Journal of Transsib Railway Studies V.1(61), 2025

The subject of this article is voltage regulation in the traction power supply system. The object is the on-load voltage regulation device (OLTC), which is responsible for regulating the voltage in the contact network by changing the transformation ratio of the power transformer of the traction substation. This device is important for maintaining the required voltage level in the contact network, but when operating in automatic voltage regulation mode, high wear of the OLTC is observed. This is due to the fact that the wear of the device directly depends on the number of switching operations it performs per day. In turn, the frequency of switching operations depends on many factors associated with the traction load. Another problem is the different levels of wear of this device in different sections of the power supply - in sections with a flat track profile and low traction load, the damage to OLTC devices is significantly lower due to rare switching operations to adjust the voltage, and in sections with a complex profile and high load, the OLTC demonstrate extremely low reliability, so much so that the personnel of traction substations turn off automatic regulation and perform switching operations manually. In order to predict the wear of the OLTC devices, it was decided to create a computer model of the traction power supply system, including automatic voltage regulation in the network, and a switching counter As a result of the work done, a computer model of the traction power supply system of the 2×25 kV traction system was created in the SimInTech software package, which shows the operation of the automatic regulation system with a switching counter.

The article explores the modeling of the interaction between the pantograph and the catenary, which is a relevant task in the development and optimization of current collection systems. The subject of the article is the modeling of the catenary, with finite element models and lumped parameter models being the most widely used approaches. Their key characteristics are highlighted: finite element models offer high accuracy but require significant computational resources, whereas lumped parameter models allow for a quicker assessment of interactions but have limitations due to their simplified representation of physical processes. The aim of this study is to improve the accuracy of modeling the interaction between pantographs and the catenary using lumped parameter models. As part of the research, an improved catenary model is proposed, in which the lumped mass is replaced with an inerter. This modification eliminates the issue of forced oscillations and enhances the accuracy of system dynamics modeling. The proposed model is implemented in MATLAB Simulink, and its validity is confirmed through correlation analysis, demonstrating better agreement between the calculated and experimental data compared to existing models. The obtained results show that the proposed approach allows for a more accurate simulation of the interaction between the pantograph and the catenary, making it a promising solution for use in the design and optimization of current collection systems in railway transport.

With the increase in the capacity of modern electric rolling stock providing freight and passenger transportation, the problem of transmitting large traction currents remains relevant, caused by the low load capacity of the pantograph, which can lead to overheating and annealing of the contact inserts with a subsequent decrease in their strength, peeling of graphite from the copper shell, and increased wear. The article considers the classification of various methods for increasing the load capacity of pantographs, the most promising of which is cooling their runners. The disadvantages of the known active and passive runner cooling systems include the need to use additional mechanisms and units to remove heat from the heated parts, which work effectively only when the electric rolling stock is moving or at a standstill. To eliminate this drawback, the authors proposed a technical solution for a pantograph runner equipped with heat pipes and capable of successfully operating in various operating modes of electric rolling stock. To test the operability of the proposed technical solution, its mathematical model was created in the SolidWorks software environment, which, using the FlowSimulation application, allows modeling the thermal processes occurring in the pantograph runner. When using heat pipes in the runner design, the heating temperature is distributed more evenly along its length, thereby improving the conditions for heat dissipation into the environment, which will allow higher load currents to pass through. The results of mathematical modeling of thermal processes in the pantograph runner in the SolidWorks software environment are confirmed by experimental studies on a specialized installation. The use of the proposed device facilitates a more uniform distribution of heat over the surface of the runner, reducing the heating of the contact inserts and increasing the load capacity of the pantograph and the reliability of its operation under conditions of high-speed, high-speed and heavy-haul train movement.

