Uncertainty management in the measurements of low frequency magnetic fields

The paper deals with low-frequency magnetic field measurements carried out by using a broadband and isotropic instrument. These measurements are characterized by very high uncertainty values, which imply a high risk of wrong decisions when there is the need to establish if a site complies or does not comply with specified emission limits. To reduce this risk, we decided to perform the so called “uncertainty management” that is the discipline of optimizing the cost of a measurement versus the uncertainty target. The task is achieved by using the PUMA method that is an iterative technique originally conceived for geometrical and mechanical measurements. The approach is completely based on the…

Realizzazione di un campione di potenza tramite una scheda di acquisizione dati commerciale

PC-Based Measurement Instruments: Uncertainty Assessment Under Electromagnetic Disturbances

Performances of rainfall energy harvester

In this paper the performances of rainfall energy harvesting by means of piezoelectric transducers is presented. Diverse studies agree on the level of suitable generated voltage on the electrodes of a piezoelectric transducer subjected to rainfall, but a complete characterization on the supplied power is still missing. This work, in order to limit optimistic forecasts, takes into account the behavior of the transducers subjected to real and also artificial rainfall, condition that has shown promising behavior in laboratory. In order to increase the energy harvesting and also define its limits different loads have been taken into account. Only commercial transducers have been considered: a l…

Design and control of an innovative electronic load for the photovoltaic module characterization

The paper proposes a new electronic load setup for a fast, low-cost and standard-compliant characterization of a photovoltaic module. The approach is based on the use of a DC-DC converter, exploiting its ability to emulate a resistor. In particular, a Buck-Boost converter topology is employed. The model is implemented in the Simulink/SimPower System environment. A commercial PV Conergy E215P photovoltaic module is used in order to evaluate the performances of the proposed electronic load and to validate the proposed approach.

The process of developing Open Data guidelines for the city of Palermo: A best practice of citizen participation

Double squirrel cage induction motors: A new approach to detect rotor bar failures

The purpose of this paper is to present a diagnosis technique, for rotor broken bar in double cage induction motor, based on a combined use of frequency sliding and wavelet transform analysis, to isolate the contribution of the rotor fault components issued from vibration signals in a single frequency band. The validity of the proposed diagnosis approach is not limited to the analysis under steady-state operating conditions, but also for time-varying conditions where rotor fault components are spread in a wide frequency range.

Characterization of interior permanent magnet synchronous motors for loss model algorithm identification

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 with the va…