Traction Calculations Research Articles

Multi-Objective Parameter Configuration Optimization of Hydrogen Fuel Cell Hybrid Power System for Locomotives

Conventional methods of parameterizing fuel cell hybrid power systems (FCHPS) often rely on engineering experience, which leads to problems such as increased economic costs and excessive weight of the system. These shortcomings limit the performance of FCHPS in real-world applications. To address these issues, this paper proposes a novel method for optimizing the parameter configuration of FCHPS. First, the power and energy requirements of the vehicle are determined through traction calculations, and a real-time energy management strategy is used to ensure efficient power distribution. On this basis, a multi-objective parameter configuration optimization model is developed, which comprehensively considers economic cost and system weight, and uses a particle swarm optimization (PSO) algorithm to determine the optimal configuration of each power source. The optimization results show that the system economic cost is reduced by 8.76% and 18.05% and the weight is reduced by 11.47% and 9.13%, respectively, compared with the initial configuration. These results verify the effectiveness of the proposed optimization strategy and demonstrate its potential to improve the overall performance of the FCHPS.

DEVELOPMENT OF A MATHEMATICAL MODEL FOR DETERMINING TRACTION AND ENERGY PERFORMANCE INDICATORS OF A MANEUVERING LOCOMOTIVE

Fuel consumption for traction significantly depends on the locomotive's operating mode, and by selecting a rational mode during station maneuvers or transit, it is possible to reduce fuel consumption. Previous works on this topic do not provide sufficient analysis of locomotive motion with varying numbers of connected engines. To optimize energy resource consumption, a combination of methods for the rational use of the locomotive is necessary. The traction and energy performance indicators for the maneuvering work of the ČME3 locomotive are calculated by performing traction calculations. In this paper, a mathematical model has been developed to determine these indicators when operating with 4 and 2 parallel-connected traction electric motors. Graphs were constructed to illustrate the relationship between traction force and locomotive speed, the time required to cover a given distance, fuel consumption for a specified distance, and the temperature rise above ambient conditions concerning 6 parallel-connected traction electric motors for the 3rd, 4th, and 5th positions of the engineer's controller. The locomotives were compared while covering the same stretch of track with the same train weight, considering wheel-rail adhesion constraints.Analyzing the obtained dependencies allows the conclusion that using different configurations of connected engines can result in fuel savings of up to 15 % during maneuvering operations, depending on operational conditions. Furthermore, the engine temperature remains within acceptable limits for insulation class F, based on the results of approximating existing locomotive characteristics and deriving analytical expressions (6, 7, 8, 24). Mathematical models of the motion of the ЧМЕ3 locomotive were created for various engine connection scenarios using the obtained mathematical formulas (9, 10, 11, 13, 20, 21, 22, 23, 24).

Research of unit train loading technologies at the sidings of grain elevators with their shunting locomotives

The purpose of the study is to increase the unit train load efficiency at the elevators having their shunting locomotives. The research is based on the analysis of time series, methods of organizing the operational work of railways, and methods of traction calculations. The paper considers the problem of organizing shunting work at elevators when loading grain unit trains. Critical wear and tear of shunting locomotives in railway transport of general use necessitates using their locomotives at the elevators. As a result of the research, the dependence of the duration of shunting and cargo operations on the number of cars in the unit train and on other factors was established. Various types of shunting locomotives were compared. Based on the analysis, it was established that it is advisable to use four-axle shunting diesel locomotives with hydraulic transmission for shunting work at the elevators. The traction force of such locomotives is sufficient to deliver empty cars to the elevator at a speed of 14–15 km/h. Loaded cars can be removed at a speed of 14–15 km/h with a slope of the connecting track up to 2–5 ‰. With greater slopes, the removal of loaded cars should be performed at a speed of 5 km/h. The main factor affecting the duration of shunting operations is the distance of delivery and removal of cars. Technologies for loading the grain unit trains at the elevators, providing for the presence of cars at the loading stations for two and three days, have also been developed. The main factor affecting the duration of unit train loading is the staff of locomotive assembly teams. The originality of the study is in obtaining the dependence between the parameters of the technical support of the elevators and the duration of the presence of cars in the connecting station – elevator’s siding system. The practical value of the paper is that its results can be used in the design of the reconstruction of existing and construction of new elevators, as well as in the estimation of costs associated with various loading technologies of the unit trains for the corresponding sidings.

