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…

Radial Basis Functions for Electronic Devices Behavioral Modeling

In this paper a black-box identification technique based on the radial basis functions is used in developing global dynamic behavioural models of electronic devices from measured transient responses. This approach allows to reproduce a non-linear dynamic model of the device under modelling automatically taking into account all the physical effects relating input and output data, from measured waveform only: no knowledge of the internal structure is needed. Original application related to a bipolar junction transistor is reported and validated by comparing simulation results with measured data.

Influenza dell'incertezza relativa alla scala delle portate sulla modellazione afflussi-deflussi a scala giornaliera

Le misure di portate defluenti in un corso d’acqua sono solitamente affette da Incertezza dovuta ad una serie di cause concorrenti che influenza fortemente la risposta dei modelli afflussi-deflussi. Nella presente memoria viene analizzata l’influenza dell’incertezza relativa alla scala di deflusso sulla modellazione della risposta idrologica di un bacino idrografico a scala giornaliera. A tal fine è stato utilizzato un modello concettuale, basato sulla teoria dell’IUH (Instantaneous Unit Hydrograph), che tiene conto insieme delle trasformazioni lineari e non lineari che conducono alla formazione del deflusso fluviale a partire da dati giornalieri di pioggia, temperatura dell’aria. La Propag…

PV Reconfiguration Systems: a Technical and Economic Study

Dynamical electrical array reconfiguration strategies for grid-connected PV systems have been proposed as solution to improve energy production due to the mismatch effect of PV plants during partial shading conditions. Strategies are based on the use of dynamic connections between PV panels given by the employment of switches that allow for each panel the series, parallel or exclusion connections, physically changing the electrical connections between the related PV modules, consequentially modifying the layout of the plant. Usually the cost of the dynamic matrix is not taken into account. This novel work evaluates the economic advantages obtained by the use of reconfiguration strategies in…

Comparison of three control drive systems for interior permanent magnet synchronous motors

In a previous paper, we proposed a control strategy for interior permanent synchronous motors, which takes into account also the reduction of the motor power losses. The novelty of the suggested approach is that it takes into consideration the variations of all the motor parameters that have an influence on its efficiency. In order to verifyon the field the effectiveness of this new method, we implemented the proposed loss model algorithm in a control drive system and compared its performances, in terms of energy losses with respect to other conventional techniques.

Modelli numerici meshfree per l’analisi di problemi elettromagnetici.

Low-cost smart energy managment based on ATmega 328P-PU microcontroller

This paper presents a real-time, low-cost, wireless, AC and DC monitoring system based on an ATmega328P-PU microcontroller. The proposed system is composed by different client nodes, which have the task to measure the main electrical quantities involved in the system, and a server node that collects the data and send them to a display device. The system is well suited for a good accuracy monitoring of either AC or DC electrical quantities. In order to verify the correct operation of the system, a case study for the simultaneous monitoring of the DC and AC voltages and currents is provided.

Spatial analysis techniques for mapping the annual surface runoff in Sicily under the Budyko’s framework

This work shows a new approach, based on the Budyko framework, for mapping the mean annual surface runoff and deriving the probability distribution of the annual runoff in arid and semi-arid watersheds. We analytically provide the annual runoff distribution as the derived distribution of annual rainfall and potential evapotranspiration. The simulated long-term annual runoff and its distribution have been compared with historical records at several gauged stations, obtaining satisfactory matching.

Replacement of Vehicle Fleet with EVs Using PV Energy

The diffusion of Electric Vehicles (EVs), the reduction of environmental pollution and the production of energy from renewable sources (RES), in particular photovoltaic system, wind farm, hydroelectric plants, bioenergy and geothermal plants are the principal aspects discussed in the world. For this reason, the goal of this work is to study for 2014 year in all Italy's Regions; the energy production obtained to photovoltaic systems (PV) and the possibility to use with different percentage this energy for recharge the electric vehicles. In particular, they have been considered different scenarios in function to the km travelled per year from the population. This paper examines the integratio…

Simulation and experimental validation of multicarrier PWM techniques for three-phase five-level cascaded H-bridge with FPGA controller

The FPGA represents a valid solution for the design and implementation of control systems for inverters adopted in many fields of power electronics because of its high flexibility of use. This paper presents an overview and an experimental validation of the MC SPWM techniques for a three-phase, five-level, cascaded H-Bridge inverter with FPGA controller-based. Several control algorithms are here implemented by means of the VHDL programming language and the output voltage waveforms obtained from the main PWM techniques are compared in terms of THD%. Simulation and experimental results are analyzed, compared and discussed.

Hybrid Solar-RF Energy Harvesting Mechanisms for Remote Sensing Devices

Recently, sensor networks effectively provide many applications in different fields. The deployment of mobile sensors, unmanned aerial vehicles is to reduce the burden of energy consumption for sensor nodes. However, saving energy in such networks is still a critical issue. This paper investigates the performance of a hybrid RF-Solar harvesting circuit for remote sensing devices. The harvesting circuit can simultaneously harvest power from solar and radio frequency (RF) sources readily available in the surrounding environment. The proposed work builds RF and solar harvester circuits to create hybrid harvesting circuits for all elements in the combined sensing networks. The stand-alone RF ha…

Experimental Evaluation of Dead-Time Impacts on the Efficiency and THD for a Three-Phase Five-Level Cascaded H-Bridge Inverter

Cascaded H-Bridges Multilevel Inverter (CHBMI) is a fascinating solution for optimization purposes in several application fields. The CHBMI performance optimization can be reached both with hardware and software solutions. In detail, the CHBMI performances are a function of the modulation strategy adopted and its parameters such as modulation index, switching frequency, and dead time. This paper presents performance experimental analysis on dead time effects on CHBMI performance in terms of harmonic distortion and conversion efficiency. In this analysis, two different modulation strategies have been considered and implemented. The paper focuses on modulation strategies implemented, the test…

Modelling of Electronic Devices using Radial Basis Functions for EMC Evaluation

In this paper a black-box identification technique based on the radial basis functions (RBF) is used in developing global dynamic behavioural models of electronic devices from measured transient responses. RBF allow to reproduce a non-linear dynamic model of the device under modelling (DUM) automatically taking into account all the physical effects relating input and output data, from measured waveform only: no knowledge of the internal structure is needed. Suitable parameters have to be evaluated by using selected voltage/current identification signals that allow to build up the global model of the DUM. The development of such global model constitutes the first step for electromagnetic com…

Experimental investigation and characterization of innovative bifacial silicon solar cells

The interest towards bifacial PV technology has increased over the last years, due to its potential capability of obtaining higher efficiencies with respect to traditional monofacial cells. Thus, the aim of this work is to present an experimental investigation on an innovative photovoltaic technology, such as the bifacial solar cells based on monocrystalline substrate. This analysis is mainly based on the determination of the current density/voltage, power density/voltage, External Quantum Efficiency (EQE) and Laser Beam Induced Current (LBIC) characterization. Interesting results are presented and discussed, demonstrating that the bifacial silicon solar cells can be a very promising techno…

The use of infliximab in pediatric ulcerative colitis: A retrospective survey