Search results for "33"
showing 10 items of 1917 documents
Metodi di Previsione del Collasso di Tensione nelle Reti Elettriche di Distribuzione
2005
Vari tipi di eventi contingenti, perturbazioni o situazioni di funzionamento critiche, possono portare un sistema elettrico in condizioni di instabilità e al blackout. Il termine stabilità di tensione è riferito in genere ad un sistema elettrico che si trova a lavorare in prossimità della condizione di carico massimo e non più in grado di soddisfare ulteriori incrementi del carico stesso, pena un progressivo e rapido abbassamento della tensione nei nodi della rete e il blackout del sistema per collasso della tensione. Nella memoria vengono presentate due diverse metodologie per lo studio della stabilità delle reti radiali di distribuzione e la previsione del collasso di tensione. La prima m…
Aspetti tecnico-gestionali della progettazione
2013
Frequency Dynamics in Fully Non-Synchronous Electrical Grids: A Case Study of an Existing Island
2022
The operation of a power system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the design and the control of the system. Existing literature on the integration of renewable energy sources in isolated systems mainly focuses on energy aspects or steady-state issues, and only a few studies examine the dynamic issues of autonomous networks operated with fully non-synchronous generation. A lack of research can be found in particular in the determination of the required amount of grid-forming power, the selection of the number and rated power of the units which should implement the grid-forming controls, and the relative locations of …
Critical Raw Materials and Supply Chain Disruption in the Energy Transition
2022
The energy transition towards efficient energy production, transport, and use, renewable energy (RE) technologies and innovative energy management brings benefits to reducing greenhouse gas (GHG) emissions and achieving climate targets. The transition requires resources, minerals, metals, and materials for RE technologies themselves, for example, solar photovoltaics (PV), hydrogen fuel cell vehicles (HFCVs) as well as innovative supporting technologies for variable RE, for example, energy storage systems (ESSs). This requirement of resources and materials occurs over the whole supply chain of the technologies, from the extraction of resources, the manufacture of technology, and the deployme…
Maximizing energy transfer and RES integration using dynamic thermal rating. Italian TSO experience
2019
The production of electricity from wind and other renewable sources is rapidly increasing all over the world, causing significant changes in the management of electrical systems. The current structural asset is not adequate to manage this growing generation of energy. The hypothesis of construction of new power lines would mean taking into consideration economic, political and social problems. The following paper reports the experience gained by the Italian TSO, Terna S.p.A, on the use of the DTR (Dynamic Thermal Rating), which is able to dynamically calculate the real transport capacity of an overhead power line. The results obtained are en- couraging as they show how it is possible to inc…
Flexibility of grid interactive water heaters: The situation in the US
2023
Among different solutions to increase flexibility of electricity system, grid interactive water heaters (GIWHs) can make a large contribution, against a relatively low cost. They can advantageously be used within a single building, a local energy community or within an entire distribution grid, thanks to the very fast response time, low cost, highly distributed resource and widely demonstrated technology. In the near future, the flexibility potential of GIWHs will certainly increase, thanks to the advantageous flexibility programs that have been implementing in some area of the world, with the aim of coordinating several million of GIWHs with the electricity network. In this study, we asses…
An analytical model for PQ sources in backward/forward methods for distribution networks analysis
2004
In this paper a model of PQ sources useful for distribution systems analysis is developed. In the considered systems there are, in addition to HV/MV sources, other PQ buses, namely active and reactive power supply nodes (Vδ nodes). The general solution strategy is an iterative forward/backward method, in which the state variables are the node voltages. If it is weakly meshed, the network is turned into radial by means of cuts and compensation currents. After the presentation of the general problem, the equations expressing the unknowns for the PQ nodes are treated in detail. These equations belong to the backward sweep of the algorithm. The methodology has been implemented and applied so as…
A new model of PV nodes in distribution networks backward/forward analysis
2004
In this paper a new model of PV nodes is developed; the model is aimed for the distribution systems load flow analysis and, in particular, for the iterative forward/backward method. If the network is weakly meshed, it is turned into radial by means of cuts and compensation currents. After the presentation of the general problem and the state of the art on the subject, the equations expressing the unknowns for the PV nodes are treated in detail. These equations belong to the forward sweep of the algorithm. The methodology has been implemented and applied so as to test its performance in terms of calculation times and precision. The obtained results confirm the efficiency of the proposed appr…
Dynamic Thermal Rating degli elettrodotti in Alta Tensione. Un caso studio nella rete siciliana
2013
I dispositivi DTR (Dynamic Thermal Rating) permettono un miglior utilizzo degli elettrodotti esistenti, in un’ottica di ottimizzazione dell’infrastruttura elettrica.
Modelli e strategie per la definizione di strumenti software per la simulazione integrata di distretti energetici in ambiente dedicato
2012
Il presente Rapporto, strutturato in due parti (Parte Prima: “Modelli e strategie per la simulazione di distretti energetici” e Parte Seconda: Definizione e sviluppo di strumenti software per la simulazione integrata di distretti energetici in ambiente dedicato), descrive le attività svolte dal personale del DIEETCAM dell’Università degli Studi Palermo nell’ambito della prima fase delle attività di ricerca dal titolo: “MODELLI E STRATEGIE PER LA DEFINIZIONE DI STRUMENTI SOFTWARE PER LA SIMULAZIONE INTEGRATA DI DISTRETTI ENERGETICI IN AMBIENTE DEDICATO”, oggetto dell’Accordo di Collaborazione tra ENEA e DIEETCAM sottoscritto in data 27 gennaio 2012. Scopo del presente accordo di collaborazio…