Study of electromagnetic processes in the system “contact network—electric locomotive” while reducing the minimum opening angle of the thyristors in the rectifier-inverter converter

Abstract. The work examines the most dangerous, according to the results of certification of workplaces, professions of railway transport: driver (assistant) of an electric locomotive and a diesel locomotive, an attendant at a railway station, a track fitter, an electrician of a contact network. An analysis of the legislative acts in force in the Republic of Belarus, as well as local regulatory legal acts created on their basis, OSH management systems based on STB ISO 45001, the results of workplace certification showed the need to create a systematic approach to managing the risks of developing occupational diseases in the most dangerous professions on the railway. The work systematizes the factors that have the greatest influence on the risk of developing occupational diseases, based on the generalization and analysis of certification of workplaces, the leading production factors of the listed professions are highlighted.

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Methodology and Models of Combined Modeling of Electromagnetic Pro-cesses in Electric Traction Systems

Science and Transport Progress Bulletin of Dnipropetrovsk National University of Railway Transport ◽

10.15802/stp2021/237404 ◽

2021 ◽

pp. 40-49

Author(s):

T. M Mishchenko

Keyword(s):

Electric Power ◽

Correlation Functions ◽

Correlation Equation ◽

Transition Function ◽

Electric Locomotive ◽

Electromagnetic Processes ◽

Electric Traction ◽

Traction System ◽

First Time ◽

Identification Model

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.

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Simulation of an ac electric locomotive operation in the regenerative braking mode

Herald of the Ural State University of Railway Transport ◽

10.20291/2079-0392-2021-2-106-114 ◽

2021 ◽

pp. 106-114

Author(s):

V. S. Tomilov ◽

Keyword(s):

Mathematical Modeling ◽

Energy Savings ◽

Rolling Stock ◽

Regenerative Braking ◽

Contact Network ◽

Electric Motors ◽

Electric Locomotive ◽

Power Circuit ◽

Electric Rolling Stock ◽

Train Speed

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.

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ELECTRIC LOSS IN RAILWAY CONTACT NETWORK AT AC ELECTRIC LOCOMOTIVE OPERATION

Bulletin of Bryansk state technical university ◽

10.30987/article_5d9317b307f835.52624411 ◽

2019 ◽

Vol 2019 (9) ◽

pp. 50-57

Author(s):

Юрий Кабалык ◽

Yuriy Kabalyk ◽

Сергей Шухарев ◽

Sergey Shuharev ◽

Денис Дроголов ◽

...

Keyword(s):

Power Consumption ◽

Power Efficiency ◽

Harmonic Distortion ◽

Contact Network ◽

Electric Locomotive ◽

Current Form ◽

Phase Alignment ◽

Traction Substations ◽

Definition Of ◽

Quantitative Definition

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.

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INCREASING THE ENERGY EFFICIENCY OF THE AC ELECTRIC LOKOMOTIVE TRACTION DRIVE

Collection of scientific works of the State University of Infrastructure and Technologies series Transport Systems and Technologies ◽

10.32703/2617-9040-2021-38-36-4 ◽

2021 ◽

Vol 1 (38) ◽

pp. 36-52

Author(s):

Y. Dubravin ◽

V. Tkachenko ◽

O. Spivak

Keyword(s):

Energy Efficiency ◽

Pulse Width ◽

Pulse Width Modulation ◽

Electromagnetic Energy ◽

Electric Locomotive ◽

Current Harmonics ◽

Electromagnetic Processes ◽

Traction Network ◽

Power Rate ◽

And Control

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.

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