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Currently, an asynchronous variable frequency drive based on semiconductor converters is widely used due to the relative simplicity and reliability of the design. The use of digital microprocessor systems ensures high accuracy and flexibility of drive control. On the domestic rolling stock, the widespread introduction of asynchronous motors began to replace DC traction motors with sequential excitation. In particular, scalar-controlled asynchronous motors are used on serially produced 2TE25A diesel locomotives and EP20 electric locomotives. The auxiliary asynchronous machines of these locomotives are controlled by the vector control method. The use of a new type of engine on the rolling stock makes it possible to achieve a significant increase in the quality of consumed energy and reduce the consumption of electricity for traction of trains. Ensuring the energy efficiency of the drive in a wide range of loads requires further research. In this regard, the issue of saving energy resources becomes very urgent. The article proposes a vector control scheme for asynchronous motors of auxiliary machines of an electric locomotive, which implements an extreme method of control according to the criterion of minimizing the consumed current. The analysis of the engine operation is carried out based on its mathematical model in a rotating coordinate system d — q, which is implemented in the MatLab/Simulink software package. As a result of simulation modeling, it was found that the extreme control system with a variable step allows for each fixed value of the electromagnetic moment of the motor in the minimum time to find the optimal (extreme) value of the magnetic flux of the motor rotor, which corresponds to the minimum value of the stator current. The developed model of the motor with vector control is supplemented with an extreme regulator device, which allows achieving the best energy performance of the motor and reducing electrical losses in all operating modes with a minimum search time. The presented research results can be used in the development of energy-saving control systems for an asynchronous motor.

In the article on the basis of the complex analysis of sources and scientific literature the attempt to investigate historical circumstances of development and construction of shunting electric locomotives at the Dnipropetrovsk electric locomotive plant has been made. It was found that during the 1960s and 1970s, the team of designers of the Dnipropetrovsk plant, having strong research and production potential, at the request of the Ministry of Railways of the USSR developed and built unique samples of shunting electric locomotives of the VL41 and VL26 series to meet the needs of Soviet main-line railways with modern high-tech electric vehicles. It is proved that in the absence of thorough experience and, accordingly, the possibility of a rapid technological breakthrough in the development of main-line locomotives, during the experimental operation of shunting electric locomotives VL41 and VL26, several design shortcomings were identified, which led to their further use exclusively on the house tracks of enterprises, and designers of Dnipropetrovsk plant later focused on the development and construction of traction units for industrial application commissioned by the Ministry of Ferrous Metallurgy of the USSR. At the same time, the construction of the main-line railway equipment to the order of the Ministry of Railways allowed the staff of the enterprise to gain valuable experience, which was later used in the implementation of the renewal program of rolling stock of Ukrzaliznytsia. Although today the Dnipropetrovsk plant is in decline, the analysis of historical circumstances of formation and design and technological heritage of electric locomotive construction in Ukraine is of fundamental importance both in the general perspective of the development of domestic transport engineering, and the railway industry in particular. Further study of the history of Dnipropetrovsk electric locomotive plant requires clarification of the historical circumstances of institutionalization of the Special Design and Technology Bureau of the enterprise from the creation of industrial electric locomotives and traction units to the development and re-equipment of main traction rolling stock and specialized repair equipment within the state enterprise “Ukrainian Research Design Institute of Electric Locomotive Engineering”.

Objective: To study the dependence of the numerical values of the bearing reactions occurring in the bolted fasteners of the gear casing (GC) on the conditions of its fastening to the traction motor. To show the resulting redistribution of the bearing reaction values in the case of the lack of load bearing in one or two bolted fasteners from the three existing design ones. To calculate the equivalent stresses that appear in the gear casing structure under various abnormal conditions of its fastening to the traction motor under static loading. Methods: The equations of statics were used for the spatial system of forces, including three vertical bearing reactions and the weight of the casing itself. To study the stress-strain state of the casing in the case of its static loading, the finite element method was used, implemented in the ANSYS Workbench software package. Results: The cause of damage to the GC during operation has been found associated with its design flaws. Calculation formulas have been obtained for determining the vertical bearing reactions of the GC. The need to take into account the GC loading in the case of redistribution of loads due to the loosening of its fastening bolts has been found. The need to improve the design of the gear casing has been indicated. Practical importance: The probable cause of damage to the GC during operation has been found. A method is proposed for assessing the GC loading in the case of redistribution of loads between its bearing points.

Purpose. The main purpose of the work is the development of identification models and a new method of modeling electromagnetic processes in electric traction systems with simultaneous consideration of all its subsystems, as well as several feeder zones of the electrified section. Methodology. To achieve this purpose, the methods of mathematical modelling, the basics of the theory of random processes and the methodology of their probabilistic-statistical processing, the methods for solving integral equations and analysis of electric traction circuits in electric traction systems are used. Findings. The requirements to be met by an adequate, stochastic identification model of electric traction devices are established. The solution of Fredholm’s integral correlation equation of the first kind is performed. The analytical expression of the identification dynamic model of the electric locomotive DE–1 is obtained and its adequacy is checked. The methodology of combined modeling of electromagnetic processes in devices and subsystems of electric traction systems is developed and presented tabularly. Originality. For the first time it is proposed to use the pulse transition function as identification models of traction substation and traction network with electric rolling stock in predictive modeling of electromagnetic and electric power processes in electric traction systems. A new method has been developed, a method of complex modeling of electromagnetic and electric power processes in the system of electric traction with simultaneous consideration of all its subsystems, as well as several inter-substation zones of the electrified section. For the first time, a method of partitioning the correlation functions for solving an integral correlation equation has been proposed, which allows defining a pulse transition function as an identification model of any subsystem of an electric traction system. Practical value. The developed identification models and the method of combined modeling make it possible to predict electromagnetic processes simultaneously in all feeder zones of the electrified section of the electric traction system. The obtained identification model of the electric locomotive DE–1 can be adapted with its subsequent use in modeling processes in the traction circuits of electric locomotives of other types. The method of factorization of correlation functions used in solving the Volterra integral correlation equation of the first kind (convolution type) can be adapted to the solution of other integral equations, which describe the processes in electric traction systems.

