1,720,962 research outputs found
30. PREDISPOSIZIONI DI STRUMENTI DI PIANIFICAZIONE E DI REGOLAMENTI PER GARANTIRE IL RISPETTO DEI LIMITI DI LEGGE, LA TUTELA DEL PAESAGGIO E PER MINIMIZZARE IL RISCHIO DI ESPOSIZIONE DELLA POPOLAZIONE AI CAMPI ELETTROMAGNETICI NEL TERRITORIO DI PARTANNA
No full textInertia Requirements Assessment for the Italian Transmission Network in the Future Network Scenario
No full textRenewable Energy Sources (RES) are replacing conventional Synchronous Generators (SGs) in the Italian generation scenario, thus leading to a decrease of the electric system inertia and to possible problems of inertia shortage. This paper provides a method for the estimation of the inertia that will be required to be installed in the Italian Grid in the 2030 year with the aim of limiting the Rate of Change of Frequency (RoCoF) within the desired interval. Four technologies are considered for the provision of additional inertia: Photovoltaic (PV) systems, Wind Turbine (WT) plants, Battery Energy Storage Systems (BESSs) and Synchronous Compensators (SCs). The proposed method provides also the optimal mix among the aforementioned technologies according to a techno-economic indicator. The 2030 scenario has been characterized thanks to the data provided by Terna S.p.A, the Italian Transmission System Operator (TSO)
An accurate measurement procedure of power losses variations in electrical drives
Full text linkThis paper presents a general procedure for the accurate measurement of power losses variations in electrical drives. More specifically, the paper addresses the issue related to the efficiency comparison of electrical drive controlled with different control algorithms. This procedure is applied to a permanent magnet synchronous motor drive, assessing its power losses by means of two different measurement systems, each one characterized by different accuracy and cost. The comparison between these two systems is carried out for different working conditions in terms of load, speed and magnetization in order to demonstrate that the power losses variations can be accurately measured even with not expensive instrumentation
Load Flow Assignments’ Definition from Day-Ahead Electricity Market Interconnection Power Flows: A Study for Transmission Networks
No full textThe mass introduction of renewable energy sources (RESs) presents numerous challenges for transmission system operators (TSOs). The Italian TSO, Terna S.p.A., aims to assess the impact of inverter-based generation on system inertia, primary regulating energy and short-circuit power for the year 2030, characterized by a large penetration of these sources. The initial working point of the Italian transmission network has to be defined through load flow (LF) calculations before starting dynamical analyses and simulations of the power system. Terna 2030 development plan projections enable the estimation of active power generation and load for each hour of that year in each Italian market zone, as well as cross-zonal active power flows; this dataset differs from conventional LF assignments. Therefore, in order to set up a LF analysis for the characterization of the working point of the Italian transmission network, LF assignments have to be derived from the input dataset provided by Terna. For this purpose, this paper presents two methods for determining canonical LF assignments for each network bus, aligning with the available data. The methodologies are applied to a simplified model of the Italian network, but they are also valid for other transmission networks with similar topology and meet the future needs of TSOs. The methods are tested at selected hours, revealing that both approaches yield satisfactory results in terms of compliance with the hourly data provided
Optimal inertia allocation in future transmission networks: A case study on the Italian grid
No full textThe paper introduces a technical-economic methodology to estimate the additional inertia required in a Transmission Network for future scenarios and presents an algorithm to optimally dispatch it among different sources and interwork busbars. First, the amount of inertia is calculated to constrain the Rate of Change of Frequency (RoCoF) within sustainable limits. Then, such inertia is allocated accounting for the contributions from Renewable Energy Sources (RESs) and Battery Energy Storage Systems (BESSs), complemented by the deployment of Synchronous Compensators (SCs) across various nodes of a Transmission Network. The methodology underwent testing within the Italian Transmission Network, utilizing the informational support furnished by the Italian Transmission System Operator (TSO). Despite its simplicity, the results exhibit notable accuracy, validated through rigorous comparisons with detailed time-domain simulations. Moreover, the low computational cost of the method, allowed a statistical analysis considering all the hours of year 2030, to get information on the distributions of the quantities of interest
RoCoF Mitigation in the Italian Transmission Network: a Methodology for Inertia Optimization
No full textThe replacement of traditional Synchronous Generators (SGs) with inverter-based sources, like Photovoltaic (PV) units, Wind Turbine (WT) power plants and Battery Energy Storage Systems (BESSs), poses critical challenges for Transmission System Operators (TSOs), related to a reduction of the system inertia. In particular, the lack of inertia may lead to issues in containing the Rate of Change of Frequency (RoCoF) within the limits prescribed by grid codes. This paper proposes a methodology for estimating the need of additional inertia for the Italian transmission network in the future 2030 scenario. The methodology sets up an optimization problem able to find the best technological mix of Synthetic Inertia (SI) providing sources (PV, WT and BESS units) and of additional Synchronous Compensators (SCs) to be installed in the Italian scenario, able to limit the RoCoF of the Centre of Inertia (COI) of the Italian network within the prescribed range, while minimizing the economic costs related to inverters' control upgrade and SCs installation. The 2030 scenario is characterized thanks to the data provided by Terna S.p.A, the Italian TSO
Congestion Management in Italian HV grid using novel Dynamic Thermal Rating methods: First results of the H2020 European project Osmose
No full textThe Italian demo of the H2020 Osmose project, which stands for Optimal System-Mix Of flexibility Solutions for European electricity, is led by Terna and aims at developing a novel Energy Management System (EMS), which allows managing distributed Renewable Energy Sources (RES) and severe grid congestions. This is obtained by properly coordinating innovative flexibility resources which include Dynamic Thermal Rating (DTR) and Demand Side Response (DSR). The DTR methods proposed under this framework have been developed by Ensiel, a consortium of Italian universities active in power systems research. These solutions include a sensor-based method, based on a self-organizing sensor network composed by cooperative smart nodes deployed along the line route, and a weather-based technique, based on a thermo-mechanical model of the monitored line. The main features of these advanced solutions are described in this paper, and the first experimental results obtained on real case studies are presented and discussed in order to prove their effectiveness
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
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