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The article presents a universal energy-efficient stand for load testing of asynchronous traction motors, and DC motors. It is proposed to use two options of schemes for testing of traction DC motors with serial excitation and asynchronous motors, and traction motors DC parallel (independent) excitation and asynchronous motors, each of which allows you to implement energy-efficient test method - the method of mutual loading. Given the advantages of the use of the proposed stand. The calculation of the main parameters recorded during the test: currents, voltages and power are invited to perform with the help of mathematical models. Each of the mathematical models takes into account the work of the subjects of the asynchronous traction motors and traction motors DC series or parallel (independent) excitation) by the method of mutual loading: electrical and mechanical link. In conclusion, the article sets out the intended results from the implementation of energy-efficient universal stand for load testing of asynchronous traction motors, and DC motors.

The subject of research is the evaluation of the effectiveness of different modes of energy-optimal control of the movement of a freight train of a unified mass by AC freight electric locomotives of the Uz-El series with asynchronous electric motors on the flat section of Kokand - Andijan of the Uzbek railway. Purpose of the study: substantiation of the main performance indicators of electric traction locomotives, taking into account the given traffic schedule, using various options for the optimal mode of controlling the movement of a freight train with a unified train mass on a real flat section of the Uzbek railway. The methods and methodology of the research are the theoretical foundations of locomotive traction, the mathematical theory of optimal object control, as well as the C # programming language (C Sharp) with the development of mock-up applications in the Microsoft Visual Studio 12.0 programming environment.As a result of the study, energy-optimal curves, kinematic parameters of the movement of a freight train and parameters of the main indicators of the energy efficiency of the investigated electric locomotive for different options for traction calculation on the real flat section of Kokand - Andijan of the Uzbek railway were obtained. The obtained kinematic parameters of the movement of freight trains with a unified mass of the train and the parameters of the efficiency indicators for the use of the studied electric locomotives can be used in the Kokand locomotive depot, which will allow developing regime maps for driving freight trains by these electric locomotives, depending on the level of complexity of the track profile and various conditions for organizing rail transportation of goods.

A study of the influence of non-linear parameters spring of a freight car suspension (stiffness spring, length base of a bogie, roughnesses railway) on the amplitude and phase fluctuations bouncing body is completed. Defined own vibrational frequency jumps car body as a function of the parameters.

The article sets the task of determining the level of dynamic loading in the «trolley-leash-traction motor» subsystem to reduce the dynamic impact in the «locomotive-path» system. The model of vertical vibrations of traction rolling stock, obtained on the basis of the Lagrange equation of the second kind, in the form of a system of fourteen differential equations allows us to estimate the loading of locomotive units in operation, integrated using the MathCAD application package. The approximation of random disturbances using the spectral density of the path irregularity of Professor A. I. Belyaev is chosen as the spectral density of random disturbances. A more detailed design scheme of the crew has been compiled and in order to simplify the calculation within the engineering error, a single-mass discrete model of the path is used. Entering symmetric coordinates allows us to obtain from the original system of differential equations a simplified system with characteristic equations with simple roots, therefore, the natural oscillation frequencies of the bouncing of the body, trolley and wheelset will be determined with minimal error. The transfer function is determined by Kramer's formulas. With the help of a computer, the values are calculated and graphs of the amplitude-frequency characteristics of vertical movements, maximum accelerations of the body, trolley, traction motor and wheelset of the electric locomotive in question are constructed. A comparative analysis of the calculation results and empirical data is carried out. Based on a comparative analysis, it can be argued that the considered mathematical model of vibrations of the electric locomotive 2ES6 «Sinara» is adequate and allows determining the dynamic loading of the locomotive for the entire range of operating speeds. The task of changing the existing design of the suspension system of the traction electric motor of the electric locomotive in question and the mathematical analysis of the vibrations of its nodes in further research is set.

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.