The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.

Mass of a passenger train and, accordingly, number of cars in its composition is selected based on the amount of passenger traffic on the section, determined by the seasonal demand for transportation in each direction. In one direction of the section serviced by an electric locomotive, the mass of a passenger train may differ several times from the opposite direction, which depends on the destination station of the train and the period of its circulation. At present, in addition to 6-axle electric locomotives of the ChS2T and EP2K series, more powerful 8-axle electric locomotives of the ChS7 series operate in the same schedule for traction of passenger trains on railway sections electrified with direct current with a voltage of 3 kV catenary. All three series of the considered electric locomotives are designed for a maximum operating speed of up to 160 km/h. In this regard, there is a situation with the underutilization of the maximum speed and excess power of the ChS7 electric ocomotives, especially when operating with passenger trains of medium and low weight and a limited speed of 120 km/h. The comparative data on the specific power consumption of the EP2K 6-axle electric locomotives and the ChS7 8-axle electric locomotives operating in the same schedule, presented in the article, indicate the need to find additional reserves for saving the specific power consumption when servicing passenger trains of medium and low weight with ChS7 electric locomotives. The electric locomotive power system includes traction and auxiliary electric machines. The article discusses ways to turn off part of traction motors, which can be carried out with a standard electric locomotive circuit. However, when one section of the electric locomotive is turned off, the power of the four traction motors remaining in operation is not always sufficient to drive a passenger train according to the schedule. Therefore, a variant of improving the power circuit of an electric locomotive in the process of carrying out its overhaul is proposed. This option represents the modernization of the power circuit of the ChS7 electric locomotive when operating on a series-parallel connection with a pair of traction motors disconnected. As a result, the power circuit of the 8-axle electric locomotive operates similarly to the circuit of 6-axle DC electric locomotives with a collector traction drive. The expected savings in specific power consumption can reach 15% in comparison with the operation of an 8-axle electric locomotive ChS7 in normal mode. Switching off one section of the electric locomotive and further running the train on four traction electric motors will reduce the specific power consumption by up to 25%.

Currently, the methods of monitoring the technical condition of locomotives using data of on-board microprocessor-based control systems are widely used. This monitoring of Russia has become an operating technology of the locomotive maintenance and repair system.The main problem of monitoring is the limited set of sensors in locomotive circuits. Increased number of sensors leads to a decrease in reliability and to an increase in the cost of a locomotive and of its life cycle, while allowing to achieve better quality of diagnostic information.Besides, it is advisable to have integrated indicators of the technical condition of a locomotive. The article presents a computer software product for analysing the technical condition of a locomotive based on dynamic data on consumption of traction active power and generation of reactive power. The software was developed by using algorithmic language Visual BASIC for Applications, embedded in MS Excel, using probabilistic and statistical methods of analysis.The method for diagnosing the technical condition of a locomotive within the monitoring system is based on a comparison of dynamics of consumption of active and generation of reactive power by two sections of the same locomotive according to the principle of functional benchmarking. For monitoring the technical condition of locomotives, the term «pre-failure» is suggested, which is defined as the operable condition of a locomotive while there are internal hidden defects or damage. Pre-failure manifests itself in power consumption. To analyse the technical condition of AC electric locomotives in terms of electricity consumption, the initial data must have a high degree of unimodality, which is determined by uniformity of operating conditions.The resulting data obtained following the analysis of the technical condition of a locomotive based on the dynamic data on consumption of tractive active energy and generation of reactive power can be used to determine a defect that causes a change in consumption of electricity at the moment when the locomotive enters technical maintenance and repair depot. *Information about the authors: Semenov, Alexander P. – Ph.D. (Eng), General Director of JSC Research Institute of Technology, Control and Diagnostics of Railway Transport, Omsk, Russia, corp@niitkd.ru. Semchenko, Victor V. – Ph.D. (Eng), General Director of JSC Railroad Centre of Technology Implementation of Krasnoyarsk Railway, Krasnoyarsk, Russia, office@dcv.ru. Khromov, Igor Yu. – Business Analyst of LLC2050-Integrator, Moscow, Russia, KhromovIYu@yandex.ru. Article received 13.05.2020, accepted 23.10.2020. For the original Russian text of the article please see p. 62.

The regulations regarding railways currently in force in Bulgaria require that each new type of locomotive, to get access to railway infrastructure, must undergo a procedure for checking its electromagnetic effect on functioning of track circuits.The relevant testing was carried out for seven types of AC and DC track circuits and for six types of locomotives intended to be put into operation (five electric locomotives and a diesel locomotive).Schematic diagrams of testing conditions are presented. During the tests the voltage waveform, frequency, and level rates at the terminals of the track receiver (on the track relay coil) were recorded for a free (normal (common) mode) and occupied (shunt mode) track circuit during the action of return traction current of electric locomotives, as well as during the action of impacts caused by operation of electrical equipment located in the body and under the frame of the diesel locomotive.For electric locomotives, the tests were carried out during the shunting of track circuits (of a tested one and of the track circuit adjacent to it), starting from the rest, lowering and raising pantographs. For a diesel locomotive, tests were carried out in a stationary mode, when inner wheelsets shunted the insulating joints of two adjacent track circuits and for different cases of arrangement of the equipment of the relay and receiver ends. During the tests, the state of the armature and contacts of track relays was monitored. The amplitude of the recorded interference was compared with voltage of reliable switching off/ on of track relays/track receivers. It was found that during the shunt mode, the recorded residual voltage in the track receiver under the action of the electric locomotive was 50 or more times lower than the reliable operate voltage and 33 or more times lower than the reliable drop-out voltage of the receiver. For a diesel locomotive, the results turned out to be similar, except for the case of shorter DC track circuits, where the amplitude of the interference was higher, but without a dangerous effect on the shunt mode.Based on the results of the tests, it was established that all types of track circuits used on the railways of Bulgaria are resistant to electromagnetic interference emanating from tested samples of traction rolling stock.