Continuously Variable Two-Flow Hydrostatic-Mechanical Transmission of Crawler Tractor

The paper proposes an original design of a continuously variable two-flow hydrostatic-mechanical transmission, which ensures division of the power flow along the sides of the crawler tractor. To ensure stability of rectilinear motion, their volumetric and mechanical efficiency, the maximum pressure of the working fluid in the hydraulic transmission, the maximum speed and torque on the shaft of the hydraulic motor. The parameters of an unregulated hydraulic motor, an adjust-table pump and mechanical transmission elements are selected. A mathematical model of the rectilinear motion of a caterpillar tractor with a continuously variable hydrostatic-mechanical transmission has been developed, taking into account the weight of the tractor, the parameters of the running system, the characteristics of the internal combustion engine, the parameters and efficiency of hydraulic machines, gearboxes, range and transfer boxes, planetary gear and allowing to determine the efficiency of individual branches and the entire transmission, carry out traction calculations of the tractor. A calculation program has been developed that implements the mathematical model. The parameters of the dual-flow transmission are selected so that most of the torque is transmitted through the mechanical branch and the transmission has a fairly high efficiency value. The maximum value of tractor traction efficiency is realized in the second and third ranges, which are designed to perform basic tillage operations.

Сравнение длины тормозных путей грузового поезда с однотрубным и двухтрубным питанием тормозной системы

Objective: to perform a comparative analysis of the length of the braking distance of a freight train with a single-pipe and two-pipe brake system supply. Based on the laboratory studies carried out, to identify the effect of the speed and amount of filling of brake cylinders on the calculated braking distance of freight rolling stock when using brake systems with two-pipe and single-pipe supply of a spare tank. These studies are aimed at improving the technical speed and safety of freight trains, as well as improving the efficiency of the braking system during cyclic braking, in order to reduce its depletion. Methods: analysis of the filling rate of the brake cylinders, in order to determine the time of preparation of the brakes for action, depending on the method of organizing the power supply of the brake system; comparison of the length of the preparatory and actual braking distance according to the method of speed intervals proposed in the Rules of traction calculations. It was also assumed that the train was braking to a complete stop on a straight horizontal section of the track, with air leaks from the brake cylinders throughout the train. Results: it was revealed that a two-pipe braking system allows to develop a significantly greater braking effect than a singlepipe braking system with a similar technical condition of the pneumatic train system. As a result, with the new method of powering the reserve tank, there is a significant reduction in the time required to prepare the brakes for action, as well as a reduction in the length of the full braking distance. Practical significance: it has been proven that the use of a new braking system will improve the efficiency of the braking system, which leads to a reduction in braking distance. This, in turn, will improve the safety and speed of trains along the sections, as well as increase the average weight of trains.

Determining the energy efficiency indicators of the diesel train DPKr-2 and the rail bus 620M based on traction calculations using the numerical method of solving the equation of train movement

The purpose of the article is to compare the technical and energy parameters of the diesel train DPKr-2 and the railbus 620M based on traction calculations using mathematical modeling when solving the train movement equation. The mathematical model of the train is adapted to determine the movement parameters of the specified rolling stock units according to different variable phase coordinates for different movement modes. To achieve this purpose, the authors used methods of system analysis, nonlinear programming, and numerical methods for solving differential equations. The accuracy of the calculations was verified using simulation modeling methods and compared with experimental data. To analyze the results, the obtained indicators of traction calculations – technical speed and specific consumption of diesel fuel – were compared. As a result of the comparison, the specific fuel consumption per ton-kilometer meter, a significant saving of energy resources is observed. Comparative specific fuel consumption per passenger-kilometer meter, on the contrary, indicates an increase in the consumption of energy resources. The mathematical model of the train is adapted to determine the movement parameters of diesel trains and rail buses according to different variable phase coordinates for different drive modes. The practical significance lies in determining the efficiency indicators of the use of different types of rolling stock on the railways of Ukraine, taking into account economic, social and migration factors.

