Search results

The experience of the railways electrification in Russia and the justification of the current type choice for the electrification of the Ulan-Bator Railway are considered. The calculation of the maximum mass of the wagons of freight trains of an AC electric locomotive of 2ES5K and an electric locomotive of direct current 2ES6 in the conditions of the Ulan Bator Railway is performed. The rationale for choosing the kind of current for the electrification of the Ulan Bator railway is presented.

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.

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 The reason for the low power factor of the electric locomotive lies in the use of an outdated element base based on thyristors, their closure is carried out only in the next voltage half-cycle, long-term switching and a large opening angle of thyristors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.

The analysis of wave processes in the system including electric transmission lines, traction substations, AC traction network and electriclocomotives is necessary to accurately assess to energy performance of its work. This system contains concentrated and distributed parameters, consequently the analysis of such a system is difficult and the rolling stock which is also a part of this system represents a dynamic load. The proposed mathematical model of the alternating current traction power supply system allows us to consider electromagnetic processes at its various points taking into account wave processes.

The article considers an approach that allows to reduce the asymmetry of consumed currents by traction substations of railways from a three-phase power supply system using a compensating device with an asymmetric structure installed at the substation. Reactive currents of the compensating device allow to redistribute between phases of the traction transformer active and reactive power of asymmetric traction load and to receive symmetric load of three-phase power supply system. The theorem is proposed to determine the conductivities and reactive currents of the branches of a compensating device with an asymmetric structure depending on the traction loads. The article presents the calculated expressions, which can be used to calculate the conductivity and reactive currents of the branches of the compensating device for any traction load of the feeders, in which the equivalent load, including the reactive currents of the branches of the device and the currents of the feeder zones will be symmetrical and active. As an example of the application of the theorem and the proposed expressions, a test problem is presented in which the secondary winding of a traction transformer with asymmetric traction load of feeders is considered, the conductivity of the branches of the device is calculated. With the use of vector diagrams shows the receipt of a symmetrical system of currents of the secondary winding of the traction transformer. Mathematical expressions allowing to realize the necessary law of regulation of reactive currents of the device are given. The necessary ranges control of reactive currents of the compensating device on traction substation on the set probabilistic laws of change of traction loadings are defined. Various options for the practical implementation of a compensating device that will provide the necessary inductive or capacitive current of each branch are considered.