass of the current collector design, including through the use of composite materials. The possibility of using composite materials in parts and assemblies of current collectors operating under conditions of increased current loads and at high speeds of movement and the mechanical characteristics of the traditional ones used in the carriage design and the composite materials proposed for use are analyzed. The design of a carriage of high-speed electric rolling stock has been developed, in which an aluminum matrix composite material was used as a structural material. Statistical modeling using the finite element method in the SOLIDWORKS Simulation software package was performed. Comparison of the strength characteristics of carriage assemblies made of traditional materials and aluminum matrix composite showed the possibility of reducing their weight in the case of composite use without reducing the strength of structural elements. The static characteristic of the carriage in which the composite material was used coincides with the static characteristic of the carriage made of traditional materials, which confirms the possibility of using an aluminum matrix composite without making significant changes to the carriage design. To evaluate the dynamic characteristics of the composite carriage and its effect on the dynamic characteristics of the pantograph, modeling was carried out using the methods of multibody modeling of SOLIDWORKS Motion. The obtained simulation results indicate an improvement in dynamic characteristics when using composite materials, which has a beneficial effect on the reliability and quality of current collection.

The method of practical realization of decision of the special case of a transport task is examined. It allows to find optimal and the set amount of routes the nearest to it on the size of criterion of optimality. A method provides large flexibility in the decision of questions of planning of optimal organization of vehicular process at making, both strategic plans and operative plans in case of origin of situations of type "accident", "congestion", or other force-majeure circumstances.

Researching subject which are presented in article is the emergency modes in 25 kV traction power supply systems caused by the short circuits (SC). The research purpose consisted in the analysis of calculation SC currents errors evolving from the reactances determined by SC power at the simplified modeling of external network. For achievement of formulated purpose comparative calculations of SC currents for a number of standard schemes of 25 kV system when using full models in phase coordinates and with use of simplified electric power system (EPS) reactances are executed. Modeling has shown that calculations of SC currents of contact network of deadlock substation by EPS reactances give the acceptable accuracy for feeder current of substation near which there is a short circuit. The calculation error of remote substation feeder current can reach +100% at SC power on inputs of substation about 300 MV·A, but decrease to values about 10% at the SC power of 2500 … 3000 MV·A. At food of group of traction substations from two 110 kV lines calculation error for equivalent reactances it is much less, however at SC power about 300 MV·A errors reach 35% and decrease to 10% at SC power on substation inputs more than 550 MV·A. Variant of traction substations power supply from two 220 kV power lines differs in small calculation errors of SC currents for equivalent external power supply reactances: differences from full scheme don't exceed 9% at SC powers of 1200 MV·A or more. The received results can be used at improvement existing and creation of new definition techniques for SC currents in 25 kV traction networks.

The aim of this article is results representing of work focused to automation of electrical machines armature coils diagnostics process based on wave response method. Technical decisions used in development of mobile device for insulation diagnostics via wave response method described. Techniques of generalized diagnostics coefficient calculation described. Article presents test results of NB436V and NB-431P auxiliary machines installed VL-10 electromotive.

The article analyzes the results of the assessment operating time and power consumption of compressor equipment service locomotive depo Moscow West-Siberian Railway. The algorithms for data preparation for modeling and evaluating the efficiency of the production process are presented. The main factors influencing the power consumption of the compressor equipment are determined and the results of the assessment of their influence are presented. On the basis of the dependences obtained, a mathematical model of the process of power consumption of compressor equipment using fuzzy neural networks and its accuracy is determined. The interface of the developed program complex is presented at an estimation of influence of factors on process of power consumption of the equipment service locomotive depo Moscow West-Siberian Railway.

The problem of the assessment of the continuous welded rail track stability at its thermal elongation is considered in this paper. The method for determining the stress-strain state of various elastic objects developed by the specialists of JSC “VNIKTI” is analyzed on the example of a rail of a continuous-welded track section. The essence of the method is to determine the dependence of the natural frequencies of rail vibrations on the applied longitudinal force. As a means of obtaining such a dependence, a modal analysis of a track section model carried out using the finite element method was chosen. The methodology for calculating the natural frequencies of rail vibrations and the description of the created model of the track section and its properties are presented in the paper, the contact interactions of the model elements and boundary conditions are defined in it. Calculations for determining the natural frequencies and modes of rail vibrations are performed, the first four modes of rail vibrations obtained by calculation and experimental methods are shown. The assessment of the adequacy of the created model of the track section is carried out by comparing the natural frequencies and modes of rail vibrations obtained by calculation, by modal analysis methods and experimentally when measuring vibrations on a full-scale object - assembled rails and sleepers, having a similar design compared with the model. It was decided to use the distance between the vibration nodes as a criterion for comparing the obtained modes of natural rail vibrations. The first mode of vibration is selected for further studies. Calculations were carried out and the dependence of the natural frequency of the first vibration mode of the rail on the longitudinal force applied to it was obtained using the created model of the track section. The obtained dependence can be used in the method proposed by the specialists of JSC “VNIKTI” in order to determine longitudinal force, applied to the rails on the full-scale section of the continuous welded rail track.