Assessment of the effect of train traction by locomotives of different types on the quality indicators of the train schedule

The precinct and technical speed of freight trains is one of the main parameters of railway transport characterizing qualitative indicators. The higher the local and technical speed, the better the quality indicators of railway transport, the higher the speed of cargo delivery to the addresses. These speeds directly depend on the distance between stations and the time of their passage. The types of electric locomotives are one of the main factors determining the travel time and energy consumption of trains moving along the site. The differentiated accounting of inter-station runs in the train schedule is based on traction calculations. This article analyzes the regulatory timetable of the trains of the “Tukimachi – Akhangaran” section of Uzbekistan Railways JSC and develops a methodology for determining the travel time of trains moving on the section for the 3VL80r electric locomotive based on traction calculations. Based on the developed methodology, the influence of the time of inter-station runs under traction conditions by locomotives of various brands on the site and technical speed of trains on the railway section was estimated.

To the effectiveness of using of UzTE16M3 diesel locomotives on a hilly section of railroad

A program algorithm and a method for producing (performing) traction calculations are proposed, based on geometric constructions of changes in the speed and time of train movement along the track, relying on the specific resultant forces of the train in the travel track of rolling stock. Calculations of the kinematic parameters of the movement of a freight train on a virtual hilly section of the railway were carried out using a graphic-analytical method when moving with stops and without stops at the intermediate and final stations. The values of the energy efficiency indicators of UzTE16M3 diesel locomotives when driving a freight train with a minimum train weight in quantitative and monetary terms are substantiated. The numerical results of the research are obtained in the form of tabular data, which specialists of the locomotive complex can use when analyzing and assessing the efficiency of the transportation work of UzTE16M3 diesel locomotives under real operating conditions.

Managing electric motive power modes with regard to traction energy operation conditions

Improving the energy efficiency of electrified railways is an urgent goal, one of the possible solutions to which is the situational control of electric traction loads depending on their priority, taking into account the instantaneous load of the traction power supply system. The aim of this research is to develop a mathematical model and principles of control of electric traction trains on the basis of instantaneous traction calculations, taking into account the modes of operation of the traction power supply system of railways in conditions of energy infrastructure limitations. The paper presents the results of mathematical modeling of mutual influence of electric traction and traction power supply system on the parameters of operation, as well as the mathematical formulation of realization of operation modes of electric traction at demand management by electric traction loads applied to the considered electrified section. As a result of the calculations for one moment of time the values of adjustment of active power of electric traction trains for fulfillment of restrictions of instantaneous load of power lines of traction equipment (15.9 MW) and provision of voltages in the traction network within permissible limits in the given train situation are obtained. The presented approach will allow to obtain restrictions of train movement in the zone between substations, to determine the maximum speed of train movement on the basis of energy conditions in the real situation, to coordinate control actions between trains on the basis of their priority (schedule adjustment) depending on the load of traction substations.

Determination of Energy-Optimized Locomotive Control During Train Acceleration

Purpose. In this article, the authors aim to improve the mathematical model of train movement by adapting the model to determine the values of diesel power at the corresponding values of train acceleration and different modes of train operation. Based on the model, it is planned to build and analyze two-parameter dependencies of locomotive control during acceleration, which provide steady acceleration on different track profile slopes for different values of train weight, which will allow for more rational management of the locomotive fleet with strict adherence to the train schedule and minimal diesel fuel consumption for traction. Methodology. To achieve this goal, we used the method of system analysis, nonlinear programming, and numerical methods for solving differential equations of train motion, taking into account that the integration of the equation of train motion can be carried out by path, time, and speed, depending on the initially set task in traction calculations. Calculations were performed for different modes and phases of train operation. Findings. To analyze the results, we compared the obtained traction calculations, such as technical speed, travel time, and fuel consumption. To solve the problem of traction calculations, we chose the Maple software package, which allowed us not only to numerically evaluate the results of solving the two-parameter mathematical model, but also to graphically and visually, which greatly simplifies their perception. The obtained results of the calculations indicate a decrease in energy consumption. Originality. The model of train movement has been further developed, taking into account the adaptation to determine the values of diesel power consumption in the case of steady-state values of train acceleration depending on the weight of the train and the slopes of the track profile. Practical value. The expediency of the study is to save energy resources, in particular diesel fuel, for train traction and allows more accurate adherence to the train schedule, which, in turn, affects traffic safety in general.

