Search results for "MISURE"

Sistema di misura per l’analisi spettrale di segnali non stazionari: implementazione in VHDL per lo sviluppo di un prototipo su FPGA

2010

Attivita’ di misura delle concentrazioni di radionuclidi naturali gamma-emittenti nel particolato atmosferico a Palermo

2013

Sulla determinazione della curva di efficienza per l’analisi spettrometrica gamma di filtri di particolato atmosferico

2011

Uno dei problemi più complessi nella misura con spettrometria gamma di campioni di particolato atmosferico raccolto su filtro è la determinazione, per la geometria di misura adottata, della curva di efficienza fotoelettrica (Full-Energy_Peak Efficiency–FEPE). La geometria di misura che viene presa in considerazione, denominata « packet-sample », dimensioni 6 cm × 6 cm × 0,7 cm, si realizza a partire dal filtro di cellulosa di grandi dimensioni (45 cm x 45 cm) adoperato per il campionamento che, dopo l’aspirazione, viene spruzzato, tagliato, composto e pressato fino a raggiungere le dimensioni indicate per la misura spettrometrica. Le principali difficoltà sono legate alle dimensioni del fil…

Rotor bar pre-fault detection in the squirrel cage induction motors

2015

The paper deals with a diagnosis technique to detect and monitor incipient faults in the rotor bars of squirrel gage induction motors. The failure mode analysis is performed monitoring the motor axial vibrations. To accomplish the task, the authors present a mathematical model that allows relating the occurrence and the severity of the faults to the presence and the magnitude of some frequency components of the axial vibration spectrum. To validate the proposed approach, the results obtained by applying the mathematical model are compared with the ones obtained by experimental tests done on both healthy and faulty motors.

Characterization of the parameters of interior permanent magnet synchronous motors for a loss model algorithm

2017

Abstract The paper provides the results of a detailed experimental study on the variations of the characteristics of an interior permanent magnet synchronous motor, when load, speed and/or magnetization conditions vary. In particular, the characterization is carried out by assessing, for several working conditions, the motor parameters that influence its efficiency. From the knowledge of the variability of these parameters, it is possible to develop a dynamic model of the motor, which accurately describes its behaviour and allows estimating the power losses for whatever speed and load. In order to validate the model, the values of the power losses obtained by using the model are compared wi…

Speed control of double-sided linear induction motors for automated manufacturing systems

2014

The double-sided linear induction motor (DLIM) is acquiring a significant relevance in the application of automated manufacturing systems. For this purpose, the modeling, simulation and determination of the parameters of a double-sided linear induction motor is presented in this paper. Furthermore, the DLIM constant voltage/frequency speed control system for this application is here described. In order to verify the performance of the proposed system, a suitable test bench for the DLIM motor is set-up. From the good agreement shown by the comparison between measured and simulated results, it can be stated that the DLIM model and the speed control system is successfully validated. © 2014 IEE…

A self-synchronizing instrument for harmonic sources detection in power systems

2004

The deregulation of energy markets holds out new prospects for contract between customers and utilities, in which the price of energy can depend on voltage quality and load characteristics, as well as on the responsibility for disturbances caused to supply voltage in power systems. In this context, harmonic sources detection is one of the main problems, because of equipment sensibility and the proliferation of loads which absorb non-sinusoidal currents. In this paper the authors present a new instrument based on a time domain method for the detection of harmonic active powers in three-phase systems, which can be usefully applied even in the presence of unbalance or asymmetry. The amplitude …

Metrological characterization and operating principle identification of static meters for reactive energy: an experimental approach under nonsinusoid…

2009

In this paper, an experimental approach is proposed for the metrological characterization of the static meters for reactive energy and for the individuation of their operating principle in nonsinusoidal conditions. The proposed approach was developed by starting from the only available accuracy test condition in the presence of the harmonics introduced by the standards for active static meters. In this paper, the proposed approach is described, and some experimental tests are presented, which were performed on some meters of different accuracy classes and with both known and unknown operating principles.

Polluting loads detection in power systems: a decision-making strategy based on nonactive power measurements

2010

In this paper a novel decision-making strategy is proposed for the detection of polluting loads in three-phase power systems. It makes use of simple indices, which are expressed as a function of some nonactive power quantities, previously proposed by the authors and derived from the approach of the IEEE Std. 1459–2000. The decision-making rules for the proposed strategy are presented and discussed, by means of some simulation tests.

The Measurement of Reactive Energy in Polluted Distribution Power Systems: An Analysis of the Performance of Commercial Static Meters

2008

This paper presents a comparative analysis of the performances of both a traditional induction meter and various types of commercial static meters for reactive energy in the presence of harmonic distortion. This is a topical issue, since there are several types of static meters on the market, based on different principles of construction. In accordance with current standards, these meters are designed to operate in sinusoidal conditions and their performance is not tested in the presence of harmonic distortion. However, with the increase of pollution levels in power systems, the meters may be used even in the presence of distorted voltages and/or currents; in such cases, their accuracy may …