1,720,977 research outputs found
A Smart Grid Modelling Tool for Evaluating Optimal Control of Electric Vehicles
No full textThe deployment of Electric Vehicles (EVs) is continuously increasing on a global scale due to governmental commitments to ensure energy security, decarbonisation and address environmental concerns, by phasing out Internal Combustion Engine (ICE) vehicles. However, if charging is not appropriately controlled, massive EV penetration can lead to significant challenges for local distribution systems. In this context, this paper presents a new extensive tool, based on a Matlab/Simulink platform, to model distribution networks and analyse the impacts of charging of EVs, generation from local Renewable Energy Sources (RES) and the use of smart grid technologies to mitigate these impacts. The tool models the geographical locations of the distribution substations and the nodes where local loads, RES and EV charges may be connected. It allows the user to study the operational framework of current and future distribution networks and enables techno-economic assessment to be made. The modelling tool simulates the daily basis operation of any low-voltage (LV) distribution grid, considering the interaction with both consumers and local RES. This is done by evaluating key system performance measures, such as nodal voltages, line currents and transformer overloading. A user-friendly Graphical User Interface (GUI) facilitates the flexible management of the input parameters. The tool was applied to analyse an existing UK LV distribution network, to demonstrate the feasibility of smart charging and V2G (Vehicle to Grid) technology and the advantages over uncontrolled charging. This paper presents the outline of the modelling tool and the results of investigation of the different scenarios considered in this research
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
Multi-objective Smart Charge Control of Electric Vehicles
Get PDFWith the increasing integration of electric vehicles and renewable energy sources in electricity networks, key opportunities in terms of a cleaner environment and a sustainable energy portfolio are unlocked. However, the widespread deployment of these two technologies, can entail significant challenges for the electricity grid and in a larger context for the society, when they are not optimally integrated. In this context, smart charging of electric vehicles and vehicle-to-grid technologies are being proposed as crucial solutions to achieve economic, technical and environmental benefits in future smart grids. The implementation of these technologies involves a number of key stakeholders, namely, the end-electricity user, the electric vehicle owner, the system operators and policy makers. For a wider and efficient implementation of the smart grid vision, these stakeholders must be engaged and their aims must be fulfilled. However, the financial, technical and environmental objectives of these stakeholders are often conflicting, which leads to an intricate paradigm requiring efficient and fair policies. With this focus in mind, the present research work develops multi-objective optimisation algorithms to control the charging and discharging process of electric vehicles. Decentralised, hybrid and real-time optimisation algorithms are proposed, modelled, simulated and validated. End user energy cost, battery degradation, grid interaction and CO2 emissions are optimised in this work and their trade-offs are highlighted. Multi-criteria-decision-making approaches and game theoretical frameworks are developed to conciliate the interests of the involved stakeholders. The results, in the form of optimal electric vehicle charging/discharging schedules, show improvements along all the objectives while complying with the user requirements. The outcome of the present research work serves as a benchmark for informing system operators and policy makers on the necessary measures to ensure an efficient and sustainable implementation of electro-mobility as a fundamental part of current and future smart grids
Development of a Biderectional Charger for Electric Vehicles
Get PDFL'incontrollata carica di Veicoli elettrici rappresenta un peso e a volte un danno per la rete. Tra le soluzioni proposte le tecnologie G2V (Grid to Vehicle) e V2G (Vehicle to Grid) sono quelle maggiormente nominate. In G2V è possibile il controllo della potenza scambiata con la rete mentre con il V2G è possibile anche fornire potenza alla rete agendo come un generatore. Nella tesi un carica batterie bidirezionale è stato simulato, costruito e testato tramite dSPACEope
Development of a Biderectional Charger for Electric Vehicles
Get PDFL'incontrollata carica di Veicoli elettrici rappresenta un peso e a volte un danno per la rete. Tra le soluzioni proposte le tecnologie G2V (Grid to Vehicle) e V2G (Vehicle to Grid) sono quelle maggiormente nominate. In G2V è possibile il controllo della potenza scambiata con la rete mentre con il V2G è possibile anche fornire potenza alla rete agendo come un generatore. Nella tesi un carica batterie bidirezionale è stato simulato, costruito e testato tramite dSPAC
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
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