The article discusses the solution of problems related to the development of a simulation model of a DC traction substation designed to evaluate energy and other performance indicators, including electricity quality indicators. The development of a simulation model makes it possible to evaluate the effectiveness of technical measures that can be used at traction substations to solve problems of improving the quality of rectified voltage, reducing non-sinusoidal busbars for their own needs, regulating the voltage on substation tires, and a number of others. Currently, the urgent tasks in the field of non-traction power supply include reducing the non-sinusoidal voltage on the busbars of alarm, centralization and blocking consumers who are sensitive to high voltage harmonics. The simulation was performed for one of the most common circuit solutions, characterized by the fact that a twelve-pulse rectification circuit of a sequential type is used at the substation. The proposed model was developed in the SimInTech software environment and allows you to evaluate the performance of a substation for various circuit states using switches inserted into the circuit. The simulation results are given for a symmetric system of sinusoidal voltages. The simulation results are compared with the results obtained on the basis of an experimental assessment of electricity quality indicators for one of the operating DC traction substations. The above measurement results at a traction substation with twelve-pulse rectifiers of a sequential type were performed synchronously for two pairs of inputs of 0.4 and 10 kV of the traction substation. A comparison of the simulation results shows the adequacy of the developed model and the equipment characteristics used in it, which makes it possible to use it to solve a number of other tasks.

The article discusses the urgent problem of upgrading non-public railway tracks through the introduction of automated loading and unloading control systems. The relevance of the study is due to the significant proportion of non-public tracks in the Russian railway infrastructure (29 % of the total length) and their constant increase, the growing volume of industrial production in the country and the need to improve the efficiency of transport services for enterprises and improve the efficiency of their use. More than 85 % of all freight traffic by rail starts and ends on non-public roads. The correctness of the service, organization and technology of the operation of the considered routes affects the operation of the entire transport network. The problem of the study lies in the fact that traditionally accepted methods of loading and unloading operations on non-public tracks do not provide the necessary efficiency of the transportation process, which leads to long downtime of rolling stock and increased operating costs for railway transport. The methods of system analysis, mathematical modeling and comparative analysis of statistical data are used in the work. Based on a study of international experience and domestic practice, it has been shown that the introduction of automated control systems can reduce the downtime of wagons by 25 - 30 % and reduce operating costs by 15 - 20 %. The article presents the definition of an automated loading and unloading management system as an integrated information management system that integrates hardware and software. A step-by-step methodology for system implementation has been developed, including seven consecutive stages from preliminary analysis to optimization and development. The proposed solutions take into account the specifics of Russian operating conditions and import substitution requirements.

A new approach to modeling the operations of railway stations and junctions using Petri nets is proposed. This method enables process analysis both analytically and through simulation, considering the topological features, operational technology of the station, and the structure of the transportation flow. The article provides a detailed examination of key properties of Petri nets, such as boundedness, liveness, and reachability, as well as methods for their analysis. These properties are applied to solve practical tasks, including resource optimization, increasing operational efficiency, and ensuring railway station safety. The proposed model identifies bottlenecks, forecasts potential operational difficulties, and develops measures to improve station performance. Various modifications of Petri nets, including timed, stochastic, and colored nets, are discussed. Each type offers distinct advantages for analyzing the temporal, probabilistic, and structural characteristics and parameters of station topology and transportation flow. The paper presents a model of the throat of a railway station’s reception yard for train passage, including its reachability tree of possible states. Analyzing the reachability tree identifies operational constraints and the sequences of events leading to these states. The model also predicts potential operational difficulties and shortages of maneuvering resources by applying an analytical method based on Petri net matrix analysis. This approach enables large systems, such as complex technical railway stations or junctions, to determine individual critical states that could lead to undesirable events without simulating all possible states.