Determination of Parameters for Limiting Longitudinal Acceleration to Optimize Energy Consumption for Train Traction

Purpose. The main purpose of the article is to improve traction calculations using mathematical modeling when solving the equation of train motion. The train model is adapted to optimize the parameters of train movement during speed gain with the determination of functional relationships between the power of the locomotive power plant and the profile of the track section with the consumption of energy resources by the locomotive. Methodology. Modern methods of mathematical modeling were used to solve the tasks. The modeling of the power plant operation was performed using interpolation and approximation methods. The simulation modeling method was used to create a model of the electrical part of the diesel locomotive transmission. The method of integrating the differential equation of motion was used to calculate the parameters and nature of the train's movement and the problem was solved, which consists in finding a solution to this equation over the length of the traction section, taking into account the variable values of the locomotive power and the slopes of the track profile. Findings. To analyze the results of traction calculations, we obtained such indicators as technical speed and diesel fuel consumption, and compared these indicators. The results show that in the case of acceleration limitation, there is a decrease in diesel fuel consumption at almost unchanged technical speed. Originality. The improvement of energy efficiency of train operation has been further developed, namely, the functional dependence of the relative power of the locomotive power plant, which takes into account the actual profile of the site, has been obtained, which makes it possible to determine energy-saving modes of locomotive control and reduce energy consumption, load on the diesel engine and elements of the diesel locomotive traction transmission during transient modes, which, in turn, in addition to saving diesel fuel, will affect the reliability of the power plant elements. The practical value of the study is to save diesel fuel in the modes of movement that provide speed gain and increase the reliability of the power plant due to reduced load.

DEVELOPMENT OF METHODS FOR SIMULATION OF RAILCARS ROLLING FROM SORTING HUMPS

Purpose. The purpose of this article is to carry out a historical analysis of the development of methods for simulation of railcars rolling from sorting humps and to determine directions for their improvement in order to solve the problems facing the railway transport of Ukraine today. Methodology. The research was carried out on the basis of the processing of literary sources of the library of the Ukrainian State University of Science and Technology, as well as scientometric databases Scopus and Google Scholar. Findings. The origin of the methods for simulation of railcars rolling from sorting humps took place at the beginning of the 20th century, when they were separated from the methods of traction calculations. Until the middle of the 20th century, the simulation of the railcars rolling was carried out in order to solve the problems of designing sorting humps. This period is characterized by the simulation of the rolling of individual curs under known conditions. The complication of the simulation methods of the sorting humps operation is connected with the tasks of automating the control of the trains breaking-up. For this purpose, the tasks of establishing the laws and parameters of the distribution of random resistance values acting on the cuts, taking into account changes in the longitudinal profile of the track under the cuts, modeling the operation of brake retarders and their control systems, etc., were solved. Originality. The scientific novelty of the work lies in the fact that, on the basis of a historical analysis of the development of methods for simulation of railcars rolling from sorting humps, the connections between the working conditions of railway transport and the methods of modeling rolling processes are established. Practical value. The practical value of the results lies in the fact that they indicate the need to develop methods development of methods for simulation of railcars rolling from sorting humps in conditions of inaccurate information about their running characteristics and rolling conditions. This will make it possible to increase the efficiency of the sorting humps operation without significant capital investments in their control systems.

Valuation of the influence of the basic specific resistance to the movement of freight cars on the energy costs of driving a train