One of the ways to increase the capacity of railways is to use long-distance freight trains with a distributed traction system. In order to reduce the influence of the human factor, it is advisable to use automatic speed control systems on the locomotives of such trains, that take into account the transients occurring in the train. Determination of the longitudinal forces that occur in the train can be carried out by using either a reference mathematical model of the train, or pre-calculated dependencies of these forces on the parameters of the train movement. The second method allows you to simplify the structure and improve the performance of automatic control systems.

A significant share of JSCo «Russian Railways» expenses falls on the purchase of diesel fuel and electric power for train traction. In this connection, the task of ensuring rational consumption of energy resources acquires special importance. Its solution is impossible without a well-functioning system for planning and forecasting the energy efficiency of locomotives. The article proposes a method for predicting specific energy consumption (SEC) for train traction, based on determining predicted values of transportation work and fuel and energy resources consumption by extrapolating time series, which consists in spreading the trends in changes in the values established in the past to the future period. A distinctive features of the developed method is the determination of seasonality indices and consideration of the rhythm of changes in the indicators. In cases where the forecast period includes months of the first or fourth quarters, a formula is proposed for determining the forecast value of the SEC, taking into account the influence of the atmospheric air temperature. The calculations performed showed that the application of the proposed method for structural divisions with different volume and nature of transportation work and the level of the SEC ensures a sufficiently high accuracy of train traction energy cost forecasting. The method is included in the Methodology for Analysis and Prediction of Fuel and Energy Resources Consumption for Traction of Trains developed by OmGUPS and implemented in the railroad network of the Russian Federation.

Transportation in tank cars of viscous liquid cargo (fuel oil, paraffins, industrial oils, cracking residues, etc.) is difficult with their solidification, accompanied by a sharp increase in viscosity. In fact, this leads to the need to warm up or partially warm up the transported oil product before unloading, usually carried out as a gravity discharge, in order to restore the fluidity of the delivered oil cargo. The process of unloading in this case with heating leads to a significant increase in the cost of transporting petroleum products, including the downtime of tank cars, and in general, a decrease in the turnover of rolling stock. According to the analysis carried out to determine the costs of the technological process of heating frozen petroleum products transported by rail, about 600 thousand tons of conventional fuel are spent per year, and the idle time of tank cars under unloading and subsequent cleaning of boilers from high-viscosity residues of oil cargo exceeds 1 million car-hours. The urgency of the issue of reducing the cost of railway transportation of viscous cargo is due to the intensive development of the Northern and Eastern regions of the Russian Federation. Important factors for transportation in these conditions are not only the negative average daily air temperature, but also long distances. The issue of reducing the cost of transportation of viscous petroleum products at low air temperatures is considered. Viscous petroleum products, when thickened, turn into a rheological liquid, which does not have a clear interface between the liquid and solid phases. The methods of transfer to the stratified state of hot fuel oil during its slow cooling and partial solidification with the formation of a heat-insulating layer of solidified fuel oil are applied. The positive effect is achieved by reducing the time and cost of thermal energy for unloading the delivered oil product by reducing the rate of its cooling during transportation. This, in turn, is achieved by suppressing the natural convection of the hot oil product on the cold walls of the boiler of the tank car in the first few hours after filling the tank. From the comparison of the experimental data and the calculation results, the values of the empirical coefficients of the equation for the heat transfer coefficient of liquid petroleum products are selected. The standard deviation of the absolute temperature of the liquid petroleum product was 8 %.

In the article the comparative analysis of the dynamic loading of the floor of the car with different types of trucks in various modes of movement (loaded, empty). Commissioning of the new trucks is due to an increase in accidents in the operation of a gondola carts 18-100.

