Development of the system of rationing and accounting for performance indicators of long distance and commuter train schedules for railways and the network as a whole

Currently, rationing and accounting of performance indicators for long distance and commuter train timetables for railways is carried out on the basis of the principle of “achieved level”. Methodology for calculating indicators based on objective conditions for organizing operational work on each railway has been developed. The generalized indicator characterizing the objective conditions is determined by the authors on the basis of an analysis of a set of factors, which include: loading of the railway infrastructure by train traffic; technical and technological state of infrastructure and rolling stock; risks associated with a possible delay of trains during the period of providing “windows” for the repair and reconstruction of infrastructure devices; number of passenger train stops; climatic conditions; technological discipline for fulfilling the traffic schedule (it is assumed to be the same for all railways); risks of violation of timetables on lines with dense train traffic. Dependencies for determining the numerical values of the factors are proposed. Taking into account the weight coefficients of each factor, the estimated indices of the objective conditions of the operation of each railway for long distance and commuter traffic are determined. The network task by the level of execution of schedules is distributed by railways in proportion to the values of their estimated indices.

The transition to the proposed system of rationing and accounting for the performance of timetables will help to improve the quality of performance of the train schedule, to ensure a positive image of the Russian Railways in the field of passenger transportation. The use of the proposed methodology for determining the target indicators of the schedules of long distance and commuter trains ensures that the real conditions of the transportation process on each railway are taken into account at the planning stage and allows an objective assessment of the quality of the organization of operational work based on the results of the fulfillment of planned targets.

General principles of expanding the speed range of operation of autonomous power supply systems for passenger cars

Authors address the issues of expanding the speed range for operation of autonomous power supply systems for airconditioned passenger cars. For the first time in the domestic car construction, the issue of reducing the minimum start-up speed of a generator-drive unit arose when the passenger fleet of the Sakhalin Railway was renewed, where the speed of passenger cars is much lower than the overall network speed. Research carried out by CJSC SO “TIV” and JSC “TVZ” has shown that the use of V-belts in the modernization of the textropic-reduction-cardan drive allows solving this problem. Kinematic diagram of the drive was adopted without changes, but with the replacement of the V-belts C (B)-2360T with new narrow belts XPC-2360 without working surface wrap and with a formed tooth on the lower base. In the tensioner, the main spring with a stiffness of 75 N/mm was replaced with a spring of increased stiffness (100 N/mm). The main change was the replacement of the 2GV003 generator with a 2GV008 low-speed generator, which has a minimum rotation at full power (700 rpm). This modernization of the drive made it possible to turn on the generator 2GV008 at rated power, starting at a speed of 30 km/h.

The article sets the task of expanding the speed range of operation of the EV-7 and EV-10 autonomous power supply systems for cars without air conditioning. It is solved by forcing the excitation of the generators.

Analysis of modern systems of autonomous power supply of passenger cars showed that the expansion of the speed range of its operation can be achieved in three ways:

• raising the gear ratio of the gearbox to ensure it is switched on to the nominal mode at a carriage speed of 15 – 20 km/h without changing the parameters of the generator and the entire system of autonomous power supply;

• modernization of the electrical equipment complex for passenger cars to ensure the operation of the main power consumers and charge the battery while driving at low speeds (over 18 km/h) without changing the mechanical parameters and composition of the serial generator-drive unit;

• modernization of the generator in order to reduce its turnon revolutions to the power required to provide the main power consumers without changing the mechanical parameters of the drive.

All three methods have its advantages and disadvantages, the choice of any of them is determined by the technical requirements for a specific car model.

Dynamic effect on turnouts of cars having wheelsets with thin flanges

Geometrical parameters of the “wheelset — rail track” system are mutually related. Currently, a very topical issue is the question of a possible adjustment of the regulatory framework in the “wheelset — rail track” system in order to take into account the actual state of the track, turnouts and wheel park on the railway network.

