Search results for "Protection system"
showing 10 items of 34 documents
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…
Threatened Plant Communities as an Indicator of Fishponds Value: An Example from Silesia (Sw Poland)
2007
This paper presents the first results of studies of fishpond plant communities of Silesia (SW Poland). On fishponds, many rare and threatened plant associations were found, especially within the aquatic, mud and rush communities. Among the most interesting are: Lemno minoris-Salvinietum natantis, Trapetum natantis, Eleocharetum ovatae and Scirpetum radicantis. The majority of the above-mentioned associations occur only in artificial fishpond reservoirs within the region. Thus, to reach an effective level of conservation, co-operation between biologists and owners, and integration of conservation and agricultural activities, have to be achieved. This would be the only way to stop the impover…
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…
A Methodology for Protection of Trees Against Lightning Strikes as a Measure to Prevent Fires and Loss of Human Life
2021
Some regions may be characterized by a very low annual lightning ground flash density, and yet lightning strikes seem to have been in those areas the cause of widespread wildfires in forested areas. Due to global climate change, these occurrences seem to be an increasing threat. In this paper, the authors discuss the withstand capability of trees against lightning and introduce the criteria for the deployment of tree lightning protection systems (TLPS) to protect forested areas, where deemed necessary by the tree risk assessment. This work analytically identifies the critical trunk radius of the tree below which the tree may explode in the case of a lightning strike and ignite the surroundi…
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…
Verifying the effect of distributed generators on voltage profile, power losses and protection system in radial distribution networks
2013
In the recent years the electrical power networks are undergoing rapid restructuring and developing process worldwide. Advancement in technologies and concern about the environmental impacts have led to increase interconnection of renewable energy based distributed generations (DGs) in distribution networks. The DGs have significant impacts on the distribution systems; these impacts may be either positively or negatively depending on the modified interconnected DG distribution network structure. It will be necessary to consider many issues concerning these impacts. In this paper, an investigation of DGs impacts on voltage profile, power losses, and protection system in radial distribution n…
Protection of Trees against Lightning Strikes as a Measure to Prevent Fires and Loss of Human Life
2021
Lighting strikes have been the catalyst of massive uncontrolled fires in areas of combustible vegetation. In some regions, lightning strikes may be a relatively unusual occurrence (e.g., California), but instead they seem to have become a major contributor to the propagation of wildfires, as a byproduct of climate change. Given such unusual weather, wildfires originating from lightning are an increasing threat. In this paper, the authors discuss the withstand capability of trees against lightning and introduce a proactive approach to prevent wildfires by the deployment of tree lighting protection systems (TLPS) to protect forested areas, where deemed necessary by the tree risk assessment.
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…
On the distribution of lightning current among interconnected grounding systems in medium voltage grids
2018
This paper presents the results of a first investigation on the effects of lightning stroke on medium voltage installations' grounding systems, interconnected with the metal shields of the Medium Voltage (MV) distribution grid cables or with bare buried copper ropes. The study enables us to evaluate the distribution of the lightning current among interconnected ground electrodes in order to estimate if the interconnection, usually created to reduce ground potential rise during a single-line-to-ground fault, can give place to dangerous situations far from the installation hit by the lightning stroke. Four different case studies of direct lightning stroke are presented and discussed: (1) two …