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Traction drives with vector control are widely used on mainline locomotives with induction motors. Traction motors can fail due to malfunctions that occur during the operation of locomotives. Real-time functional diagnostic systems are necessary to prevent the failure of traction motors. The implementation of such systems will allow to detect the occurrence of malfunctions in the traction motor at the initial stage and prevent the further development of the defect. In the work, a structural diagram of functional diagnostics for monitoring the condition of the rotor of an induction motor is proposed and an algorithm for its operation is developed. [ABSTRACT FROM AUTHOR]

The method of improving a two-section mainline diesel locomotive by using energy storage in the traction system is considered. A mathematical model was developed to study the movement of a diesel locomotive based on the recommendations and provisions of the theory of locomotive traction. For this purpose, the movement of a diesel locomotive as part of a train along a given section of a track was studied. It was determined that the use of an energy storage device on a diesel locomotive will allow up to 64% of the energy spent on train traction to accumulate. The use of energy storage in the accumulator during electrodynamic braking ensured a reduction in fuel consumption by about 50%, regardless of the options for equipping the traction system of the diesel locomotive with an energy accumulator. It is established that regardless of the options for equipping the traction system of the diesel locomotive with an energy storage device, the indicators characterizing the degree of use of the diesel engine do not change. These research results can be used in works devoted to the improvement of the control system of energy exchange between the accumulator and traction engines of diesel locomotives. [ABSTRACT FROM AUTHOR]

The object of research is the processes of intelligent management of the computer environment of data objects of the critical infrastructure of railway transport. When developing an innovative model of deep mutual integration of the architecture of an intelligent computer environment for the management of objects in the power supply system of railway transport, the only urgent task is to solve the problems of efficient and reliable power supply of electricity for train traction to ensure the transportation process. The approaches, mathematical models and methods that became the basis for the creation of an innovative model and a new structure of the management system, the integration of the architecture of the computer environment of data of critical objects of the infrastructure of railway transport, meet the requirements of modernity and the strategy of sustainable development of the transport infrastructure. Management of an intelligent computer environment in the context of the railway power supply system is a complex process that includes the use of various technologies and strategies to optimize the functioning of systems, increase reliability, ensure efficient use of electricity, and ensure the transportation process. The basis of the creation of an intelligent computer environment is the principle of a single informational and synchronous space for the formation of primary information, which is an important concept in the development of intelligent control systems for the power supply system of railway transport. This principle requires that all parameters and data that are collected from different systems of power supply facilities should be combined in a single information space and be available for analysis and management in real time. This principle creates the basis for innovative solutions in the field of railway power supply system management, and the use of the Internet of Things, artificial intelligence, machine learning and deep learning allows the development of systems that meet modern requirements for the efficiency and reliability of energy systems. The use of the approach of deep mutual integration of the architecture of the computer environment is key in the possibility of automating the processes of data collection and analysis, as well as in improving the interaction between the components of the systems of power supply facilities of railway transport, the reliability and efficiency of the system, which makes it more flexible and adaptive to changes in load and working conditions. The research presented in the work can be used in practice in organizations, structural units and at the levels of the management system of critical infrastructure objects in railway transport, transport sector enterprises, which will allow a quick response to an emergency situation and switch to backup modes, ensuring reliability and availability of power supply in conditions of challenges. [ABSTRACT FROM AUTHOR]

An analysis of the operating conditions of the traction drives of an electric rolling stock with asynchronous traction motors was conducted. In the process of operation, the electric traction drive with both direct torque control and vector control was found to possibly experience unstable modes, both in terms of power supply and load. The models of electric locomotive traction drives with asynchronous electric motors with either vector or direct torque control were adapted to account for the possible presence of the aforementioned operational factors. As a result of the modeling, the starting characteristics of the electric traction drives with different control systems were obtained both in the absence and in the presence of power supply and load disturbances. The following cases were investigated for the drive with vector and direct torque control in the absence of power supply and torque disturbances: drive output at the rated speed of rotation of the electric motor shaft; 10% reduction in the rated speed; 10% increase in the rated speed. The comparison of the results obtained has demonstrated that, at lower than nominal frequencies, the electric traction drive with direct torque control has higher accuracy in its regulation of the rotational speed and torque, lower power consumption from the power supply, lower torque overshooting, but a higher level of torque pulsations than the electric traction drive with vector control. Meanwhile, at higher than nominal frequencies, the vector control has higher accuracy in its regulation of the speed, lower torque overshooting, shorter duration of transient processes, and lower torque pulsations than the direct torque control. Moreover, as a result of the investigations, the traction drive with direct torque control has been found to be more resistant to power supply and load disturbances. The results of this work are applicable to the investigation of the influence of electric traction drive control methods on the energy efficiency of the traction drive of an electric locomotive with an alternating current (AC). [ABSTRACT FROM AUTHOR]