Any changes made in order to reduce the maintenance of wheelsets or tracks are possible only when the safety of train traffic is unconditionally ensured.

The most difficult problem in determining the possibility of changing the standard for the minimum thickness of the flange of car wheels is the problem of passing the turnouts. In the event of an incorrect setting of the standard for the minimum thickness of the flange of the wheels, the passage of carriage along the turnout can be accompanied by unfavorable and even dangerous phenomena. The most dangerous of these are wheel strikes against retracted point rail, ramps on the crosspiece at large angles, and strikes against counter rails. These phenomena cause both disruptions in the geometry of the rail track of the turnout switches and crosses, and fractures of the elements of the turnouts. They should be excluded.

Calculations and modeling based on the results of the study of statistical distributions of dimensions obtained by mass measurements on the railway network are the basis for the assignment of norms and tolerances in the “wheelset — rail track” system. The results obtained in the calculations should be verified by dynamicstrength tests directly on the track.

The article discusses the results of dynamic and strength tests to determine the effect of cars with different geometric parameters of wheelsets on turnouts with pre-formed average network and maximum permissible dimensions of the rail track parameters on the turnout and in the cross node. The minimum thickness of the wheel flange in the tests was 21.5 mm. The carriages of the test train during the test trips were loaded to the maximum permissible size and in an empty state. The tests were carried out at the Test Center of the JSC “VNIIZhT”.

Performance assessment of railway track under the impact of longitudinal forces during the implementation of maximum traction modes when using electric locomotives with an asynchronous traction drive

Strategic task of increasing carrying capacity of railways requires a constant increase in the mass of trains due to the passage of heavy and coupled trains. Development of heavy haul traffic is one of the most significant technological solutions aimed at increasing efficiency of using the infrastructure's capacity. In this case, capabilities of the track infrastructure become decisive.

The article presents the results of experimental studies of the performance of a continuous welded track under the influence of longitudinal forces arising from the motion of modern locomotives with an asynchronous traction drive in the modes of maximum traction and electrodynamic braking. It is shown that it is necessary to take these forces into account when calculating continuous welded track for strength and stability.

The object of testing was a railway track under the influence of increased longitudinal forces during the motion of the 2EV120 electric locomotive with the implementation of various traction modes and electrodynamic braking. Tests were carried out on three sections of the Test Center’s track of the JSC “VNIIZhT”, the experimental joint was equipped with special strain gauge pads designed to measure longitudinal forces.

According to the research results, it can be noted that the longitudinal forces in the rails caused by the implementation of the maximum traction forces and electrodynamic braking can reach up to 25 % of the maximum temperature forces.

The real forces of resistance to the longitudinal displacement of rails in the nodes of intermediate fasteners when tightened with the force provided by the standards are about 3 – 4 kN, which is significantly lower than the standard values of 14 – 16 kN, and may be a consequence of the wear of the elements of intermediate fasteners and

the state of friction surfaces. These phenomena can cause longitudinal displacement of both individual rail lines and the grid as a whole. The development of a set of measures to prevent this phenomenon requires a wide range of studies in real operating conditions, including optimization of traction and braking modes of driving heavy haul trains.

New anti-friction aluminum alloys for cast monometallic plain bearings. Bench tests

The work was carried out with the financial support of the Ministry of Education and Science of the Russian Federation under the Agreement No. 074-11-2018-011 of May 31, 2018 on the topic: "Development and organization of high-tech production of innovative electric heating systems for inter-industry use with breakthrough performance" in the framework of the implementation of the RF Government decree No. 218 dated April 09, 2010.