The Ukrainian transport engineering industry has a deep historical tradition that goes back to the activities of the Odesa railway workshops and the establishment of specialized locomotives in Kharkiv and Lugansk. The electric locomotives industry in Ukraine is represented by the products of the Dnipro plant, which for a long time produced electric locomotives of a purely industrial purpose. In the early 1990s, to upgrade the locomotive fleet of Ukrainian railways in the absence of foreign exchange funds for the purchase of traction rolling stock abroad, the management of Ukrzaliznytsia, together with the line ministries, decided to provide the organization of the main-line electric locomotives based on the Dnipro plant. During the implementation of the state program of mainline electric locomotives construction, the Dnepropetrovsk plant developed, and subsequently implemented, projects of a freight DC electric locomotive DE1, an AC cargo and passenger electric locomotive DS3, and also based on DS3 began technical research on a two-system electric locomotive with an asynchronous drive DS4. The Dnipro electric locomotive engineering plant, with its powerful scientific and production potential and clear development strategy, carried out the development and created the next generation's main electric locomotives to meet the needs of Ukrainian railways with modern electric transport. Unfortunately, due to the traditional lack of funding and lobbying on the part of Russian machine-building enterprises, the Dnieper electric locomotives have not become the main locomotives of Ukrainian railways. Unfortunately, due to the economic-financial crisis of 2008, all the prospective achievements of the said enterprise were virtually offset and the plant itself was in a difficult position. However, it is clear that the historical experience of becoming a Ukrainian scientific and production base of railway engineering needs to be properly considered. The proposed study does not deplete the raised problem in the field of the Dnipro electric locomotive plant`s activities, but only provides a general analysis and factual basis for further, more detailed review of the maintenance and development of national railway engineering in independent Ukraine, leaving considerable space for further scientific research.

The article attempts to investigate the historical circumstances of the development and serial construction of narrow-gauge electric locomotives at the Dnepropetrovsk Electric Locomotive Plant based on a comprehensive analysis of sources and scientific literature. It is determined that during the 1960s and 1990s the staff of the Special Design and Technology Bureau of the Dnipropetrovsk Plant, having a strong research and production potential, developed and created projects of unique narrow-gauge electric locomotives of PEU 1 series (IELNG1 – industrial narrow-gauge electric locomotive type 1) and PEU 2 (IELNG2 – industrial narrow-gauge electric locomotive type 2) to meet the needs of the Soviet mining industry in the complex mining and geological conditions of Central Asia with modern high-tech electric vehicles. The development of the research and production base of the machine-building enterprise is traced, the production nomenclature of which, originally represented exclusively by electric locomotives and traction units for industrial purposes, was expanded to the production of main traction rolling stock and special repair equipment. It was found that due to the economic crisis of the CIS countries in the first half of the 1990s, the rupture of economic ties of the former Soviet republics and the lack of need for such equipment on electrified access roads of narrow-gauge Ukrainian mining enterprises all work on designing promising projects and serial production of narrow-gauge electric locomotives at the Dnipropetrovsk Electric Locomotive Plant were stopped, and the Special Design and Technology Bureau of the enterprise, having received a state order, was reorganized into the Ukrainian Research Design Institute of Electric Locomotive Construction and focused on the development of main wide-gauge locomotive fleet of the railway network of Ukraine. Despite the fact that the Ukrainian Research Design Institute of Electric Locomotive has been liquidated and the Dnipropetrovsk plant is in decline, taking into account the historical experience of electric locomotive building in Ukraine is of fundamental importance in the general perspective of Ukrainian transport engineering and the domestic railway industry in particular. Further study of the history of Dnipropetrovsk Electric Locomotive Plant requires analysis of the historical circumstances of the institutionalization of the Special Design and Technology Bureau of the enterprise from the creation of shunting electric locomotives and traction units for industrial purposes to the development and re-equipment of main traction rolling stock and specialized repair equipment within the state enterprise «Ukrainian Research Design Institute of Electric Locomotive Engineering» under the leadership of Academician Victor Bratash.

This article presents a traction converter configuration using modular multilevel converter (MMC) for interfacing the single-phase ac railway power line with the multiple traction motors of an electric locomotive. The conventional grid frequency step-down transformer used in electric locomotive is replaced by a medium frequency transformer (MFT). The system consists of two sets of MMCs: one to interface the power line with the MFT, and another to interface the MFT with the traction motor. The overall control philosophy of the system is presented. Furthermore, a control technique is proposed that reduces the peak to peak ripple voltage of the submodule capacitors of the motor side MMC. The system is simulated in MATLAB Simulink. The proposed control technique for the motor side MMC is experimentally verified in a laboratory prototype.

Regenerative braking is one of the most important energy-saving resources on electric rolling stock (EPS) of railways and feasibility of its use is confirmed by a rich half-century history. The development of the recovery mode begins with the release of the experimental AC electric locomotive of the VL61 series № 012 and continues with the release of the modern series of electric locomotives 2 (3, 4) ES5K and EP1v/i. The use of recuperation allows you to achieve significant energy savings, to ensure the safety of driving heavy trains on the track profile with long descents. In the regenerative braking mode, the EPS has rigid braking characteristics, ensuring maintenance of constant train speed, increasing the technical speed of the train and capacity of the railway section. This article presents the results of mathematical modeling of operation of an AC electric locomotive in the regenerative braking mode using a standard rectifier-inverter converter (RIC) and presence of ballast resistor blocks (BRB) in the power circuit, and using a promising RIC based on IGBT transistors, for which a method for implementing regenerative braking on AC electric locomotives without the use of BRB in the anchor circuit of traction electric motors is developed, with the help of which it is possible to increase the amount of electricity given to the contact network, as well as to expand the area of braking characteristics of the electric locomotive.