This article presents an analysis of the causes behind the development of asymmetric modes in a traction drive system that features direct torque control (DTC) of a rolling stock with asynchronous traction motors. The development of asymmetric modes in the traction drive system was found to be caused by the asymmetry of the supply voltage system, the asymmetry of the traction motor windings, and transient processes triggered by a change in the inverter supply voltage and variation in the traction motor load. At the same time, the asymmetric modes caused by the asymmetry of the feed voltage system and the windings of the traction motor are the emergency modes. The influence of the asymmetry of the feed voltage system and asymmetry of the windings of traction motor on the starting characteristics of the phase currents and flux linkages of the stator in the steady-state mode was investigated. In these cases, the ratio of the amplitudes of phase currents and flux linkages of the stator of different phases was found to be constant. The effect of a variation in the feed voltage and load acting on the motor shaft on the starting characteristics of phase currents and flux linkages of the stator was investigated in the case of absence of the emergency modes. In these cases, the ratio of the amplitudes of phase currents and flux linkages of the stator of different phases was found to not be constant. The amplitudes of the phase current and stator flux linkage were proposed as criteria for diagnosis and identification of asymmetric emergency modes. An algorithm and a structural scheme have been proposed for the diagnosis of emergency asymmetric modes in the traction drive system with direct torque control. Modifications to the traction drive system with direct torque control are suggested in order to diagnose the presence of faulty asymmetric modes and identify the damaged traction drive element. [ABSTRACT FROM AUTHOR]

Operation modes of rolling stock at mining enterprises are considered and analyzed. The justification of the need to replace it with a modern specialized electric locomotive for quarry railway transport, equipped with an asynchronous traction electric drive and an on-board energy storage system, is presented. The determination of the parameters and structure of the on-board energy storage system, based on the condition of power compensation with limited power consumption from the traction network and ensuring the autonomous movement of the electric locomotive, is considered. This study was carried out by modeling the processes of energy exchange in the traction system of an electric locomotive. The use of lithium cells and supercapacitors in energy storage is considered. Variants of the hybridization of energy storage were studied from the standpoint of minimizing the weight, size, and cost indicators. It was established that reducing the mass of the energy storage device, which includes lithium cells and supercapacitors, leads to an increase in the cost of one kilowatt-hour of energy storage capacity, which reduces the attractiveness of capital expenditures for the creation of such an energy storage device. Hybridization of the energy storage device by combining lithium cells of different types practically does not improve its weight, size, and cost indicators. The recommended option is a storage capacity of energy based on LTO elements, for which it is necessary to select elements in order to minimize weight, size, and cost indicators. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, in transport systems, as part of the main and auxiliary equipment, a large number of induction motors with a squirrel-cage rotor of different capacities are used. Their wide application in the transport industry is associated with the main advantages over other types of machines - a fairly high reliability, low cost and ease of maintenance. However, during the operation of these motors, a number of malfunctions can occur that affect the deterioration of the performance of the entire drive, the accuracy of its functions, or accelerate an emergency stop. To ensure proper control of the technical condition of electric motors, modern diagnostic systems are required that operate in real-time and operational loading mode with the transmission of data on the instantaneous state of the main control elements. The paper proposes a block diagram of the diagnostic built-in system and developed a modular unit for it to set the type and degree of the most complex damage - inter-turn short circuit in the stator winding. [ABSTRACT FROM AUTHOR]

