Search results

Considered the features of modern automatic control systems of pantographs. The spectral density analysis of pantograph contact force at high speeds showed requirements for robust control systems, which allows to significantly improve the quality of the current collection. Proposed the ways to improve the automatic control systems for pantographs, aimed at improving the speed and reducing the inertia of the system.

A variant of application of a contact compensated chain suspension with levers and lateral current collection for a three-phase traction power supply system (TSTE) is considered. Two different-phase contact suspensions are located on different sides of the track axis. The electric rolling stock must have two current collectors that press on the contact wire from the track axis in opposite directions. The description of the design of the contact suspension as a whole and the main components, in particular, the fastening of the rods, which makes it possible to provide a vertical zigzag and limit the transverse movement of the contact wire, is made. At points at the supports, the levers are connected to the consoles and have a knot to create angular rigidity. In addition, the rotation of these levers is limited towards the axis of the path and in the opposite direction. This prevents the possibility of lashing of different-phase contact wires. In accordance with this design, a mathematical model of this contact suspension was developed based on the finite element method, which provides calculation in statics and dynamics, taking into account the current collector. To describe the pantograph, a common three-mass model is used. Based on the analysis of the results obtained using this model, the influence of the design parameters of the suspension, cross wind and the speed of the pantograph movement on the quality of the current collection is determined, the limits of applicability of the suspension under consideration, depending on the value of these parameters, are established. It has been determined that, in contrast to a conventional contact suspension with a vertical current collection, for suspensions with a lateral current collection, a side wind has a significant effect on the quality of the current collection. It is the wind speed that is the main factor limiting the possibility of using a suspension with lateral current collection.

The article presents a method of calculation of the thermal state of the pantograph head. The density of the suspension zigzag distribution, taking into account a number of assumptions, has replaced the contact wire position function in the plan. Results of calculating the temperature of the pantograph head at different width of the zigzag of the typical suspension, including zero, are presented. The influence of sinusoidal and tangential contact suspensions on the temperature distribution of the pantograph head is estimated.

In article advanced techniques of laboratory and natural aerodynamic researches of a pantograph and its elements are considered. It is specified that carrying out modeling by means of computational fluid dynamics methods doesn't allow to replace pilot studies completely now. Need of correction of the received results because of influence of change of density of the environment during experimental studies locates. Density of the environment is offered to consider it as an integrated indicator. The main methods of measurement of density of the environment are given, their advantages and shortcomings are listed. The conclusion is drawn that it is most expedient to use ultrasonic measuring instruments to control of an indicator of density. The principle of operation of these measuring instruments is described. The example of use of an advanced technique of laboratory researches of the aerodynamic device for regulation of force of contact pressing of a current collector is given. Researches were conducted for device wing angles of rotation from zero to fifteen degrees with an interval of five degrees. After that aerodynamic characteristics of a wing of the aerodynamic device were under construction and comparison to results of modeling was carried out by means of a computing hydraulic gas dynamics them. The results received in OSTU laboratory well were correlated with results of computational fluid dynamics modeling that testified to adequacy of the applied technique.

The article is devoted to the improvement of the testing method of current collectors of electric rolling stock considering collision efforts from the overhead catenary. The article discusses the features of collision effects on pantographs of electric rolling stock at high speeds. An analysis of the existing methods for testing collision effects on pantographs in laboratory installations and in linear conditions has been carried out. The analysis is carried out and the drawbacks of the percussion pendulum installation for testing current collectors, described in GOST 32204-2013, are identified, and its characteristics are calculated. The design of a shock stand with smaller dimensions and expanded functionality is proposed, and its parameters and characteristics are calculated. When calculating the characteristics of the test bench, mathematical and computer modeling was applied using the MATLAB Simulink environment. The method of bench collision testing using accelerometers and high-speed video camera. It was established that the proposed test bench retains the full functionality of the test facility regulated by GOST, while having smaller dimensions and wider functionality.

The article provides for the design features of pantographs of an electric drive train, a system of movable frames, which are made in the form of two articulated rod-type levers. Single-lever pantographs are distinguished by improved mass-dimensional indicators, which allows them to be used in the cramped conditions of the roof space of two-system electric locomotives. This requires high mechanical characteristics, as well as the need to use structural materials of increased strength, precision processing methods and high precision during assembly. It becomes especially important to control the transverse and advanced cruelty of the moving frame system during research, periodic and qualification tests, as well as during operation. The article describes a methodology that allows conducting research with a high degree of labor intensity, increasing the speed of measurements, and reducing the influence of the human factor.

The contact line is a special kind of power overhead line with multiple electrical connections of wires, which form a complex topology of the linear electrical circuit. Analytical models simplify the real topology of the contact line and it limits their functional application. It is possible to take into account the topology of contact line when using tools of computer simulation, but it entails complicating the computational algorithms of the model. The aim of this article is to determine the conditions for the application of current distribution models and the development prospects in this area. The article describes the existing models for calculating the current distribution in DC contact line: a model of natural current distribution, linear analytical models, model with an infinite number of droppers, a model with a direct application of Kirchhoff's circuit laws in matrix form, and a finite element model. The article contains the main provisions and calculation capabilities of each model. Contact line KS-250-3 acts as a calculation catenary for the comparison of current distribution models. You can use the results of the article to select the optimal design distribution model for the design of the contact line, thermal analysis, current-carrying capacity calculation, identification and elimination of «weak point».