This article presents the modelling of vibroacoustic characteristics, vibration rates of transport vehicle bodies during abrasive processing of welds. Welding is one of the most comprehensive technologies for joining metal structures. However, one of the mandatory steps after welding is the mechanical processing of welded joints. To control the vibroacoustic characteristics, reduce the noise and vibration, energy balance equations are obtained for the conditions of the abrasive treatment of welds in the body of an electric locomotive. The energy flows and sound power emitted by each element of the body structures are determined during the abrasive treatment of welds. Theoretical and experimental assessment of noise and vibration levels during the abrasive processing of welded joints of plate structures is carried out. It is shown that in the frequency range from 0.25 kHz and higher, the sound power exceeds the maximum permissible values.

The world community carries out large-scale research into reducing the consumption of electric power, while keeping living needs at the same level. Transport sector consumes a vast amount of electric energy, particularly, electric-driven rolling stock of railways. The paper deals with finding the trajectory of train motion, which is going to be the most energy efficient to run along. There is also presented analysis of specific power consumption for traction of trains of the largest Railway network in Russia. Criteria for optimization of freight trains handling with electric locomotives by the means of differential equation of motion of center of mass of a train. There is proposed a mathematical model for movement of a train and a theorem on dividing motion of the system into fast and slow components. Restrictions for state variables of a train and objectives for optimization of operation mode on the given locomotive run are formulated. The paper describes the solution of optimization with the use of innovative software for mathematical simulation through directed graphs (or digraphs) of movement of a freight train with an electric locomotive on the haul. A new Lagrange coefficient is proposed, which is the cost of time in units of specific power consumption. There are determined parameters that should be considered when developing a technical passport for a railway section.

In order to improve the working efficiency of underground electric locomotive robots in complex geological coal mines and realize the automation of underground scheduling system, the scheduling model of electric locomotive robots is established based on the underground track layout. Firstly, the cooperative operation routes of different types of electric locomotive robots are planned based on deadlock-free and collision rules. Then, according to the planning route, the scheduling parameters are set, and the transportation mode of electric locomotive robots is determined as interlaced transportation. The scheduling model is proved to be conflict-free by theory. Then the scheduling parameters are optimized by simulation under the scheduling rules of electric locomotive robots. Finally, the practicability of the scheduling strategy is verified by experiments. The research shows that the scheduling strategy improves the transportation efficiency by 47.6 % compared with manual scheduling. It can organize the transportation activities of electric locomotive robots scientifically, safely and efficiently, ensure the orderly distribution work and improve the intelligent degree of transportation system.

Purpose. The purpose of the work is to conduct experimental studies to determine the parameters of DC motors of sequential excitation in dynamic modes of operation for use in setting up the control system of the electric drive. The paper presents the results of experimental studies to determine the parameters of the traction electric drive of direct current quarry electric locomotive. The research was conducted on the basis of Kremenchuk Mykhailo Ostrohradskyi National University with the use of a laboratory research stand with electromechanical equipment that simulates the operation of a traction drive, namely slippage of traction wheels when changing clutch conditions and differences in electrical parameters of traction motors. Methodology. The parameters were determined on the basis of a set of methods based on the measured instantaneous values of the state variables of the electric drive. The efficiency of application of the method of state space and the method which uses instantaneous values of current and voltage of the motor in the quasi-constant mode at power supply from the valve energy converter is proved. Results. The results obtained in the course of research indicate the possibility of calculating the parameters with an accuracy of 10 %. The verification of the obtained results is checked by subtracting the coefficient of determination and the sum of the squares of the deviations for the experimental data calculated on the basis of certain parameters. Originality. The accuracy of parameter determination is ensured by the use of instantaneous values of current and voltage at adjacent time intervals, and the voltage at the armature is formed by the control system and changes over time, ensuring the start of the motor with starting current limitation. Practical value. The developed computerized laboratory stand allows to measure instantaneous values of state variables and to carry out calculations of electric parameters of traction engines, and also to investigate static, power and dynamic operating modes of electromechanical transmissions of vehicles, both in regular operating modes, and to simulate various emergency operating modes, in particular. Figures 5, tables 2, references 7.

The partitioning of railroads electrified on dc is done with the help of insulating air gaps (IAGs). When the pantograph collector of an electric locomotive crosses the branches of an IAG, an increment in current occurs in the feeder of the traction network entered by the electric locomotive. In these cases, the nonselective operation of a high-speed circuit breaker (HSCB) results in its false response, disconnection of the traction network power supply area, and, ultimately, stops the train. To preserve the reaction of the protection to a remote short-circuit and avoid false tripping in circuit-breakers, an interlocking circuit is proposed that prevents the tripping of HSCBs of adjacent dc traction network feeders at an instantaneous increment in current.

Targeted at the issue of electric locomotives passing the neutral section in ac electrified railway, a novel intelligent electric phase separation system is proposed in this article, which is also named smart electric neutral section executer (SENSE). It consists of thyristors, several voltage and current transformers, and the control system. On one hand, the thyristors are used to replace the traditional high-voltage circuit breakers so that the power interruption time is significantly reduced when the locomotive passes the neutral section. On the other hand, an automatic pantograph location technique based on the traction network voltage and current information is presented. When the electric locomotive passes the neutral section, its pantograph is located through the voltage and current signals collected by the voltage and current transformers. All pantographs of a train are directly located, which can distinguish different marshaling modes and thus shorten the neutral section length significantly. The basic structure of SENSE and the principle of the pantograph location method are provided in this article. The SENSE equipment is commissioned in the Shenshuo heavy-haul railway in China, where the proposed pantograph location algorithms are verified as well.

