Artem Maslii

Purpose. The objective of this work is to develop a method for the optimal control of multiple unit electric train with a multi-motor traction electric drive motion that minimizes energy consumption while maintaining a fixed travel time over a given section, taking into account actual traction and braking characteristics, track profile, and the variable number of traction motors in operation. Methodology. The problem is formulated as an isoperimetric optimal control problem with a constraint on the total travel time. To solve it, the dynamic programming method is applied in the discrete “path–speed” state space. The time constraint is accounted for by introducing a Lagrange multiplier, whose optimal value is determined iteratively using the bisection method. The model accounts for the nonlinear traction and braking characteristics of the rolling stock, speed limits along the track, resistance forces, and the influence of the track profile. Particular attention is paid to the correct description of braking modes, including the transition from electric to mechanical braking at low speeds. Additionally, an approach has been developed to optimize the number of active traction motors, which allows the motor load mode to be aligned with their energy efficiency. Findings. The proposed algorithm enables the generation of energy-optimized speed profiles within specified time constraints. It has been established that the use of the dynamic programming method allows for the generation of optimal traction, coasting, and braking modes while accounting for all constraints. Taking into account the optimal number of operating traction motors provides an additional reduction in energy consumption compared to modes with a fixed configuration. According to the results of the numerical experiment, energy consumption was reduced by 30–35 % relative to the suboptimal (aggressive) mode while maintaining the specified travel time. Originality. A generalized approach to optimal train motion control is proposed, combining dynamic programming, adaptive selection of the Lagrange multiplier, and optimal selection of the number of active traction motors along the route of multiple unit electric train. The motion model has been improved by introducing a terminal speed zone and correctly accounting for braking modes, which increases the stability and accuracy of the numerical solution. Practical value. The results obtained can be used in the development of automated train control systems, the optimization of schedules, and the improvement of energy efficiency in the operation of electric traction rolling stock.

The global energy transition necessitates innovative solutions to reduce fossil fuel dependence in the railway sector. This paper analyzes the architectural integration of electrochemical On-board Energy Storage Systems into plug-in hybrid traction systems. The objective is to formulate an engineering approach for energy-efficient rolling stock operating on high-voltage networks (3 kilovolts) and autonomous power. The methodology synthesizes circuit designs, focusing on Bidirectional Direct Current converter topologies and Battery Management Systems. It compares Lithium-Ion cells (Lithium Nickel Manganese Cobalt Oxide, Lithium Iron Phosphate, Lithium Titanate Oxide) to identify suitable heavy-duty configurations. The study identifies isolated Bidirectional Direct Current converters, specifically the Dual Active Bridge topology, as critical for safety in high-voltage environments. It substantiates the transition to Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistors, reducing switching losses by 50–70 % versus Insulated-Gate Bipolar Transistors. However, switching frequencies must be limited to 1.5–2 kilohertz to comply with EN 50121 Electromagnetic Compatibility standards. The analysis shows mono-chemical Lithium Nickel Manganese Cobalt Oxide batteries are unsuitable due to thermal risks. Instead, a hybrid architecture combining Lithium Iron Phosphate for capacity and Lithium Titanate Oxide for peak power is proposed. Traditional Proportional-Integral-Derivative regulators are deemed insufficient for complex hybrids; the study advocates for Model Predictive Control to optimize energy flow based on route topography. Furthermore, a modular Battery Management System with high precision (1%) is required to maximize battery range. The optimal architecture integrates an isolated Silicon Carbide converter, a hybrid Lithium Iron Phosphate and Lithium Titanate Oxide battery, and Model Predictive Control, ensuring balanced safety, efficiency, and cost.

This study examines the rolling stock that currently employs or could be equipped with plug-in hybrid traction systems. Existing methodologies for selecting energy storage systems often limit their applicability, which creates certain constraints when choosing a solution for hybrid traction systems. As a result of the study, a well-founded preliminary selection of an energy storage system based on expert evaluation and the Harrington desirability function was carried out. Engaging experts in relevant fields makes it possible to obtain up-to-date information on technology development and assess whether parameters meet specific requirements. The application of methods for evaluating expert consensus provides a foundation for using the results in subsequent calculations. Harrington desirability function makes it possible to combine parameters with varying units of measurement and other differences, yielding a single value that can simplify decision-making. Using expert-derived evaluations, weighting coefficients for various parameters were calculated for the defined types of rolling stock. In the current research, three types of energy storage systems were selected for locomotives and multiple-unit rolling stock, meeting the specified conditions. These include battery, supercapacitor-based and flywheel-based storage systems, with overall desirability scores (without weighting coefficients) of 0.638, 0.636, and 0.573, respectively. Modifying the set of parameters, introducing additional constraints, and adjusting weighting coefficients in conjunction with motion optimization tasks makes it possible to adapt the methodology to the requirements for specific projects for constructing or upgrading rolling stock with plug-in hybrid traction systems

