Browsing by Author "Yashchuk, Kateryna I."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Investigation of Train Shunt Problem in Track Circuits of Signalling and Interlocking Devices(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Razgonov, Adam P.; Zhuravlov, Anton Yu.; Yashchuk, Kateryna I.; Shcheka, Vadym I.EN: Abstract. The problems of electric track circuits calculating were investigated in the works of various authors, it is noted that there is no complete clarity on the definition of shunt resistance. The value of the calculated train shunt resistance in many respects affects the area of signaling systems rail channel stable operation and train traffic safety. It is relevant to study the possibilities of changing the standard value of and the conditions for the execution of track circuits shunt mode, especially for sections of railway with low resistance insulation of the rail line. The surface area of the “wheel-rail” skating, taking into account the different conditions of interaction dynamics and wear of rails and wheel elements were obtained in article. It is shown that the reduction of the normative value of the resistance of the train shunt is appropriate for signaling systems, especially for sections of railway with low resistance insulation of the rail line. An approximate estimate of the geometric parameters of the membrane that forms on the “wheelrail” surface is obtained; proposed a more complete electrical replacing scheme for the train shunt circuit, which allows analyzing the influence of the circuit elements parameters values and the frequency of the signal current. A method for calculating the correlation dependence of the train shunt resistance from wheel-rail surface membrane parameters is proposed.Item Potentials Railwise Propagation Study(Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Dnipro, 2017) Yashchuk, Kateryna I.EN: Purpose. The article deals with conducting the study of the potentials and currents propagation along the rails to evaluate the potential difference and the current asymmetry in the rails that may have an impact on the work of railway automatics and supervisory systems. Methodology. To compass the purpose, the author applies methods of analysis and synthesis of track circuit electrical engineering calculations, mathematical modeling and methods of homogeneous and heterogeneous ladder circuits. Findings. The conducted theoretical studies indicate that in the mountainous sections of DC traction railways there are very high-level currents, whereby even at nominal asymmetry ratio the asymmetry current will be unacceptably high. The re-equipment of running line with the automatic blocking system with tonal rail circuits resulted in reduction of the number of impedance bonds, the equalizing functions of which required further advanced research, that allowed obtaining the potential railwise propagation curves when installing the impedance bonds every 6 and 5 km. The resulting potential difference was too high for railway automation systems, so the potential propagation study was conducted with impedance bonds placed every 3 and 3.5 km, which greatly improved the operation conditions of track circuits. Originality. The proposed method for calculating the propagation of potentials and currents in the rail network of DC traction line is characterized by the representation of the common ladder circuit of each rail as a series of T-shaped four-poles connected in cascade, taking into account the grounding of the contact-line supports on the nearer rail. It has allowed estimating the levels of asymmetry currents that branch into the equipment of track circuits and have a negative impact on their operation. Practical value. The obtained results can be used in designing and re-equipping the running lines with new railway automatics and supervisory systems, as well as for evaluating the influence of high asymmetry currents on the railway automation systems operation.