Journal of Transsib Railway Studies V.2(42), 2020

This article discusses the improvement of the electrical component of the wear model of the elements of contact pairs of current collector devices under conditions of high-speed movement. The histograms of the electrical wear of contact elements obtained by calculation using the existing and improved mathematical models are presented. Analysis of the obtained histograms allows us to conclude that the calculation accuracy is improved according to an improved mathematical model by taking into account the influence of the aerodynamic effects of the air flow and the speed of the rolling stock.

The article presents the results of research on the efficiency of the electric energy storage system in traction power supply on the example of one of the sections of JSC "Russian Railways". The results of measurements of electric values of electric rolling stock when moving along the railway section under study are considered. Based on simulation modeling, an assessment of the impact of power storage systems on the capacity of the railway section is obtained. Graphs of changes in the minimum travel interval and the minimum voltage on the current collector of an electric moving train depending on the power of the storage system, energy intensity, and threshold voltages for charge and discharge modes are constructed. An algorithm for the operation of the power storage system at a traction substation or linear device has been developed. Based on the simulation results, a graph of the degree of charge is constructed and a series characteristic is determined that allows maintaining the discharge depth at the level of no more than the specified one. Based on the results of calculations, the power, energy intensity and charging characteristics of the storage system are determined, which provide the required voltage level at the current receiver of an electric moving train within the boundaries of interstation zones.

This article contains results of experimental studies on the formation of corrosion products as a result of aggressive environment and electric currents action on the reinforced concrete structures. There are discussed a method of creating models with artificial electrocorrosion under conditions close to real working. The results of testing models using the X-ray method and modeling their strength characteristics are presented.

The article is devoted to one of the urgent problems in the activities of JSC “RZD“- increasing the energy efficiency indicators of locomotives, namely, new generation locomotives running on liquefied natural gas (LNG) - GT1h series gas turbine locomotives. The results are presented for the analysis of typical diagrams of traction work at hauling trains by the gas turbine locomotive on the Surgut - Voinovka section of the Sverdlovsk Railway. Measures are proposed to reduce the specific consumption of the fuel used for hauling operations for various running duties of a gas turbine locomotive (traction mode, idling, transient modes). The justification and description are given for the selected technical solutions to reduce fuel consumption by the “gas turbine engine-traction generator” system during gas turbine locomotive operation in idle and traction modes. The results of tests of the gas turbine locomotive during idling and in traction mode using the proposed technical solutions are presented. The comparative analysis of the results obtained is carried out and the economic assessment of the effectiveness of the selected measures is given when the gas turbine locomotive is operating in idle and traction modes. A mathematical model is proposed for the electric traction drive and the automatic control system of the gas turbine locomotive, developed using the Matlab Simulink environment and designed to study the operation and optimization of electromagnetic processes occurring in the electric traction drive of the gas turbine locomotive in various modes of its operation. Based on the results of modeling the algorithms for the operation of the automatic control system (CAP) allowing to provide energy-optimal loading paths for the “gas turbine engine - traction generator” system in the entire power control range, the economic assessment of the effectiveness of the CAP algorithms is given. The economic assessment is presented for the implementation of a set of proposed measures to improve the energy efficiency of gas turbine locomotives.

The article presents the results of the research conducted by the authors, the purpose of which was to development a model for recognizing defects in axle caps of a wheel-motor block of a locomotive in order to implement automatic advance notification of management structures about the need for maintenance or repair operations to eliminate defects at an early stage of their occurrence. The research used the following interdisciplinary and mathematical methods: computer and mathematical modeling, methods of mathematical statistics, methods of the theory of artificial intelligence and parametric reliability. As a result of the research, a mathematical formalization of the model for recognizing one of the defects in the axle caps of the wheel-motor block of the locomotive - the groove (chipping) of the babbitt layer was obtained. With the help of the obtained model, it is possible to implement automatic recognition of defects, pre-failure states not only of axle caps, but also of other units of technical systems. The developed model can be used in monitoring systems, control, diagnostics of the technical condition of the locomotive fleet, in order to reduce downtime in repairs and forced costs for scheduled operations. The proposed model solves the range of problems described in the development concept of JSCo Russian Railways associated with the implementation of the actual repair system for the current technical condition of the locomotive, as well as with the digitalization of the company's advanced areas.

