Design criteria of tubular linear induction motors and generators: A prototype realization and its characterization

In this paper a mathematical model of tubular linear induction machines (TLIM) with hollowed induced part is recalled. Moreover the design criteria of a TLIM with hollowed iron induced part are presented as well as the technological processes to be adopted and the choice of materials to construct the various parts. The methodologies for mechanical assembling and electric wiring are considered too. A prototype with bimetallic induced part has been designed and built. Finally some experimental results on electrical and mechanical variables, when the machines are used as motors, are shown.

Componenti di un impianto fotovoltaico

A prototypal architecture of a IEEE 21451 network for smart grid applications based on power line communications

This paper deals with the development of reliable measurement and communication devices and systems and their integration on a prototypal network architecture for smart grid applications, based on the use of narrowband power line communications (PLCs). The proposed solution is presented and discussed in the framework of the ISO/IEC/IEEE 21451 family of Standards. Currently, PLCs are not properly addressed by the aforesaid Standards; on the other hand, by including such issue, their guidelines could represent a common platform for the integration and interoperability of the proposed systems and devices. This would allow to exploit the benefits of the IEEE 21451 approach also for PLC-based sm…

Convolutional Neural Network for Dust and Hotspot Classification in PV Modules

20th IEEE International Conference on Environment and Electrical Engineering, EEEIC 2020, online, 9 Jun 2020 - 12 Jun 2020; Energies : open-access journal of related scientific research, technology development and studies in policy and management 13(23), 6357 (2020). doi:10.3390/en13236357 special issue: "Special Issue "Selected Papers from 20 IEEE International Conference on Environment and Electrical Engineering (EEEIC 2020)" / Special Issue Editor: Prof. Dr. Rodolfo Araneo, Guest Editor"

Environmental Impact Assessment (EIA) of Wave Energy Converter (WEC)

The Environmental Impact Assessment (EIA) is an environmental management instrument implemented worldwide. In the last years the development of Wave Energy Converter (WEC) influenced environmental research to quantify impacts on marine life. In this paper we present a case study of EIA: a real application and study of device installed in Tirren Sea (near Castellammare — Sicily).

Aspetti tecnico-gestionali della progettazione

Proof of Concept of an Irradiance Estimation System for Reconfigurable Photovoltaic Arrays

In order to reduce the mismatch effect caused by non-uniform shadows in PV arrays, reconfigurable interconnections approaches have been recently proposed in the literature. These systems usually require the knowledge of the solar radiation affecting every solar module. The aim of this work is to evaluate the effectiveness of three irradiance estimation approaches in order to define which can be well suited for reconfigurable PV arrays. It is presented a real-time solar irradiance estimation device (IrradEst), implementing the three different estimation methods. The proposed system is based on mathematical models of PV modules enabling to estimate irradiation values by sensing a combination …

Numerical Analysis of a Transposed Multiwired Armature in Electromagnetic Rail Launchers

Solid armatures in electromagnetic rail launchers have to undergo severe electromagnetic, mechanical, and thermal stresses. These stresses are unevenly distributed in the armature mainly due to the velocity skin effect. Contrasting this effect reduces the peak to average ratio of the stresses and allows better performance of the device. In this article, the behavior of a transposed multiconductor solid armature is numerically investigated by the research code electric network for electromagnetics (EN4EM) developed at the Department of Energy, System, Territory and Construction Engineering (DESTEC), University of Pisa, Pisa, Italy. The code is based on an integral formulation that reduces th…

Experimental EMF characterization of a secondary substation

This paper presents the results of the experimental EMC characterization of a new medium/low voltage (MV/LV) secondary substation, which was developed in the framework of the research project "NEW CAB ELARC". It has two MV/LV transformers, with total rated power of 1000 kVA. To perform the experimental characterization, firstly an analysis was performed of the Italian and European standards recommendations. Different approaches were highlighted and the most appropriate procedures were identified for the measurement of the magnetic fields emissions, at power systems frequency (50 Hz) in steady-state conditions. A dedicated test lab was set up for the secondary substation characterization. Th…

A Procedure for the Producibility Curve Identification of a Dish-Stirling Plant, Starting from Experimental Data

This article presents a procedure for the producibility curve identification of a dish-Stirling plant, starting from experimental data. The producibility data was measured, recorded, analysed, filtered and monthly aggregated. Moreover, the incidence of the ambient temperature and of the mirrors cleaning on producibility data is highlighted and a procedure to normalize the measured data in temperature and cleaning level was developed. To provide a validation of the developed procedure the producibility curves at 25 °C have been obtained and compared with the one issued by the manufacturer. The two curves are in good agreement, presenting a maximum deviation of the 7 %.

