Search results

The purpose of this article is to analyze the voltage drop in the contact network caused by poor-quality operation of an alternating current electric locomotive when passing heavy trains. Heavy-haul traffic is considered today as a valid and necessary tool for increasing weight norms and increasing the throughput of railway sections. The article provides statistics on the passage of heavy and connected trains on the Krasnoyarsk railway for 2019 and 2020. For the effective use of heavy traffic, it is necessary to solve a number of problems, one of which is to reduce the voltage in the overhead network when passing heavy trains, this negatively affects the speed of the train along the haul, the conditions for cooling the power equipment of the electric locomotive deteriorate, etc. As a result of the analysis of the operation of the thyristor rectifier-inverter converter, a number of disadvantages were revealed. The reason for the low power factor of the electric locomotive lies in the use of an outdated element base based on thyristors, their closure is carried out only in the next voltage half-cycle, long-term switching and a large opening angle of thyristors leads to a significant reactive current in the contact network. Based on the analysis the voltage losses at the current collector, it was concluded that it is necessary to reduce the duration of the switching process of the arms of the rectifier-inverter converter, in which a short circuit occurs in the secondary winding of the traction transformer. An alternative version of the converter based on fully controlled semiconductor devices - IGBT transistors is proposed. The ability to open and close at any time of such elements allows you to minimize the phase angle and increase the power factor. Due to the almost instantaneous switching of transistors, the distortion in the contact network is minimized.

This paper considers a continuous automatic locomotive signalling (CALS) receiver with a correlation decoder. The aim of this paper is to investigate the influence of harmonic interference from a high-voltage power line on the operation of a non-linear CALS receiver with a correlation decoder. The experimental study of the quality of operation of a non-linear CALS receiver with a correlation decoder under the influence of harmonic interference from high-voltage power lines was carried out using the simulation method. Simulation models of interference from a high-voltage power line (VPL), a receiver and a correlation decoder of the CALS channel were used in the study. The analysis of oscillograms obtained as a result of the study has shown that the correlation decoder has a number of features due to the algorithm of its functioning. The correlation decoder more confidently accepts code combinations with a duration of 1.6s (generated by the code track transmitter of CTT-5 type), than the duration of 1.86s (generated by the code track transmitter CTT-7). This is expressed in a shorter time interval of disturbance of the CALS non-linear receiving device. At decoding of the code combination (CC) with the duration of both 1.6 s and 1.86 s the situation of short-term decoding of the more permissive CC «Y» instead of «RY» was observed. However, the duration of these situations did not exceed two code cycles and would not have caused a more permissive light to appear at the locomotive traffic light. In general, the experiments have shown that the CALS CC correlation decoding algorithm needs improvement for more confident decoding of CCs produced by a code track transmitter of the CTT-7 type(1.86 s).

A mathematical model of thermal processes (dynamic) contact current collector with contact suspension (in motion), which allows to estimate the temperature distribution of heating the current collector during movement. The experimental evaluation of the proposed cooling device performance is given. The thermal model of the current collector in motion mode has been verified.

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.

The purpose of the article is to consider the issue of calculating and selecting the settings for the operation of the short-circuit switch KZKS-3.3 when organizing the protection of a direct current contact network in emergency mode. The shorting circuit is measured by the voltage module. When the triggering conditions are met, it is the voltage module that collects the circuit to turn on the switching device of the short circuit. The important question is to choose the optimal installation location of the short-circuit switches and the voltage trip settings. The initial information necessary for the calculation of the settings is determined. The calculation procedure and equivalent circuits for the most common power supply circuits and sectioning of the contact network are given. For current protection of high-speed circuit-breaker feeders, contact formulas are given for determining the sensitivity zones. To select the optimal installation location of the short-circuit and select the voltage pick-up setting from the allowable range, a potential diagram of the contact network section is constructed. The analysis based on the potential diagram allows us to conclude that the organization of protection of the contact network in emergency mode using short circuits is effective.