The article provides for the design features of pantographs of an electric drive train, a system of movable frames, which are made in the form of two articulated rod-type levers. Single-lever pantographs are distinguished by improved mass-dimensional indicators, which allows them to be used in the cramped conditions of the roof space of two-system electric locomotives. This requires high mechanical characteristics, as well as the need to use structural materials of increased strength, precision processing methods and high precision during assembly. It becomes especially important to control the transverse and advanced cruelty of the moving frame system during research, periodic and qualification tests, as well as during operation. The article describes a methodology that allows conducting research with a high degree of labor intensity, increasing the speed of measurements, and reducing the influence of the human factor.

To increase the level of mechanization and automation of the assembly processes of rail and sleepers, link assembly lines are installed at the production bases of the track machine stations. In 2012, a semi-automatic link assembly line of KB03 brand was introduced on the Belarusian Railways for the assembly of a rail-and-sleep grid on reinforced concrete sleepers with an SB-3 intermediate fastening. Increasing the productivity of this line is a priority area in research, since in modern conditions there is an increase in the volume of overdue railway track repairs. In the course of the study, it was determined that the most rational solution for studying the work of a link assembly line and finding ways to increase the productivity of its work is to use simulation tools. After studying the technical and other accompanying documentation, a simulation model of the KB03 assembly line was developed. Then the developed model was validated, during which it was found trustworthy and suitable for experiments. Based on the analysis of the results of the experiments carried out on the model, solutions were formed to control the production process of the KB03 assembly line to obtain the maximum increase in its productivity. The calculation of the economic feasibility of introducing the proposed changes and adjustments to the technological process of the link assembly line in production was carried out.

The article deals with the organizational features of the Federal law of the Russian Federation on "transportation security compliance requirements to ensure transport security objects (buildings, structures), not related to transport infrastructure objects and located on land adjacent to transport infrastructure objects in the security zones of land transport. Systematized the activities required for the implementation of such transport facilities. In the work used techniques of systems analysis, comparative method, methods of theoretical knowledge (formalisation), obshhelogicheskie methods and techniques of research (analysis, synthesis, classification, the analogy).

Described the prospects for the use of highly efficient boilers as an autonomous source for generating heat for the priority tasks implementation of the strategy for the development of railway transport in the Russian Federation until 2030 approved by the Government of the Russian Federation. The features of operation and design of a vacuum boiler, advantages and disadvantages are considered. The necessity and method of heat exchange processes intensification in a vacuum boiler to increase its efficiency and reduce fuel consumption are substantiated. The main provisions of the mathematical model for thermal calculation of a vacuum boiler using the k-ε model ANSYS CFX to describe turbulent flows of a reacting gases mixture, taking into account heattransfer by radiation and convection, and the RPI ANSYS CFX model, describing the liquid boiling processes. The results of computational studies using the RPI ANSYS CFX model for boiling on smooth and finned cylindrical surfaces are presented. The computational studies results of the pressure effect in a rarefied volume on thermophysical characteristics and operating parameters of the boiler, such as wall temperature from the water side, heat losses with exhaust gases on a smooth and ribbed surface are shown. The influence of the ribbing coefficient on fuel economy is shown at various pressures. Reasonable recommendations for creating a design of energy-efficient vacuum boilers with improved weight and size characteristics are presented. The application of the design for an energy-efficient of vacuum boiler with transverse ribbing on the outer flame tube surface with rational geometric characteristics is substantiated; a rational coefficient of ribbing Ψ = 1,89 is presented.

The article presents a criterion for choosing the optimal type of wavelet function for digital processing of current and voltage values in the analysis of the electric network mode. The increase in the share of electric receivers that distort the quality of electricity sets the task for researchers to use more advanced mathematical tools for analyzing and modeling such power supply systems. The discrete wavelet transform allows the harmonic analysis of currents and voltages under non-stationary non-sinusoidal modes. One of the key tasks in the development of digital technologies in the electric power industry is the creation and development of intelligent electric networks with the introduction of new algorithms for digital data processing and decision making. In this case, algorithms for compression and remote recovery of data on the consumption and production of electrical energy in the cloud should be developed. The wavelet transform eliminates the negative spreading effect characteristic of the Fourier transform in the analysis of non-sinusoidal non-stationary modes. Based on the Parseval equality, the wavelet transform makes it possible to determine the spectrum energy of individual frequency ranges determined by the depth of decomposition and the sampling frequency of the signal under study. The calculation of the energy of the spectrum of wavelet coefficients allows the compression of the flow volume of instantaneous values of voltages and currents. The article presents the results of continuous and discrete wavelet current conversion when switching a battery of static capacitors. Information compression ratio exceeded 5.3. The wavelet transform was performed using eight different wavelet functions. The criterion for choosing the optimal mother wavelet determines the condition of the maximum energy of the spectrum and the minimum standard deviation when restoring the original signal.

