Factors Causing Unreliable Accounting of Electricity Consumption on the Electrified Transport “Two Wires-Rail” Longitudinal Power Supply Lines

2021 ◽  
pp. 67-72
Author(s):  
Elena Yu. SEMENOVA ◽  
Keyword(s):  
Power Supply ◽  
Electromagnetic Compatibility ◽  
Power Supply System ◽  
Electricity Consumption ◽  
Contact System ◽  
Centralized Control ◽  
Power Capacity ◽  
Traction Substation ◽  
Almost All ◽  
Different Levels

As is known, the “two wires–rail” power supply system (TWR line) does not meet the modern electromagnetic compatibility requirements, which is a factor causing increased damageability of alarming, centralized control and interlocking devices, as well as other non-traction electric power consumers. In addition, there often occur unexplained differences (unbalance) in the accounting of electricity received by end users and consumed by the TWR line at a traction substation. The accomplished studies have shown that in almost all sections of the network, the actual electricity consumption is significantly lower than that recorded by the TWR line metering devices. The discrepancy in the readings could be explained by unauthorized taps of electricity. However, such a statement will be superficial. The article considers the real factors causing the unbalance in accounting the electricity consumed on the TWR line, which are explained by the magnetic influence of the contact system. An equivalent circuit of the contact system magnetic influence on the TWR line is presented for any configuration of the section with different placements of self-contained transformer substations at different levels of their power capacity. The magnetic influence of the contact system on the TWR line is illustrated by a phasor diagram.

Improvement of grounding system of DC traction substation in railway power supply system

2012 ◽  
Author(s):  
Hitoshi Hayashiya ◽  
Norio Koguchi ◽  
Hiroshi Yamamoto ◽  
Takashi Ozaki ◽  
Takashi Sakurai ◽  
...  
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Supply System ◽  
Grounding System ◽  
Traction Substation

Transient Responses in Continuous Co-Phase Traction Power Supply System

2014 ◽  
Vol 1006-1007 ◽  
pp. 955-961
Author(s):  
Xing Wang Li ◽  
Ju Rui Yang
Keyword(s):  
Contact Line ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Supply System ◽  
Transient Responses ◽  
Traction Substation ◽  
Traction Power Supply System ◽  
Traction Power Supply ◽  
Traction Power

Continuous co-phase traction power supply system is the major change of the traction power supply. It is important to analyze the transient response characteristics of overhead contact line for the traction substation feeder protection. This article introduces the main structure of continuous co-phase traction power supply system and the control strategy of traction substation. Meanwhile, transient responses of overhead contact line in the earth short circuit are studied, including metallic earth short circuit and non-metallic earth short circuit (high resistance ground). In the PSCAD/EMTDC electromagnetic transient simulation environment, the effects on the system and the recovery process are studied which the fault occurred in the output interface of traction substation and occurred in overhead contact line.

scholarly journals Choosing the type of equivalent circuit of traction substation when calculating short-circuit currents in 25 kV power supply system

2020 ◽  
Vol 79 (3) ◽  
pp. 139-144
Author(s):  
E. P. Figurnov ◽  
Yu. I. Zharkov ◽  
N. A. Popova
Keyword(s):  
Equivalent Circuit ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Supply System ◽  
The Other ◽  
Equivalent Circuits ◽  
Traction Substation ◽  
Traction Network ◽  
Short Circuit Currents

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.

scholarly journals Measurement of currents and voltages non-sinusoidal parameters in power supply systems with rectifier load

2018 ◽  
Vol 245 ◽  
pp. 06007 ◽  
Author(s):  
Valery Vanin ◽  
Alexandr Bulychov ◽  
Maxim Popov ◽  
Olga Vasilyeva ◽  
Maria Shakhova
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Negative Impact ◽  
Supply System ◽  
Municipal Services ◽  
Quality Indices ◽  
Electric Drives ◽  
Traction Substation ◽  
Railway Traction ◽  
Supply Systems

