scholarly journals A Novel Diagnosis and Location Method of Short-Circuit Grounding High-Impedance Fault for a Mesh Topology Constant Current Remote Power Supply System in Cabled Underwater Information Networks

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 121457-121471 ◽  
Author(s):  
Zheng Zhang ◽  
Xuejun Zhou ◽  
Xichen Wang ◽  
Lei Wang
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Supply System ◽  
Information Networks ◽  
Constant Current ◽  
Location Method ◽  
Mesh Topology ◽  
High Impedance ◽  
High Impedance Fault

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 Accounting power supply schemes for traction substations in the calculation of short circuits in the AC traction network

2019 ◽  
Vol 78 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Yu. I. Zharkov ◽  
N. A. Popova ◽  
E. P. Figurnov
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Supply System ◽  
Power Sources ◽  
Traction Network ◽  
Traction Substations ◽  
External Power ◽  
External Power Supply

When calculating short-circuit currents in the AC traction network, it is assumed that each of the traction substations receives power from uncoupled external power supply sources with known resistances. In some cases, especially when powering a group of traction substations from a high-voltage power line of a longitudinal power supply, the external power supply system affects not only the magnitude of short-circuit currents, but also their redistribution between adjacent traction substations of the interstation area where this circuit is considered. Such unrecorded redistribution can have a negative effect on short circuit protection. The article considers the equivalent circuit of the traction network, taking into account resistance of the external power supply system. Particular attention is paid to the fact that in replacement circuits of direct and negative sequence value of reduced resistance of one phase of a multiwinding transformer, calculated from the short circuit voltage, does not depend on the connection scheme of its windings. It is noted that in some cases it is difficult to obtain a complete scheme of an external power supply system. Considering that the short circuit in the traction network for the external power supply system is remote, it is proposed taking into account the reference network or traction substations as power sources, from which high-voltage transmission lines power the traction substations. Resistance of the supporting substations as power sources must takes into account connected equivalent power system.Such equivalenting should be carried out by known values of currents or short-circuit powers at the inputs of the reference substation or, if such information is not available, by the rated values of the switched-off currents or powers of the switches of high-voltage line connections.The following power schemes for traction substations are considered: each from its own supporting substation, which is part of an electrically uncoupled external power supply system; from the double-circuit high-voltage line of longitudinal power supply when it is powered from different supporting substations; from the supporting network substation, the traction substation receives power from two lines, and from this the traction substations receive power from two lines in a circle pattern.These three common cases cover all the most common power schemes for traction substations. For each of them formulas are given to determine the resulting equivalent resistance of the external power supply circuit, which should be taken into account in the replacement circuit of the traction network.

A Short-Circuit Current Study for the Power Supply System of Taiwan Railway

2001 ◽  
Vol 21 (8) ◽  
pp. 61-61
Author(s):  
S. Huang ◽  
B. Chen ◽  
Y. Kuo ◽  
K. Lu ◽  
M. Huang
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Supply System

Research and Application of Wind-Solar Hybrid Power Supply System in Environmental Monitoring System

2013 ◽  
Vol 313-314 ◽  
pp. 833-836
Author(s):  
Chang Wu Xie ◽  
Yan Gao ◽  
Guo Feng Zhang
Keyword(s):  
Environmental Monitoring ◽  
Monitoring System ◽  
Power Supply ◽  
Power Supply System ◽  
Supply System ◽  
Experimental Result ◽  
Constant Current ◽  
Battery Life ◽  
Multi Stage ◽  
Environmental Monitoring System

A wind-solar hybrid DC power supply system for small wireless sensor devices is introduced in this paper. The environmental monitoring system is selected as the application platform, and ARM microprocessor is selected as the control core. With the use of the multi-stage constant current technology, the battery life and charge efficiency are optimized. With the design of LCD module and RS232 interface in the system, the difficulty of the system debugging and maintenance are reduced while the flexibility of the system is increased. The experimental result shows that the most use of wind and solar energy is realized in this system.

Study on Preventing Override Trip System for High-Voltage Power Grid of Coal Mine Underground Based on the EtherCAT

2013 ◽  
Vol 273 ◽  
pp. 389-393
Author(s):  
Yu Mei Wang ◽  
Xu Yang ◽  
Hao Zhang
Keyword(s):  
High Voltage ◽  
Coal Mine ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Power Grid ◽  
Supply System ◽  
Quality Requirements ◽  
Master Station ◽  
Short Circuit Fault

When the power supply system for coal mine underground take place a short circuit fault, multilevel switch often respond at the same time. And the existing comprehensive protector cannot satisfy the real-time and rapid quality requirements of preventing override trip system for high-voltage power grid of coal mine underground. So this paper put forward the research for comprehensive protector of preventing override trip based on the EtherCAT. This paper first analyzes the principle and characteristics of the EtherCAT technology; and then puts forward the overall scheme of preventing override trip system; Finally, study and design the slave station and master station of preventing override trip system based on the EtherCAT.

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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