Study and identification of short-circuit currents at the Complex Distribution Network SIDER-EL Hadjar (ex ArceloMittal-Algerie)

Because of an upcoming the modernization of the electricity distribution network in the SIDER EL-HADJAR steel complex, a new calculation of the short-circuit current must be taken into account. The objectives pursued in this article, is to determine the precise values of the currents of maximum and minimum fault by each start 225kV, 63kV and 15kV of the distribution network to ensure the reliability of the existing system, on the other hand is to validate the sizing of the 63kV bus bar follows the increase of the load of the transformer station P4 by replacing the 70MVA transformer with a 120MVA transformer and comparing the results to the old computation. The calculation of short-circuit currents is a key step in qualifying the equipment to withstand the thermal and electromagnetic effects. So it was question of appreciating the reliability of numerical computation of the currents of short-circuits which requires modeling and simulations with software NEPLAN V5.

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Study and identification of short-circuit currents at the complex distribution network SIDER EL Hadjar (ex ArceloMittal-Algerie)

Global Journal of Computer Sciences Theory and Research ◽

10.18844/gjcs.v8i1.3287 ◽

2018 ◽

Vol 8 (1) ◽

pp. 24-31

Author(s):

Benhamida Hakim ◽

Mesbah Tarek

Keyword(s):

Power Supply System ◽

Short Circuit ◽

Distribution Network ◽

Short Circuit Current ◽

Supply System ◽

Electricity Distribution ◽

Short Circuits ◽

Short Circuit Currents ◽

Complex Distribution ◽

Peak Value

Because of an upcoming modernisation of the electricity distribution network in the SIDER EL HADJAR steel complex, a new calculation of the short-circuit current must be taken into account. The objectives are to determine the precise values of the currents of maximum and minimum fault by each start 225 kV, 63 kV and 15 kV of the distribution network to ensure the reliability of the existing system, and to validate the sizing of the 63 kV bus bar follows the increase of the load of the transformer station P4 by replacing the 70 MVA transformer with a 120 MVA transformer and comparing the results to the old computation. The calculation of short-circuit currents is a key step in qualifying the equipment to withstand the thermal and electromagnetic effects. So, to appreciate the reliability of numerical computation of the currents of short circuits requires modelling and simulations with software NEPLAN V5. Keywords: Initial short-circuit current, power supply system (SIDER EL HADJAR), IEC 60909-0, peak value of short-circuit current, NEPLA software.

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Effect of Distributed Photovoltaic Generation on Short-Circuit Currents and Fault Detection in Distribution Networks: A Practical Case Study

Applied Sciences ◽

10.3390/app11010405 ◽

2021 ◽

Vol 11 (1) ◽

pp. 405

Author(s):

Daniel Alcala-Gonzalez ◽

Eva Maria García del Toro ◽

María Isabel Más-López ◽

Santiago Pindado

Keyword(s):

Renewable Energy ◽

Radial Distribution ◽

Short Circuit ◽

Renewable Energy Sources ◽

Distribution Network ◽

Distribution Networks ◽

Energy Sources ◽

Protection Devices ◽

Short Circuits ◽

Short Circuit Currents

The increase in the installation of renewable energy sources in electrical systems has changed the power distribution networks, and a new scenario regarding protection devices has arisen. Distributed generation (DG) might produce artificial delays regarding the performance of protection devices when acting as a result of short-circuits. In this study, the preliminary research results carried out to analyze the effect of renewable energy sources (photovoltaic, wind generation, etc.) on the protection devices of a power grid are described. In order to study this problem in a well-defined scenario, a quite simple distribution network (similar to the ones present in rural areas) was selected. The distribution network was divided into three protection zones so that each of them had DG. In the Institute of Electrical and Electronic Engineers (IEEE) system 13 bus test feeder, the short-circuits with different levels of penetration were performed from 1 MVA to 3 MVA (that represent 25%, 50%, and 75% of the total load in the network). In the simulations carried out, it was observed that the installation of DG in this distribution network produced significant changes in the short-circuit currents, and the inadequate performance of the protection devices and the delay in their operating times (with differences of up to 180% in relation to the case without DG). The latter, that is, the impacts of photovoltaic DG on the reactions of protection devices in a radial distribution network, is the most relevant outcome of this work. These are the first results obtained from a research collaboration framework established by staff from ETSI Civil and the IDR/UPM Institute, to analyze the effect of renewable energy sources (as DG) on the protection devices of a radial distribution network.

