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The subject of the research is the power thyristor converter of AC electric locomotives and its influence on the power factor of the locomotive. A new method for increasing the power factor of AC electric locomotives with thyristors power converters is proposed and analyzed. These electric locomotives include locomotives of the 2ES5K, VL85, EP1 series, etc. At the initial of the paper, the existing methods of increasing the power factor are briefly considered and their disadvantage in comparison with the proposed method is indicated. The drawback of existing converters is also analyzed, which consists in the presence of a thyristor opening delay at the beginning of the supply voltage half-cycle. The proposed method implies the modernization of the control circuits of the thyristors of the converter, due to which, at the beginning of the half-period, a control current is spontaneously created on the control electrode by means of the supply voltage. As a result, the thyristors open with a minimum delay after the start of the half-cycle. To verification the effectiveness of the proposed solutions, a computer simulation of the operation of the power circuit of an electric locomotive in the ORCAD program was carried out. Simulation was carried out for two options: a power circuit with standard converters and a power circuit with converters upgraded in accordance with the proposed method. During the simulation, the change in the value of the power factor of an electric locomotive was investigated at different currents of traction motors, zone and angle of regulation. Analysis of the oscillograms of converter various arms currents the revealed that when using the modernized converters, the moment of the end of the network switching occurs earlier than in the standard circuit. There is also no area with negative voltage at the output of the converter at the beginning of the half-cycle. At the end of the paper, the values of the electric locomotive power factor are given under various conditions. These results show that the use of the proposed method increases the power factor of an electric locomotive by an average of 1.2 percentage points.

The reasons of a case-type vibration in the frictionless bearings in the assembled machine are studied. The method of identification of the radial clearances in the bearings without disassembling is suggested on the basis of the conducted measurements and analysis. The algorithm of vibrational prognostication of operating conditions of the frictionless bearings in the locomotive traction motors is suggested and grounded

In this article, the authors have studied the electromagnetic processes of an inverter based on thyristors and IGBT transistors of an AC electric train in the regenerative braking mode. To accomplish this task, a method was used to compose instantaneous replacement schemes and systems of differential equations corresponding to a certain time interval of the rectified voltage diagram and the currents of the inverter arms. On the basis of the study were given the disadvantages of thyristor inverter and the advantages of transistor.

The article presents a method for determining the thyristor shoulders of the rectifier-inverter converter (inverter) of an electric locomotive, on which the control pulses are passed. The method is based on the analysis of the duration of the current switching of the thyristors of the inverter shoulders and the rate of rise of the rectified current in the inverter circuit of the electric locomotive. The implementation of the method is carried out by refining the software of the microprocessor control system of the electric locomotive. The simulation of electromagnetic processes of rectifier inverter Converter of AC locomotive series 3es5k "Ermak" in the mode of regenerative braking during emergency operation is carried out on the example of missing control pulses on thyristor shoulders VS2 and VS7. As a result of modeling, data are obtained that confirm the effectiveness of the method proposed by the authors

In the article suggests a changing the algorithm of the rectifier-inverter converter electric locomotive VL85. This will allow the individuallyto regulatevoltageon traction engines. In this case willpreserve a singlecentralized system ofcontrol of allelectricconverters. The proposed solutions may be used for liquidation started spinning of wheel locomotive. Tractive force the remaining wheelsets will not decrease.

This article presents the results of changes calculations in the energy efficiency indicators of the Moscow Central Ring, such as the specific consumption of electricity released for traction by trains of traction substation meters, specific recovery, technical losses of electricity in the traction power supply system when it is transferred to electric rolling stock, including technical recuperation energy loss, depending on various installation options of rectifier-inverter converters in traction substations part.

