Search results for "PROTECTION SYSTEMS"
showing 10 items of 12 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…
SISTEMI DI CORONAMENTO E SMALTIMENTO DELLE ACQUE METEORICHE : LA REGOLA DELL'ARTE DAI TRATTATI AI MANUALI
2018
Il saggio approfondisce gli aspetti storici e costruttivi dei cornicioni che, da elementi di protezione, possono divenire, a causa della propria forma, talvolta anche elementi di degrado e dissesto. La struttura del testo del presente volume si compone di tre parti principali, presentando alcuni aspetti tecnici e questioni di non comune attenzione. La prima parte analizza una disamina sui valori formali e materiali del cornicione; esso presenta, infatti, caratteri complessi e riassume, proprio per la doppia valenza di ornamento (coronamento dell’edificio) e componente funzionale (sistema di allontanamento delle acque meteoriche dalla facciata) le problematiche che derivano da esigenze forma…
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…
DEVELOPMENT ANALYSIS OF SMART DISTRIBUTION GRIDS IN PRESENCE OF DISTRIBUTED GENERATION
The integration of distributed generation (DG) units in power distribution network has become increasingly attractive multi-faceted paradigm as economic and environmental factors drive new technologies to be more efficient and less polluting than their earlier counterparts. The installation of DGs impacts critically on the planning and operating characteristics of the distribution network. Type, location, number and capacity of DG are essential factors for studying the effect of DGs on the system behavior. Some possibilities to handle grid planning and operating issues are addressed in this thesis. Firstly, the effect of DG on the power losses of a distribution network is introduced and the…
An interface protection system based on an embedded metrology system platform
2021
Abstract The aim of this work is to present an interface protection system (IPS) for Distributed Generators (DG) and Energy Storage Systems (ESS). The new prototype of IPS guarantees standard protection requirements, in terms of both voltage and frequency measurement accuracies and trip times. Moreover, it has the additional functionalities of implementing a communication link between the Distribution System Operator (DSO) and the DG and ESS Inverter. The new IPS is based on a smart meter platform with an integrated power line communication modem. Moreover, it has also an integrated metrology section. Experimental tests will show how this last feature allows a significant reduction of the m…
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…
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…
Constitutional Law II Lecture Handouts
2019
El documento forma parte de los materiales docentes presentados a la convocatoria de incentivos del Servicio de Política Lingüística de la Universitat de València. El Derecho Constitucional II es una asignatura obligatoria que se imparte durante el primer semestre del segundo año académico del Grado en Derecho, y aborda el sistema de derechos fundamentales y libertades públicas en el ordenamiento constitucional español. Los principales contenidos de la asignatura son: la importancia de los derechos fundamentales y algunas cuestiones terminológicas; la evolución histórica (en general y dentro del constitucionalismo español) de los derechos y libertades; Una teoría general de los derechos y d…