A new method is proposed for increasing the power factor of an electric locomotive by changing the minimum opening angle of thyristors α 0 of a rectifier-inverter converter. The decrease in the angle α 0 is due to changes in both the structure of the transducer and the zone of its regulation. A pulse synchronization device has been developed that makes it possible to generate pulses with strong distortions of the mains voltage U c at the points of natural transition of the voltage of the fundamental frequency U с through the zero line. Based on this device, an α 0 pulse-forming device was developed that eliminates the influence of pre- and post-switching voltage fluctuations. A “contact network—electric locomotive” model was created in the environment of MatLab/Simulink, taking into account the nonlinearity of the longitudinal parameters of the contact network. The effect of decreasing the angle α 0 on the character of pre- and post-switching voltage fluctuations was analyzed, and the parameters of transient processes were calculated. Particular attention was paid to modeling the parameters of traction network. The primary network parameters adopted in the model correspond to theoretical parameters for the selected type of contact suspension. Their high convergence is confirmed by the calculation of the coefficient of determination R 2. Calculations on the “contact network — electric locomotive” model show that compared with the standard scheme of the electric locomotive, where the minimum opening angle of the thyristors is α 0 = 9° el., the decrease in the angle α 0 to 4.5° el. leads to an almost twofold decrease in the amplitude of pre-switching voltage fluctuations and a small decrease in the amplitude of post-switching voltage fluctuations. The model results indicate that a decrease in the minimum thyristor opening angle α 0 leads to an increase in the power factor of the electric locomotive.

Three-motor synchronous drive system is a multi-input multi-output, nonlinear and strongly coupled system, which is widely used in the driving field of high precision coordinated control such as paper-making, printing, electric locomotive, etc. A mathematical model of three-motor drive system is analyzed and a new control strategy is proposed for the decoupling control of speed and tension of three-motor drive system, in which the core is fuzzy first-order active disturbance rejection controller (ADRC). Various disturbances from the outside and the inner model are observed and compensated by an extended state observer. As the parameters of the active disturbance rejection controller are adjusted online by a fuzzy controller, the performance of the controller is thus effectively improved. The anti-interference performance, decoupling performance and tracking characteristics were tested based on laboratory-developed multi-motor experimental platform. The experimental results demonstrate that the proposed strategy can effectively decouple speed and tension. The system has fast dynamic response, low overshoot, high steady-state accuracy and good tracking performance.

The purpose of this work consists in obtaining power indices of a freight electric locomotive at the specified schedule of motion, but at different laws of speed changes and on different track profiles. CAD methods are used, at that, the further comparison of the results obtained with the records of the locomotive crew recorder has shown an actually complete coincidence. As expected, a minimum work performed for a train hauling is achieved in an ideal case – at the motion without stops at a constant speed on a straight horizontal track. When moving along an actual profiled track a work performed for hauling changes by a difference of potential energy of gravity in the initial and end points. Often accelerations and slowdowns result in the work increase for hauling, for that there are obtained quantity values. In order to avoid excess power waste it is necessary to move possibly without sharp accelerations and hard braking. To support motion uniformity it is expedient to use a speed controller. There are obtained the values of a specific work for train hauling in different cases which define limits for a purpose index on the

One of the promising ways to increase the capacity of railways is the way to reduce the interval between trains and its packet-mode handling. This method is implemented through the introduction of technology for interval regulation of train traffic. More advanced at present is the technology of interval regulation of train operation according to the "virtual coupling" type, which organizes the operation of trains with a minimum interval between them, which is safe for motion at and between stations. This technology removes the problem of extending the receiving and departure tracks, reduces peak loads on the traction power supply system and the formation time of the virtual coupling structure, and increases the train speed to the yellow traffic signal with safety guaranteed. The technology is implemented due to the presence of an interval control system for train operation, the introduction of on-board automatic locomotive signaling devices ALS-EN and ALS-R, on-board complexes BLOK and KLUB-U (safety devices with satellite navigation and electronic route map), ISAVP-RT-M (auto-driving system for coupled trains) and radio modems for data transmission. The use of these devices in packet mode traffic schedule will reduce the time interval along the sections of the railway and reduce the loss of time when the train runs to the yellow traffic signal. The set of tasks to increase the energy efficiency of applying the technology of interval regulation of train operation according to the "virtual coupling" type should also include the tasks of developing modern rectifier-inverter converters VIP-4000M on AC electric locomotives together with the reactive current block developed in the Railway Implementing Center of the Krasnoyarsk Railway. These developments provide a high power factor of the electric locomotive in the traction and regenerative braking modes (up to 0.96), which will reduce the specific electric energy consumption by electric locomotives for train traction, which will increase the efficiency of the application of the technology of interval regulation of train operation according to the "virtual coupling" type. In July 2019 pilot operational tests of this technology were carried out on the Far Eastern Railway, which showed generally positive results. The paper also presents an analysis of the results on the specific consumption of electric energy for traction and its return to the contact network during regenerative braking by 3ES5K electric locomotives participating in the technology of interval regulation of train operation of the "virtual coupling" type in the sections Khabarovsk-2-Ruzhino and Ruzhino-Khabarovsk-2 of the Far Eastern Railway. These results show an increase in the energy efficiency of electric locomotives using this technology.

This paper presents the results of a study of the effect of the characteristics of the traction power-supply system on the indicator of the energy supply of electric rolling stock. The power-supply indicator of the electric locomotive is described as a function of the indicators of the load capacity of a traction power system and operational indicators of the transportation process: the mass of trains, speed, headway, and a number of others. Statistical methods and results of the evaluation of the effectiveness of the use of traction resources for the territorial branch of the operating domain on the basis of rolling stock quality indicators have been presented. The organizational structure and model of the management of traction resources taking into account the inclusion of the functions of the relationship with the territorial directorates of Transenergo have been presented.

