1,720,975 research outputs found
Voltage control on LV distribution network: Local regulation strategies for DG exploitation
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Sizing a storage system useful for the provision of ancillary services [Dimensionamento di un sistema di accumulo utile alla fornitura di servizi ancillari]
No full textVirtual Power System: modello di microrete connessa al sistema primario
No full textL’articolo propone un modello, denominato Virtual
Power System (VPS), atto a coordinare le risorse di generazione e
di carico, siano queste connesse in un unico nodo o distribuite su
più nodi, al fine di regolarne i flussi di potenza all’interfaccia con
la rete primaria. Il modello VPS ha come obiettivo la
massimizzazione della capacità del sistema elettrico di integrare
Fonti Energetiche Rinnovabili (FER). Data la natura delle FER,
intermittenti e non programmabili, l’articolo si focalizza sul
dimensionamento di un Sistema di Accumulo per
approvvigionare le risorse di regolazione (servizi ancillari)
necessarie alla loro efficiente integrazione: regolazione primaria
di tensione, di frequenza e correzione degli sbilanciamenti fra
produzione programmata e misurata
COORDINATION OF INTERFACE PROTECTION SYSTEMS FOR DG APPLICATIONS IN MV DISTRIBUTION NETWORKS
No full textThe Dispersed Generation (DG) is a form of production based either on renewable energy sources (such as wind and solar photovoltaic) or on conventional energy (such as small gas engines, tipically CHP). In the near future, the growing concern for environmental issues as well as for the security of the supply system is expected to lead to the development of local renewable DGs connected to the distribution network, both Medium Voltage (MV) and Low Voltage (LV) system, which has been designed to host only passive users. Such network architecture, chosen when DG was rare, today can be considerably impacted for operation, control, protection and reliability issues
Distributed Generation Integration in the Electric Grid: Energy Storage System for Frequency Control
Full text linkDuring the last few years generation from renewable energy sources (RESs) has grown considerably in European electrical networks. Transmission system operators are greatly concerned about the impact of RESs on the operational security and efficiency of their networks and more in general of the ENTSO-E interconnected system. Grid codes are to be revised in order to harmonise the rules regarding the connection of RES power plants. A main issue concerns frequency control: frequency is greatly affected by RESs intermittency and its deviations must be limited as much as possible in order to guarantee a suitable level of power quality. To improve frequency stability, in the future, Grid codes could extend frequency control requirements also to RES units, whereas today they are applied only to conventional power plants. Energy storage systems can be a possible solution to increase the flexibility and performance of RES power plants: they allow generators to modulate their power injections without wasting renewable energy. In this paper, the authors studied the suitability of extending frequency control to RES units integrating them with energy storage systems. In particular, the paper focuses on the impact of frequency control on the storage lifetime by analysing the power charge/discharge in response to real frequency oscillations
AlpStore Project: A Viable Model for Renewables Exploitation in the Alps
Full text linkAbstractNowadays, the integration of intermittent and unpredictable Renewable Energy Sources (RESs) has led to new issues for the electrical system. The paper proposes a model, named Virtual Power System (VPS), which enables the management of generators and loads as a single (virtual) entity in order to achieve a “global” benefit, i.e. to improve the capability of the grid to host RESs. Moreover Energy Storage Systems (ESSs) could be integrated in the VPS in order to provide ancillary services: voltage regulation, primary frequency regulation and exchange profiles adjustment for a better RESs programmability. This work proposes a quantitative approach for ESSs design and integration in a VPS. Numerical results are reported with respect to an experimental application in the AlpStore project (Alpine Space Program 2007-2013)
Dispersed generation in MV networks: performance of anti-islanding protections
No full textThe growing development of Dispersed Generation
drives to a novel management of distribution networks in order
to take advantages of this new form of generation. In particular
the DG determines different power flows along distribution
feeders modifying voltage profiles and fault levels and
introducing new issues in protection systems. This paper
addresses the issues of islanding of a portion of the medium
voltage system in different operating conditions. The aim is to
evaluate the most used passive methods performances, in
particular with respect to the Italian anti-islanding protection
systems. On the basis of the results new schemes will be proposed
to reduce anti-islanding protection bad operation
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