Analysis of Control Methods for the Traction Drive of an Alternating Current Electric Locomotive

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.

SRM with 8/6 magnetic system topology for electric drive of mine battery electric locomotives: design and modelling

The paper deals with the development and simulation results of the switched reluctance motor for electric drive of mine battery electric locomotives instead of the DRT-14 DC motor. The switched reluctance motor parameters are obtained based on numerical calculation of the magnetic field by QuickField program and are embedded in MATLAB/Simulink model of a switched reluctance motor created for 8/6 magnetic system configuration. SRM-14-615 has the mechanical characteristics as DC motor DRT-14 and meets the required operating modes as part of the AM8D mine battery electric locomotive. Also two types of models using methods and techniques of the artificial intelligence theory are presented: a model with a fuzzy control system in the Fuzzy Logic Toolbox package and a model with a neural network control system in the Neural Network Toolbox package.

INCREASING THE ENERGY EFFICIENCY OF THE AC ELECTRIC LOKOMOTIVE TRACTION DRIVE

The study of the energy characteristics of the active traction converter with pulse-width modulation as part of the traction electric drive of an AC electric locomotive was held during the research. Active traction converter provides pulse-width control of the collector DC traction motors voltage and belongs to the basic AC / DC circuit. The transient process when switching transistor switches is accompanied by significant voltage surge, due to the scattering inductance reaction of the traction transformer. Studies have shown that the diode discharge buffer circuits do not provide discharge of the electromagnetic energy accumulated in the winding of the transformer. An active traction converter control algorithm has been developed, which implies the use of pulse-width and phase regulation of rectified voltage. Switching of transistor switches occurs in the presence of a parallel current circuit. This creates the conditions for the discharge of electromagnetic energy accumulated in the secondary winding circuit of the traction transformer. The developed mathematical model allows to investigate the electromagnetic processes that occur during the switching of transistor switches and to evaluate the energy efficiency of the electric locomotive with active traction converter. In the simulation process, the influence of active traction converter parameters and control algorithms on the power rate of the converter, the total THD distortion rate of current and voltage and the relative values of the rectified voltage were investigated. Measures to increase the power rate and to reduce the emission level of higher current harmonics into the traction network were proposed.

Research of the Modes of Starting and Braking during Work of the Systems of Group Electric Drive of Mine Electric Locomotive with the Different Types of Electric Engines

In the article the results of research of work of mine electric locomotive are driven on condition of stability of the system "A wheel is a rail" on coupling of wheels of electric locomotive with rails. It is marked that work of mine electric locomotive transport is conditioned by the row of specific terms. It is indicated that for realization of the electromechanics systems of mine electric locomotives structures are used with the hauling electric engines of direct and variable current. During working as of mine electric locomotive an important question there is coupling of wheels of electric locomotive with rails. Investigation of worsening of coupling of wheel with a rail is an origin of processes of skidding in the mode of creation of tractive or юза force in the mode braking of electric locomotive, that influence negatively for other knots of hauling electromechanic. In turn stability of the system "A wheel is a rail" depends on the type of hauling electromechanic. At consideration condition of stability of electromechanic on coupling of wheels of electric locomotive with rails important is inflexibility of descriptions of hauling electric motors. What more inflexibility, the higher stability of the system "A wheel is a rail". More hard descriptions can be got in the system of electromechanic with hauling asynchronous engines that give an opportunity to use this fact for realization of proportional distribution of efforts between the wheelpairs of electric locomotive. The systems ticker-coil on speed allow to carry out distribution of hauling and brake efforts that is attached to the wheelpairs of electric locomotive, in accordance with distribution of efforts from these wheelpairs on rails, only after the beginning of processes of skidding or skidding. For the decision of this problem a sufficient condition there is a limit of currents of hauling electric motors on the set level. In this connection possibility of distribution of hauling and brake efforts appears at any moment to time. For the decision of task of rational distribution of efforts of electric locomotive, distribution of forces was analysed between his wheelpairs in the function of total force that pulls an electric locomotive on his coupling. On the basis of analysis an idea was got about the redistribution of loading on the axes of electric locomotive. This distribution is in direct ratio to his total tractive force and coupling height, and in inverse ratio to inflexibility of corps. As a result, in order that propelling and brake forces on the axes of electric locomotive corresponded to distribution of weight on rails on wheelpairs, it is necessary to support identical correlation of weight and efforts on the axes of electric locomotive. The design of transients was conducted in the system of group electric hauling drive of mine electric locomotive in the mode of starting and braking. A design is executed for the engine of direct-current with successive connection of poles and hauling asynchronous engine. The charts of transients in the system of group electric hauling drive of mine electric locomotive in the mode of starting and braking showed absence of processes of skidding and slipping at application of the offered principle for the control system.