The high-frequency instability (HFI) issue results in serious harmonic overvoltage phenomena in the electrification railway system. This issue is rooted in the range that is not only below, but also above half the switching frequency. The commonly used small-signal averaging model is a single-frequency model in which the corresponding frequency component with perturbation frequency is considered merely. The inherent sampling nature has been neglected by the moving average operator. Therefore, it cannot reveal the effect of sideband components and may not be valid for predicting the high-frequency input admittance of a locomotive. To investigate the HFI issue, the sideband components generated by analog/data (A/D) sampling process and pulse width modulation (PWM) are taken into consideration. Then the multifrequency model of a locomotive is developed for evaluating the influences of sideband components. Meanwhile, the proposed model is validated by means of the frequency scan method, including the identification of PWM transfer functions and crossed-frequency transfer functions. Several HFI cases are summarized for comparing the accuracy between the traditional single-frequency model and the proposed multifrequency model. It denotes that the multifrequency model is more accurate to assess the high-frequency input admittance of a locomotive, especially the regions around the sampling frequency. Hardware-in-loop (HIL) results validate the theoretical analysis.

Severe vibrations and an increase in structural component fatigue failures have been observed on a freight locomotive class operating in South Africa. The cause of the severe vibration was linked to polygonal wheel wear dominated by the 20th order. This locomotive is powered by an alternating current traction system, which is controlled by a variable frequency drive. The variable frequency drive generates interharmonics that produce torque pulsations in the torque output from the motors. Interharmonics are determined by the alternating current supply frequency ([Formula: see text]) and the fundamental frequency ([Formula: see text]) of the variable frequency drive. The interference of the torque pulsations with a coupled resonance mode is reaffirmed as the root cause of the polygonal wheel wear. An experimental investigation of this phenomenon was performed by means of on-track testing. It was found that the [Formula: see text] interharmonic excited the coupled resonance mode at approximately 42 km/h, which fixes the 20th-order polygon on the wheel. Two approaches that may eliminate the polygonal wheel wear were introduced and discussed. It was found that the forced excitation of the coupled mode by the [Formula: see text] interharmonic could be avoided by postponing the speed where the alternating current traction motor's pulse mode changed.

A dc electric locomotive simulation model is considered that makes it possible to study transient and steady processes and may serve as a basis for the notion of a “digital locomotive” being implemented within the “Digital Railway” project. One of the most popular electric locomotives is selected, which is designed for pulling freight trains along long-distance railways electrified with direct current with a voltage of 3000 V. The electric locomotive model is based on a mathematical model of a collector traction engine. The model takes into account the nonlinearity of the main pole’s magnetic characteristic, as well as the effect of eddy currents in solid magnetic circuit sections on the magnetic flux variation. The model provides a mechanism for regulating motors in the course of investigations in accordance with operating conditions. The processes of resistor starting and voltage regulation by connection to resistors by means of transposition, as well as motor regulation by changing the magnetic flux, are taken into account. The possibility of using the developed model to study the traction substation–traction network–electric rolling stock system, which is determined by different operating modes of the traction network in the process of converting electrical energy into mechanical, is shown. Calculations of various locomotive operating modes in the event of failure in the contact network are carried out.

A significant number of failures, violation of smooth running, as well as exceeding the noise ranges raise the problem of the quality of engagement of the traction gear of the 2ES6 electric locomotive. The article presents an analysis of statistical data collected on planned and unplanned repairs of 2ES6 series electric locomotives operated on the Sverdlovsk railway. The positive dynamics of the growth of traction drive failures confirms the urgency of the problem. One of the main reasons for the loss of performance of the traction drive is the failure of the traction gear elements. The gearing quality is checked according to geometric parameters, which confirms an error in the design of the traction gear of the 2ES6 electric locomotive as an element of the traction drive. The recommended value of the overlap coefficient was exceeded, which leads to a violation of smoothness of the ride, exceeding the noise ranges, rapid wear and early failures. A method is proposed to reduce the number of failures in 2ES6 electric locomotives by increasing the displacement coefficients, at the initial stage, in order to reduce the quality of the gear ratio - the overlap coefficient.

The article focuses on monitoring of wheelset binding bands condition of electric locomotives with rotary-field traction motors and, since it is a very important factor in reliability of the electric locomotive by and large, the obtained decisions are based on its results. In analysis there were examined wheelset defects of common occurrence and their natural wear during exploitation. The electric rolling stock works under complicated conditions which affect the nature of wear and electric and mechanical equipment damage. One of the main tasks is to ensure reliable operation of different machinery, as failures on track disorder the traffic schedule, distort the transportation rhythm, leading to considerable loss of throughput capacity of sections, which also reduces movement safety and results in great economic losses. Reliability evaluation is a set of measures aimed at monitoring of condition of electric locomotives, which is based on real operational particulars. By virtue of these particulars one can see an ultimately complete picture, analyze it and correct the structure of repair cycle of electric locomotive particulars. The article accentuates the analysis of risks, related to probable defects, unexpectedly high wear out, incorrect choice of repair cycle structure, ways and tools of reliability evaluation, incorrect statutory, results of incorrect measurement.

The article discusses the choice of control parameters to ensure a constant power in the Switched Reluctance Motor of a mine electric locomotive with a capacity of 13 kW and a rotation speed of 562 min-1. The analysis of articles published during 2000-2018 in Ukraine and abroad on Switched Reluctance Motor for various drives in transport, where this mode is mandatory. The analysis showed that there is a great diversity in the choice of control parameters among different authors, and also the majority of authors do not have an analysis of transients when using the selected control parameters. The author of the article in previous works used two control methods: phase regulation over the entire range of rotation speed changes with constant power and only phase regulation at the beginning of the range and phase plus switching the connection of phase coils from serial to parallel at a certain speed. Using the first method leads to a significant increase in the ripple of the moment with increasing speed, the use of the second method leads to a sharp increase in the inverter current. It is proposed to increase the supply voltage by switching the connection of the batteries. Transients in the mode of constant power are considered when the load moment changes from the nominal to the moment at the maximum speed equal to three nominal. For analysis, we used the author's engine model for transients in the Simulink program of the Matlab software package. The control parameters were determined using mechanical calculated on the engine model for steady-state conditions. The proposed method allowed to reduce the ripple of the moment and the maximum current of the inverter. The results of the analysis can be used when developing a program for the microprocessor of the controller.