The article presents aluminum antifriction alloy from a series of newly developed alloys to replace bronzes for monometallic plain bearings. Complex alloyed aluminum alloys are developed using methods of nonequilibrium thermodynamics and the theory of selforganization. According to the results of applying nonequilibrium thermodynamics and the theory of self-organization to the friction process, the wear rate of rubbing bodies can decrease several times as the self-organization passes through the tribosystem and dissipative structures form. Complex alloying facilitates self-organization. Self-organization is determined by the intense occurrence of physicochemical processes with negative entropy production, i.e. such processes proceed in the direction of increasing free energy. Self-organization is expressed in the formation of the necessary secondary structures. The complexity of the system in our case was increased due to an increase in the complexity of antifriction materials, i.e. increase in the number of alloying elements. The results of the study of secondary structures on the friction surface of antifriction aluminum alloys are presented.

The differences in the compositions and microstructure of secondary structures from the composition and microstructure of the alloy to friction are shown. The role of various chemical elements in the formation of the necessary secondary structures is discussed. Chemical elements could get into secondary structures from an antifriction alloy, steel counterbody, lubricant, atmosphere.

The mechanical and tribological properties of aluminum alloys are determined. The properties of aluminum alloys with bronzes are compared.

Aluminum antifriction alloys, inferior to bronzes in mechanical properties, significantly surpass them in tribological properties. Aluminum alloys are 6 times smaller than bronze, wear a steel counterbody; the load of the seizure of aluminum alloys is 2.5 times the load of the seizure of bronze; the wear rate of aluminum alloys is 2 times less than the wear rate of bronze. A pilot batch of monometallic plain bearings was manufactured from the new alloy and bench tests were carried out for comparison with bronze bearings. The bench test results confirmed the advantages of aluminum alloy over bronze, given that the lubrication and cooling conditions of aluminum bearings were more stringent than the conditions for lubricating bronze.

On the double-deck transportation of large-tonnage containers: start of work, suspension of the program, measures for its prolongation

At the beginning of the XXI century in order to increase the competitiveness of container transportation on the railways of Russia, comprehensive studies were carried out on the possibility of transporting large-capacity containers loaded in two decks. In contrast to the world experience in the development of this method of transportation, where they are carried out on lines with diesel traction, the possibility of transporting containers loaded in two decks on electrified domestic mainlines is determined by the presence of an overhead wire, which creates an additional restriction for increasing the height of the freight.

The article discusses the results of many years of comprehensive research on the creation of a specialized well platform and the development of a technology for transporting large-capacity containers in it with loading in two decks, carried out by the VNIIZhT in the early 2000s. The article provides the features of the structure of the well platform, the layout of containers in it, the types of tests carried out and data on the experimental transportation of the platform loaded with containers in two decks. Information on the suspension of work on the introduction of double-deck container transportation is provided and measures are proposed that must be performed in case of resumption of work on the introduction of this method of transportation on the Russian railways network.

Research carried out by scientists and specialists of the VNIIZhT on the implementation of transportation of large-capacity containers of the 1AA, 1A, 1CC and 1C types with loading in two decks on a well platform have shown the high efficiency of the developed transportation technology. It still retains its relevance and can be implemented at the present time. The measures listed in the article to be implemented to resume work on the implementation of this technology are proposed to be included in the program for the introduction of this type of transportation.

To the determination of the capacity descheduling coefficients of railway sections

The article investigates factors arising from the use of new technologies for  organizing train operation, features of the topology of the railway network and affecting the calculation and use of the available capacity of railway sections. Based on the result generalization of such actions as mass analytical calculations in the automated development of data sheets for the available capacity of the Russian Railways network, analysis of standard train schedules and building of experimental traffic schedules, it has been established that when calculating the capacity of sections with an unparalleled train schedule and sections with an intensive suburban and suburban-urban traffic one should take into account the need to ensure the continuity of trains of different categories between service stops, the mutual arrangement of trains in the clock schedule and on adjacent sections. Authors carried out an evaluation of the influence of various topology options of calculated sections on its capacity. Recommendations are given for changing the criteria for dividing railway lines into calculated sections: separately for calculating the capacity and separately for calculating the capacity descheduling coefficients. The influence of adjacent infrastructure elements on the loss of available capacity is considered when it is impossible to synchronize approaching trains with periods of free runs and station elements for its passage; recommendations are formulated for its calculation experimentally — by building intensive train schedules or simulation modelling. The calculation formulas have been developed for the train descheduling coefficients when using the clock schedule in various types of passenger traffic and the impact of the considered types of traffic on the schedule exception of the available capacity have been assessed. The research results are intended for use in regulatory and methodological documents and automated systems for calculating, analyzing the use and justifying the development of throughput and carrying capacity of railways.

