Search results

The article discusses the causes of freight train breakage, which occur due to a number of reasons, but one of the main ones is a sudden transition from a compressed state to a stretched one. This becomes possible due to a malfunction of the braking system (leaks, blockage of the calibrated air distributor openings) and, of course, the train control technology. Train control technology depends on the characteristics of the traction and braking systems of the rolling stock, as well as on the experience and skill of the driver in difficult track conditions. The dependence of breaks on the season has been established due to the frequent jamming of the wheelset and a decrease in the strength characteristics of the metal of the coupling. In this regard, it is important to solve the problems of train dynamics to determine the rational methods of train driving. The existing methods of model construction are considered. The results of studies of the longitudinal dynamics of a train based on a discrete model are presented. The calculation was performed for two modes: braking and traction, in the time domain, for which the forces acting on wagons and locomotives were determined in advance, depending either on time (traction and braking force) or on the speed of movement (drag force). As a result of mathematical modeling, the values of displacement and speed for each wagon with a multiple of five were obtained. An analysis of the results showed that significant longitudinal forces occur in the middle of the train during braking. The resulting model allows us to study the forces acting on trains with empty wagons, which require relatively minor forces to squeeze out of the train.

Rational way to improve the operational efficiency of the locomotive is adjustable power.The implementation of this method possible with the use of automatic power regulation implementing the optimal load,the operation mode of the traction and energy unit (TEU) of the locomotive. The aim of this work is to obtain mathematical relationships,establishing the optimal ratio between the number of employees of TD given thrust and speed. Determination of the optimal ratio being in the traction motors is based on finding the minimum power losses at the nodes of the TEU. Search the minimum of complex functions is an optimization problem,which from a mathematical point of view is to determine the minimum of function of several variables with a number of constraints,and relationships. To solve the problem of finding the minimum of a complex function,we used the method of indeterminate Lagrange multipliers. The optimization process is considered at a constant value of the voltage supplied to the TD and sold power.Variables - the force of traction,speed of movement,the ratio of incremental losses,the resistance of the circuit of the armature of TD was assumed constant,which allowed to simplify the solution of the problem,reducing it to find three unknown quantities - current,the number of TD and magnetic flux. The solution to this system of equations for the number TD,participating in the work were obtained analytical dependences the optimum values of the TD depending on the speed,the thrust force on the rim of the driving wheels of the locomotive and tension. Analytical expressions for determining optimal parameters of power regulation of electric DC,allow to obtain the optimal values of the number of workers so and the load depending on the given values of thrust and speed in the entire range of load modes of EPS. The analytical expressions can be used when drawing up regime maps and energy performance certificates EPS,and also in the most important automatic devices of power control of the rolling stock to set the optimal ratio of number of employees and so on.