This study focuses on the harmonized definition of sets of source data and criteria for creating an optimal container handling model at a terminal of type «dry port» served by rail and road transport. The model development process should consider priority in managing rail and road transport, balancing their interests and the cost-benefit relationship between cargo equipment and inactivity of vehicles and/or containers, depending on the technology and speed of cargo handling. The article noted that in the part of setting the task, many authors have limited approaches to the concept of «optimal terminal operating model» and the applied criteria of optimality. The study proposes a set of initial data intended to create an optimal work model, which includes data on the characteristics of the container flow, terminal, transport and handling mechanisms and processing. When creating the optimal terminal operation model, it is possible to evaluate the efficiency of the process in isolation or in a complex at once in several aspects depending on the purpose of the simulation. The valuation can be performed using a value criterion (cost of processing TEU), a criterion in terms of the natural value (maximum amount of processing to be realized, duration of processing) or an integral criterion (natural-cost value). The work has shown that the completeness of the sets of source data and the determination of calculation parameters in several possible units of measurement make the model adaptive for various modeling tasks and application of different criteria of optimality. For data that is dynamic by nature, the procedure for automated retrieval from existing information management systems significantly accelerates and simplifies calculation, allowing its use for operational planning and management purposes.

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

Incorporating passenger perspectives on the quality of ground public transport is paramount for enhancing urban mobility. This study champions the idea of making service quality perception the linchpin of urban transport policy formulation, thereby underscoring a user-centric methodology for cultivating sustainable transportation habits. By integrating passenger feedback, cities can effectively bolster user loyalty and entice new riders to embrace public transport. The research based on the importance of evaluating quality indicators within multimodal systems, which is essential for deciphering the spectrum of passenger sentiments. For urban transport to truly cater to citizen expectations, it is imperative to harmonize city authority ambitions, operator capabilities, and public desires, thereby creating sustainable urban ecosystems. At the heart of this approach lies a holistic planning system that encompasses operator-provided quality, regulator-set target quality, perceived quality, and desired quality. The study places emphasis on formalized assessment processes, acknowledging that passengers make rational choices, gravitating towards the most advantageous travel options. Integrating perceived quality indicators is invaluable for fostering informed management decision-making, which benefits both city administrations in strategic planning and transport companies in route and service optimization. Therefore, a comprehensive, user-centered quality assessment mechanism is pivotal for enhancing efficiency and satisfaction in urban transport, ultimately fostering a more sustainable and user-friendly urban environment.

The article considers methods for optimizing traffic flow management in large agglomerations by using clustering, routing and principles of queuing theory. The main study is devoted to the redistribution of resources by introducing a priority system in request processing. The influence of urgency, density and throughput of cargo flow on the system operation is analyzed and optimization algorithms are proposed to reduce waiting time, reduce costs and improve the efficiency of transport processes. The research methodology includes the use of a multi-channel queuing model to assess the impact of priority distribution of requests on the system throughput. Mathematical modeling, linear programming methods and NPV calculation for assessing economic efficiency are used to analyze the redistribution of resources. The results of the study show that the priority service system reduces the waiting time for urgent requests, but under high load it can increase the waiting time for less priority clients. The developed resource redistribution algorithm adapts the system to changes in flow intensity. The use of the proposed methods made it possible to reduce the average waiting time for priority requests by 1.5-2 times and reduce operating costs. The practical significance of the study lies in increasing the efficiency of transport processes due to the dynamic redistribution of resources. The implementation of the proposed methods can be used in logistics, courier services and transport companies to optimize the processing of requests, improve customer service and reduce costs.

Modern requirements for the organization of the transportation process depend on technological and infrastructural aspects. Traditional approaches to regulating car flows, including using methods to minimize empty runs of rolling stock, lead to the loss of profitable options for JSC Russian Railways to interact with customers in terms of organizing exports and imports with subsequent sale of these goods (products) in Russia. The technology of transporting coal in «Open Top» containers with back loading with imported cargo has advantages arising from foreign and domestic experience in implementing such transportation. This article focuses on the economic aspects of the technology under consideration, including reflecting the specifics and prospects for the development of container transportation of coal. A comparative analysis of economic indicators for several options for transporting coal is performed. For customers of railway transport and JSC Russian Railways, the feasibility of organizing freight transportation in «Open Top» containers with the formation of closed routes with back loading with imported cargo to an intermediate station is substantiated. It is noted that the savings of the closed ring route of coal and anhydrous calcium chloride in containers reach from 30% to 65% compared to the use of universal gondola cars. Given the current conditions of congestion of the railway infrastructure, the use of «Open Top» containers for the transportation of various goods is a key advantage of ring routes. This is important to consider when developing export-import relations with friendly countries.