The use of frequency-controlled electric drives in industry and municipal services is accompanied by the problem of their negative impact on the distribution network. As examples, the results of measurements of power quality indices in the power supply system of an oil producing enterprise and on the supply input of a railway traction substation are given. It is shown that the voltage subgroup total harmonic distortions (THDS) can exceed their rated permitted values in 100% of the measurement time.

scholarly journals Diversification of energy supply to the agricultural sector in the conditions of Uzbekistan

2021 ◽  
Vol 264 ◽  
pp. 04022
Author(s):  
Abdujolol Bokiev ◽  
Nodira Nuralieva ◽  
Sanjarbek Sultonov ◽  
Abror Botirov ◽  
Urolboy Kholiknazarov
Keyword(s):  
Energy Balance ◽  
Power Supply ◽  
Power Supply System ◽  
Energy Use ◽  
Systematic Approach ◽  
Agricultural Sector ◽  
Electricity Consumption ◽  
Supply System ◽  
Fruit And Vegetable ◽  
Mobile Methods

At present, the power supply system of the agricultural sector consists only of centralized networks. There are no autonomous-stationary and mobile methods of supply. The current situation of energy consumption in horticulture, such as Beruni district, Karakalpakstan, and further diversification, is analyzed. A systematic approach is applied to the analysis of electrical installations and energy use during agricultural processes, and the corresponding calculation and analytical methods are used to ensure sufficient reliability of the results obtained. The energy balance is compiled in the context of agrotechnical and production processes in fruit and vegetable growing. The issues of central, local, and mobile power supply are studied based on the corresponding energy balance and schedules of electricity consumption. Economic experiments were carried out on a prototype of a mobile power plant “Sun-Wind,” with a capacity of 4.5-4.7 kW·h (in the daytime), 0.8-1.0 kW·h (in the evening). Based on the results obtained, the current and prospective ratios of all three power supply methods are justified. Based on the research results, a system of diversified electricity supply for fruit and vegetable farms was developed and proposed.

scholarly journals Improvement of electromagnetic compatibility and efficiency of power supply circuits of electric arc furnaces in nonlinear asymmetric modes

2021 ◽  
Vol 5 (8 (113)) ◽  
pp. 6-16
Author(s):  
Volodymyr Turkovskyi ◽  
Anton Malinovskyi ◽  
Andrii Muzychak ◽  
Оlexandr Turkovskyi
Keyword(s):  
Power Supply ◽  
Electromagnetic Compatibility ◽  
Power Supply System ◽  
Electric Arc ◽  
Supply System ◽  
Constant Current ◽  
Published Data ◽  
Sinusoidal Voltage ◽  
Electric Arc Furnaces ◽  
Arc Furnaces

AC steel arc furnaces are the most powerful units connected to the electrical grid, the operating mode of which is dynamic, asymmetrical and non-linear. That is why these furnaces cause the entire possible range of negative effects on the quality of electricity in the grid, in particular, fluctuations, asymmetry and non-sinusoidal voltage.Known proposals for improving the electromagnetic compatibility of electric arc furnaces are mainly focused on eliminating the consequences of their ne­gative impact on the power grid.The proposed approach and the corresponding technical solution are aimed at reducing the level of generation of a negative factor and at the same time reduce fluctuations, asymmetry and non-sinusoidal voltage. This result is obtained due to the fact that the proposed solution takes into account the peculiari­ties of the range of modes natural for arc furnaces. Optimal for such consumers is the use of a constant current power supply system I=const in the range of modes from operational short circuit to maximum load and the system U=const in the whole other range of modes. The implementation of such a system is carried out on the basis of a resonant converter «constant current – constant voltage».Studies have found that the use of such a power supply system, in comparison with the traditional circuit, makes it possible to reduce the non-sinusoidal voltage in a low-power grid from 3.2 % to 2.1 % and the unbalance coefficient from 3.66 to 1.35 %. Previously published data on a significant reduction in voltage fluctuations was also confirmed.The positive effect of such a system on the energy performance of the furnace itself is shown, manifes­ted in an increase in the arc power by 12.5 %, and the electrical efficiency by 5.1 %. This improves the productivity and efficiency of electric arc furnaces

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