Method of Selecting Energy-Efficient Parameters of an Electric Asynchronous Traction Motor for Diesel Shunting Locomotives—Case Study on the Example of a Locomotive Series ChME3 (ЧMЭ3, ČME3, ČKD S200)

One of the assumptions made during the modernization process of diesel shunting locomotives is the replacement of a diesel traction motor with a DC generator with an electric asynchronous traction motor. The article aimed to develop a method of selecting energy-efficient parameters of an asynchronous electric traction motor for diesel shunting locomotives, which will ensure that its operating energy efficiency will be as high as possible. The method was verified on the example of a locomotive series ChME3 (ЧMЭ3, ČME3, ČKD S200). It has been found that using a traction asynchronous electric drive on a ChME3 locomotive, its efficiency increases in comparison with DC electric motors by 3–5% under the long-term operation modes and by 7–10% during locomotive operation with traction at the adhesion limit. Using a new traction gearbox with a higher gear ratio expands the speed range in which the asynchronous traction drive operates with a high-efficiency factor. It is effective to use a traction asynchronous electric drive to modernize ChME3 diesel locomotives in case of their use under the modes requiring the implementation of maximum traction forces at low speeds. A further increase in the efficiency of the traction asynchronous electric drive is possible based on the optimal design of the wheel-motor unit and the asynchronous traction electric drive.

Обзор и классификация пространственно-временных векторов дискретных состояний семифазного преобразователя

The subject of the research is the control algorithms for a seven-phase converter that implement space-vector voltage modulation of a seven-phase motor as an alternative to a three-phase engine in modern electric traction. The study used elements of set theory, combinatorics, Fourier series expansion and vector analysis. Checking research results was implemented on a special stand for experimental studies of spatial vector voltage modulation of a seven-phase motor.

Running gears of sets of freight wagons coupled with diesel or electric traction vehicle

W artykule przedstawiono przegląd rozwiązań konstrukcyjnych układów biegowych wagonów towarowych wynikających z wymagań zawartych w krajowych jak i europejskich przepisach. Przedstawiono krótką charakterystykę pojazdów trakcyjnych poruszających się w trakcji towarowej. Opisano główne typy wózków stosowanych w Polsce i Europie przede wszystkim rodzinę wózków typu Y25. Zawarto krótki rys historyczny układów biegowych wagonów towarowych. Przedstawiono wymagania zamienności układu biegowego jako układu standardowego. Omówiono główne zagadnienia związane z projektowaniem układów biegowych, wymaganiami, kryteriami, specyfikacją techniczną.

Optimization of Train Energy Cooperation Using Scheduled Service Time Reserve

The main aim of the paper was to develop an innovative approach to the preliminary estimation possibility of train energy cooperation based on data from timetables, without traction calculations. The article points out the need to strive for sustainable and environmentally friendly transport. It was pointed out that rail transport using electric traction is one of the more ecological branches of transport. It also offers a number of possibilities for improving energy efficiency and reducing energy consumption, one of which is the recovery and reuse of energy lost in the electrodynamic braking process. The main ways in which such energy can be used are listed, but the focus is mainly on the aspect of the so-called “energy cooperation” of trains. Then, the current state of the research and knowledge on the narrowed scope of rail traffic management and recuperative braking in rail transportation is presented; an innovative approach to the indirect optimization of the amount of recuperated electrical energy immediately usable by another vehicle by maximizing the duration of energy co-optimization is proposed; and the authors’ function is proposed to enable optimization, taking into account various parameters. The optimization was performed with the use of a proprietary, multi-criteria objective function and the Solver optimization module. Finally, the results obtained using the proposed approach are presented and illustrated with the example of train timetables used by some of the largest railway stations in Poland.

Modeling, Simulation and Monitoring of Electrical Contacts Temperature in Railway Electric Traction

The paper presents a mathematical modeling approach to determine the permanent regime temperature of an electric contact found in the supply system of the railway electric traction. Mathematical modeling is a basic procedure in the preliminary determination of parameters of interest in various fields of scientific analysis. The numerical modeling method used for determining the electric contact temperature represents the base for developing a finite-element thermal model. The simulation of the electric contact was verified by an experimental infrared investigation of an electric contact realized on a realistic laboratory setup. The results interpretation reveals a good synchronization between the calculated, simulated and measured temperatures.

