1,720,979 research outputs found
Intelligent Low Voltage Regulator for Solving PV Overvoltages Problems in Power Distribution Systems
No full textThe connection of photovoltaic systems on weak electrical distribution networks can lead to unsatisfactory operating conditions for renewable energy producers due to the occurrence of overvoltages or undervoltages. In such critical situations, where electrical parameters are outside standard regulatory levels, the intervention of electrical protections can cause damage to power generation. For this purpose, the paper presents the application of an intelligent voltage regulator capable of solving voltage regulation problems in low-voltage networks. A real case study shows the results of the application of the device in electrical distribution networks with a high penetration of photovoltaic type renewable source plants. The results show the effectiveness of its application in terms of both technical and economic aspects related to the use of the proposed voltage regulator and its comparison with traditional strategies of planning expansion, highlighting the benefits for the distributor and the owners of photovoltaic plants
Economic benefits redistribution methodology for renewable energy communities
No full textA large number of renewable energy communities are expected to be created in the near future, and, also in view of the funding that has been allocated in the various national climate and energy plans, there will be interest in their development from entities with different needs belonging to the institutional, industrial, commercial, and tertiary sectors. Given the possibility that these entities will be participated in by a variety of parties (individuals, SMEs, local governments, etc.) and in view of the particular "ethical nature" of RECs, it is to be expected that the remuneration of members will be in accordance with a principle of equity and in proportion to the ability to generate income for the community itself. For these reasons, a categorization of members according to their characteristics as renewable energy producers, prosumers or mere consumers is necessary. In this context, this article, with reference to an example case related to current legislation in Italy, proposes a model for the distribution of benefits related to energy production and sharing within the renewable energy community. These benefits concern those of the energy produced and simultaneously shared/absorbed by the members of the energy community as well as those related to the valorization of the energy fed into the grid, in excess of the consumption of the users of the energy community itself. The results obtained by applying the proposed methodology for the redistribution of the economic benefits accrued by the community among its participants show the usefulness of this distribution model in quantitative and qualitative terms, according to principles of equity and proportionality
Impact of renewable energy sources and energy storage technologies on the operation and planning of smart distribution networks
No full textRenewable energy sources (RES) are gaining an increasing importance in the distribution system and they are predicted to play a more important role in the near future. Indeed, each year new generation plants are connected to the distribution networks and it appears clear that they can be no longer considered as negative loads to be connected and forgotten. The connection to power distribution networks of the growing number and capacity of RES installations implies overcoming several technical challenges for distribution network operators, that perceive RES systems has troublemakers for the electricity system.
The chapter offers a detailed view of the impacts of renewable energy sources and energy storage technologies considering their planning, management and operation on future distribution networks
Active distribution network reliability assessment with a pseudo sequential Monte Carlo method
No full textThe increasing penetration of renewable intermittent generation imposes challenges on the existing distribution infrastructure and the system operator. New power flow patterns may require changes to control strategies, enhanced distribution automation, enforcement of distribution network infrastructure and/or greater degrees of information management and control according to the active distribution network paradigm (ADN). ADN might improve the quality of service or might lead to a more risky distribution system depending on the reliability of its communication and management system. In order to provide a measure of this risk, the reliability of ADNs operation is assessed in the paper with a pseudo sequential Monte Carlo method. The procedure is used to assess the reliability of a given active distribution network in different real case scenarios
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Techno-economic evaluation of photovoltaic installations located on the premises of an end-use electric consumer
No full textThis paper focuses on the techno-economic evaluation of photovoltaic power systems after the era of feed-in tariffs in Italy. The importance of the optimal sizing of the PV system and the role of self-consumption are investigated considering two typical industrial and commercial users with different load profiles, both equipped with a photovoltaic plant. By considering the actual Italian regulatory framework, the actual costs of photovoltaic installations, and the cost of electricity, the study illustrates the conditions when investments on photovoltaic may result cost-effective with no need of direct incentives or subsidies
Variations on the Author
Full text link“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
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