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The deepening penetration of distributed energy resources into distribution networks (DNs) is causing relevant issues to be addressed by distribution system operators (DSOs), such as quality of service, security and safety, both at medium-voltage and low-voltage distribution levels. This paper presents how Unareti SpA, an Italian DSO, has addressed those challenges launching a set of research activities in different areas of distribution automation. Results collected during field experiences have been used to design the reference model of the next generation of DN secondary substations. [ABSTRACT FROM PUBLISHER]

This paper deals with the possibility of installing a double-circuit gas insulated transmission line (GIL) in the pilot tunnel of the planned new railway galleries Bolzano (Italy)- Innsbruck (Austria). This EHV transmission line could represent a new fundamental step in reconstructing the transnational networks. The high GIL power ratings together with very low power losses would be a strong and highly efficient transmission tie between Italy and Austria particularly useful for the future European Market. The steady-state regime of the line and the electro-magnetic field impact are analyzed. Moreover, the paper discusses the necessary studies to be carried out and the problems that have to be faced. [ABSTRACT FROM PUBLISHER]

The Italian regulatory authority is working toward the introduction of voltage-quality regulation. To this end, it initiated a power-quality measuring campaign and a study of customer costs. This paper summarizes the main results of these activities and provides evidence that economic losses due to very short interruptions and voltage dips can be very relevant for several sensitive industrial sectors in Italy. Despite the fact that these losses present an uneven distribution over the national economy, their magnitude justifies the intervention of a regulatory authority to limit the number of the most severe events. Nonetheless, the identification of severe events (those that fall under the responsibility of the network operator) is a difficult task. Using the available data, we test the classification table proposed in the latest version of the European Standard EN 50160 and confirm, albeit preliminarily, the usefulness of this classification for regulatory purposes. [ABSTRACT FROM AUTHOR]

In Italy, the increase of railway traffic and of the power demand by the trains, especially the high-speed trains, has caused a continuous increase of the currents through the electric traction lines rated at 3 kVdc. As a consequence, in some cases, the load currents may approach the value of the fault currents for faults located far from the supply stations. The detection of the faults in such a situation has become difficult for the electromechanical protections at present in operation in Italy in the lines above. In addition, transient phenomena related to the train absorption, frequently cause untimely trippings of the protections above. For such a reason, in the years 1999-2000, a field test campaign was performed in the 3-kVdc lines Campoleone—Cis-terna and Farneta—Montallese in Italy, in order to investigate the phenomena that lead to the untimely trippings above. On the basis of the field test campaign, it was found that such an inconvenience is related to the inner characteristics of the electromechanical protections in use. A digital protection, operating on new protective algorithms, was thus set up and thereafter put in operation in the years 2003-2004. This paper presents the basic principles of the new protection above and the results of the first two years of operation. [ABSTRACT FROM AUTHOR]

In the analysis of reliability performance of distribution utilities, as well as in continuity of supply regulation, criteria are needed for separating normal operation data from exceptional events. In recent years a number of statistical methodologies has been proposed for this purpose. We present here the new methodology that was adopted by the Italian regulatory authority at the beginning of 2008. The decision is supported by a statistical analysis of the number of faults on the medium voltage (MV) and low voltage (LV) networks, for each six-hour time interval in a three year time span, for different provinces and distribution companies. The new methodology is employed in the reward and penalty mechanisms that regulate the SAIDI, SAIFI, and MAIFI indicators and, with some original provisions, also in the Guaranteed Standard on maximum restoration times. [ABSTRACT FROM AUTHOR]