The method of determining the durability indicators of wheel pairs of locomotives is considered on the example of diesel locomotives of the 2TE25KM series operated on the Volga railway. For this purpose, the 90% resource of the wheel pairs of the studied series of locomotives was determined, and it was compared with the accepted standard indicator. In addition, a controlled parameter of the wheelset is selected, limiting the reliability of this node. To conduct the study, methods of mathematical statistics and probability theory were used, in particular, the Laplace distribution function, the Student's criterion, as well as the results of calculations of the dependencies of the mean value and the standard deviation of the controlled parameters, the initial values of developments and operating time corresponding to the probability of failure 0.5. In this study, a mathematical model for assessing the durability of wheelsets from the point of view of reliability theory was developed. The evaluation of the durability indicators of the wheelset elements was carried out on the basis of the type of random variable distribution law with its parameters obtained on a computer and adopted according to the Pearson criterion. As a result of the calculations, 90% of the life of the wheelset was obtained according to two controlled parameters, which amounted to 476.6 thousand km for the thickness of the bandage, and 282.6 thousand km for the thickness of the ridge. The results obtained were compared with the values adopted in the Technical Specifications for this series of locomotives (800 thousand km). km), as well as with statistical data on the values of controlled parameters obtained during processing and analysis - 240 thousand km. Due to the fact that in operation the average life of the wheelset is determined by a larger number of controlled parameters, taking into account unscheduled repairs, and in this study - only on the basis of the thickness of the bandage and the ridge, it is not possible to talk about full compliance with the calculated and actual data. According to the results of calculations, the limiting reliability of the wheelset is such a controlled parameter as the thickness of the ridge. For a more accurate assessment of the durability of wheelsets, it should also be taken into account that the intensity of wear of rolling stock equipment is affected by specific operating conditions, in this regard, inter-repair runs should be adjusted taking into account the influence of external factors during operation. In order to fully assess the durability of wheelsets in the future, it is necessary to take into account additional factors, in addition to those that affect the parametric change of random variables, as well as the fact that takes into account the monitoring and analysis of all controlled parameters of this node during the operation of locomotives.

The article discusses the possibility of extending the service life of passenger cars. The analysis of the state of the passenger car fleet has established that the rate of replenishment of reserved cars has been reduced by more than 40 % over the past 10 years, therefore, it is possible to ensure coverage and replenishment of the retirement of rolling stock of this type after the expiration of the standard service life only by extending the service life of existing cars by carrying out capital repairs with the establishment of a new standard service life. When analyzing the power frame of a reserved seat passenger car, it was found that the greatest static and dynamic loads are perceived by its center beam. It is precisely because of the stresses arising in it that an assessment is formed of the further possibility of operating a car both during its life cycle and further use in diagnostics for the possibility of assigning a new service life to it during overhaul repairs. Studies of a number of elements of center beams cut from passenger cars that have expired the standard period have established that the main characteristics of the metal meet the requirements of safety standards, this indicates that the safety margin and resource inherent in them has not been fully depleted. In the study of the presence of residual stresses that have arisen in the elements cut from the ridge beams, depending on the depth of etching carried out according to the method of N. N. Davidenkov in accordance with the TSNIITmash methodology, the most vulnerable and dangerous places of corrosion that require more careful control during the car maintenance and scheduled preventive repairs were identified. In order to reduce the development of residual stresses and the corrosive effect on the load-bearing frame of a second-class car, recommendations and technological operations have been developed for strengthening the ridge beam by the method of shot-blasting with the formation of a uniform fine-pored structure, which ensures uniform application of paint and varnish coating.