WITHDRAWN: Perspective on hydrogen energy carrier and its automotive applications

First successful eradication of invasive Norway rats Rattus norvegicus from a small Mediterranean island (Isola delle Femmine, Italy)

Invasive alien species, once introduced, may affect local biodiversity, both directly (e.g. by predation) and indirectly (e.g. by reducing the vegetation cover). Among those, rats (Rodentia, Muridae) are listed among the most invasive species, exerting strong impacts particularly when introduced to island ecosystems. Accordingly, black rats Rattus rattus have been eradicated from a number of islands in the Mediterranean basin to protect breeding seabirds. Where the larger Norway rat Rattus norvegicus is present, extent of damage may be even higher. In our work, we present the results of the first eradication program dealing with Norway rats in a small Mediterranean island (Isola delle Femmi…

Axial Flux Permanent Magnet Synchronous Generators for Pico Hydropower Application: A Parametrical Study

A pico hydropower plant is an energy harvesting system that allows energy production using the power of the water flowing in small watercourses, and in water distribution network. Axial Flow Flux Permanent Magnet Synchronous Generator (AFPMSG) are particularly suitable for this application, being efficient machines that achieve high power with small dimensions. This paper presents a parametrical study of several configurations and topologies of three-phase and single-phase AFPMSG, for pico hydropower application, to assess the most suitable dimensional characteristics for the most energy production using a safe voltage of 25 V. The AFPMSGs here considered has a simple single stator and roto…

Design of Bilateral Switched Reluctance Linear Generator to Convert Wave Energy: Case Study in Sicily

The aim of this work is a case study of the adaptation bilateral switched reluctance linear generator to the exploitation of energy of the sea. This type of generator can be used to convert wave energy in electrical energy. In this paper we present an analytical sizing and FEM simulation. As for the results, analysis of the data extracted through the simulations it was possible to calculate the emf. The emf was calculated in two cases of motion of the slider: first hypothesis has set the constant speed while the second is a variable speed according to the law of an oscillatory motion of the sea.

SISTEMI FOTOVOLTAICI PER LA PRODUZIONE DISTRIBUITA DI ENERGIA ELETTRICA: ARCHITETTURE DI IMPIANTO E CRITERI GENERALI DI DIMENSIONAMENTO.

A comparison among different kinds of stator lamination in tubular linear machines

In this paper the authors perform a comparison among three different stator structures for a Tubular Permanent Magnet Linear Machine. Each structure is characterized by its own lamination which is expected to contribute to the overall performance of the machine. A detailed analysis of the main figures of merit of the three configurations has been carried out in order to identify the configuration with the best characteristics. Significant data such as flux distribution, rated voltage and current, force on the moved and power losses have been compared. The results show that the choice of a mixed stator lamination allows to improve the performance of these machines.

Experimental Test and Simulations on a Linear Generator-Based Prototype of a Wave Energy Conversion System Designed with a Reliability-Oriented Approach

In this paper, we propose a reliability-oriented design of a linear generator-based prototype of a wave energy conversion (WEC), useful for the production of hydrogen in a sheltered water area like Mediterranean Sea. The hydrogen production has been confirmed by a lot of experimental testing and simulations. The system design is aimed to enhance the robustness and reliability and is based on an analysis of the main WEC failures reported in literature. The results of this analysis led to some improvements that are applied to a WEC system prototype for hydrogen production and storage. The proposed WEC system includes the electrical linear generator, the power conversion system, and a sea-wate…

Synchronizing Interactions Between Different Types of Grid-Forming Converters in Smart Grids

