Search results for " protection system"
showing 10 items of 15 documents
Enhanced islanding detection in smart interface protection systems of distributed generation
2021
The widespread presence of distributed generators (DGs) and storage systems (DSSs) in electricity grids has increased the risk of islanding occurrence. This phenomenon must be suitably managed by Distribution System Operators (DSO), in order to avoid adverse situations, in terms of grid-protection problems, equipment damage, safety hazards, power quality problems and so on. Currently anti-islanding protection functions are handled by interface protection systems (IPSs), which are built in accordance with relevant standards for DGs and DSSs connection to power systems. However, some problems may occur in case of operation within the so-called non detection zone (NDZ). This paper presents an …
Experimental evaluation of an hybrid communication system architecture for smart grid applications
2015
In this paper a new communication system architecture is proposed for the development of a SCADA system which can remotely monitor and control intelligent electronic devices (IEDs) connected to the low voltage distribution networks, i.e low voltage smart meter (SM), interface protection devises (IPS). New distributed metering systems and interface devices, together with a proper communication infrastructure (HiperLAN and narrowband power line communication (NB-PLC) on low voltage network), have been developed to allow monitoring the whole power system and controlling the distributed generators of a Smart Grid also in the presence of harmonic distortions. In this way, the electrical energy d…
A New Solution for Low-Voltage Distributed Generation Interface Protection System
2015
In this paper, a new solution is proposed for the remote monitoring and control of distributed generators (DGs) and energy storage systems (ESSs) connected to low-voltage distribution networks. The proposed system fulfills the in-force standard requirements for the connection of DGs to the utility grid. Moreover, it allows implementing some enhanced functions for the remote control of inverters of DGs and ESSs, not only in terms of disconnection but also in terms of voltage regulation and power shuttering. The proposed solution is based on a new interface protection system and a dedicated secondary substation concentrator, which allows the communication between the distributed system operat…
Child Protection in Mediterranean Countries: Italy and Greece
2023
Abstract This chapter explores the child protection systems in Italy and Greece. Both countries have to deal with immigrant children due to the conflict between the rights of minors and immigration laws on control and defense. In Italy, the child protection system is the result of a patchwork of norms and regulations addressing different societal demands and pressures. Family and cash-transfers are fundamental factors in Italy’s child welfare system. Greece, on the other hand, has adopted fragmented measures and policies connected with financial benefits, income support, social security, social care for disabled people, and rehabilitation for children at risk. The chapter also notes how the…
An Approach for the Evaluation of Risk Impact of Changes Addressing Uncertainties in a Surveillance Requirement Optimization Context
2014
This paper presents an approach for the evaluation of risk impact of Surveillance Requirement changes addressing identification, treatment and analysis of uncertainties in an integrated manner, which is intended to be used in an optimization context. It is also presented an example of application of the methodology to study a SF change of the Reactor Protection System of a Nuclear Power Plant.
Growth, Yield and Fruit Quality of 'Peluche' Loquat under Windbreak Nets.
2011
The advantages of protecting 6-year-old ‘Peluche’ loquat trees (Eriobotrya japonica Lindl.) with nets were investigated in Sicily. Vegetative and reproductive growth were measured on 20 trees under net protection and 20 in open field conditions. A neutral, 50% windbreak net (yielding 70% of light penetration) was positioned around the field and above trees to cut down wind action and other occasional extreme atmospheric phenomena. Side openings were left on the nets to provide the entrance for pollinators. Compared to trees in the open field, trees under nets showed increased vigor (trunk cross-sectional area) and fruit growth (relative growth rate), and higher yields due also to larger fru…
Unaccompanied minors: a route of childhood along Mediterranean sea
2017
In the last ten years, Mediterranean sea, seen from the island of Sicily has been a big scenery for the arrival of thousands of people from Africa, in particular from the area of Maghreb (Egypt, Tunisia, etc) and also from the Sub-Saharian area such as Gambia, Guinea, Mali and so on. In particular, Sicily has been and it continues to be a big harbor where people arrive, crossing the Mediterranean and even risking death. So, many Ong’s have met people from whatever age, whatever socio-economic condition, gender and so on who have passed through the Island. The plan of research focuses on the trip of the unaccompanied minors arriving to Sicily: in fact, analyzing the migratory phenomena which…
Open air ruins: protection systems for Lucentum Rovine all’aria aperta: sistemi di protezione per Lucentum
2013
John H. Stubbs scrive che le costruzioni, opera dell’uomo, si trovano tutte in un dinamico stato d’interscambio verso un equilibrio con le forze della natura e che il patrimonio archeologico, per la sua particolare e intrinseca fragilità, essendo costituito di materia in avanzato stato di deterioramento, è particolarmente esposto all’azione degli agenti naturali, pertanto i problemi della conservazione e della presentazione in situ dei reperti archeologici rappresentano una delle maggiori difficoltà cui vanno incontro archeologi e conservatori di elementi architettonici. Tale giudizio, profondamente vero per tanti siti archeologici extra-urbani spesso lontani da qualsiasi possibilità di tut…
Results of Angioplasty With Double-Layer Mesh Stent and Protection Systems of the Extra- and Intracranial Dissection of Cephalic Arteries
2023
Purpose: Although a majority of cervical artery dissections can be managed conservatively, patients presenting with cerebral embolization or significant stenosis require a more aggressive approach. However, complications associated with endovascular repair are quite frequent and optimal interventional technique still remains to be established. Materials and methods: The aim of this post hoc survey was to analyze results of endovascular treatments for symptomatic dissections of the internal carotid and vertebral arteries, which were performed under protection and with the use of double-layer mesh stents. During endovascular procedure catheters, stents and protection systems were tailored acc…
Un modello dinamico per la simulazione della ionizzazione di terreni non omogenei in presenza di elettrodi disperdenti elevate correnti impulsive
2008
La caratterizzazione elettromagnetica del comportamento dinamico di elettrodi interrati, disperdenti elevate correnti impulsive, costituisce uno degli aspetti primari nella progettazione di un sistema di protezione dalle fulminazioni atmosferiche (LPS). D’altra parte, elevate correnti impulsive possono causare l’insorgere di fenomeni di ionizzazione del terreno, nelle zone prossime agli elettrodi interrati, nei punti in cui il campo elettrico totale supera il valore critico. Modelli teorici e misure sperimentali correlano l’insorgere di variazioni di conducibilità del terreno in prossimità di elettrodi interrati interessati da elevate correnti impulsive al fenomeno della ionizzazione del te…