The article considers the analysis of the features of the asynchronous traction electric drive of the DS-3 electric locomotive with an active four-quadrant converter when powered by a contact AC network. The calculation of the model parameters was performed and the transient process when switching power keys is studied on the basis of a mathematical description of the processes of the four-quadrant converter. Expressions are given for determining the power factor and phase shift between voltage and current. A simulation model of the four-quadrant converter of the DS-3 electric locomotive has been developed. The relative parameters of the traction transformer are calculated based on the passport data. A study of the model of a four-quadrant converter was carried out, the dependences that were obtained: phase shift between the input voltage and current on the modulation depth and phase shift of the clock signal; output voltage on modulation depth. The values of the phase shift angles were determined during the implementation of traction and regenerative braking modes. The influence of the parameters of the four-quadrant converter on the energy characteristics of the traction converter were analyzed. Measures are proposed to increase the power factor, improve the quality of the current consumed from the contact network and reduce the level of voltage ripple in the DC link.

The article proposes and implements a mathematical model of an induction motor in "brake coordinates". This will allow the application of this model in the study of the operation of the induction motor under conditions of asymmetry of the system of supply voltages and in the non-sinusoidal state of these voltages. In the power supply system of the induction motors of the auxiliary drive of electric locomotives of the VL-80T, K series, a phase splitter is used to convert a single-phase supply voltage into a three-phase voltage system. It is an induction motor with a short-circuited rotor, operating in the set mode as a generator. For the established mode, it is proposed to replace the phase splitter with a system of three-phase asymmetric EMF. For this purpose, vector diagrams of phase EMFs are calculated and constructed, from which the amplitudes and phases of each phase of EMF are determined. A model of an auxiliary electric locomotive drive system was proposed and implemented in the MATHCad software environment using the obtained model of induction motor in "braked coordinates" and the obtained phase EMF system. On the obtained model, the influence of the asymmetry of the system of supply voltages of the induction motor on the energy performance of the drive was initially investigated. Then, considering the parameters of the voltage of the contact network, the effect of the asymmetry and non-sinusoidal power supply system on the specified indicators of the drive of the auxiliary machines was investigated. It is proposed to replace the phase splitter with a static converter to improve these performance in the auxiliary drive system.

The selection and supply of electric locomotives based on the life cycle contract requires a more thorough review of indicators of their effectiveness implemented in operation. This study examines the main operation indicators currently used: coefficients of operational availability, technical availability, intrinsic availability (instantaneous), availability of the locomotive fleet, performed ton-kilometer operation, and electric power consumption. However, these indicators are not comprehensive and do not provide an overall economic assessment of operation. For a comprehensive assessment of the effectiveness of operation of locomotives, an online calculation of the life cycle cost is proposed. This involves directly using operating and service data for its performance, and the calculation of an indicator — life cycle specific cost (LCSC). The online LCSC is a uniform criterion associated with the energy efficiency of the performed transportation, volume of the ton-kilometer operation, operation expenses, reliability of electric locomotive, and its equipment availability ratio (EAR). The LCSC analysis enables assessment of deviations of the operation effectiveness indicators from those planned, and determining a strategy for improvement of the electric locomotive. It helps to define peculiarities in the operation of an electric locomotive and to forecast its condition and potential properties. Additionally, the LCSC facilitates analyzing the condition of a group of electric locomotives when changing the operation technology (for example, operation starting with increased rolling stock weight), including assessment of the extent of economic benefits of fulfilled measures.Currently, scientists of the JSC “VNIIZhT” and specialists of LLC “Ural Locomotives” are conducting tests on the electric locomotives 2EC6 on the Oktyabrskaya railroad using the “Online LCC” server. This allows online analysis of information collected on the operation and servicing of locomotives under the life cycle contract, pro viding effective and prompt control of the electric locomotive fleet.

In particular locations of the railway track, the excessively polished rail in the inner corner and the large rail cant will lead to an extremely low wheel–rail contact conicity. Consequently, the ...

The purpose of this work is a quantitative definition of electric power loss in a railway contact network. Electric locomotive power supply is carried out from traction substations through a contact network. During electric locomotive operation power losses take place in a contact network as a result of which voltage decreases on the electric locomotive pantograph and also decreases electric motive power efficiency. Such losses of power and voltage depend upon electric locomotive location in an inter-substation area, its power realized and a power factor. At the same time current consumed by an electric locomotive contains higher harmonics which can cause additional losses in a contact network. For the definition of a loss level there was carried out a computer modeling with the use of Cadence OrCAD program. During modeling there was simulated an electric locomotive operation in a contact network area. The modeling results have shown to what extent a current form of an electric locomotive differs at different quality of power consumption. The quantitative values of the computation characterize the level of power and voltage losses at different forms of power consumption. It is proved that the use of the ideal compensator for a phase alignment is less efficient than the use of the passive compensator of jet power. It tells of that along with the phase alignment it is necessary to pay a particular regard to the harmonic distortion of power consumption.

The relevance of the work lies in the possibility of using a computer model in the development and research in the FC-AD (Frequency Converter – Asynchronous Drive) system for the electric drive of an electric locomotive. On the developed dynamic computer model of an asynchronous motor for a shunting locomotive, studies of gap selection in the coupling and skidding have been carried out. The purpose of the article is to conduct research on transient processes of the gap selection and skidding on a dynamic computer model of a traction asynchronous electric drive based on the FC-AD system with various control systems. The developed computer model is based on specific parameters of the traction asynchronous electric drive, allows calculating transient processes in the FC-AD system, taking into account skidding and the gap selection. The article has structural diagrams of mathematical models that take into account the operation of the traction electric drive, taking into account various control and skidding systems. On the basis of a dynamic computer model, computer models have been developed for studying transient processes in various control systems when choosing the gaps in the coupling and skidding.