The work investigates the transient synchronizing interactions between different types of grid-forming controls. Two well-known grid-forming schemes are implemented and considered for analysis: a droop-based control and a swing-based control. The two controls are examined for a temporary loss of synchronism. The analysis is performed considering two different conditions for the grid interconnecting the converters: a resistive-inductive grid and a mainly inductive grid. The first case corresponds to actual conditions in low and medium voltage applications. The second case is realized with the implementation of a virtual reactance in the grid-forming control scheme. The analysis of the result…

A Model of DC-DC Converter with Switched-Capacitor Structure for Electric Vehicle Applications

In this paper, a DC-DC converter with an innovative topology for automotive applications is proposed. The goal of the presented power converter is the electrical storage system management of an electric vehicle (EV). The presented converter is specifically compliant with a 400 V battery, which represents the high-voltage primary source of the system. This topology is also able to act as a bidirectional power converter, so that in this case, the output section is an active stage, which is able to provide power as, for example, in the case of a low-voltage battery or a supercapacitor. The proposed topology can behave either in step-down or in step-up mode, presenting in both cases a high gain…

Il Laboratorio per lo Sviluppo Sostenibile e il Risparmio Energetico (SDESLab) nell’ambito industriale siciliano

L’articolo presenta le attività del Laboratorio per lo Sviluppo Sostenibile ed il Risparmio Energetico (SDESLAB) dell’Università degli Studi di Palermo nei confronti dell’ambito industriale, con particolare riguardo a quello siciliano. Vengono illustrati gli ambiti di intervento del Laboratorio: ricerca scientifica di base, consulenza alle industrie e alle imprese, formazione, informazione e divulgazione nei vari campi dello sviluppo sostenibile con particolare riguardo a energie rinnov- abili, azionamenti elettrici, automazione industriale e gestione automatizzata dell’energia. Vengono descritte le attrezzature di cui il Laboratorio si avvale per le proprie attività, i progetti di ricerca i…

Perspective on hydrogen energy carrier and its automotive applications

The paper outlines the concept of energy carrier with a particular reference to hydrogen, in view of a more disseminated employment in the field of automotive applications. In particular hydrogen production is analyzed considering the actual state of the art and recent technologies applied in production from the primary sources (fossil fuels, renewable energies, and water electrolysis). Then the problem of hydrogen storage is considered both from technical and economical point of views. In particular, differences between physical and chemical storage are here considered with a particular glance to the most innovative technologies including carbon nanostructures. A review on the main problem…

Economic analysis on dynamic photovoltaic systems in new Italian "feed in tariffs" context

Dynamic photovoltaic generators, based on the application of solar-trackers, are able to give an increment to the electric energy production from solar source. Their realization and maintenance costs are certainly higher than those of fixed ones. In this paper the Authors propose a method to estimate the increment of electrical energy generation that must be guaranteed by a dynamic photovoltaic generator, so as its realization could be more favorable with respect to that of a fixed generator one with the same rated power. This method, developed by means of classical economic indexes like the Pay-Back-Period and the Net Present Value, takes in to account the economic incentives for the PV sy…

Vehicles PEMFC Power System Mathematical Model for Integrated Design

A magnetostrictive generator for sensors network

In this paper we present a vibration harvesting electric power generator based on magnetostrictive effect for sensors network in hazardous area and we validate it experimentally. The generator has been designed by using Dynamic Preisach hysteresis Model (DPM). DPM is a development of classical Preisach Model which is able to include dynamical features in the mathematical model of hysteresis. We measure the output power capability of the generator and we estimate its power density generation capability.

Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

We demonstrate an innovative CIGS-based solar cells model with a graded doping concentration absorber profile, capable of achieving high efficiency values. In detail, we start with an in-depth discussion concerning the parametrical study of conventional CIGS solar cells structures. We have used the wxAMPS software in order to numerically simulate cell electrical behaviour. By means of simulations, we have studied the variation of relevant physical and chemical parameters-characteristic of such devices-with changing energy gap and doping density of the absorber layer. Our results show that, in uniform CIGS cell, the efficiency, the open circuit voltage, and short circuit current heavily depe…

The evolution of the FIT mechanism in Italy for PV systems: a critical analysis

The paper presents an analysis of the Feed'in Tariffs (FIT) mechanism development in Italy from 2005 to 2013 and named “Conto Energia”. In particular the work examines the five editions of the “Conto Energia”, highlighting both advantages and critical issues for the PV market development in Italy; this analysis is particular interesting due to the fact that the cap on FITs in Italy has been reached in June 2013.