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 goal of the research is to development of a synchronous-replicated model for the assessment of the technical state of a locomotive as a technical system to reduce the occurrence of failures during operation, and as a result, reduce downtime in repairs. When performing the research, the following interdisciplinary and mathematical methods were used: system analysis, computer and mathematical modeling, methods of the theory of artificial neural networks, mathematical analysis. As a result of the research, a mathematical synchronously replicated model for assessing the technical condition of a locomotive based on an artificial multilayer forecasting neural network was obtained. The developed model can be used in monitoring systems, control, diagnosing the technical condition of the locomotive fleet. The original features of the developed model are a low sampling period between polling monitoring tools, versatility, adaptability, efficiency. Based on the developed model, a generalized algorithm for managing the technical condition of the locomotive fleet is built. The proposed model and algorithm solves the ranges of tasks described in the development concept of Russian Railways OJSC related to the implementation of the actual repair system according to the current technical condition of the locomotive, as well as the digitalization of the company’s advanced areas.

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.

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 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 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 paper considers the influence of the force characteristics of the damping apparatus on the value of the maximal longitudinal forces arising between the cars. Using the computer program MSC.ADAMS, we performed the simulation of shunting collisions of cars and train transient movement modes. The dependences of the maximal forces at cars' collision at various velocities on the shape of the elastic elements' force characteristics are determined. The operation of various shock dampers for the case of the train starting off electric braking and movement through the parts of the longitudinal track profile was estimated. It is shown that shock dampers with a rapidly growing line of load lead to the emergence and propagation of large shock forces along the train, while a slow growth of the force leads to their reduction due to the amplitude increase in elastic vibrations propagated along the train length . We propose to use high-energy-damping devices to reduce the longitudinal forces in the train, which are characterized by the force slew rate substantially depending on the compression velocity of the shock damper.

The article is devoted to the development of a methodology for monitoring the alignment and radial runout of the inner cylindrical seating surfaces of locomotive motor-axle bearings. The main reasons for the wear of the working surfaces of the bearings and the consequences of the influence of the clearances in the interfaces of the plain bearings and the axles of the wheelsets on the increase in the intensity of wear of the parts and the deterioration of the dynamic characteristics of the running gear of the locomotive are listed. The paper presents a basic diagram of the basing and control of deviations from alignment and radial runout of the inner cylindrical surfaces of bearings, describes the design and principle of operation of a special control device for measuring these deviations. The purpose of the work is to substantiate the feasibility of monitoring deviations from the shape and location of surfaces during the repair of motor-axial bearings. The paper describes the sequence of steps for measuring the alignment and radial runout of bearings and the interpretation of the measurement results. The features of the design of the control device are considered, the advantages of its use are listed in comparison with the existing analogues of the devices used to control the alignment of the holes of the body parts located on the same axis. At the same time, it was found that the control of alignment and radial runout must be carried out in order to assess the possible degree of misalignment of the traction motor frame and the axle of the wheelset of the locomotive after repair. Thus, the conclusions obtained confirm the need to tighten quality control of the restoration of locomotive motor-axle bearings by introducing into the production process the operations to control the alignment and radial runout of motor-axle necks and motor-axle bearing liners made of lead bronze, tin or lead-tin babbits.

The article presents statistical studies of acoustic control signals when diagnosing power transformers of the railway power supply system. Statistical processing of acoustic monitoring data was carried out on the example of transformers with different levels of insulation condition. Comparisons of histograms of the experimental distribution of amplitudes and dominant frequencies of signals with the nearest theoretical distribution laws, performed in the STATISTICA program according to control data obtained from the automated system. The conducted studies have shown a close correlation of defects registered by the acoustic method with the distribution of signals in the form of laws of distribution of random variables. It is shown that for power transformers with mechanical oscillations, both during the passage of the train and at idle, the distribution of amplitudes and dominant frequencies of the recorded signals corresponds to a uniform law. The distribution of amplitudes and dominant frequencies is not centered around a certain average value. For power transformers containing partial discharges, the cause of which is the deterioration of the insulating properties of the windings under the influence of high voltage, the best approximation, both amplitudes and dominant frequencies, showed the Lognormal distribution. The signals are centered around a characteristic mean value. When the train passes, the acoustic system registers both high-frequency signals from the PD and low-frequency signals from body vibrations. There are two components in the distribution law - uniform and lognormal distribution densities. Thus, by the type of distribution of the recorded signals, their amplitude and dominant frequency, it is possible to determine the presence of a defective state of the insulation of power transformers. The study was carried out with the financial support of the Russian Foundation for Basic Research within the framework of the scientific project No. 20-38-90231.

