scholarly journals Romanenko N. G. Increasing efficiency of ship cables defectation

2021 ◽  
Vol 2021 (4) ◽  
pp. 98-106
Author(s):  
Sergey Vladimirovich Golovko ◽  
Julia Aleksandrovna Golovko ◽  
Maksim Almansurovich Nadeev ◽  
Nikolay Gennadievich Romanenko
Keyword(s):  
Absorption Coefficient ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Electrical Energy ◽  
Technical Condition ◽  
Cable Insulation ◽  
Common Causes ◽  
Cable Lines ◽  
Cable Damage

The ship power supply system is a complex system that supplies electrical energy to various mechanisms and devices using wires and cables. The reliability of power supply largely depends on the technical condition of the cable lines. During operation, cable lines are regularly exposed to mechanical stress, both from external factors and from people. Some of the most common causes of cable damage are: aging insulation, overvoltage, thermal stress, boat vibration, and corrosion and moisture. Leaving the operating state of the cable line can lead to emergencies. A cable with damaged insulation can cause an electric arc with a metal object. If several phases of a cable with damaged insulation, then when they touch, a phase-to-phase short circuit occurs, as a result of which a large amount of heat is released, from which the cable insulation and other nearby combustible materials can ignite. There is considered the principle of operation of DIPCEL (a device for diagnosing ship cables) and shown its main disadvantages in determining the aging and moisture indicators of cable insulation. It is proposed to use the absorption coefficient for increasing the efficiency of measuring the ship’s cable insulation moisture. For insulating materials, in which the absorption current decreases rapidly, resistance measurements should be taken after 15 sec and 60 sec. The absorption coefficient is defined by measuring the ratio of a sixty-second insulation resistance to a fifteen-second resistance. If the value of the obtained coefficient is less than 1.25, then the insulation is unsatisfactory; if the value is within 1.25 - 1.6, than the insulation is normal, if more than 1.6 - the insulation is excellent

scholarly journals Determination of the technical condition of electrical equipment in power supply systems

2021 ◽  
Vol 939 (1) ◽  
pp. 012014
Author(s):  
A Rakhmatov ◽  
N Rajabov ◽  
Kh Yakubova
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Electrical Energy ◽  
Electrical Equipment ◽  
Technical Condition ◽  
Supply System ◽  
Operating Modes ◽  
Quality Of Electrical Energy ◽  
Supply Systems

Abstract This article describes the methods and means for determining the technical condition of electrical equipment in power supply systems, particularly in transformer substations. There are many ways to determine the technical condition of electrical equipment. However, their implementation requires complex and additional equipment and devices. In addition, these tests must be carried out when the power supply system is off. This will lead to a decrease in the quality of electrical energy. Determination of the technical condition of electrical equipment using thermal imagers is performed under the voltage and in operating modes, the measurement process does not affect the parameters of the power supply system. The results of research in energy enterprises of the Syrdarya region are presented.

ASSESSMENT OF THE CONDITION OF HIGH-VOLTAGE ELECTRICAL EQUIPMENT OF THE MULTI-LEVEL POWER SUPPLY SYSTEM OF THE SHOPS OF THE PRODUCTION METALLURGICAL LINE

2021 ◽  
Vol 3 (1) ◽  
pp. 054-057
Author(s):  
Yu. N. KONDRASHOVA ◽  
◽  
I. V. NOVIKOV ◽  
A. M. MARKIN ◽  
◽  
...  
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Power Supply System ◽  
Electrical Equipment ◽  
Technical Condition ◽  
Supply System ◽  
Power Lines ◽  
Reliability Indicators ◽  
Multi Level ◽  
Cable Lines

The paper analyzes damage along overhead and cable power lines. The calculation of the main indicators of reliability is carried out to predict the value of the actual resource of the main high-voltage electrical equipment for the shops of the production metallurgical line. The calculations were performed for the existing circuit using the software package [1]. The performed analysis of the obtained results of the developed algorithm and methods for calculating reliability indicators made it possible to assess the technical condition of overhead and cable lines subject to intense aging in terms of voltage levels and to estimate the number of outages at nodal substations.

scholarly journals Innovative Integrated Solution for Monitoring and Protection of Power Supply System from Railway Infrastructure

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7858
Author(s):  
Mihai Andrusca ◽  
Maricel Adam ◽  
Alin Dragomir ◽  
Eduard Lunca
Keyword(s):  
Mobile Communications ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Technical Condition ◽  
Supply System ◽  
Railway Infrastructure ◽  
Remote System ◽  
Electric Traction ◽  
New Sensors

This paper describes an innovative integrated solution for monitoring and protection of the power supply system of electric traction. The development of electronics devices, new possibilities to communicate (wireless), and new sensors makes it possible to design, develop and implement new hardware–software structures in various fields such as energy systems, transportation infrastructure, etc. This contributes to increasing developments in the monitoring and protection of railway infrastructure. A monitoring and protection system that uses sensors and devices to acquire electrical parameters from railway infrastructure has been developed and applied for fault detection and protection of power supply systems from electric traction. The solution of monitoring and protection presented are composed of a hardware–software structure with Global System for Mobile Communications (GSM) communication for monitoring of power supply installations from the electric traction and a central remote system composed of a device with GSM communication and a server that will allow, among others things, accurate detection of the block section (SC), in which an electrical fault (short circuit) has occurred, determination of the circuit breakers electro-erosion from the railway installations and an indication of the opportune moment for maintenance activity, respectively, as well as knowledge of the technical condition of some equipment from the return circuit. The proposed and developed method for monitoring devices has been validated in the railway laboratory to confirm its capability to detect defects and was tested in the field. Experimental results in the field and appropriate data analysis are included in this article.

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 An Efficient Hybrid AC Metro Power Supply System Integrating PV With Grid

2019 ◽  
pp. 314-321
Author(s):  
J. Prince Joshua Gladson ◽  
A. Ravielango
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Reactive Power ◽  
Control Method ◽  
Electrical Energy ◽  
Supply System ◽  
Urban Rail Transit ◽  
Traction Power Supply System ◽  
Traction Power Supply ◽  
Photovoltaic Plants

Metro is integral to the urban rail transit with the expansion of the city. Due to the tremendous power consuming of the traction load which is generally considered to be megawatt class, the attendant problems concerning energy-saving and emission-reduction cannot be neglected. An approach wherein the photovoltaic plants are connected into the metro traction power supply system to provide electrical energy is proposed in this paper. Given the deterioration of power quality brought about by PV connection, the photovoltaic inverter adopts output reactive power control method.

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.

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