The primary specific resistance to the movement of freight wagons is a key parameter for normalizing the time and energy consumption of trains. Although the “Rules of Traction Calculations” calls for dividing wagons into six groups when calculating this resistance, in practice (using the traditional method), appropriate regulations are developed based on the separation of train wagons into two groups (4th and 8th lips). One of the main reasons for this is the inability to account for the unique features of each wagon in a given train. To address this issue, a program was developed for determining the necessary parameters of wagons for traction calculations based on their identification numbers. This software can be accessed through the website https://trainlocomotive.netlife.app/. Using this program, a method for calculating the primary specific resistance to the movement of freight wagons has been developed. Field sheets of freight trains moving through the Uzbekistan Temir Yullari railway station were analyzed. As a result, it was discovered that nearly half of the freight train composition consists of empty wagons, while the proportion of loaded gondola cars and tanks is 23%. The primary specific resistance to the movement of wagons in such a mixed composition is calculated using both traditional and developed methods. The impact of the primary specific resistance on the energy costs of maintaining the train is evaluated. As a result, the feasibility of utilizing the developed method for normalizing electricity consumption based on traction calculations is demonstrated.

Имитационное моделирование движения поезда по перегону с применением тяговых расчётов

Within the framework of the conducted research, the necessity for developing a highly detailed simulation model of interval regulation of train traffic is substantiated. The advantages and disadvantages of current universal and specialized programs of simulation modeling of processes in railway transport are analyzed. By means of the universal simulation tool AnyLogic, the model of train movement along the running line is constructed using traction calculations and implementation of interval regulation. In the model, the agent-based modeling approach is used to simulate train movement modes, the process approach is used to implement the logic of the operation of interval control systems, and the elements of system dynamics are used to calculate the speed of the train. The adequacy of the model is justified by analyzing the train travel times in traction mode along the lines belonging to the four types of track profile with varying the mass of rolling stock and the power of train locomotives.

To the efficiency of locomotives of electric tractions on a hilly of section of the railway track

The article provides a rationale for the kinematic parameters of the movement of freight trains with masses different and the energy efficiency parameters of 3VL80S electric locomotives on a virtual hilly section of the railway. In order to implement this justification, a method of graphically integrating the differential equation of train motion is used, which is the basis of the algorithm for performing traction calculations for the movement of the freight trains under study without stoppings at an intermediate station. Kinematic parameters of the movement of freight trains and energy efficiency indicators of 3VL80S electric locomotives are obtained in the form of tabular data and regression equations according to their definition on railway sections with the second type of track profile, which can be used in predicting and normalizing the consumption of electrical energy for traction of trains. The research results are recommended for implementation into work by specialists of the locomotive depots operation workshop of «Uzbekistan Temir Yollari» JSC.

Logistic indicators of locomotives of diesel traction on high-speed section of the railway

The results of a theoretical study evaluating the effectiveness of using Uzbek diesel locomotives of the UzTE16M3 series during the non-stop movement of freight trains on the hilly-mountainous high-speed section Marokand - Kattakurgan of the Uzbek railway are presented. The reference point for the implementation of this assessment was the mathematical model of the movement of a freight train developed by the authors and the algorithm for performing traction calculations, which are prerequisites for substantiating the numerical values of the parameters of the logistic indicators for the process of railway transportations of goods in real conditions of the organization of operation. The authors obtained the parameters of logistics indicators in the form of numerical tabular values and graphical dependencies, and the corresponding regression equations were proposed to calculate the indicators of transport logistics. The data obtained by the authors can be used by specialists of the locomotive depots “O’zbekiston temir yo’llari” JSC, whose production activities are related to the issues of forecasting and normalizing the consumption of full-scale diesel fuel by diesel locomotives on the hilly-mountainous, of hi high-speed sections of the Uzbek railways.

Оптимизация эксплуатационных расходов за счет улучшения условий взаимодействия подвижного состава и пути по параметру эквивалентной конусности

Purpose: Calculation of an economic effect by introducing the parameter of equivalent taper of wheel pairs on account of reduction of operating costs on high-speed train motion and track facility maintenance. Methods: The study used the methods of computer simulation of interaction between a rolling stock and a railway track, methods of mathematical statistics, methodology to make traction calculations in automated system. Results: Measures have been proposed to reduce the forces of a drag for a high-speed rolling stock motion. We’ve calculated an economic effect from introduction of wheel pair equivalent taper parameter on Russian Federation high-speed railroads. Practical importance: Recommendations have been proposed on consideration of wheel pair equivalent taper parameter for to reduce the forces of drag to the motion and on pursuing rail mobile treatment on the sections of high-speed train traffic sections.

