1,720,988 research outputs found
Real-time Smart Microgrid Simulation: The integration of communication layer in electrical simulation
No full textMicrogrids are smart electrical grid composed of the communication network among its power devices for better operation and control. The information sharing is done locally through measurement but globally by adopting a protocol over the communication network for fast and reliable information exchange for microgrid protection and coordination among the devices present in the power network. In this article, a real-time simulation of a smart microgrid with the emulation of the intelligent electronic devices present in the grid that takes action over the events is proposed using the hardware-in-the-loop methodology. The information exchange between the simulated microgrid and the emulated intelligent trip unit of the circuit breaker is adopted using a physical communication network and User datagram protocol over Ethernet. The unique aspect is to approach the problem of co-simulating the power system simulator with the communication network without platform dependencies to obtain more realistic results. The mathematical models are created using model-based design approach with which a C code can be generated and can be simulated in real-time with any of the digital twins available. The proposed framework is used to test a protection scenario in the microgrid that exchanges the information over Ethernet for measurement and action coordination with the emulated trip unit for stable operation of the microgrid
Hardware in the Loop Simulation of the Smart Grid with the inclusion of IEC61850 Communication Protocol
No full textSmart gird is intelligent and interactive among its power devices using the communication network running a protocol for reliable transfer of messages from one device to another or with the system operator for critical operation and control of the substation. Employing protocol such as IEC61850 globally in the electrical substation need to be well tested for time critical operations, physical security of the substation with proper logic implementation for power flow in case of an event. If the substation is connected to the internet then the problem gets more complex with respect to cyber security challenges faced over this protocol.In this work, Hardware-in-the-loop simulation methodology of Smart grid including the physical IEC61850 communication net-work layer using Intelligent electronic devices of circuit breakers is presented. GOOSE messages and MMS server communication using IEC61850 in the smart grids are investigated inside the real-time simulation boundaries. The unique aspect of this work is the logic implementation among the protection devices are tested with real communication delays over the protocol that can occur between them, and these results are more realistic matching the real world scenario
Average Modeling of DC-DC Converters for DC Shipboard Microgrids with Constant Power Loads
No full textDC microgrids represent an interesting opportunity for shipboard power system applications, where the integration of dc-interfaced resources is needed. However, maintaining system stability becomes a major challenge in the presence of constant power loads, which exhibit a negative incremental resistance behavior. This work is focused on developing an equivalent linearized model of a DC microgrid, composed by a DC-DC converter used to interface a DC source, such as a battery, with a main dc-bus supplying a constant power load. The state space averaging technique has been employed to develop an unified continuous model of the system under study. The model is then linearized to allow the tuning of regulators and ensuring system stability. Finally, real-time simulations are exploited to validate the proposed methodology
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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