A method is proposed for determining the number of damaged stator windings in the presence of an asymmetric power supply system for an induction electric motor based on the Park vector hodograph. As a result of the experiments on the simulation model, it was found that with the symmetry of the system of supply voltages and stator windings, the hodograph of the Park vector describes a circle; in all other cases it is an ellipse. It has been established that the presence of asymmetry in the supply voltage system is indicated by the angle of inclination of the ellipse, and the indicator of the presence of the asymmetry of the stator windings is the angle of ellipticity. In order to identify the presence of asymmetry of the stator windings in the conditions of asymmetry of the supply voltage system, an algorithm for recalculating the ellipse parameters for the condition of the symmetry of the supply voltage system was proposed. Recalculation errors did not exceed 6%. It has been established that the dependence of the increment of the amplitudes of the phase and angles of the phase currents of the stator on the number of damaged turns of the stator winding is linear. Based on this fact, an algorithm for determining the number of damaged turns was proposed. The results of this work can be used to build systems for diagnosing the interturn short circuit of the stator of an induction electric motor built into the drive. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper deals with the analysis of the operating conditions of traction drives of the electric locomotives with asynchronous traction motors. The process of change of the catenary system voltage was found to have a stochastic character. The method of current controller synthesis based on the Wiener–Hopf equation was proposed to enable efficient performance of the traction drive control system under the condition of the stochastic nature of the catenary system voltage and the presence of interferences, when measuring the stator current values of the tractor motor. Performance simulation of the proposed current controller and the current controller used in the existing vector control systems of the traction drives used in the electric locomotives was implemented. The results of the performance simulation of the proposed current controller were compared with the performance of the current controller in existing vector control systems of the traction drives. The results are applicable to the design of vector control systems of traction drives in electric locomotives and to the study of the influence of performance of electric traction drives in electric locomotives on the quality indicators of the power supplied by the traction power supply system under the actual operating conditions of the locomotive. [ABSTRACT FROM AUTHOR]

The object of research is the electrical processes in the control system of the traction drive of the electric locomotive VL-80K (Russia). To improve the accuracy of its mathematical model, it is necessary to use the values of the parameters determined during experimental studies of the traction drive control system. In particular, it is important to use in the traction drive model the value of the voltages on the arms of the rectifier installation of the electric locomotive, taking into account the position of the driver’s controller. The complexity of the simulation lies in the fact that the reference does not provide the value of the voltage on the arms of the rectifier for each position of the driver’s controller, which makes it difficult to verify the resulting model. A scheme for measuring the voltage value on the arms of the rectifier installation of an electric locomotive for each position of the position of the driver’s controller is proposed. On its basis, a simulation model is developed in the MATLAB software environment. The simulation model implements an algorithm for closing the contactors of the electric group contactor for each position of the position of the driver’s controller. Approbation of the voltage measurement technique was carried out on an electric locomotive of the VL-80K series during a trip on the Darnytsia – Myronivka section (Ukraine). Comparison of the voltage values on the arms of the rectifier installation, obtained experimentally, with the passport data showed that the measurement error was 0.5 %. In addition, the experimental results showed that the voltages on the arms of the rectifier for paired positions of the position of the driver’s controller are the same, for odd ones they are different. Therefore, when simulating the operation of the traction drive control system, the voltage values on different arms of the rectifier installation were taken separately. Comparison of the simulation results for the nominal mode with passport data showed that for this mode the measurement error was 3.78 %. For all others, it did not exceed 5 %. [ABSTRACT FROM AUTHOR]

This paper has proposed and substantiated the application of an additional diagnostic parameter for assessing the state of stator windings of induction motors during operation. The dependences of the values of phase shifts between phase currents and phase voltages have been obtained. These dependences showed that when an interturn short circuit occurs in the stator windings, the phase shifts are the same for all phases of the motor. That has made it possible to obtain the dependence of the change in phase shift on the change in the engine shaft rotation frequency. This study’s result has established the dependence of the rates of change of the phase angle on the engine shaft rotation frequency for both one and two damaged phases with varying degrees of damage. When analyzing these dependences, it was found that with an increase in the number of damaged phases of the electric motor, the linear section of the dependences decreases. In addition, with an increase in the degree of phase damage, the angle of inclination of the linear sections of the characteristics decreases. That has made it possible to determine an additional parameter for diagnosing the place and degree of an inter-turn short circuit of the windings in an induction motor with a squirrel-cage rotor. The values of the additional parameter, termed by this paper’s authors as a “phase criterion” can be used to assess the condition and degree of damage to the stator winding of induction motors. The values of the phase criteria for various types of damage were: when phase A is damaged by 90 %, ξ=0.634, (deg)²/(rpm)²; when phase A is damaged by 80 %, ξ=0.393, (deg)²/(rpm)²; when phase A is damaged by 80 % and phase B is damaged by 90 %, ξ=0.25, (deg)²/(rpm)²; when phase A is damaged by 80 % and phase B is damaged by 90 %, ξ=0.173, (deg)²/(rpm)². The results of this research could be used to select an effective method for diagnosing an inter-turn short circuit in the stator winding when building a diagnostic system for induction motors as part of drives of transport equipment. [ABSTRACT FROM AUTHOR]

