The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.
The paper considers the possibility to use KS-400 high-speed catenary suspension for direct current traction systems with increased voltage of 12, 18 and 24 kV. It also presents the temperature of catenary wires at tractive rolling stock passing with maximum possible current. It is established that the passage of a current collector under the worst conditions of heat release is insignificant for catenary wires even at a voltage of 12 kV. According to the results of calculations at voltage of 12 kV and 18 kV, the current collector is the limiting element in the standby and traction modes with maximum current.
The paper presents a mathematical model that describes interaction of a current collector of high-speed rolling stock and catenary suspension in various conditions of operation such as rolling stock speed, current collector opening height, wear rate of current collection plates, ambient temperature, wind and glaze. The authors have determined limits of permissible operation according to quality of current collection, have established parameters of climatic and technogenic factors at which it is necessary to restrict speed on high-speed lines according to conditions of current collection. Results of the study can be used at development and production of domestic high-speed current collectors and catenary suspensions and at adaptation of import models for operation in Russia.
The manufacture of current transformers is associated with many design constraints, which include the restricted dimensions of its installation places, requirements for the accuracy class, as well as the limitation on the safety factor or the minimum factor of the accuracy limit factor. In a design sense of current transformers, these requirements are contradictory, which resulting in a flexible approach to the manufacture of current transformers. The use of combined magnetic cores can be referred to one of these areas, in other words magnetic cores consisting of materials with different magnetic properties, which allows to obtain unique magnetic properties that are inaccessible when using magnetic cores of the same type (material), thus providing a rational model of production. The article presents a feature of calculating of current transformer with combined magnetic cores.
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