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Comparative Analysis of High-Voltage Power Line Models for Determining Short-Circuit Currents in Towers Earthing Systems

Energies ◽

10.3390/en14164729 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4729

Author(s):

Rafał Tarko ◽

Jakub Gajdzica ◽

Wiesław Nowak ◽

Waldemar Szpyra

Keyword(s):

High Voltage ◽

Current Distribution ◽

Single Phase ◽

Short Circuit ◽

Short Circuit Current ◽

Power Line ◽

Power Lines ◽

Distribution Analysis ◽

Short Circuits ◽

Short Circuit Currents

The article deals with the problems of single-phase short-circuit current distribution in overhead power lines. Short-circuit disturbances cause many negative phenomena in power networks. Since experimental studies of short-circuits in real networks are practically impossible to perform, these effects can be evaluated only theoretically, based on short-circuit current calculations with the use of appropriate mathematical models. Although short-circuit modeling is considered to be one of the simplest power system calculations, the exact mathematical description of the phenomena occurring at short-circuits is complex. Simplified normative methods are often used for short-circuit current calculations; however, this does not give ground for a thorough analysis of short-circuit current distribution in power lines. The distributions are analyzed using power line models with different degrees of complexity in line with the assumptions made for a given model. The paper presents the problem of current distribution analysis in high-voltage overhead lines for single-phase faults to the tower structures. Simulation studies were conducted on the models developed for the calculation of short-circuit currents in the high-voltage power line earthing. The objective of the analysis was to assess the validity of simplification assumptions followed by practical recommendations on the applicability of the models.

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Protection Coordination of 33/11 kV Power Distribution Substation in Iraq

Engineering and Technology Journal ◽

10.30684/etj.v39i5a.1790 ◽

2021 ◽

Vol 39 (5A) ◽

pp. 723-737

Author(s):

Yamur M. Obied ◽

Thamir M. Abdul Wahhab

Keyword(s):

Time Delay ◽

Power System ◽

Power Distribution ◽

Software Package ◽

Short Circuit ◽

Distribution Network ◽

Circuit Breaker ◽

Short Circuit Current ◽

Earth Fault ◽

Current Characteristics

The coordination between protective devices is the process of determining the most appropriate timing of power interruption during abnormal conditions in the power system. The aim of this work is to coordinate the protection of the 33/11 kV power distribution substation in Iraq using the CYME 7.1 software package. In this paper overcurrent and earth fault relays are simulated in two cases, with time delay setting and instantaneous setting, to obtain the Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay of Al-Karama substation (2×31.5 MVA, 33/11 kV) in Babil distribution network. The short circuit current at each CB is calculated and accordingly, the protection coordination for Al-Karama substation has been simulated. The TCC curves have been obtained in two cases for overcurrent and earth fault relays; in a case with time delay setting and in the case with the instantaneous setting. The setting takes into consideration the short circuit current at the furthest point of the longest outgoing feeder and the shortest outgoing feeder.

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Na and Cl Transport across the Isolated Anterior Intestine of the Plaice Pleuronectes Platessa

Journal of Experimental Biology ◽

10.1242/jeb.90.1.123 ◽

1981 ◽

Vol 90 (1) ◽

pp. 123-142

Author(s):

M. M. P. RAMOS ◽

J. C. ELLORY

Keyword(s):

Chloride Transport ◽

Short Circuit ◽

Short Circuit Current ◽

Negative Potential ◽

Loop Diuretics ◽

Significant Part ◽

Cl Transport ◽

Anterior Intestine ◽

Short Circuit Currents ◽

Na Uptake

1. The tissue was found to have a serosa negative potential, and short-circuit currents equivalent to the net Cl transport. 2. A significant part of the Cl uptake was Na dependent and a similar fraction of the Na uptake was Cl dependent. 3. Short-circuit current and uptake of both ions were inhibited by loop diuretics and analogues. 4. I80 and P.D. were abolished by ouabain. 5. The observations are consistent with the idea of a coupled NaCl entry into the cell, using the energy inherent in the Na gradient; Na being pumped out of the cells by the Na pump and followed electrically by Cl−. Net chloride transport and the serosa negative potential would be a consequence of the permselective properties of the junctions allowing Na but not Cl to recycle back to the mucosal solution.