Introduction. The article is devoted to the development of the microprocessor automatic control system for a gearless controlled electric drive of a mono-switch tie based on a linear inductor electric motor. This solution provides control the position of the switch point, to carry out the transfer process with a smooth drive of shanks to the frame rail, to protect electric motor elements from overloads. Goal. development and study of the behavior of microprocessor automatic control system for mono-switch tie type with linear inductive electric motor and discrete PID speed controller which coefficients are adjusted according to Chin-Hrons-Reswick method to meet modern traffic safety requirements and improve operational reliability factors. Methodology. On the basis of electric drive theory, a kinematic line of a mono-switch tie type with nonlinear friction characteristic is presented. Using differential equation theory and Laplace transformation, a mathematic description of a linear inductor electric motor has been made. Using the z-transform method, a difference equation for describing a discrete PID speed controller is obtained, the coefficients of which are derived using the Chin-Hrons-Reswick method. A simulation mathematical model of the electric drive mono-switch tie type as the microprocessor automatic control system with linear inductive electric motor and discrete PID speed controller and nonlinear friction characteristic was built in MATLAB. Results. Simulation modelling of a mathematical model of the microprocessor automatic control system of the electric drive mono-switch tie type with the linear inductive electric motor and discrete PID speed controller and nonlinear friction characteristic have been developed and performed. Studies of dynamics of switch point movement have shown that, a drive time of less than 0.7 s at a constant speed motor armature of 0.2 and 0.3 m/s provides to meet modern requirements for railway switch points. The application of discrete PID speed controller has shown improved dynamics of switch point. Originality. First for the electric drive of the mono-switch tie type with linear inductive electric motor a mathematical model of the discrete PID speed controller and nonlinear friction characteristic as an object of speed control of switch point movement, has been developed. Practical value. Mathematical model of a railway track switch of the mono-switch tie type with linear inductive electric motor and discrete PID speed controller has been developed to carry out the control of the position of the switch point, process with a smooth drive them to the frame rail, to protect electric motor elements from overloads.

Based on the study of projects of electric drives with complex mechanisms and frequency converters (FC), artificial intelligence tools are proposed for modeling and analyzing the consistency and validity of technical solutions in different engineering domains. The developed design methodology takes into account design features of the mechanisms and describes the process of creating and transforming descriptive semantic models of electric drives. Different forms of such models on the one hand provide a visual representation of design factors, on the other allowing the use of a known mathematical apparatus to automate the search and analysis of design decisions. For electric drive requirements modeling SysML language is used. Further obtained model is converted into a semantic network in the form of a conceptual graph (CG). This graph has a mathematical description in the form of logical expressions and can be used by an inference machine for automatic analysis and synthesis of technical solutions. Other knowledge models of electric drives design are considered. To take into account the inconsistency of the requirements, the model in form of conceptual graph is transformed into description necessary for applying the GORE methodology tools. To take into account the incomplete certainty of design factors, a Bayesian network is built on the basis of the conceptual graph. The proposed set of semantic modeling tools is aimed at ensuring the completeness of the technical description of electric drives and automating the stage of their conceptual design.

Introduction. The study is devoted to the development of the functionality of a railway track switch by introducing a switched-inductor electric drive. This solution justifies simplifying the mechanical part of the switches by changing the gearbox to a ball-screw and locating the all kinematic line of the switches on the mono-sleeper type. Goal. A study of the mono-sleeper turnout type behaviour to meet modern traffic safety requirements and improve operational reliability factors. Methodology. Based on electric drive theory, a kinematic line of a mono-switch turnout type with nonlinear friction characteristic is presented. Using differential equation theory and Laplace transformation, a mathematic description of a four-phase switched-inductor motor with ball-screw in a mechanical line of a single-mass electromechanical system has been made. A simulation mathematical model of the electric drive of mono-sleeper turnout type as the control system with a switched-inductor motor and nonlinear friction characteristic was built in MATLAB. Results. Simulation modelling of a mathematical model of a mono-sleeper turnout type with a switched-inductor motor and ball-screw gear has been developed and implemented. Studies of dynamics of turnout point movement have shown that, in contrast to the motors used today, the switched- inductor motor makes it possible to simplify the mechanical part of the drive, which leads to reduced time spent on laying and maintenance of turnout points, and therefore makes the design more reliable. The application of PID controller and fuzzy speed controller has shown improved dynamics of turnout point, while the fuzzy PID controller provides better performance of the set values and turnout point movements. Originality. First developed a mathematical model of the electric drive of the mono-sleeper turnout type, taking into account nonlinear friction characteristic, as an object of speed control of turnout point movement, is developed. Practical value. The developed mathematical model of a railway track turnout of the mono- sleeper type with a switched-inductor motor and ball-screw gear enables more efficient use of a microprocessor control system, creation of promising electric motor protection means and control of a turnout point. References 18, table 2, figure 14.

Purpose. To establish analytical expressions of machine constant and electromagnetic parameters for a specific circuit of the armature winding of an electromechanical converter of an inertial energy storage device, which is a DC electric machine with a semiconductor switch and excitation from permanent magnets. Methodology. For research the theory of electrical circuits is used to create a mathematical model of the processes of electromechanical energy conversion in an inertial storage device. The plots method is used to find the mutual inductance of the armature winding coils, which are presented in the form of infinitely thin single-turn contours of rectangular shape, located in three-dimensional space. Results. Mathematical models of the processes of electromechanical energy conversion in an inertial storage device are obtained reflecting the relationship between the exchange energy and drive power with geometric and electrophysical parameters of both the energy accumulator and the system of its electromechanical converter. A connection of the parameters of machine constant, active and inductive resistances with the configuration, wiring diagram and the geometric dimensions of the armature winding has been established The wiring of sections in the phase of the armature winding depends on the required value of the voltage and current of the machine. The possibility of regulating the voltage of the drive by switching on and off the working phases of the system of electromechanical converter, as well as by changing the angle of the load is shown. Originality. Mathematical models are obtained that relate the indicators of the energy of exchange and the power of the drive to the geometrical and electro physical parameters of both the energy accumulator and the system of its electromechanical converter. A feature of these models is operating with an average value of induction and machine constants when determining the electromotive force and electromagnetic moment Practical value. Recommendations are developed for determining the machine constant and electromagnetic parameters of electromechanical inertial energy storage devices. This allows to evaluate the properties of devices of this type in the modes of storage and delivery of energy during their operation on board the rolling stock.

Analysis of optimization criteria for the process of switch displacement in a DC railroad turnout