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.

The need to apply various methods for predicting the technical condition of reinforced concrete supports of the contact network is currently a necessary condition for ensuring the safety of train traffic. Such a need arose due to the presence in operation of supports with extended service life, in the absence of a reduction in loads, without the presence of various kinds of redundancy. The article describes a method for predicting the technical state of the supports of the contact network. Solving the problem of exploitation, which consists in the fact that it is rather difficult to reveal the system of failures of the considered object of exploitation, under the influence of many factors. The probability of finding the contact network supports in a certain state is expressed through the statistical properties of the contact network supports, based on the change in the carrying capacity

In this article, the process of wear of the material of the ridge of the wheel brace during the movement of the locomotive in a curve of a given radius is considered. The methodology of the study considered in this article was that, based on the expression for the depth of penetration of the rail head into the material of the bandage ridge, the movement of the wheel along the inner rail in the curve was considered. It was taken into account that the contact point on the ridge of the bandage will move along the edge of the rail with slippage and that the contact area is a fairly narrow surface with a border close to an ellipse. Formulas for calculating the speed and the slip path of the contact point of the ridge of the locomotive wheel brace with the rail are obtained. As a result of the study, equations were derived to estimate such quantities as the volume, intensity and wear rate of the bandage (per revolution of the wheel). It is shown that the expressions obtained as a result of the work carried out can be used to calculate the intensity of wear of the brace ridge when the locomotive is moving in a curve of a given radius. The amount of the ridges material wear of the wheelset bandages can be determined on the basis of the equations obtained individually for a specific locomotive series and a given range of its operation.

The factors affecting the operational reliability of the assembly platform of a rail service car maintaining the repair and installation on the railways are considered in the paper. An assessment and analysis of a system of quantitative indices of reliability is performed, the methods for their separate determination by mechanical equipment and hydro and electrical equipment is described. The strategy of maintenance and repair combined with the use of methods and means of a modern diagnostic system is considered; it ensures the estimation of the object reliability during its design, operation and repair.

The article deals with the issue of improving the energy efficiency of DC and AC electric locomotives operated at the enterprises of JSC “Russian Railways». The main goals and objectives of the development program and energy strategy of JSC «Russian Railways» are analyzed and briefly considered. In accordance with these tasks, the relevance of scientific research in the field of improving the energy efficiency of electric locomotives is substantiated. The current data on traction rolling stock, on modern traction resource management systems and on Russian and foreign scientific research in the field of energy efficiency are analyzed. As a result of the analysis, it was found that most of the studies are aimed at studying the influence of key operational factors on energy efficiency indicators, so, in this case, on the specific power consumption for train traction. However, the reverse question has been poorly studied - the selection of the train mass and the technical speed on the basis of a preliminary assessment of the specific power consumption for train traction by analyzing the statistical data of trips on a certain section of the railway. The purpose of this study is to assess the possibility and develop a method for determining the optimal values of the key parameters of the operation of electric freight locomotives in order to achieve maximum operational efficiency in relation to them according to the criterion of energy efficiency. Two models were created in the program «Complex of calculations of traction power supply» (CORTES) - for DC and AC electric locomotives, describing the dependence of the energy efficiency indicator (specific power consumption for train traction) on operational indicators, such as the train mass and the technical speed. The initial data for further modeling were obtained by modeling trips on a conditional site.

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 %.