Application of the train congestion recovery method for constructing an instantaneous direct current railway section

Improving the energy efficiency of the transportation process is one of the key tasks, the solution of which is one of the priority areas of the holding JSC «RZD» research. The successful solution of this problem depends, among other things, on the effectiveness of measures taken to reduce energy losses arising from electricity transmission to the consumer, which is the rolling stock of electrified railways. To develop a set of organizational and technical measures aimed at minimizing electricity consumption, an effective apparatus that provides determination of energy losses amount of in the electric-traction netware in real time is needed. The article proposes a method for hardware-analytical calculation of energy losses, which is based on an algorithm for processing the results of direct measurements. It is proposed to calculate power losses using laws and relationships known from the course of electrical engineering. A distinctive feature of the proposed method is the function of recreating the instantaneous circuit based on the data of currents and voltages measurements at the control points of a given section. The proposed method is suitable for use exclusively on DC electrified railways. Also, the paper presents the methods for determining energy losses used today in Russia, and gives their brief characteristics. The logical and mathematical apparatus of the method is described in detail, indicating the possible reasons that, in the process of synthesizing instantaneous circuits, can affect the occurrence of errors. An assessment of the study results of this method application in the electric-traction netware of railways is given.

Thermomechanical voltages in the insulation of traction electric machines of locomotive

In recent years, the production of locomotives in our country has increased significantly. At the same time, a lot of efforts are made to increase the power, reliability and efficiency of their work. One of the key components of any locomotive is electric traction machines, which are usually designed to the limit in order to obtain maximum torque and power density in the limited space of the rolling stock. Previously, this problem was solved by increasing the electromagnetic properties of materials, thermal conductivity of insulating materials. However, this path has exhausted the possibilities for increasing the efficiency of traction electric machines. As the design of traction electric machines improves, their level of functionality, reliability and durability increases, electric traction systems become more relevant and important for reducing the cost of materials, maintenance and ensuring traffic safety. The insulation state of the windings of traction electric machines mainly determines their reliability and performance, affects the service life and the cost of maintenance. Therefore, when designing a traction electric machine, it is important to take into account all operational factors that determine the optimal service life of a locomotive. The article discusses the effect of thermomechanical stresses in the insulation of traction electric machines on their reliability and durability.

Vector control system of electric traction drive with power losses minimization

Based on the operating conditions analysis of electric traction drives of locomotives, it has been established that the vector control systems for an asynchronous motor fully satisfy all the requirements. On the basis of a T-shaped equivalent circuit, a mathematical model of an induction motor is presented, taking into account losses in the stator steel, the effect of the rotor current and saturation displacement. An algorithm for the formation of the optimal, from the point of view of power losses, task for the rotor flux linkage when using a vector control system with the orientation of the axes of the coordinate system along the rotor magnetic field, is developed. The limiting factors are the limitations on the current and voltage of the motor stator, the diesel generator set power. A shared control system for an electric traction drive with asynchronous motors has been developed, which provides direct control of wheel slip with a subordinate vector control system that minimizes power losses. The results of modeling in a steady-state operation and a start-up mode for an electric traction drive of a two-axle bogie with axial support and 630 kW asynchronous motors with the use of various options for organizing circuit reentrances are presented.

Automation of ac electric-traction NetWare digital protective relay operational control

The widespread use of microprocessor-based digital protective relay from various manufacturers, the expansion of the programmable protective relay terminals’ functional composition, the lack of hardware, software and algorithmic support unification, problems of electromagnetic protection necessitate consideration of the issues of digital protective relay operational control automation [1-3]. The authors believe that the attention paid by operating services to the means and methods of the AC electric-traction netware protective relay Functional check is insufficient. Monitoring the correct protection functioning in real time when it is triggered by a short circuit makes it possible to identify all types of incorrect actions of the instrument units until the failure of the entire protection as a whole. The most common failures, such as “false response” and “unnecessary operation”, are detected with a probability close to unity [4-6]. The article discusses the principles of building a system of protective relay Functional check, applicable for all types of electric-traction netware protection that are currently in operation. Logical equations are given to identify incorrect actions of protective relay.

Application of the recurrent mathematical model for estimating the electric-traction NetWare parameters at their dynamic change

The article is devoted to the possibility of applying the methods of successive approximations in the analysis of the instantaneous scheme of the electric-traction netware. The described approach makes it possible to improve the accuracy of modeling the dynamic modes of traction power supply sections operation, and also makes it possible to significantly improve the process of modeling diagnostic and control systems for electric rolling stock at the design stage, based on a more accurate model of dynamically changing input parameters of the electric-traction netware, depending on their required level.