Collaudo, verifiche tecnico-funzionali e manutenzione

Valutazioni tecniche ed economiche sull'uso degli inseguitori solari

I processi di antropizzazione connessi allo sviluppo del settore energia hanno determinato delle “impronte” sul nostro pianeta ormai indelebili. Non resta che provare a ridurre i consumi energetici e affidare la produzione dell’energia ad un mix equilibrato di fonti. In questo contesto, con particolare riferimento alla produzione dell’energia elettrica, lo sfruttamento della risorsa solare ha assunto un ruolo di primo ordine. Gran parte delle attività di ricerca e sviluppo del settore si è concentrata sulle tecniche e sulle metodologie innovative di conversione della fonte in energia elettrica. Accanto a queste, a parità di tecnologia di conversione adottata, altre attività di ricerca e svi…

Dynamics photovoltaic generators: Technical aspects and economical valuation

The strategy adopted from many European nations and not, to entrust the electric energy production to differently energetic sources has determined an increment of the scientific research for the solar resource exploitation. These scientific community activities follows with attention from the entrepreneurial world have concentrated on the innovative techniques and methodologies of the source conversion, solar concentration and the direction's device optimization. This job focuses its attention on the simple application of solar-track device, based on consolidated technologies. The diffused application of these dispositive, could be, shortly, an important increment of electricity generation …

A new control system prototype for the energy production maximization of a unequally irradiated PV system

This paper deals with the mismatch effect due to a unequally irradiation on a PV (PhotoVoltaic) system. The mismatch effect due to the partial shading of a PV module can be limited thanks to the installation of both bypass and block diodes. Unfortunately, this solution cannot fully solve the disvantages related to the mismatch effect. The Authors, in previous papers [1, 2], have theoretically demonstrated that the mismatch effect can be solved by changing the parallel/series connections of the modules of a PV system, taking into account each module radiating condition. This paper represents a first step of the experimental development of the above mentioned theoretical result. Specifically,…

Optimization of cogging force in a linear permanent magnet generator for the conversion of sea waves energy

In this paper an approach to the optimization of cogging force in a linear permanent magnet generator for the conversion of sea waves energy is presented. We have optimized the cogging force of a linear permanent magnet generator by using a 3D FEM parametric simulation. Several possible design solutions have been computed. A generator has been built and the results of the minimization procedure has been experimentally validated.

A back to back method for the temperature rise test of prefabricated substations: A case study

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…

A measurement setup for electric bicycles powered from renewable energy sources

In this paper a measurement system for a pedalassist rickshaw is described. It has been designed and realized with the purpose of a deep analysis of operating time, range and general performance of the prototype vehicle. The three-wheel velocipede under test, developed in the SDES laboratory of the University of Palermo, is equipped with two battery packs, and a photovoltaic panel which is used to recharge one of the packs at a time. To further improve the autonomy of this mean, a fuel cell will be added as a power source, whose consequent improvement in performance could be easily investigated by the presented measurement setup. An Arduino board has been employed to receive and store all c…

High Performance Field Oriented Rotor Control of Induction Generators

Analysis of a Fast Reserve Unit Behaviour with Additional Modular Synthetic Inertia Control

The paper presents the results of a theoretical study on the behaviour of a battery storage system operated as a Fast Reserve Unit and equipped with additional synthetic inertia control. The Fast Reserve Unit is assumed connected to the transmission system of Sicily, operated as an isolated grid in order to show more clearly the effect of the Fast Reserve Unit intervention during a power imbalance. The unit is controlled also to provide synthetic inertia with a conventional control scheme and with a new scheme proposed by the authors and named “Modular Synthetic Inertia”. The latter has been conceived for offering a modular response as a function of the Rate of Change of Frequency, to avoid…

A standard-compliant prototype for PV module curve detection

In this paper, a prototype for PV module curve detection which features low cost and size and ensures high accuracy is proposed. The proposed architecture is based on a buck-boost converter in open-loop configuration. The proposed architecture is fully compliant with actual standard IEC60904. The duty-cycle control algorithm and its own effects on system performances are accurately investigated. The comparison of different duty-cycle patterns is carried out and performance evaluation is performed. Simulation results are shown to perform a valuable comparison of control algorithms. Preliminary experimental results on a laboratory prototype are presented.