The analysis of operating conditions of induction traction motors as part of traction electric drives of electric locomotives reported here has revealed that they are powered by autonomous voltage inverters with asymmetric non-sinusoidal voltage. It was established that the induction motor operation may be accompanied by defects caused by the asymmetrical modes of the motor stator. A model of the induction motor has been proposed that takes into consideration changes in the values of mutual inductance of phases and complete inductance of the magnetization circuit due to changes in the geometric dimensions of the winding caused by a certain defect. An algorithm that considers the saturation of the magnetic circuit of the electric motor has been proposed. This approach to modeling an induction motor is important because if one of the stator's windings is damaged, its geometry changes. This leads to a change in the mutual inductance of phases and the complete inductance of the magnetization circuit. Existing approaches to modeling an induction motor do not make it possible to fully take into consideration these changes. The result of modeling is the determined starting characteristics for an intact and damaged engine. The comparison of modeling results for an intact engine with specifications has shown that the error in determining the controlled parameters did not exceed 5 %. The modeling results for the damaged engine demonstrated that the nature of change in the controlled parameters did not contradict the results reported by other authors. The discrepancy in determining the degree of change in the controlled parameters did not exceed 10 %. That indicates a high reliability of the modeling results. The proposed model of an induction electric motor could be used to investigate electromagnetic processes occurring in an electric motor during its operation as part of the traction drive of electric locomotives [ABSTRACT FROM AUTHOR]

The object of research is a pulsating current traction motor. To improve the accuracy of its mathematical model, it is necessary to use the values of the parameters that are determined in experimental studies of the electric motor. In particular, it is important to use in the model of the electric motor inductance obtained experimentally. A method is proposed for calculating the inductance of the armature winding, main poles, additional poles and compensation winding and the total inductance of the traction motor armature circuit. The calculations are based on the results of the indirect inductance measurement method, in which the electrical values of various modes of power supply of the electric motor windings are directly measured, and the inductances are determined by auxiliary calculations. The inductances of the traction motor armature circuit have a non-linear dependence on the current flowing through them. The main difference of the study is that the measurements of the electrical parameters required for calculating the inductance are carried out over the entire range of operating currents of the windings. The essence of the proposed technique is to measure the active power in the armature winding, the winding of the main and additional poles, and the compensation winding, as well as in the armature circle as a whole when they are supplied with alternating current. According to the obtained values of active power losses and phase displacement, the corresponding reactive power losses are determined, with the help of which the inductances of the motor windings are calculated. Approbation of the methodology for calculating the conduction inductance for an electric motor of a pulsating current NB-418K6 (country of origin Russia), is used on electric locomotives of the VL80T and VL80k series (country of origin Russia). A scheme for measuring electrical parameters necessary for calculating inductance is proposed. The graphical dependences of the inductance on the armature current, built on the basis of calculations, confirmed the hypothesis about the nonlinear dependence of these inductances on the armature current. For further application of the results obtained in the simulation of the operation of the traction electric motor NB-418K6, a polynomial approximation of the total inductance of the armature circuit was performed. [ABSTRACT FROM AUTHOR]

An improved method for spectral analysis of traction current of an Alternating Current (AC) electric locomotive is considered in the article. A new method of spectral analysis considers the change in voltage in the catenary system as a non-deterministic, non-ergodic and non-Gaussian process. It has been established that higher voltage harmonics in the catenary system have a significant negative effect on the operation of non-traction railway consumers of electricity. In addition, electric locomotives operating in the same feeder zone have a mutual influence on each other. Electric railway transport is a source of higher voltage harmonics and strongly distorts the shape of the sinusoidal voltage of the catenary system, which are caused by the higher spectral components of the current in the electric locomotive traction drive circuit. These spectral components of the traction current arise in the traction drive circuit due to the nonlinearity of the current-voltage characteristics of the electronic devices of an electric locomotive, for example, a contact rectifier, a capacitor circuit of traction motors. Reactive power compensators are used in electric locomotives to eliminate components of higher harmonic traction current in the catenary system. Traditionally, spectral analysis in such systems is performed using Fourier methods. However, the determination of the spectral components of the traction current by the Fourier method for constructing a control system for a reactive power compensator is possible only if the process of voltage variation is a deterministic or ergodic Gaussian process. Otherwise, the application of Fourier transform methods will be incorrect. An analysis of the factors that affect voltage changes in the catenary system showed that this process is significantly different from the ergodic Gaussian process. Such factors include the following: the operating mode of the electric locomotives; number and total capacity of electric locomotives in one feeder zone; electric locomotives passing through feeder zones; instability of collection current. Thus, in the case under consideration, the application of the Fourier methods is incorrect for the analysis of the spectral components of the traction current. This affects the quality of compensation of the higher harmonic components of the traction current, and in some cases, the unstable operation of the control system of the active part of the reactive power compensator. Proposed scientific approach is based on the Levinson-Durbin linear prediction algorithm. On the one hand, this allows adapting the control system of the compensator to the voltage parameters of the catenary system. On the other hand, this allows taking into account the operating modes of electric rail vehicle with reactive power compensation. The construction of a compensator control system using the Levinson-Durbin algorithm significantly simplifies the synchronization scheme of the compensator and power circuits of the traction electric drive of AC electric locomotive. A comparison of the traditional method of spectral analysis, based on the Fast Fourier Transform (FFT), and the method, based on the Levinson-Durbin algorithm, proposed by the authors, showed the high efficiency of the latter. [ABSTRACT FROM AUTHOR]