The article presents an analysis of the failures of the mechanical components of the mainline electric locomotives 2ES6 «Sinara» in operation at the landfill of the West Siberian Railway, the causes and consequences of failures of the most vulnerable nodes are determined. The analysis of failures of the mechanical components showed that a significant share of them falls on the components of the wheel-motor unit of the locomotive. The analysis of the design features of the crew part is carried out. The main structural difference of suspension is the absence of leaf springs in the axle box stage, which were widely used on electric locomotives of previous generations. In the body stage, helical springs (Flexicoil) are used instead of the cradle suspension. The connection of the traction motor with the trolley frame is a pendulum. The suspension of the traction motor to the trolley frame is carried out through a leash. When considering the vibrations of railway carriages, it is customary to represent the locomotive and the track as a single mechanical system. The task of forming a mathematical model of the «electric locomotive - path» system is set and a mathematical model of vertical vibrations of an electric locomotive is formed taking into account the dynamics of wheel-motor blocks based on the Lagrange equation of the second kind in the form of a matrix equation, which allows us to assess the loading of mechanical components in operation. The mathematical model represents a system of differential equations in which six equations determine the fluctuations of the bouncing and galloping of the body and trolleys, four - the galloping of wheel-motor blocks, four - the bouncing of wheel pairs together with the reduced mass of the track. The obtained mathematical model makes it possible to determine the level of dynamic loading of the components of the mechanical part of the electric locomotive 2ES6 «Sinara» by integrating the matrix equation using the MathCAD application package.

The article provides a brief theoretical analysis of railway vehicle with nonlinear elastic elements. Considered distinctive features of spring suspension electric locomotives of the old and the new generations. On the basis of differences of a calculation scheme and derived a mathematical model of vertical dynamics of conditional «uniaxial» electric locomotive of new generation allows to estimate the critical speed train crew and indicators of its dynamic qualities.

Analysis of failures of axlebox units of bogies for freight cars in the network of JSC «Russian Railways» for the period from 2010 to 2012, disadvantages of this node known construction trucks of the car of model 18-100. Defined vertical, horizontal and longitudinal loads acting on the buchs site. Mathematical modeling of the dynamic loading roller bearing axle-box under radial load. The influence of dynamic loads and defects in a roller bearing axle-box site on a safety of movement of the carriage.

The development of railway transport is currently impossible to imagine without the use of mathematical models and algorithms. Consider the increase in speeds, reduction of travel time, while minimizing costs, is possible only with the qualitative and full use of the mathematical apparatus. The use of information technologies makes it possible to take an effective decision in the development of a project for the reconstruction of a railway line. The current state of the theory of railway transport is characterized by the presence of a developed system of mathematical models and algorithms for analyzing various features of railways. This opens up possibilities for building an approach to the problems of searching and optimizing design solutions on a mathematical basis, with the reduction to a minimum of costly and time-consuming physical modeling procedures. One of the main tasks that are set for the railway transport in the near future is to increase the speed of trains on existing railway lines with the use of computer technology (computer-aided design). The article deals with the problems of technical reconstruction of the railway plan to increase the speed of train movement. The urgency of the use of computer mathematical methods for the development of an optimal plan for increasing the speed of trains. A pair of mutually dual problems of optimal reconstruction of railway curves to increase the speed of trains with minimal capital investment is considered. As methods for solving the problems posed, the following methods were proposed: the method of steepest descent, a modified method of dynamic programming (the Cattell method), the method of indefinite Lagrange multipliers. The expediency of using each method to solve the problem is indicated. The considered methods allow to implement a number of computer-aided design procedures for the reconstruction of the railway plan.

The article describes three variants of the mathematical model of the sensitivity function of the magnetoinduction sensor for assessing the influence of various sensor parameters in the electromechanical system «wheel - rail - magnetoinduction sensor» for diagnosing the technical condition of the rolling surface of the rolling wheels of rolling stock in the process of its movement over the sensor. An example of an algorithm for identifying defects located on the surface of the wheel rolling circle is described. The proposed multi-vector mathematical model allows simulating various defects on the rolling surface of the wheel, developing and testing new algorithms for processing the output signal of the sensor on the basis of modern hardware and software. The implemented defect identification algorithm is based on the property of the centrally symmetric form of the sensitivity function of the magnetoinduction sensor and the allocation of a useful signal corresponding to a certain type of defect, based on the application of a mutual correlation function and the assessment of its maximum and minimum values in comparison with the specified thresholds and confidence intervals. The main requirement for the implementation of the model is the uniform movement of the train above the sensor along a straight section of the rail track. This article discusses only one of the possible digital signal processing algorithms, but the proposed model allows us to compare the efficiency of other possible algorithms identification of defects in the rolling surface of wheelsets. The developed model confirms the prospects of using magnetic induction sensors for identification of not only visible, but also hidden defects on the rolling surface of the wheel in the process of movement of the train.

