Search results for " misure"
showing 10 items of 421 documents
A back to back method for the temperature rise test of prefabricated substations: A case study
2015
In this work a back to back method is presented which allows to develop heating tests of prefabricated secondary substations with a limited number of supplying equipment (an induction regulator and a capacitor bank). The proposed method makes use of the transformer tap changers to create a voltage difference on the medium voltage side. In this way, only an adjunctive low voltage supply is needed. With the proposed test system, the heating tests are developed on a 1000 kVA prefabricated substation. Thanks to the experimental tests, the class of enclosure of the substation and the operating temperature and resistance of the power transformers are determined, according to the recommendations o…
Hybrid passive and communications-based methods for islanding detection in medium and low voltage smart grids
2013
Islanding condition takes place when a distributed generator (DG) continues to power a part of the grid even if power from electric utility is no longer present. Adverse effects of islanding are power quality deterioration, grid-protection interference, equipment damage, and personnel safety hazards. For these reasons, DG systems must detect an islanding condition and immediately disconnect from the grid (anti-islanding protection). This paper proposes an hybrid solution, for both low voltage (LV) and medium voltage (MV) applications, which makes use of passive and communication-based methods for islanding detection. Among the existing communication technologies, the study is focused on pow…
GEL DOSIMETERS FOR RADIOTHERAPY APPLICATIONS: RESULTS OF A “RESEARCH PROJECT OF NATIONAL INTEREST” (PRIN)
2016
Introduction: Gel dosimeters for three-dimensional mapping of radiotherapy doses were introduced at Yale University in the mid-1980’s. Soon after, research and development in this field also started in Italy. Early work was done at the Istituto Superiore di Sanità and at the Universities of Pisa and Milan. Several institutes now collaborate on this topic with the goal of developing new formulations of hydrogel matrices with improved characteristics of stability, sensitivity and spatial resolution compared to those of earlier Fricke-gel and polymer-gel systems. Materials and methods: Contrary to earlier gels based on natural gelling agents, such as porcine skin gelatin and/or agarose, which …
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…
Development of a Coupling System for Medium Voltage Power Line Communication in the CENELEC A Frequency Band
2016
In this paper the performances of a new power line communication (PLC) coupling system for medium voltage (MV) smart grids are investigated in the CENELEC A frequency band (i.e. 3 - 95 kHz). The new coupling solution is based on the use of the capacitive divider of the voltage detecting system (VDS) as PLC coupler to the MV network. According to IEC 61243-5, VDS are worldwide used to reveal the presence of the mains voltage to ensure the safety of the operators. A proper interface circuit has been invented and patented to couple the PLC signal through the VDS. In this way no dedicated MV PLC coupler is required, thus avoiding the related costs of the coupler, of its installation, and those …
Electromagnetic immunity analysis of a new interface device with power line communication for smart grid and energy storage applications
2013
An analysis of EMC standards related to smart grid devices with PLC port has been carried out and the standardization lacks have been pointed out with reference to the evaluation of electromagnetic immunity to narrowband, coming from other communication systems connected to the grid, and RF disturbances conducted disturbances, usually present in a power grid. In particular, the paper analyses the electromagnetic conducted immunity of a new interface protection device (ID) for smart grid and energy storage applications. The new ID is equipped with a measuring board, a STM32 microcontroller, for data elaboration and memorization, and a ST7580 N-PSK powerline transceiver. An experimental test …
Environmental Radioactivity Measurements in the Mediterranean Area
2010
In the framework of an environmental radioactivity monitoring program, a research activity concerning an optimization of techniques for sampling and measurement of environmental radioactivity was performed at the Nuclear Engineering Department (DIN) of Palermo University. Al-though initially aimed to the analysis of monitoring data of the local network installed at the nuclear research reactor AGN-201 "COSTANZA" of Palermo University, in the following years the studies were oriented to improve the sampling facilities and measurement systems with the aim to achieve also detection limits as low as possible. The activity has allowed to collect numerous data of nuclide activity concentration fo…
L'allontanamento del detenuto-padre dal domicilio al vaglio della Corte costituzionale
2019
Con la sentenza n. 211 del 2018, la Corte costituzionale ha dichiarato l’illegittimità costituzionale dell’art. 47-ter, comma 1, lettera b), e comma 8, della legge 26 luglio 1975, n. 354, nella parte in cui non limita la punibilità, ai sensi dell’art. 385 del codice penale, al solo allontanamento che si protragga per più di dodici ore, come stabilito dall’art. 47-sexies, commi 2 e 4, della legge 26 luglio 1975, n. 354, sul presupposto, di cui all’art. 47-quinquies, comma 1, della medesima legge, che non sussista un concreto pericolo di commissione di ulteriori delitti. Sebbene le tappe del percorso argomentativo seguito dalla Corte costituzionale possano considerarsi prevedibili, la sentenz…
Impiego di tecniche di misura DIC per lo studio di sistemi di sintesi ortopedici
2009
Nel presente lavoro si esamina la possibilità di impiego di tecniche di correlazione digitale di immagini in configurazione stereoscopica per la valutazione sperimentale in-vitro del campo tridimensionale di spostamento e deformazione generato sottocarico sull’osso trattato con un impianto di sintesi intramidollare. L’inserimento di una rima di frattura praticata sulla diafisi media dell’osso sintetico, ha consentito di studiare il differente comportamento nelle due condizioni limite del decorso clinico a seguito del trattamento chirurgico di impianto. I risultati preliminari riportati nel lavoro dimostrano l’efficacia dell’approccio proposto, che consente di valutare sperimentalmente lo st…
Improvement of Hall Effect Current Transducer Metrological Performances in the Presence of Harmonic Distortion
2010
The performance of Hall effect current transducers (HECTs), under distorted waveform conditions, is usually characterized by means of a frequency response test. In this paper, it was investigated if frequency response is able to correctly evaluate the ratio and the phase errors under distorted conditions. Two HECTs, with the accuracy class level of 1% and 0.5%, respectively, were experimentally characterized under two conditions: 1) sinusoidal excitation with frequencies ranging from 50 to 750 Hz, which is the well-known frequency response test, and 2) nonsinusoidal excitation using fundamental frequency and one harmonic with adjusted amplitude and phase shift. It was found that ratio and p…