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ATP stimulates Ca2+ release from a rapidly exchanging pool in cultured rat epididymal cells

AJP Cell Physiology ◽

10.1152/ajpcell.1993.264.6.c1388 ◽

1993 ◽

Vol 264 (6) ◽

pp. C1388-C1394 ◽

Cited By ~ 25

Author(s):

A. Y. Leung ◽

H. L. Tai ◽

P. Y. Wong

Keyword(s):

Short Circuit ◽

Short Circuit Current ◽

The Other ◽

Free Solution ◽

Tetraacetic Acid ◽

Cl Secretion ◽

Transient Rise ◽

Extracellular Compartment ◽

Dose Dependent Fashion ◽

Dose Dependent

A study was carried out to investigate an ATP-sensitive Ca2+ pool in rat epididymal cells and its role in transepithelial Cl- secretion. In normal buffered solution containing 2.5 mM free Ca2+, ATP triggered single calcium spikes in a dose-dependent fashion. In nominally Ca(2+)-free solution, the peaks of successive Ca2+ spikes diminished after repeated ATP stimulations. Addition of Sr2+ (2.5 mM) to Ca(2+)-free solution after ATP stimulation did not cause changes in fluorescence signals. However, in the presence of Sr2+, ATP gave rise to apparent repetitive Ca2+ spikes of similar magnitudes after repeated stimulations. Increasing the time of exposure in Ca(2+)-free solution containing 50 microM ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid rapidly decreased the intracellular Ca2+ concentration ([Ca2+]i) response to subsequent ATP stimulation. On the other hand, increasing the time of exposure in Sr(2+)-containing solution in Ca(2+)-depleted cells rapidly increased the apparent [Ca2+]i response to subsequent ATP stimulation. These observations suggested the existence of a Ca2+ pool that was rapidly exchanging with the extracellular compartment. Apical application of ATP elicited a transient rise in short-circuit current across the epididymal epithelium in a dose-dependent fashion, and the response was reduced by prior stimulation with thapsigargin. Ca2+ released from a rapidly exchanging ATP-sensitive store might stimulate Cl- secretion in the epididymis, thereby maintaining the electrolyte contents and fluidity of the epididymal microenvironment.

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ENGINEERING ANALYSIS OF THE THREE-PHASE SHORT CIRCUIT MODE IN THE 10 KV ELECTRIC NETWORK TAKING INTO ACCOUNT THE INFLUENCE OF LOAD CURRENTS

AGRICULTURAL ENGINEERING ◽

10.26897/2687-1149-2021-6-74-83 ◽

2021 ◽

pp. 74-83

Author(s):

YURI D. VOLCHKOV ◽

Keyword(s):

Remote Monitoring ◽

Short Circuit ◽

Short Circuit Current ◽

Load Current ◽

Electric Network ◽

Operating Modes ◽

Three Phase ◽

Feed Network ◽

Short Circuits ◽

Switching Devices

Abstract. The load current aff ects the value of the short-circuit current in the electric network and, consequently, the voltage value. In some cases, this infl uence must be taken into account for the correct choice of switching devices, remote monitoring the operating modes of electric networks, and determining the modes. It is possible to disconnect loads connected through magnetic starters and contactors. Failure to consider the infl uence of the load current can lead to an incorrect interpretation of the identifi ed grid operating modes during remote monitoring and, as a result, incorrect dispatcher’s decisions. In addition, it is also insuffi cient to specify the choice of switching devices in the 10 kV feed network. The article describes a method for analyzing the three-phase short circuit mode in a 10 kV feed network, taking into account the infl uence of load currents. The method is exemplifi ed by the case of an actual electric network – the 10 kV ring feed network containing reclosers and receiving power from diff erent sections of lowvoltage buses of the “Kulikovskaya” 110/35/10 kV substation, belonging to the Branch of PJSC «DGC of Center”-“Orelenergo.” For this network, the values of the three-phase short-circuit currents at points with diff erent distances from the substation buses have been determined. The authors have fi guredout the values of the load currents and their shares in the total short-circuit current. The voltage values at different points of the network in the case of short circuits have also been determined. The research proves that the effect of the load current on the total short-circuit current should be taken into account for the case of remote short circuits.