Определение затрат энергии в синхронных тяговых генераторах тепловозов при различных режимах нагружения

Purpose: To develop a methodology for determining energy consumption in synchronous traction generators depending on implemented workload mode. To calculate traction characteristics of a locomotive it is necessary to obtain analytical dependences of energy losses in a synchronous traction generator from rotation frequency of its shaft, electric current and voltage at rectifier plant. To solve the problem of determining significance of various components of losses in a synchronous traction generator under different operating modes. Methods: Investigation of all components of energy losses in a traction synchronous generator. Conclusion of analytical dependencies that allow calculating all components of losses in generator depending on its design parameters by obtaining constant coefficients that depend on design parameters of generator. Results: The values of capacity spending for energy conversion in a synchronous traction generator are determined. The obtained dependences allow us to perform refined analysis of losses in a traction drive. It is shown that the capacity of mechanical losses at a nominal speed reaches 50 kW, capacity of electrical and magnetic losses can reach 20 kW. Practical importance: The results obtained allow us to clarify the amount of energy consumption in a traction drive of locomotives and improve the accuracy of traction calculations. The nature of the change in losses in a synchronous traction generator depending on speed, voltage and current at the output of rectifier plant and its design parameters is shown. The results can be used, among other things to clarify traction characteristics of locomotives.

Justification of the Structure of the Electric Traction Drive of the Electric Locomotive for Railway Quarry Transport

Purpose. The study is aimed at substantiating the structure and determining the main parameters of the traction electric drive of an electric locomotive for railway quarry transport, taking into account its modes of operation. Methodology. The research was carried out by means of mathematical modeling, which included solving the traction problem and evaluating the parameters of the energy exchange processes between the components of the traction electric drive. The simulation was carried out for the movement of the train along the track section and during shunting, which differ significantly in their mathematical description. During simulation of movement along the track section, the traction problem was solved using recommendations for traction calculations for train operation. A simplified model was developed to simulate movements during shunting. Determination of the parameters of the traction electric drive components is carried out by analyzing the processes of energy exchange in the traction electric drive based on the power balance. During the studies, it was assumed that the on-board energy storage in the traction mode feeds the traction electric motors of the booster section. In the electrodynamic braking mode, the energy accumulator stores energy from all traction electric motors of the electric locomotive. Findings. The authors obtained time dependences of the parameters that characterize the train movement at all stages of the cycle «empty half passage – loading – loaded half passage – unloading» (on the example of an electric locomotive for PJSC «Ferrexpo Poltava Mining»). The analysis of the obtained dependencies made it possible to determine the parameters of the main components of the traction electric drive for the proposed storage operation scenario. It was established that the energy capacity of the energy storage should be 250 kWh for one movement cycle. The energy storage power is 6000 kW. Originality. The authors of this paper for the first time proposed the structure of the traction electric drive of an electric locomotive for quarry railway transport, in which the electric motors of the control electric locomotive are powered from the catenary network, and the electric motors of the booster section are powered from the energy accumulator and are included in the operation at a load that exceeds 50% of the nominal one. Practical value. The practical value lies in the developed mathematical models of movement and energy exchange processes, which can be applied to the study of traction electric drives of vehicles of various purposes.

Оптимизация кривой движения поезда для минимизации энергопотребления на базе ж. д. Узбекистана

Objective: Analysis of existing methods for finding optimal modes of driving electric locomotives on the Pap — Kokand — Andijan section, which is part of the Uzbek Railways landfill, in order to minimize the electrical energy used for traction, taking into account such restrictions as the travel time on the stretch, the maximum permissible driving speeds, available traction power, etc. Methods: The method of selecting the train motion curve provides for three approaches to solving the problem and takes into account two tasks for solving the equation of train motion. Results: Compared with the data obtained from the service of the “Locomotive Operation Management” of Uzbek Railways, the results show that energy efficiency ranges from 4 to 30 %. The resulting maintenance regime is qualitatively different from the regime maps currently used on the Pap-Kokand-Andijan section for energy-optimal train management. Practical importance: The described calculation method using three approaches to solving the task makes it possible to simplify significantly and speed up traction calculations, ensure high accuracy of the results and present them in a convenient and visual form.