This paper is devoted to studying a freight electric locomotives efficiency increasing. Energy efficiency indicators for various operating conditions were analyzed. The locomotive efficiency in function of tractive power was found by statistical processing of on-board recorder data. The experience shows that electric locomotives energy efficiency in operational conditions is less than nominal value. A locomotive efficiency control system for multi-engine traction drive has been developed, the power utilization factor is chosen as a criterion. As a result, this increases the locomotive efficiency distributing the tractive force over the optimum number of traction motors when operate at partial load. Direct confirmation of the reduction in energy consumption was obtained from operational tests. All other things being equal, when the electric locomotive operates in discrete-adaptive mode in combination with automatic speed control, an increase in the efficiency by 11.1% and a decrease in the specific power consumption for traction by 25% are achieved.

The results of studies of open-loop system and closed-loop control systems for the electric drive of mine electric locomotive ARP14 with the direct-current series motors are presented. The analysis of quality indicators of systems built by algorithms of the system of subordinate control, modal control with and without state observer, and on the basis of multilayer neural network is done. The advantages of the perceptron neural network synthesized by a genetic algorithm as a teaching procedure are shown.

This article shows the results of the development and modeling of a neural network control system for a two-mass electromechanical system of the main-line electric locomotive DS3. The simulation model of the electric drive of rail vehicles has the integration of the computer vision unit. The developed systems can automatically speed control rail vehicles, depending on the curvature of the track, to increase the level of automation and secure traffic.

Recent years have witnessed a rapid development of Electrified railway. A large amount of reactive power can be generated when the electric locomotive is too much on the traction network, It Cause a serious decline in power quality, Harmonics and reactive power has negative impacts on stability and security of locomotive running. Traditional reactive power compensation technologies are difficult to meet system requirements due to the switching frequency and voltage limit. In order to overcome the contradiction between the switching frequency of power device and power capacity in the traditional SVG, the principle and topology of H-Bridge SVG were studied, Control strategy adopts Carrier phase-shifted SPWM which is applicable to Cascade H-Bridge Multi-level Converter. The SVG designed adopt the control strategy based on instantaneous reactive power voltage and two closed loop, which can quickly follow the voltage changes controlling the output of SVG..MATLAB simulation results prove the validity of the control method and the performance of cascade H-bridge SVG for reactive power compensation.

The questions of propagation of traction current harmonics along the length on an homogeneous feeder zone at the one- and two-end power supply and the definition of their influence on code current flowing in rail lines were elaborated. The mathematic modelling of a traction supply net was carried out. The spectrum of traction current and the most dangerous harmonics influencing the track circuits were assessed for the application of electric locomotive with the PWM-invertors. To this end, the values of current and voltage on the primary winding of the traction transformer of the double-section electric locomotive were determined.

The paper deals with development of the mathematical model of the two-mass electric drive of a direct current of the electric locomotive with the observer of a full order. The model provides an opportunity to study the change in the ratio of the moments of inertia of the two masses of the electric drive in order to reduce speed fluctuations and inconsistencies in the speeds of these masses. The observer estimates the speed on the basis of information about the supply voltage and motor current. Instead of directly measuring the speed, an observer is used, who uses the measured armature current and supply voltage to change the task to speed. As a comparison, the classical model of subordinate coordinate control for a two-mass electric drive is considered. The disadvantages of the latter are the complexity of calculating the parameters of the links during debugging. Identification and description of the load moment is carried out by a system of differential equations. Reproduction of the vector of coordinates of the system and the vector of perturbations (load moment) is carried out by the observer with an error in the steady state. To compensate for it, the load torque signal in the static is fed to the input of the speed circuit through the debugging link. The results of research on the mathematical model, with its appropriate adjustment under the conditions of a particular electric drive, can significantly reduce the impact loads on the electric drive by accurately matching the speeds of two masses and from a practical point of view provide information on calculations of the kinematic circuit and selection of optimal gear ratio.

In this paper, an energy storage-type railway power quality control system (ES-PQCS) is given to improve the power quality of traction power supply system (TPSS) and recover considerable braking energy generated by electric locomotive. First, the topological structure and mathematical model of the system are analyzed, revealing the relationship of compensation current with the primary power factor (PF) and the load current. Then, the partial compensation strategy (PCS) is proposed to optimize the compensation capacity of railway power conditioner (RPC). Besides, the active power flow and power compensation under system operation scenarios are analyzed, and the power-flow management scheme with 11 classic cases is listed. Furthermore, the capacity configuration of ESS is designed. Finally, based a substation’s data, typical scenarios, system design and simulation are carried out, which verify the effectiveness of compensation strategy and its ability of capacity decreasing and energy saving.

This study provides a description of a unified model of a passenger train, including an AC electric locomotive with a ЄII1M series DC commutator traction motor, as well as 61–836 (reserved seat) and 61-820K (compartment) series passenger cars. This unified model combines three subsystems - electrical, mechanical and pneumatic. The initial data for the selection of control actions during movement can be both the recorder of motion and automatic operation parameters data and the calculated parameter values. The developed model quite accurately describes the processes of movement, their numerical values and the nature of changes in all modes of train movement, the error is no more than 4.5%. Such an approach allows precisely reproducing the real train movement and investigating various processes.

In the development process of large-scale railway transportation system, there are various line structures, resulting in drastic fluctuations of traction power supply system, which brings great difficulties to ensure the power supply capacity of traction power supply system. Traditional power flow calculation methods, such as N-R method and PQ decomposition method, can only calculate highly linearized direct power supply system, and are no longer applicable to new power supply systems. Therefore, it is necessary to study a suitable method to analyze the power supply capacity of AT traction power supply system effectively and accurately. In this paper, firstly, the AT traction power supply system model is built, including substation, substation and AT substation. Then, according to the basic parameters and operation characteristics of electric locomotive, the equivalent circuit model of electric locomotive is built to realize the complete restoration of traction power supply system. Then, the power flow of traction power supply system under different working conditions is calculated, and the power supply capacity under single-vehicle light load, single-vehicle heavy load, multi-vehicle light load and multi-vehicle heavy load is explored. Finally, the model is used to verify it again, and a substantial conclusion is obtained.