Energy and Economic Comparison of different conditioning system among traditional and eco-sustainable building

Cabine secondarie: nodi intelligenti e sicuri delle smart grid

Nel futuro panorama delle Smart Grid, le cabine secondarie assumeranno il ruolo di nodi intelligenti e sicuri della rete di distribuzione, integrando diverse soluzioni innovative di monitoraggio, comunicazione, controllo e richiedendo maggiori caratteristiche di sicurezza come proposto nei due progetti di ricerca REIPERSEI e NewCabElarc

Il vettore energetico idrogeno e le sue applicazioni in automotive.

Test Bench Realization and Application of Specific Working Cycles for the Characterization of Wheelchair Electrical Drives

The life quality of motion disabled people is increased by the use of more and more sophisticated electrical wheelchairs. Despite the diffusion of such aid tools, specific technical standards for the determination of characteristic parameters of their electric drives are not so developed as the ones available for urban electric vehicles. In this paper, in order to define new technical standards for wheelchairs electrical drives, a wheelchair test bench has been purposely carried out. Moreover two specific working cycles, previously conceived and defined by some of the Authors to characterize the performances of the propulsion systems suitable for electrical wheelchair applications, have bee…

Characterization of the Magnetic Induction Field produced by Secondary Substations

The aim of this paper is to develop a methodology for measuring the magnetic field distribution around the prefabricated secondary substations in vibrated reinforced concrete, as well as the definition of a methodology to determining the maximum value of magnetic induction produced by the substations in correspondence to nominal current of the transformer. As proposed has been developed in conformity with laws and standards and can be applied to active and passive secondary substations. The experimental validation of the proposed methodology, carried out by a measurements campaign whose results are reported, confirms the validity and returns a versatile and simple tool for the verification …

Caratterizzazione del campo di induzione magnetica prodotto da cabine secondarie

L’articolo presenta una metodologia per la caratterizzazione del campo di induzione magnetica nei pressi di cabine secondarie di tipo a box prefabbricato in cemento armato vibrato, che costituisce un valido strumento per la verifica del rispetto degli obiettivi di qualità imposti dalla legislazione vigente.

A Magnetostrictive Electric Power Generator for energy harvesting from traffic: Design and experimental verification

In the last decades, the growth in energy demand, the decrease of fossil fuels available in the market and the impact of anthropogenic factors on climate change has given new impulse to research on renewable energy systems, particularly those known as energy harvesting devices (EHDs) [1]. A large number of EHDs have been proposed, using different operating principle [1-4]. Among them, piezoelectric and magnetostrictive seem to be particularly suitable for the application in EHD. In these materials the application of external mechanical stress induces a change in the level of magnetization and therefore an electromotive force (emf) can be generated and collected in order to produce electrica…

Una Via Elettrochimica per la Fabbricazione di Celle Solari a Semiconduttori Nanostrutturati

Nella memoria si presentano i risultati preliminari su un processo di crescita elettrochimica di materiali nanostrutturati mediante l’impiego di stampi nanoporosi. Vengono quindi analizzate le possibili applicazioni del processo alla fabbricazione di semiconduttori nanostrutturati di interesse nel settore fotovoltaico, quali il CIGS, e le implicazioni dal punto di vista delle tecniche di caratterizzazione e di modellazione per dispositivi basati su tale tecnologia.

