scholarly journals FAST ADAPTIVE PROTECTION AGAINST SHORT CIRCUITS IN MICROGRID ELECTRIC NETWORKS WITH DISTRIBUTED GENERATION

2021 ◽  
Vol 2021 (1) ◽  
pp. 57-60
Author(s):  
N.V. Grebchenko ◽  
◽  
Y.V. Yeromenko ◽  
Keyword(s):  
Distributed Generation ◽  
Short Circuit ◽  
Electric Networks ◽  
Stable Mode ◽  
Power Sources ◽  
Entire Line ◽  
Mode Of Operation ◽  
Operating Current ◽  
Short Circuits ◽  
Response Current

Protection against short circuits in microgrid networks with distributed generation is proposed, in which the power of the power sources and loads are constantly changing, which leads to a change in the sensitivity of relay protection. The response current of the proposed protection automatically adapts to the current value of the line operating current. The protection includes measures to block its action in the event of short-term interference in current circuits. Protection is installed on both sides of the line and protects the entire line, provides a stable mode of operation of the network due to the quick shutdown of short circuits. The algorithm of operation and the scheme for implementing protection are given. The protection operation was tested using the parameters of the real short circuit mode. References 7, figures 3.

Design and Development of a Battery Internal Short Circuit Test Machine

2017 ◽  
Author(s):  
Scott C. DeLaney ◽  
Mary B. Burbules ◽  
Mayank Garg ◽  
Adam S. Hollinger ◽  
Christopher D. Rahn
Keyword(s):  
Short Circuit ◽  
High Energy ◽  
High Energy Density ◽  
Test Machine ◽  
Power Sources ◽  
Short Circuit Test ◽  
Internal Short Circuit ◽  
Short Circuits ◽  
Penetration Tests ◽  
Lithium Cells

The use of lithium-based batteries, due to their high energy density, has become popular for power sources in portable electronic devices. Safety concerns over lithium cell applications have arisen due to their lower abuse tolerance compared to standard battery designs. Internal short circuits present one of the more dangerous abuse situations since there is a great potential of thermal runaway leading to fire and explosion. Field failures and recalls associated with internal short circuits demonstrate the risks of lithium batteries. Understanding the response of lithium cells under internal short circuit conditions is of great importance to ensure the safe development of lithium battery application. In this work, an internal short circuit test machine was designed to conduct nail penetration tests of lithium chemistry cells. The test machine successfully provides the required force to allow for multi-cell penetration. The test machine also provides accurate control of the penetrating nail’s position and velocity. This testing will support the development of models to simulate the mechanism of internal short circuits of lithium cells.

A Way to Chips Diagnosis by Short Circuits

2014 ◽  
Vol 918 ◽  
pp. 307-312
Author(s):  
Nikolay V. Kinsht ◽  
Natalia N. Petrun’ko
Keyword(s):  
Analog Circuits ◽  
Short Circuit ◽  
Technical Diagnostics ◽  
Large Set ◽  
Power Sources ◽  
Active Analog ◽  
Destabilizing Factors ◽  
Short Circuits

The various formulations of the technical diagnostics problem are possible when creation and use of analog circuits. One approach allows deviation a sufficiently large set of the elements parameters. The results of this diagnosis can be used to improve the technology of analog circuits or predict their behavior depending on the time of exposure or destabilizing factors. The power sources (current sources and emf) commonly used as a testing influence on circuit in realization test diagnosis. A short circuit approach of the testing experiments organization with active analog circuits with partly inaccessible nodes is considered.

scholarly journals Optimization-Based Formulations for Short-Circuit Studies with Inverter-Interfaced Generation in PowerModelsProtection.jl

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2160
Author(s):  
Arthur K. Barnes ◽  
Jose E. Tabarez ◽  
Adam Mate ◽  
Russell W. Bent
Keyword(s):  
Optimization Problem ◽  
Short Circuit ◽  
Problem Formulation ◽  
Power Delivery ◽  
Fault Current ◽  
Protective Device ◽  
Protective Relaying ◽  
Overcurrent Protection ◽  
Short Circuits ◽  
Optimization Problem Formulation

Protecting inverter-interfaced microgrids is challenging as conventional time-overcurrent protection becomes unusable due to the lack of fault current. There is a great need for novel protective relaying methods that enable the application of protection coordination on microgrids, thereby allowing for microgrids with larger areas and numbers of loads while not compromising reliable power delivery. Tools for modeling and analyzing such microgrids under fault conditions are necessary in order to help design such protective relaying and operate microgrids in a configuration that can be protected, though there is currently a lack of tools applicable to inverter-interfaced microgrids. This paper introduces the concept of applying an optimization problem formulation to the topic of inverter-interfaced microgrid fault modeling, and discusses how it can be employed both for simulating short-circuits and as a set of constraints for optimal microgrid operation to ensure protective device coordination.