Analysis and prediction of the stability of train control systems to ultra-wideband electromagnetic pulses of intentional action

Problem of ensuring stability of railway automation systems to ultra-wideband pulses of an electromagnetic field is considered. These pulses can be used to intentionally affect the equipment of these systems. It is shown that modern complex systems of control and safety of train traffic are vulnerable to electromagnetic impulses of intentional action. The features that determine the difference between the problem of ensuring the stability of railway automation systems from information systems are highlighted. In particular, microprocessor-based automation systems are geographically distributed and accessible for action from a short distance.

The test generators used to prove immunity to electromagnetic impulses from intentional exposure are unique installations. Therefore, to reduce the number of tests design estimates and comprehensive tests for immunity to electromagnetic interference are required. Electrostatic discharges have the widest frequency spectrum. They act on the same apertures in the housings of technical means of railway automation systems as impulses of intentional action. The level of energy absorbed in electronic nodes can be calculated using the Rayleigh theorem. The electromagnetic field inside the housing is determined by the known relations for the radiation of the antennas and depends on the spectrum of the electric component of the field in the antenna aperture. This spectrum, in turn, depends on the spectrum of the electrostatic discharge pulse and the geometric parameters of the antenna.

When an electromagnetic wave of an intentional impulse is incident, the aperture releases this impulse and transmits it into the housing. Therefore, the intentional impulse emitted into the housing and the electrostatic discharge impulse can be compared in shape and amplitude. Pulses of different shapes, in turn, can be compared using the spectral-energy equivalence condition. Intentional impulse equivalent to an electrostatic discharge impulse and, accordingly, having the same energy with it, causes exactly the same failures or setback of the element base. The amplitude of the pulse received by the aperture and the amplitude of the transmitted pulse are related by the utilization of the antenna. Thus, authors have obtained a technique for indirectly assessing the influence of an electromagnetic pulse of intentional action based on the calculated prediction of the resistance of railway automation systems to electrostatic discharges. An analogue of the equation of power suppression of radioelectronic means is obtained, which allows finding the parameters of an electromagnetic pulse generator that creates dangerous pulses for railway automation systems. Also, this equation allows calculating the size of the suppression zone for a given generator.

Calculation of specific operating modes of relay protection for AC traction networks

Relay protection of traction networks against short-circuit currents in alternating current sections should have both selectivity and speed. However, in areas with an increased probability of burnout of contact wires during a short circuit, selectivity is often put away to increase the speed of response. Such operating modes of relay protection in the traction network are specific. The author considers one of these modes, namely, the operation of distance protections with an increased step area without time delay with a partially non-selective protection system, which ensures the fastest possible shutdown of damage within the entire protected area. At the same time, it is indicated that an increase in the coverage area of a step without a time delay to the size of the protected area can cause non-selective tripping of a number of switches in case of damage near substations or a sectioning post. Therefore, it is proposed to select the optimal value of the tunable zone of non-selective protection action, at which the probability of non-selective tripping of switches will be minimal. For this, the author presents an analytical solution to this problem, which allows automating calculations when forming proposals for setting up protection in a specific operating mode. It is noted that by choosing the sensitivity coefficient value in the formulas, it is possible to adjust the zone of non-selective action of distance protections so that its real value will approach the size of the protected area, while remaining strictly larger than it, which will eliminate the danger of burnout of contact wires in case of a short circuit and reduce the probability non-selective disconnection of switches on the site.