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Frequency and time fault diagnosis methods of power transformers

Measurement Science Review ◽

10.1515/msr-2018-0023 ◽

2018 ◽

Vol 18 (4) ◽

pp. 162-167 ◽

Cited By ~ 13

Author(s):

Miroslav Gutten ◽

Daniel Korenciak ◽

Matej Kucera ◽

Richard Janura ◽

Adam Glowacz ◽

...

Keyword(s):

Fault Diagnosis ◽

High Voltage ◽

Impact Test ◽

Power Transformer ◽

Short Circuit ◽

Small Deformation ◽

Short Circuit Current ◽

Diagnostic Methods ◽

Response Analysis ◽

Short Circuit Currents

Abstract The authors describe experimental and theoretical analyses of faults of power transformer winding. Faults were caused by mechanical effect of short-circuit currents. Measurements of transformer were carried out in high-voltage laboratory. Frequency and time diagnostic methods (method SFRA - Sweep Frequency Response Analysis, impact test) were used for the analyses. Coils of transformer windings were diagnosed by means of the SFRA method and the time impact test. The analyzed methods had a significant sensitivity to a relatively small deformation of coil. In the analysis a new technique for analyzing the effects of short-circuit currents is introduced. This technique is developed for high-voltage transformers (different types of power). The proposed analyses show that it is necessary to analyze the value of short-circuit current. Short-circuit current represents a danger for the operation of the power transformer. The proposed approach can be used for other types of transformers. Moreover, the presented techniques have a potential application for fault diagnosis of electrical equipment such as: transformers and electrical machines.

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Two calcium channels in basolateral membranes of rabbit ileal epithelial cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1989.257.1.g86 ◽

1989 ◽

Vol 257 (1) ◽

pp. G86-G93

Author(s):

F. R. Homaidan ◽

M. Donowitz ◽

G. A. Weiland ◽

G. W. Sharp

Keyword(s):

Epithelial Cells ◽

Calcium Channels ◽

Calcium Channel ◽

Short Circuit ◽

Short Circuit Current ◽

The Other ◽

Channel Blockers ◽

Binding Studies ◽

Rabbit Ileum ◽

Basolateral Membranes

The actions of three different types of calcium channel blockers on short-circuit current (Isc) in rabbit ileum were studied. These included the phenylalkylamines, verapamil and (l)-desmethoxyverapamil (D888); the dihydropyridines, nifedipine and nitrendipine; and the benzothiazepine, diltiazem. All of the drugs decreased Isc, a change associated with increased Na and Cl absorption. Verapamil and D888 had the largest effects. The dihydropyridine, BAY K 8644, a calcium channel activator, increased Isc and decreased Na and Cl absorption, effects not inhibited by tetrodotoxin. The phenylalkylamines had an additional effect on Isc in the presence of a maximally inhibitory concentration of the dihydropyridines, suggesting the possibility of two distinct calcium channels, one of which is the L-type voltage-activated, dihydropyridine- and phenylalkylamine-sensitive channel, and the other is a channel only sensitive to phenylalkylamines but not to dihydropyridines. [3H]nitrendipine and [3H]D888 binding to an enriched preparation of basolateral membranes from ileal epithelial cells was characterized. Each ligand bound specifically and saturably to an apparently single population of high-affinity sites with [3H]D888 having three times as many binding sites as [3H]nitrendipine. [3H]nitrendipine binding was partially inhibited by verapamil and D888 and was increased by diltiazem; whereas [3H]D888 binding was inhibited completely by verapamil but only partially by nitrendipine and diltiazem. These transport and binding studies suggest the presence of two types of Ca2+ channels in ileal epithelial cells, one of which interacts with the dihydropyridines, the phenylalkylamines, and the benzothiazepines at three different sites and the other channel that only binds the phenylalkylamines.

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