The article highlights the importance of the international transport corridor “North - South” for our country. It is important to consider that the Astrakhan region is a gateway to international transport links. Both water and road routes, which are part of the North-South ITC, pass through the city of Astrakhan and the Astrakhan region. Road communication routes are extremely in demand due to the multimodality of cargo transportation, as well as the decrease in volumes when using waterways due to the shallowing of the Volga-Caspian Canal. Existing road transport routes pass through the urban environment, significantly increasing the traffic load. This leads to a deterioration in the condition of the road surface, negatively affects the economic and environmental components, and there is an increase in the number of congestion conditions. To improve the efficiency of the North-South international transport corridor, planning solutions have been developed. The planning task was to redirect transit traffic flows in order to divert them from the city, reducing the length of road communications. The implementation of planning solutions was carried out using the PTV Vision® VISSIM software product. The article presents the developed scheme of an alternative route, implemented through the construction of the Northern Bypass, which includes the construction of a new bridge across the Volga River, as well as road interchanges. This planning solution will allow the length of road communications, which are a regional part of the international transport corridor “North-South,” to be halved. If implemented, the proposed project will relieve congestion on the highways of the city of Astrakhan, increase traffic capacity and traffic safety.

This article examines the development of Uzbekistan’s transport and logistics system, focusing on optimizing the piggyback train schedule. Due to its strategic geographic location, Uzbekistan serves as a crucial transit hub connecting Europe and Asia. The continuous growth in freight traffic and the increasing need for greater logistics efficiency require a comprehensive approach to modernizing railway infrastructure and optimizing transportation processes. The study provides a detailed analysis of the current state of Uzbekistan’s railway network, identifying key areas for improvement. Special attention is given to the implementation of piggyback transportation, which offers significant advantages such as reducing transport costs, improving cargo delivery reliability, and minimizing environmental impact. To evaluate the efficiency of transport solutions, mathematical models are applied to assess station capacity and train scheduling. A comparative analysis of different freight transportation methods is conducted using Laplace and Wald decision-making criteria, enabling the identification of the optimal transportation mode and route. The results demonstrate that a well-planned train timetable facilitates increased freight volumes, enhances logistical coordination, and strengthens Uzbekistan’s role as a major transit corridor. Additionally, the study highlights the economic and operational benefits of implementing optimized piggyback train schedules. The findings of this research contribute to the development of strategies for railway infrastructure modernization, providing practical recommendations for improving freight transportation efficiency. These insights can support policymakers and industry stakeholders in making informed decisions to enhance the competitiveness of Uzbekistan’s transport corridors in the global logistics network.

The desire to reduce carbon dioxide emissions and the transition to electric transport are becoming key areas for the development of transport infrastructure in cities and agglomerations of the European part of Russia. For an effective transition to electric vehicles, it is necessary to develop a network of charging stations capable of meeting the growing demand for environmentally friendly modes of transport. The subject of the study is the analysis of the spatial and temporal characteristics of the movement of cars to optimize the location of the charging infrastructure. The aim of the work is to develop a methodological approach to determining the concentration zones of transport activity based on real data, which will make it possible to reasonably select locations for the installation of charging stations. This article discusses the approach of using the DBSCAN clustering algorithm to analyze the spatial and temporal characteristics of car movement based on real data on taxi rides in Omsk. This algorithm is implemented in the Python programming language. In the course of the study, the main spatial and temporal patterns of taxi movement in the studied region were identified and the initial and final points of taxi routes were combined into well-founded clusters. The analysis makes it possible to identify the main areas of concentration of transport activity, which forms the basis for further modeling of traffic flows in order to optimize the location of the charging infrastructure. The scope of the results includes the planning of urban transport infrastructure, the development of a network of charging stations for electric vehicles and the optimization of traffic flows. The findings of the study confirm the effectiveness of using the DBSCAN algorithm to identify areas of high traffic activity, which can significantly improve the quality of charging infrastructure planning and accelerate the transition to environmentally friendly transport.