The purpose of this article is to analyze the voltage drop in the contact network caused by poor-quality operation of an alternating current electric locomotive when passing heavy trains. Heavy-haul traffic is considered today as a valid and necessary tool for increasing weight norms and increasing the throughput of railway sections. The article provides statistics on the passage of heavy and connected trains on the Krasnoyarsk railway for 2019 and 2020. For the effective use of heavy traffic, it is necessary to solve a number of problems, one of which is to reduce the voltage in the overhead network when passing heavy trains, this negatively affects the speed of the train along the haul, the conditions for cooling the power equipment of the electric locomotive deteriorate, etc. As a result of the analysis of the operation of the thyristor rectifier-inverter converter, a number of disadvantages were revealed. The reason for the low power factor of the electric locomotive lies in the use of an outdated element base based on thyristors, their closure is carried out only in the next voltage half-cycle, long-term switching and a large opening angle of thyristors leads to a significant reactive current in the contact network. Based on the analysis the voltage losses at the current collector, it was concluded that it is necessary to reduce the duration of the switching process of the arms of the rectifier-inverter converter, in which a short circuit occurs in the secondary winding of the traction transformer. An alternative version of the converter based on fully controlled semiconductor devices - IGBT transistors is proposed. The ability to open and close at any time of such elements allows you to minimize the phase angle and increase the power factor. Due to the almost instantaneous switching of transistors, the distortion in the contact network is minimized.

An urgent issue is to increase the power factor of electric rolling stock. One of the ways to increase the power factor in the traction and regenerative braking modes was proposed by the scientists of IrGUPS - this is the use of a rectifier-inverter converter on IGBT with modified control algorithms. This solution allows to significantly reduce the consumption of reactive current from the contact network, increase the capacity of railway sections, increase the technical speed, increase the efficiency of the traction power supply system, and also increase the amount of electricity returned to the contact network in the regenerative braking mode. The study of the performance of this converter is of interest. The transported volumes of goods on the railway lines of the Russian Federation continue to increase. One of the key links in ensuring the specified growth rates of tonne-kilometer work is the availability of powerful traction rolling stock equipped with an appropriate traction drive. A powerful traction drive is characterized by the consumption of significant current. To ensure its flow over the arms of the converter, a parallel connection of power semiconductor devices is used. For modern converters of electric locomotives, 4 parallel branches of power switches are used in the arm. The features of the parallel operation of the arm branches affect the performance of the converter on IGBT transistors. This article proposes to consider one of these features, namely the influence of parasitic inductances on the distribution of currents in the parallel branches of the converter, depending on the connection point of the AC power bus. The study was carried out using the Matlab Simulink software package. The article discusses various options for the topology of connecting power buses and presents diagrams of the distribution of currents in the parallel branches of the arm for each connection method. An assessment was made of such parameters as the spread of the peak current of switching on the branches of the arm, the time of current equalization during the conduction period, and the difference in the magnitude of the current in specific branches. Based on the results of the study, as well as taking into account the existing dimensions for the equipment of AC electric locomotives, a conclusion was made about the most optimal option for connecting power buses.

The paper deals with benefits of a new rectifier-inverter converter of an electric locomotive based on IGBT-transistors. Main directions of heavy haul traffic's development are considered for Siberia and Russian Far East electrified railways. Throughput and carrying capacity of power supply devices extremely depends on the voltage level in the catenary network of electrified sections of railways. Objects of our research are electric parameters of the 25 kV, 50 Hz AC traction power supply system. Operation parameters of two different types of the electric locomotive’s rectifier-inverter converters are calculated and discussed. We investigated operation parameters for thyristor-based and IGBT-transistors- based rectifier-inverter converter. Current and voltage curves for the thyristor and the transistor type of the rectifier-inverter converter are given and discussed. Similarity factor of current curves for electric locomotives was calculated by equivalent sinusoid’s .method. Quantitative assessment of the voltage level, currents and voltage losses in the AC catenary network is given. The graph-analytical method was used for constructing currents and voltages vector diagrams. It is proved that electric locomotives with a new rectifier-inverter conversion based on IGBT transistors provides a reducing of the total voltage losses in three times in the traction network comparing the thyristor conversion's operation.