Model of pulsating current traction motor taking into consideration magnetic losses in steel

The aim of the work is to develop a mathematical model of the traction motor of the pulsating current of an electric locomotive taking into account the magnetic losses in the motor steel to determine the starting parameters depending on the voltage of the armature winding. Methodology. Mathematical modeling of electromagnetic processes in a traction motor of pulsating current is applied taking into account the nonlinear nature of the armature inductance, the inductance of the excitation winding and the nonlinear nature of the universal magnetic characteristic. The magnetic losses in the steel of the traction motor were taken into account by establishing the dependence of these losses on the frequency of reversal, the magnetic flux in the magnetic circuit of the motor and the geometric dimensions of the motor. Results. The mathematical model of calculation of starting parameters of the traction engine of the pulsating current of the traction drive of the electric locomotive of alternating current taking into account the equation of instantaneous value of losses in engine steel is developed. The dynamic characteristics of the traction motor with pulsating current are obtained. It allows to investigate starting parameters of the traction engine on the basis of the received mathematical model and to design elements of the traction drive of the electric locomotive according to the specification, to choose optimum design parameters. Originality. For the first time a comprehensive study of the pulsating current traction motor was carried out taking into account the nonlinear nature of the armature inductance, excitation winding inductance and nonlinear nature of the universal magnetic characteristic and taking into account the magnetic losses in the motor steel. Practical significance. The model of the traction motor of pulsating current taking into account losses in steel of the engine on the basis of the carried-out calculation is developed. Experimental studies have confirmed the adequacy of the model, which allows to apply the obtained model to develop a mathematical model of an AC electric locomotive to study the electrodynamic processes in it at different modes of operation of the electric locomotive.

Comparative research of electrical energy transformation processes in locomotive traction drives with asynchronous motors and series-wound brushed DC motors

An estimate of the Russian railways expenses level for the purchase of fuel and energy resources is given. It is shown the costs for the purchase of electric energy for train traction account for more than half of the total costs. In this regard, the problem of increasing the traction rolling stock energy efficiency seems certainly relevant. The diagram of voltage and current measurements at the primary winding of the AC cargo electric locomotive transformer is given. The experimental data processing algorithm is proposed. A comparative analysis of the results obtained for electric locomotives with series-wound brushed DC motors (throughout what follows will be denoted as BTMs) and asynchronous traction motors (will be denoted as ATMs) showed that the power factor of the asynchronous drive is higher: 0.99, compared to 0.65 for the drive with BTMs; and the coefficient of nonlinear current distortions is only 0.15, compared to 0.53 for the BTMs. The conclusion is made about higher efficiency of electric energy conversion process in asynchronous traction drive in trust mode.

Historical experience and prospects of corporatization of the Dnipropetrovsk electric locomotive plant (1988–2021)

The article provides a retrospective analysis of the historical experience and problems of corporatization of the Dnipropetrovsk electric locomotive plant – a leading domestic manufacturer of industrial electric vehicles and railway rolling stock. The author traces historical circumstances of development and preconditions of diversification of production activity of the enterprise on the background of market economy in Ukraine and decrease in demand for narrowly specialized products. It was found out that during the 1990s–2000s the staff of SPA «DEVZ», having a promising research and production potential, mastered a wide range of production of mainline equipment to meet the needs of railways for innovative electric vehicles. However, due to low product quality and inefficient management system, the company is currently on the verge of bankruptcy, and its outdated design and technological improvements are not able to ensure competitiveness in the global railway market. It is proved that given the strategic importance of SE «DEVZ» for the national economy as the last profile locomotive company, its corporatization can be a real alternative to privatization, providing effective capitalization, financial and technological recovery and improving the culture of production with a state guarantee of preservation of the enterprise, as well as obtaining additional funds through the placement of securities on stock exchanges, and attracting private investment and innovation from international manufacturers. Further research on the historical aspects of the development of domestic engineering enterprises and their impact on the fleet of JSC «Ukrzaliznytsia» should be carried out taking into account the achievements of domestic science on the problems of structural adjustment of the economy and the use of modern strategic management tools.

Power supply for a CIP position for bearings

Objective: Two possible options for power sources are considered: a controlled three-phase bridge rectifi er circuit with a step-down transformer and a pulse converter receiving power from the network through an uncontrolled three-phase bridge rectifi er to drive the wheel-motor units of electric locomotives and electric trains into rotation with the required frequency at the position of CIP bearing diagnostics. In both cases, it is assumed that the power supplies receive electricity from the 380/220 V, 50 Hz network. The power source is loaded with traction motors of the ER2R, ER2T, ET2, ET2M electric trains and the VL-10 electric locomotive. Methods: Mathematical modeling is used in the MatLab/Simulink environment for analytical calculations. Results: The currents and voltages of the load were determined, based on the calculations, the control angles and power factors of the rectifi er with a step-down transformer, the duty cycle of the pulse converter. Practical importance: A variant of an energy-effi cient power supply is proposed, including an uncontrolled rectifi er and a pulse converter.

Calculation of aerial contact wire volume heated by a moving electric ARC

The article is devoted to the study of the problem of electrified railways electric locomotive current collectors’ interaction violation with an aerial contact wire, accompanied by the occurrence of an electric arc. Current collection disorders, accompanied by arcing, have a destructive effect on the contacting elements, causing their thermal erosion. Places where current collection violations occur should be registered and diagnosed in a timely manner in order to prevent an emergency situation associated with burnout or breakage of the aerial contact wire. In order to further develop the system of technical diagnostics for current collection disorders accompanied by arcing, it is necessary to study the nature and parameters of the processes occurring during these violations. The main part of the article is devoted to the study of the area of heating the aerial contact wire by a moving electric arc. The characteristics describing the heated area are geometric parameters, including the area in the cross section of the wire and the volume of the area. To obtain the necessary data, the method of heat sources was applied, which is a mathematical model that describes the process of heat propagation in an aerial contact wire. The electric arc arising when the current collector breaks off is considered as a mobile heat source distributed over the aerial contact wire surface in the heating zone and having a limited radius of the heating spot. Based on the heat propagation process peculiarities inside the aerial contact wire, a method for calculating the volume of the heated area bounded by an isothermal surface of a certain temperature is presented. The heated area was visualized using the PTC MathCAD.