In general, improvement of methods for electrical calculations aimed at increasing the accuracy of the results. One of the ways to improve the methods of calculation is the account in the calculation of the various factors that affect the accuracy of calculation of the traction power system parameters. This article describes an approach aimed at improving the method of calculation in the electrical part to improve the accuracy by changing the algorithm for calculating and accounting for a number of additional factors.

The article considers the processes of current collection in the system of AC electric traction in high-speed traffic. The existing devices of pantograph and catenary interacting by means of a sliding electrical contact are presented. The comparison of solutions with different horizontal geometry of the contact wire, which affects the speed of the lateral displacement of the contact wire at the catenary supports relative to the axis of the railway track, is given. It is shown that the speed at which the contact point moves along the pantograph strip is also important for assessing the wear of the sliding contact, as is the span length of the catenary supports, the curvature of the track and the speed of the train in the span limits. For the synthesis and analysis of the pair "pantograph strip - contact wire" with a sliding contact, a model for calculating the contact surface is obtained and the energy processes leading to wear of the components of the current collection system are considered. The results of modeling the interaction of the pantograph and the catenary with various variants of the zigzag arrangement of the contact wire are obtained. When implementing a technical solution in areas with high-speed traffic, the preferred method proposed in the article is the arrangement of the contact wire of a chain suspension with a zigzag period increased by two times compared to the traditional one. This solution provides a reduction in the speed of lateral displacement and increases the dynamic stability of the pantograph, reduces the cyclic load on the supporting and supporting structures of the catenary and increases the life of the contacting elements of the current collection system during high-speed traffic.

The article presents an improved mathematical model of the thermal state of the pantograph head for calculating the temperature distribution when interacting with different catenary with a double contact wire. The model takes into account the unevenness of the pantograph contact pressure on the wires along the suspension span and between them, allows using the databases of the car-laboratory for testing the contact network, calculating the thermal conditions of the skid on various sections of electrified Railways, including transients between them. The paper presents graphs of the zigzag distribution density of the contact wire of the Moscow - Saint Petersburg high-speed line, and defines the transient and steady state thermal states of the pantograph head when the pantograph interacts with them.

The article describes the design of a universal measuring pantograph, designed to obtain during the test trips sets of accurate and adequate information on the quality of current collection due to the possibility of modeling parameters and characteristics of advanced domestic and foreign current collectors, mounted on a modern electric rolling stock. Presented the results of his testing at the West-Siberian railway.

A mathematical model of thermal processes (dynamic) contact current collector with contact suspension (in motion), which allows to estimate the temperature distribution of heating the current collector during movement. The experimental evaluation of the proposed cooling device performance is given. The thermal model of the current collector in motion mode has been verified.

The actual process of interaction of pantograph with catenary associated with random processes. The main factors affecting the pantograph are vibrations of the rolling stock, aerodynamic, the instability of the dynamic properties of the pantograph and overhead catenary, etc. In view of the plurality of influencing the current collection of factors theoretically investigate the dynamical system "Pantograph - catenary" in full It is a complex task. A more rational to theoretical studies and sufficient for practical use is to consider deterministic processes. In the numerical simulation of the current collectors are the most common types of the following design schemes (models): lumped mass pantograph model; pantograph multibody schematics; pantograph multibody schematics in CAD-systems, which describe in detail the geometric dimensions and physical properties of each element of the pantograph. In the design of the pantographs is an integral part of the calculation of interaction of pantograph with contact suspension. Contact suspension counted in the calculations in the form of a concentrated mass interacting with the pantograph skid or a spatial system composed of resilient elements of finite length (catenary with distributed parameters). The second type of catenary model is used in the interaction with the first two types of models considered by the current collectors. Based on the features of each of the presented kinds of models, present the technique of the pantograph model selection, depending on the purpose of the simulation.

Resistive heating of the pantograph head due to the flow of traction current through the conductive elements of the upper node, has an uneven distribution along the frame structure and depends on the location of the contact wire on the insert. The aim of the work is to develop a mathematical model for calculating power losses in the pantograph panhead, allowing to estimate its value, taking into account the zigzag of the contact wire during the movement of electric rolling stock. The subject of the study is the pantograph panhead. The paper gives an example of calculating the frame skid of a pantograph equipped with carbon strips. Experimental studies of the current distribution over the shunts of the panhead depending on the position of the contact wire were carried out in February 2021 in the laboratory "Designs of contact networks, power lines and current collection devices" using a complex for testing current collection devices. The calculation of the heating power of the panhead is determined by the Joule-Lenz law. The results of the calculation showed that the maximum heating power is observed when the contact wire is in the middle of the panhead, while the places of the greatest losses located along its edges are above the places where the shunts are attached. The model makes it possible to obtain a functional dependence of the heating value along the panhead. The obtained results of the skid heating power distribution make it possible to supplement the complex model of the thermal state of the pantograph developed at the Omsk State Transport University with the participation of the authors of the article. The versatility of the developed model makes it possible to investigate various zigzags of the contact wire and evaluate the effect on the distribution of traction current along the panhead, depending on the location of the shunts and their number.