Fault Location Estimation Technique for AC Railway Power Supply System Considering of the Other Line’s AT Boosting Current Characteristics

2019 ◽  
Vol 68 (11) ◽  
pp. 1482-1488
Author(s):  
Hosung Jung ◽  
Joo-Uk Kim ◽  
Hyungchul Kim ◽  
Myung-Hwan Min ◽  
Tae-Pung An
2014 ◽  
Vol 556-562 ◽  
pp. 2008-2012 ◽  
Author(s):  
Jian Bao Liu ◽  
Le Ping Bu ◽  
Xin Xin Qin

When main discharge switch is put in discharging course of pulsed power supply in stored energy capacitor branch, the stored energy capacitor may have reverse charging phenomenon. Because of unilateral conductivity of the main discharge switch, the reverse voltage cannot be released and this would adversely affect service life of the stored energy capacitor and reduce working efficiency of the pulsed power supply. Through detailed deducing the discharging course of stored energy capacitor in pulsed power supply system, this paper analyzed relative factors affecting reverse charging voltage of stored energy capacitor and discussed necessary means that could reduce reverse charging voltage of stored energy capacitor. Based on this, a circuit structure with the main discharge switch in load branch is proposed and release of reverse charging voltage of stored energy capacitor is realized without affecting discharge current characteristics of the load. Simulation and test results show that the load current characteristics of the pulsed power supply after adjusting location of the discharge switch is basically the same as before the adjustment is made and completely meet requirement of electromagnetic emission. As a result, timely release of the reverse voltage extended working life of the stored energy capacitor and also improved efficiency of the electromagnetic emission system.


2020 ◽  
Vol 79 (3) ◽  
pp. 139-144
Author(s):  
E. P. Figurnov ◽  
Yu. I. Zharkov ◽  
N. A. Popova

When calculating short circuit currents in the traction network, it is necessary to take into account the input resistance of the traction substation, including the resistance of the transformers of the substation and the resistance of the power supply system. The input resistance during short circuit is determined based on the equivalent circuit of the external power supply system, of which this traction substation is an integral part. Traditionally equivalent circuit of a three-phase system has the form of a star, in which the resulting resistances in each phase are connected in series with a source of phase electromotive force, and these sources have a common point. Another equivalent circuit in the form of a triangle is possible, in which on each side the resulting resistances are connected in series with the source of linear electromotive force. It is important to note that neither one nor the other type of equivalent circuit is determined by the connection scheme of the transformer windings of the traction substation. It is only necessary to take into account the absence of a circuit for zero sequence currents. All elements of the equivalent circuit, as is known, should be brought to uniform basic conditions. If the parameters of these elements are expressed in named units, then the basic values are the effective voltage values of the main stage and the rated power of the power transformer of the traction substation. If the components of one and the other equivalent circuits are reduced to one stage of the operating voltage, for example 27.5 kV, then for the same elements of the power supply system, the resistance values in the equivalent circuit in the form of a triangle are three times larger than in the equivalent circuit in the form of a star. In this case, the input resistances of the traction substation for the one and the other equivalent circuits are absolutely identical. Therefore, in the calculation of short circuit currents of the traction network, you can use any of these equivalent circuits of the power supply system and traction substation. Formulas for calculating the resistances of the elements of the power supply system and electrical installations, given in the standards, manuals and reference books, relate to the equivalent circuit of the short circuit in the form of a star. When using an equivalent circuit in the form of a triangle, these resistances must first be tripled, and then divided by three when calculating the short-circuit currents. The meaninglessness of such an operation is obvious. The equivalent circuit of the traction substation and the external power supply system in the form of a triangle when calculating short circuits in the traction network has no advantages compared to the traditional equivalent circuit in the form of a star. The information on the linear currents on the primary and secondary windings of the traction substation transformer during a short circuit in the traction network is given, which is necessary to select the settings of its relay protection kit.


2019 ◽  
Vol 68 (2) ◽  
pp. 165-175
Author(s):  
Przemysław Duer ◽  
Stanisław Duer ◽  
Paweł Wrzesień

The article presents the problems of building a damage location program in a technical facility based on the theory of the “decision tree”. The basis in such a decision-making process is the functional and diagnostic analysis of the tested technical device. The result of this analysis process is a set of basic (functional) elements with a set of weighting factors assigned to them. An algorithm of fault location is developed in the theory of the “decision tree” in the process of locating faults in the tested vehicle power supply system. Keywords: technical diagnostics, diagnostic reasoning, artificial intelligence.


2014 ◽  
Vol 577 ◽  
pp. 572-575
Author(s):  
Lei Tian ◽  
Yuan Hong ◽  
Wen Yuan Li ◽  
Qing Feng Zhang

Management of power supply reliability is not only the quality management of equipment and power supply system, but also the safety management of equipment’s operation and power supply system’s maintenance. In order to analysis the reliability of 10kV distribution grid, on the one hand, this paper analyzed the structure characteristics of 10kV distribution grid and four kinds of wiring patterns, which were the main parts of 10kV distribution grid. On the other hand, it pointed out the reasons, which affected the distribution grid’s reliability and discussed the ways to improve the 10kV distribution grid’s reliability.


2019 ◽  
Vol 2 (1) ◽  
pp. 8-16 ◽  
Author(s):  
P. A. Khlyupin ◽  
G. N. Ispulaeva

Introduction: The co-authors provide an overview of the main types of wind turbines and power generators installed into wind energy devices, as well as advanced technological solutions. The co-authors have identified the principal strengths and weaknesses of existing wind power generators, if applied as alternative energy sources. The co-authors have proven the need to develop an algorithm for the selection of a wind generator-based autonomous power supply system in the course of designing windmill farms in Russia. Methods: The co-authors have analyzed several types of wind turbines and power generators. Results and discussions: The algorithm for the selection of a wind generator-based autonomous power supply system is presented as a first approximation. Conclusion: The emerging algorithm enables designers to develop an effective wind generator-based autonomous power supply system.


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