A mathematical model for diagnosing the state of solid insulation of high-voltage transformers based on an informational assessment of indirect indicators, i.e. entropy, for example, by the content of impurities of various gases dissolved in transformer oil, which allows to determine the technical condition without removing the workload. The values of the average information on the working and faulty state of insulation for various types of gas impurities are calculated.

This article presents an algorithm and a method for calculating power flow of an open electric network with a voltage of 6-35 kV, taking into account the temperature dependence of active resistances. Calculation of the electric and thermal conditions of the electric network is carried out with a joint solution of the equations. The determination of stresses in the nodes is carried out using the inverse matrix of the nodal and intrinsic conductivities. The inverse matrix of nodal and intrinsic conductivities is determined based on the well-known direct Jordan-Gauss method. The equation of the heat balance of the wire used to calculate the actual temperature is solved numerically. Convective heat transfer is recorded only for forced convection, because wires of overhead power lines with a voltage of 6 kV and higher are located on various types of poles, at a height of at least 10 m. This fact allows us to abandon the use of formulas for natural convection and use expressions only for forced convection. Accounting for solar radiation in the presented algorithm is possible on the basis of two methods: simplified and considered in the standard of PJSC FGC UES, which allows you to take into account the actual location of the wire relative to the north. Using the test circuit as an example, the steady-state mode was calculated taking into account the temperature dependence of the active resistances. The results of a numerical experiment are presented, confirming the operability of the developed algorithm. The refinement in determining active power losses with and without taking into account the heating factor for the considered circuit is about 13%. Verification of the algorithm that implements the method of calculating the steady state (SS) of an open electrical network of a medium voltage class taking into account the temperature dependence of active resistances showed that in technically acceptable modes the developed algorithm has good accuracy in comparison with the RastrWin3 software package.

Using the example of operating gas fields in the Western Siberia, the issue of the correct choice of voltage class, considering all the periods of gas fields life cycle, appears. Wrong choice of the voltage class leads to braking development of a gas field. Gas field technological scheme during the each period of the life cycle is considered, the dynamics of the electrical load is estimated. The analysis of existing methods of choosing the voltage class is carried out and their flaws are revealed. Mathematical models of the optimal voltage class calculation and discounted costs calculation are developed using the theory of experiment planning. An algorithm of choosing the optimal voltage is developed and the distribution and supply networks of the external power supply system of the existing gas fields in Western Siberia are investigated. Progressive voltage class for power supply and distribution network is proposed. Conclusions are made.

The article presents the results of research of a point magneto-induction sensor based on a mathematical model, which allows you to increase the reliability of automated systems for diagnosing technical condition rolling stock in the course of train movement by improvement the accuracy of the initial information, that is, the moments of fixation passing of wheelset axles over magneto-induction sensors. At the first stage of developing a stigmatic mathematical model the analytical dependence of the value of the magnetic flux in the magnetic core and the output EMF value on resistance of the air gap between the sensor and the wheel crest. At the second stage of development of the mathematical model found time dependence of the magnetic resistance of the air gap between the core of the magneto-induction sensor and the comb wheels of a railway car moving along a straight track at a constant speed. On the basis of application the developed stigmatic model allows evaluating the energy parameters of magneto-induction sensors depending on the properties of modern magnetic materials. The simulation results showed that the MMF value is constant the magnet determines the main parameters of magneto-induction sensors, so the use of modern magnets based on rare earth they allow to eliminate the traditional disadvantage of outdated types of magneto-induction sensors, that is, to reduce their size and weight. The application of the proposed stigmatic model expands the scope of possible solutions to extreme problems for selection and justification parameters of magneto-induction sensors, helps to improve the accuracy of systems for diagnosing the technical condition of the car fleet and traffic safety on railway transport.

Microminiaturization elements of communication systems contributed to development Internet of Things, which led the expansion of various railway transport services. One of the Internet of Things component`s is the wireless sensor network (WSN). Feature of WSN is a dynamically changing spatial and information network environment. It complicates the adoption of promptly reliable management decisions based on assessments of the states of network elements. One of the directions of making a reliable decision in a complex network environment on the WSN is using cognitive maps in the WSN control nodes. In this article discusses various models of cognitive maps for assessing the states of network elements and network processes, which can also be used for railway transport services.