1,721,055 research outputs found
La sessione 6 della conferenza Cired 2009. La rete di distribuzione: mercato elettrico e regolazione
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Dispersed generation impact on distribution network losses
No full textDistribution systems are subject to increasing penetration of dispersed generation. The energy injections of the generators impact on many technical issues, including energy losses occurring in the grid. Given the technical and economic importance of losses, several statistical approaches are proposed in the literature to evaluate the effects of dispersed generation on the energy lost in distribution networks. In principle, these approaches require a great number of load flow calculations. This paper provides a novel index aiming to avoid complex and computationally expensive statistical analysis for loss assessment. Such an index does not require any detailed characterisation of the energy flows over the network (load flow calculations). The performance of the index is tested using a model of a real medium voltage network in a wide set of generation scenarios. Each scenario is defined by a Monte Carlo algorithm that was developed ad hoc for this study. Moreover, advanced convergence criteria are provided to optimise the number of scenarios to process
L'accumulo elettrico nelle reti di distribuzione
No full textIl presente articolo esplora le opportunità di utilizzo di sistemi di accumulo dell’energia elettrica di tipo elettrochimico (batterie) nelle reti di distribuzione nazionali. A partire da una panoramica delle possibili funzionalità implementabili dall’accumulo, sono poi presentate analisi numeriche atte a valutare le prestazioni dello storage nel realizzare alcune tra le funzionalità con le maggiori prospettive applicative all’interno delle reti
Hosting Capacity Analysis: A Review and a New Evaluation Method in Case of Parameters Uncertainty and Multi-Generator
Full text linkThe rapid growth of distributed energy resources exploitation can cause voltage violations and overloading on distribution grids due to the uncontrolled and unprogrammable power injections associated with dispersed generators. To overcome these issues, distributed system operators have to evaluate the maximum generation that can be hosted by distribution grids without violating the technical constraints and find the ways to increase it. In this paper, different methodologies for hosting capacity evaluation are reviewed, and a novel model to determine the hosting capacity considering grid parameters uncertainties and multi-generator connection is proposed
Electrification Processes in Developing Countries: Grid Expansion, Microgrids, and Regulatory Framework
Full text linkShortages and poor diversification of generating
capacity, high environmental impacts, and low qualities of supply
and affordability are common characteristics of the electricity
sector in most developing countries (DevCs). Recent cost
reductions in the telecommunication sector and some generation
technologies, especially renewable-based, with improved
economic feasibility have paved the way for new electric
infrastructures. This is especially true for emerging economies,
as locally dispatched hybridmicrogrids introduce flexibility and
show the promise of technical and economic advantages. The
design and integration of microgrids require detailed assessments
to ensure the effective deployment of capital to minimize
the risk of stranded assets and capital waste. Microgrids
can be considered an affordable option for a rapid response
to the electrification challenge, recognizing that, in the longer
horizon, a sharing of resources with the bulk electrical power
system will remain, technically and economically, advantageous.
This article presents a comprehensive review of the
approaches commonly adopted for microgrid electrification.
A “real-life” study case is reported to highlight the operational
challenges of a stand-alone microgrid versus a grid-connected
system. The need for an improved regulatory framework is
presented as the cornerstone problem to be solved to allow
an effective integration of microgrids in the national grid
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