scholarly journals CALCULATING SHORT CIRCUIT CURRENTS IN ELECTRICAL POWER SYSTEMS

2015 ◽  
pp. 29-45
Author(s):  
Krystyna Baran ◽  
Keyword(s):  
Power Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Electrical Power Systems ◽  
Short Circuit Currents

High-voltage electrical equipment in electrical power systems: diagnostics, defects, damage, monitoring

2019 ◽  
Author(s):  
Александр Хренников ◽  
Alexander Khrennikov
Keyword(s):  
Power Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Electrical Equipment ◽  
Diagnostic Methods ◽  
Power Transformers ◽  
Electrical Power Systems ◽  
The Impact ◽  
Short Circuit Currents ◽  
Detection Of Defects

The analysis of the main methods of diagnostics of electrical equipment for detection of defects and damages in the course of operation is presented. Analysis of the effectiveness of the main diagnostic methods is accompanied by examples of detection of defects and damage to specific equipment: power transformers, reactors, current and voltage transformers, disconnectors, turbogenerators, OPN, etc. Examples of damage and investigation of technological violations of oil-filled transformer-reactor equipment during operation, associated with the loss of electrodynamic resistance of the windings during the flow of through short-circuit currents (short-circuit). The analysis of efficiency of application of methods of diagnostics at detection of defects and damages of power transformers because of the impact of fault current. The questions of electrodynamic tests of power transformers (reactors) for resistance to short-circuit currents, which serve as a tool to improve the reliability of their design, are considered.

scholarly journals Assessment of the Impact of the Rigidity of Nodes on the Operating Reliability of EPSs

2019 ◽  
Vol 139 ◽  
pp. 01070
Author(s):  
Nailya Chemborisova
Keyword(s):  
Power Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Operating Conditions ◽  
Electrical Power Systems ◽  
Operating Reliability ◽  
The Matrix ◽  
Active Power Losses ◽  
The Impact ◽  
Short Circuit Currents

The operating reliability of electrical power systems is mostly based on the topology and parameters of the schemes considered in this article. The preliminary (before the calculation of operating conditions) analysis of the rigidity or sensitivity of nodes, based on the matrix of node conductivity, allows for evaluating and increasing the controllability of conditions by voltages and limiting short-circuit currents, making the reduction of active power losses in the grid more efficient. A conclusion was made regarding the consistent effects of changes in the node rigidity on increasing the EPS operating reliability.

scholarly journals Determine the Optimum Efficiency of Transformer Cores Using Comparative Study Method

2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Nabeel Zahoor ◽  
Abid Ali Dogar ◽  
Akhtar Hussain
Keyword(s):  
Power Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Operating Cost ◽  
Open Circuit ◽  
Core Material ◽  
Local Market ◽  
Electrical Power Systems ◽  
Research Perspective ◽  
Core Losses

The transformer is one of the most discussed and important components of electrical power systems because of its reliability, durability and energy conversion capability. It is also useful in load sharing, which reduces system burden, but is also responsible for a sufficient number of losses, as it is used in different types of electric appliances that require voltage conversion. The no-load losses of transformers have gained much attention from research perspective because of its operating cost throughout its lifetime. Many studies were carried out to achieve the highest possible efficiency, decreasing certain losses by using different methods and materials. However, the local market in Pakistan is far behind in the field of efficient core material manufacturing of transformers, which is why consumers are unable to obtain efficient electric appliances. Due to these loss-making appliances, the overall residential load increases and the consumers are charged with heavy electricity bills. This proposed study discusses core losses, different core comparisons, T/F efficiency and advancement in the core material. To accomplish a core comparison, two locally available core materials are used to fabricate two different T/F, and some tests such as open-circuit and short-circuit tests are performed to discover their losses, thermal degradation, and output efficiencies.

scholarly journals Mechanical-Stress Analytical Modeling for the Design of Coils in Power Applications