When studying transients in pulsed current traction motors, it is important to take into consideration the eddy and hysteresis losses in engine steel. Magnetic losses are a function of the magnetization reversal frequency, which, in turn, is a function of the engine shaft rotation frequency. In other words, magnetic losses are a function of time. Existing calculation procedures do not make it possible to derive the instantaneous values of magnetic losses as they are based on determining average losses over a period. This paper proposes an improved model of magnetic losses in the steel of a pulsed current traction motor as a function of time, based on the equations of specific losses. The adequacy criteria of the procedure for determining magnetic losses in electrical steel have been substantiated: the possibility to derive instantaneous values of magnetic losses in the magnetic material as a function of time; the possibility of its application for any magnetic material; and the simplicity of implementation. The procedure for determining magnetic losses in the steel of a pulsed current traction motor has been adapted by taking into consideration the magnetic properties of steel and the geometry of the engine's magnetic circuit. In order to determine the coercive force, the coefficient of accounting for the losses due to eddy currents, as well as the coefficient that considers the losses on hysteresis, the specifications' characteristics of specific losses in steel have been approximated using the pulsed current traction motor as an example. The simulated model of magnetic losses by the pulsed current traction motor has demonstrated the procedure for determining average magnetic losses and time diagrams of magnetic losses. The proposed model for determining magnetic losses could be used for any magnetic material and any engine geometry under the condition of known material properties and the characteristics of change in the magnetic flux density in geometry. [ABSTRACT FROM AUTHOR]

This article is devoted to development of a method for calculating the parameters of an asynchronous motor of an electric locomotive with asymmetrical windings of stator and rotor. A method for determining self and mutual inductances of the stator and rotor phases of an asynchronous motor with asymmetric windings and their relations to mechanical variables is proposed. It is based on comparing two equations of stored magnetic energy, one equation calculated through induction, magnetic field strength and geometrical dimensions and another equation calculated through the parameters of the motor circuits. It is shown that the obtained solutions correspond to the previously existing methods, but they give the additional possibilities in mathematical modeling. The proposed technical solution allows higher accuracy developing of a mathematical model of a drive with an asynchronous motor having asymmetrical stator and rotor windings for studying dynamic processes during the operation of the specified drive, in particular, the drive of auxiliary machines for electric locomotive, where an asynchronous motor with asymmetrical stator windings is used as a phase release. [ABSTRACT FROM AUTHOR]

The analysis of operating conditions of traction drives of electric locomotives with asynchronous traction motors has been carried out. It was found that during operation in the output converter of an asynchronous motor, defects may occur, which leads to asymmetric modes of its operation. Models of a traction drive of an electric locomotive with asynchronous motors with scalar and vector control of the output converter are proposed, taking into account asymmetric operating modes. As a result of the simulation, the starting characteristics of the traction drive were obtained for various control methods both in normal and emergency modes of the drive. For the drive-in emergency mode, the following cases were investigated: the balance of the converter output voltages and the turn-to-turn circuit of 10% of phase A winding of the motor stator; imbalance of the output voltages of the inverter and an intact motor; imbalance of the output voltages of the converter and interturn short circuit of 10% of phase A winding of the motor stator. Comparison of the simulation results have shown that in emergency modes in the traction drive, the torque ripple on the motor shaft in the drive with vector control is 13% less, and in scalar control, the phase current unbalance coefficient is 22% less. The results of this work can be used to study the influence of the output converter control methods on the energy efficiency indicators of the traction drive of an AC electric locomotive. [ABSTRACT FROM AUTHOR]