The article presents the equivalent circuit of three conductors, taking into account their mutual influence. The equivalent circuit contains the resistance and inductance of each conductor, the conductivity and the capacitance of their insulation relative to the earth, as well as the mutual inductances, conductivities and capacitances of the insulation between the conductors. The mathematical foundations of calculating the distribution of electrical quantities in the system of three conductors are considered, taking into account their mutual influence. An iterative incremental model of the software life cycle was chosen as the basis for automating this calculation, taking into account existing approaches to software development. Specific features of specialized software are specified. A structural scheme of the software complex and a block diagram of the calculation algorithm are proposed. The algorithm is based on the iterative calculation of currents and voltages for three conductors, taking into account their mutual influence. In accordance with the chosen model of the life cycle of the software, three versions of software with different functionality have been developed. This allowed us to effectively organize the processes of testing, debugging and implementation. As a result, the software complex has a window interface containing four tabs and allowing to enter the initial data for the calculation, display the results in the form of graphs and tables. For saving the results of calculations, a connection with the database has been implemented.

Under consideration the method to determine the positive and negative sequences of fundamental voltage and current harmonic in the three-phase power supply systems, based on the Clark transformation and adaptive filtering.

The article covers stability and accuracy for restoration of uneven sampled signals, using basis functions. The accuracy and stability are explored for different transfer system orders, period between basis functions and offset of the basis functions system against restored samples.

In article the issues of electric power imbalance in train traction research are considered, including the method providing an estimation of the contribution of imbalance components to its total value with the possibility of their separation between the participants of the transportation process: the electrification and power supply service, the automatics and telemechanics service, the directorates of locomotive traction and motorized rolling stock. Described method allows in more detail to analyze the factors that affected the change in the components of imbalance and further develop organizational and technical measures to reduce it.

Efficient use of railway rolling stock is an important aspect of the transportation industry. The presence of wagons on access roads plays a significant role in the overall performance of logistics chains. The article discusses the main approaches to rationing the time spent by wagons, analyzes existing problems and suggests optimization techniques based on modern technological solutions. The purpose of this work is to develop a methodology for rationing the time spent by wagons on access roads, aimed at reducing downtime and increasing the speed of cargo turnover without compromising the quality of cargo handling. The research method includes an analysis of the current state of operation of access roads, identification of the main problems and limitations, as well as the application of the principles of queuing theory. The technological and interoperable components of the time spent by wagons on access roads, including unproductive downtime, are considered. Special attention is paid to the complexity of applying the analytical method due to the difficulties of classifying access roads, the need for accurate data collection and the approximation of the formulas used. The scope of the results includes planning and optimizing the operation of access roads of industrial enterprises, terminals and warehouse complexes integrated into multimodal supply chains. The proposed methodology makes it possible to take into account the specifics of technological operations, the technical characteristics of rolling stock and infrastructural constraints. The practical significance of the work lies in the possibility of reducing the downtime of wagons, improving the use of rolling stock and increasing the overall efficiency of the transport system. The implementation of the proposed approaches contributes to the adaptation of access roads to changes in external and internal conditions, as well as the integration of advanced technologies into logistics process management.

The analysis of wave processes in the system including electric transmission lines, traction substations, AC traction network and electriclocomotives is necessary to accurately assess to energy performance of its work. This system contains concentrated and distributed parameters, consequently the analysis of such a system is difficult and the rolling stock which is also a part of this system represents a dynamic load. The proposed mathematical model of the alternating current traction power supply system allows us to consider electromagnetic processes at its various points taking into account wave processes.

In this article, the problem of assessing the stability of a continuous welded rail track during its thermal elongation is considered. The article considers the method of determining a stress-strain state of continuous welded rails proposed by specialists of JSC “VNIKTI”, which is based on the use of the dependence of natural frequencies of rail vibrations on the applied longitudinal force. Such a dependence can be obtained with the help of the calculation method using a finite element model of a track section. The reliability of such a dependence can be assessed by comparing the results obtained using the calculation method with the actual values of natural frequencies of rail vibrations, depending on the longitudinal tensile and compression force applied to a full-scale facility. The track panel is chosen as such a facility. In order to obtain the actual dependence of natural frequencies of rail vibrations on the applied longitudinal force, a specialized test bench is developed. The development of the test bench included designing the test bench elements and creating finite element models of main load-bearing elements of the test bench - a stop, support and traction, as well as their subsequent strength calculation to confirm the operability of the selected design under necessary loading conditions. The strength is assessed using the safety factor for the yield strength. Calculations using the finite element method have shown that the test bench design has sufficient strength. The developed test bench will allow performing tests for the purpose of the verification obtained using the calculation method of the dependence of rail vibration frequencies on the longitudinal tension and compression force applied to it, as well as for testing the proposed method to assess the rail longitudinal force during its thermal expansion.

Optimization of insulation of walling of building walls is proposed, taking into account the relationship of structural, heat engineering, operating parameters and economic indicators. The purpose of research is to determine the optimal value of the thickness of the insulation with the heat-insulating material of the object, taking into account the thermal energy released to it. The study used methods of mathematical modeling of heat transfer, an optimization problem. The results of the study of the influence of the thickness of the insulating material on the technical and economic efficiency of the building's consumption of energy resources and material costs are presented. The results showed a decrease in heat losses through the building envelope, consumption of heat and electric energy for the heating, ventilation system and reduced costs.

The paper is devoted to the calculation of the electrical quantities distribution in the system of three conductors. The first conductor is located on the surface of a uniform soil and the other two conductors are located at depths of h and h . As result, analytic expressions of current, potential and leakage current density in the first underground construction with considering the influence of the second construction was obtained. The influence of second construction increases the value of electrical quantities in the underground construction. The analytic expressions were obtained using Fourier transform method. The analysis showed the influence of the leakage current and insulation resistance of the second construction on the electric quantities distribution in the first construction