The quality of a track circuit monitoring system is defined to the great extent by its ability to automatically analyse the acquired data, i. e. identify the state of a track circuit. Machine learning techniques can be applied to implement this functionality. Designing a machine learning algorithm requires a learning data set from the subject domain. In this article we discuss a basic principle of track circuit mathematical model design that could be used to generate such data set. We also apply this principle and a combination of some existing methods to design and demonstrate a mathematical model of the 25 Hz AC track circuit.

The results of mathematical modeling of the optimization of maintenance cable lines are presented in article. The results can be used to calculate the optimal frequency and number of major repairs and substitutions of cable lines.

The article presents a nonlinear mathematical model of heating a two-layer body with allowance of the finite velocity of heat propagation and the temperature dependence of the properties of materials. A numerical solution of the nonlinear hyperbolic heat conduction problem is obtained for the case when the absorption of the radiation energy is modeled by a volumetric heat source. The implementation of the grid method using a three-layer implicit difference scheme in solving a nonlinear heat conduction problem in a two-layer body with allowance for the relaxation of the heat flux and the conjugation conditions in the case of ideal contact at the interface junction is considered. The described algorithm for calculating the temperature field for high-intensity heating of a coated body, taking into account the dependence of the thermophysical characteristics of materials from temperature, is based on the implementation of the sweep method with iterative correction of the coefficients. Programs are developed and the results of calculating the temperature fields are presented using nonlinear hyperbolic heat conduction equations and the corresponding linear ones taking into account the average integrated thermal and optical characteristics of the materials. Based on a comparison of the results obtained the necessity of taking into account the temperature dependence of the properties of materials during the study of processes of high-intensity heating of bodies.The developed mathematical model on the basis of a system of nonlinear hyperbolic equations can be used to create technological processes using methods for processing the surface of multilayer bodies by laser radiation.

The article is devoted to numerical methods for solving nonlinear heat conduction problems with considering for the relaxation of heat flow. A mathematical model is developed on the basis of a non-linear heat equation of the hyperbolic type for calculating the temperature field in an infinitely extended (unlimited) plate. The implementation of the grid method using a three-layer implicit difference scheme for solving the nonlinear hyperbolic heat conduction problem is presented for the case when the absorption of radiation energy is modeled by a volumetric heat source. A numerical solution of the nonlinear heat conduction problem in an unbounded plate is obtained taking into account the relaxation of the heat flow on the basis of the finite difference technique using the sweep method and iterative refinement of the coefficients. A calculation algorithm with a graphical representation of the results of calculating the temperature field in an unbounded plate under the influence of concentrated energy flows is described. A comparison of the results of calculations of temperature fields in mathematical modeling on the basis of the nonlinear hyperbolic heat equation and the corresponding linear model using the mean integral values of thermophysical and optical characteristics is presented. The significant differences obtained between the temperature fields corresponding to the nonlinear and linear problems justify the need to take into account the temperature dependence of the thermophysical characteristics and the absorptivity in the study of high-intensity processes of heating the bodies. The developed nonlinear mathematical model of body heating with allowance for the finite speed of heat distribution and the temperature dependence of the material properties, can be used to select the modes for processing mode bodies with high-intensity energy flows.

Analysis of failures bogie side frames of freight cars in the network of JSC «Russian Railways» for the period from 2006 to 2013. Disadvantages of the well-known constructions of trucks of the car of model 18-100. Mathematical modeling of movement of a wheel pair bogie 18-100, set the negative impact of the spread of the values of structural parameters of the chassis of the car on the indicators of its dynamic qualities and driving safety.