Identification of Electrical Fire Melted Marks of Copper Wires by Electron Backscattered Diffraction (EBSD)

2014 ◽  
Vol 513-517 ◽  
pp. 281-285
Author(s):  
Cheng Sun ◽  
Min Ju Ding ◽  
Yong Feng Zhang ◽  
Xun Tan ◽  
Peng Wang ◽  
...  
Keyword(s):  
Copper Wire ◽  
Short Circuit ◽  
Testing Methods ◽  
Electron Backscattered Diffraction ◽  
Qualitative And Quantitative ◽  
Metallographic Method ◽  
Short Circuits ◽  
In Fire ◽  
Misorientation Of Grains ◽  
Electrical Apparatus

A variety of electrical apparatus used in daily life can cause fires because of internal or external factors. During cause identification of an electrical fire, the first short circuit melted marks of copper wire have been considered highly important because they are direct proofs. Additionally, overloaded short circuit caused by the overload of current due to excessive electrical usage can give rise to an electrical fire. Despite extensive research on the first short circuit in fire scenes, the overloaded short circuit remains difficult to be distinguished because of the limitation of commonly used testing methods. Conventional metallographic method is intuitionistic and simple, but may not provide detailed data of crystals such as misorientation of grains. Here a new method (electron backscattered diffraction, EBSD) is applied for identification of the first and overloaded short-circuited melted marks of copper wires in electrical fire scenes. Results show obvious morphological distinctions in melted marks of copper wires between the first and overloaded short circuits. Qualitative and Quantitative differences obtained from the contrast of the above two short circuit situations may assist for cause identification of electrical fires in the future.

scholarly journals Capacitor Commutation Method for MVDC Hybrid Circuit Breakers

Designs ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 28
Author(s):  
Hyosung Kim
Keyword(s):  
Short Circuit ◽  
Circuit Breaker ◽  
Reverse Current ◽  
Resonant Circuit ◽  
Power Circuit ◽  
Power Sources ◽  
Semiconductor Switch ◽  
Current Commutation ◽  
Dc Circuit Breaker ◽  
Hybrid Circuit

The medium voltage DC (MVDC) type system can connect multiple terminals to a common MVDC bus, so it is possible to connect several renewable DC power sources to the common MVDC bus, but a DC circuit breaker is needed to isolate short circuit accidents that may occur in the MVDC bus. For this purpose, the concept of a hybrid DC circuit breaker that takes advantage of a low conduction loss contact type switch and an arcless-breaking semiconductor switch has been proposed. During break the hybrid switch, a dedicated current commutation device is required to temporarily bypass the load current flowing through the main switch into a semiconductor switch branch. Existing current commutation methods include a proactive method and a reverse current injection method by a LC (Inductor-capacitor) resonant circuit. This paper proposes a power circuit of a new MVDC hybrid circuit breaker using a low withstanding voltage capacitor branch for commutation and a sequence controller according to it, and verifies its operation through an experiment.

Influence of distributed power supply in distributed power distribution network

2021 ◽  
pp. 1-8
Author(s):  
Xin Shen ◽  
Hongchun Shu ◽  
Min Cao ◽  
Nan Pan ◽  
Junbin Qian
Keyword(s):  
Power Supply ◽  
Power Distribution ◽  
Short Circuit ◽  
Power Grid ◽  
Distribution Network ◽  
Distribution Networks ◽  
Power Supplies ◽  
Power Distribution Network ◽  
Power Sources ◽  
Distributed Power

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.

Overview and Prospects of Black Start

2014 ◽  
Vol 533 ◽  
pp. 401-408
Author(s):  
Zi Ying Chen ◽  
Jia Lin Hu ◽  
Jia Yao Li ◽  
Wei Xun Long
Keyword(s):  
Electric Vehicle ◽  
Distributed Generation ◽  
Power Grid ◽  
Rapid Development ◽  
Research Development ◽  
Power Sources ◽  
Technical Problems ◽  
Grid Construction ◽  
Microgrid Control ◽  
Operation Characteristics

With the rapid development of power grid, black start has been an indispensable part of power grid construction, and the gradually mature microgrid technology will play an important role in solving power system problems. Otherwise, plug-in electric vehicle will become an important load in future power grid. The black start concept, research status, black start scheme development and its verification are stated in detail; distributed generation and microgrid are introduced; the strategy about taking microgrid as black start power sources is proposed; and key technical problems existing on the combination of black start, microgrid and plug-in electric vehicle are explored according to the microgrid control and operation characteristics. On the basis of summarizing black start and microgrid research development and achievements in the globe, this paper discusses prospects of black start and provides new views and suggestions for its further research.

scholarly journals Design and computational modeling of fault current limiter topologies

2020 ◽  
Author(s):  
Alexandre Bitencourt ◽  
Daniel H. N. Dias ◽  
Bruno W. França ◽  
Felipe Sass ◽  
Guilherme G. Sotelo
Keyword(s):  
Electric Power ◽  
Distributed Generation ◽  
Distribution System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Economic Feasibility ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Fault Current Limiters ◽  
Current Limiter

The increase in demand for electric power and the insertion of a distributed generation led to the rise of the short-circuit current in substations. Most of these Brazilian substations were designed decades ago, because of that their equipment may not support the new short-circuit current levels. To protect the installed equipment and avoid excessive costs replacing old devices, it is possible to install Fault Current Limiters (FCLs). This document is a report from an R&D project that evaluated FCL topologies considering real parameters in simulation from used equipment, concluding that the selected FCL topologies accomplished their technical objective. However, before implementing these topologies in the distribution system, one should consider the technical and economic feasibility of using semiconductor switching devices.

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