2014 ◽  
Vol 63 (4) ◽  
pp. 579-590
Author(s):  
D. Bellan
Keyword(s):  
Power Systems ◽  
Mechanical Stress ◽  
Short Circuit ◽  
Electrical Power ◽  
Short Circuit Current ◽  
Geometrical Parameters ◽  
Electrical Power Systems ◽  
Inrush Currents ◽  
Current Flows ◽  
The Relationship

Abstract Modern electrical-power systems are often exploited for transmitting high-frequency carrier signals for communications purposes. Series-connected air-core coils represent the fundamental component allowing such applications by providing a proper filtering in the frequency domain. They must be designed, however, to withstand also the line short-circuit current. When a high-magnitude current flows through a coil, strong mechanical stresses are produced within the conductor, leading to possible damage of the coil. In this paper, an approximate analytical model is derived for the relationship between the maximum mechanical stress and the electrical/geometrical parameters of the coil. Such a model provides the guidelines for a fast and safe coil design, whereas numerical simulations are only needed for the design refinement. The presented approach can be extended to other applications such as, for example, the mechanical stress resulting from the inrush currents in the coils of power transformers.

scholarly journals Modeling and Validation of a Directional Overcurrent Relay as an Island Interconnection Device

2020 ◽  
Author(s):  
Wandry R. Faria ◽  
Jonas V. Souza ◽  
Rodrigo B. Otto ◽  
Benvindo R. Pereira Jr.
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Distribution Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Distribution Networks ◽  
Test System ◽  
Electrical Power Systems ◽  
Distributed Generators ◽  
Overcurrent Relay

The growing number of decentralized generators in the distribution systems and the consequent increase in the penetration level in the networks have prompted the inclusion of this scenario in researches involving the planning of electrical power systems. The planning of protection systems for distribution networks considering distributed generators requires adaptations in the approach due to modifications in characteristics of the network, such as passivity and unidirectional power flow. Furthermore, the insertion of generators in distribution networks allows the implementation of new operation methods, such as the possibility of disconnecting some loads from the main feeder and supplying them through distributed generators. The island operation can improve the service continuity indexes, as well as reduce the costs of non-supplied energy. Although the island operation is widely proposed in the literature as a means to improve the system's reliability, the simulation of a protective device to intentionally island a region and the verification of its limitations is not. In this paper, we present the modeling of a directional overcurrent relay through ATP-EMTP, and its employment as a device for island interconnection, analyzing its zone of non-operation. CIGRE 14-bus test system is used to conduct short-circuit tests with the variation of resistance and type of fault applied. Theresults show the effectiveness of the device, which is able to identify all faults with real impact on the network, placing the region in island operation in less than 20 ms.

Protection Study in the EPS, Electrical Power System

2021 ◽  
pp. 377-394
Author(s):  
Gustavo Vinicius Duarte Barbosa ◽  
José Ronaldo Tavares Santos
Keyword(s):  
Power Systems ◽  
Power System ◽  
Regulatory Agency ◽  
Short Circuit ◽  
Salt Spray ◽  
Electrical Power ◽  
Electrical Power System ◽  
Electrical Power Systems ◽  
Two Phase ◽  
Three Phase

Electrical power systems are susceptible to faults caused, for example, by storm, pollution, vandalism, lightning, salt spray, etc. The unscheduled interruption in the supply of electricity to consumers, whether industrial, residential, or commercial, entails severe fines for the transmission utility and/or electricity distributor, imposed by the regulatory agency. Thus, the EPS must have a well-dimensioned protection system, capable of identifying the fault, which is characterized by a single-phase, two-phase, three-phase short circuit, among others, and interrupt the missing section in the minimum time so that the effects of this lack are as small as possible for the SEP, especially with regard to its integrity and operational security.

Voltage Quality in Electrical Power Systems

2001 ◽  
Author(s):  
J. Schlabbach ◽  
D. Blume ◽  
T. Stephanblome
Keyword(s):  
Power Systems ◽  
Electrical Power ◽  
Electrical Power Systems ◽  
Voltage Quality
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