Coupled Electromechanical Analysis of a Permanent-Magnet Bearing

In this paper we present a new Permanent Magnets (PMs) bearing, which is composed of a rotor capable to levitate at a short distance from a dedicated stator. Proper configurations of PMs arranged on both the stator and the rotor allows having the magnetic suspension. Intrinsic mechanical instability characterizes the device; a passive stabilization is attempted exploiting eddy currents on a conducting sheet that surrounds the magnets on the stator. The system has been simulated by means of a dedicated numerical code that takes into account the effects of magneto-mechanical coupling. The coupled problem has been integrated by means of a prediction-correction nested scheme. Some interesting r…

Reconfigurable electrical interconnection strategies for photovoltaic arrays: A review

Non-uniform irradiance significantly decreases the power delivered by solar photovoltaic arrays. A promising technique for compensating these power losses relies on dynamically reconfiguring the electrical connections between photovoltaic modules. This paper presents the current state-of-the-art strategies for photovoltaic array reconfiguration in order to increase the power output under partial shading and mismatch conditions. The different approaches have been compared in terms of effectiveness of the control algorithms, monitored electrical and environmental variables, overall hardware complexity and specific features of each solution. Finally, the most challenging aspects of the reconfi…

ANALYSIS OF INTERCONNECTION SUBSTATIONS FOR SEAWAVE POWER FARMS

In this paper we analyse the interconnection of a seawave power farm to the grid. The generator type used in the farm is a linear synchronous generator driven from the seawaves that generates, highly distorted emfs. We presents two possible ways to interconnect the farm to the grid. One is based on an approach where for each generator there is a conversion subsystem that permits the direct connection of each generator to the a.c. network, the other one is based on an a.c.-d.c. converter that is connected to the generator, the converter is connected to a dc link that can receive the power from every unit and that can supply a dc-ac converter directly connected to the main.

The use of sea waves for generation of electrical energy and Hydrogen

Recently linear synchronous generator for the exploitation of sea wave energy has been proposed. That solution does not require reactive power to magnetize but needs permanent magnets to assure the excitation. The electrical energy generated by such a device must be converted and conditioned in order to match the instantaneous utility requirements and a power link from the sea to an interconnection is needed. In this paper in order to overcome that difficulty, the authors propose the use of the electrical energy generated to generate “in situ” hydrogen. As a result the output of the generation would be hydrogen that can be stored and used when needed The proposed electrical generator is a P…

Design of wave energy converter (WEC): A prototype installed in Sicily

The purpose of this work is to describe a possibility of installation of a wave converter in Sicily, in the Mediterranean Sea. In this paper we present the design of buoyant electrical generator, in particular, wave linear permanent magnet generator which can make wave energy converted to electrical energy.

A linear generator for a waveroller power device

In this paper experimental tests on a small scale tubular linear generator to be applied to wave rollers device are presented. A reduced scale of gnerator is presented and experimental results obtained in on test bench are shown. Experimental waveforms of current and voltage are recorded. Simulation results are compared to the experimental ones in order to validate the mathematical models used.

The helicoidal magnetic generator

Recently helicoidal generator for the exploitation of sea wave energy has been proposed. This device can convert both the vertical and rotational movement of seawaves. The electrical energy generated by such a device must be converted and conditioned in order to match the instantaneous utility requirements and a power link from the sea to an interconnection is needed. In this paper, the authors propose a mathematical model of this device and preliminarily present a prototype of the machine.

A new modified Inc-Cond MPPT technique and its testing in a whole PV simulator under PSC

In this paper a new modified Inc-Cond MPPT technique able to lead PV plants to work in the real MPP (Maximum Power Point) under PSC (Partial Shading Condition) is proposed. The new Inc-Cond MPPT technique working principle is fully explained, discussed and then successfully tested in a whole and reliable PV simulator conceived and set-up by the Authors in order to test and compare several new MPPT algorithms. The simulation results show that the proposed Inc-Cond MPPT technique is able to successfully lead the PV plant to work in the real MPP both in the cases of instantaneous and gradual changing of shading and of temperature conditions.

Application of Thermographic Techniques for the Detection of Failures on Photovoltaic Modules

The paper focuses on thermography as a useful investigation tool for diagnosis, detection and prevention of failures of photovoltaic modules. The paper describes the faults detectable by thermographic investigations and how to conduct these investigantions. Then the results of some analyses conducted on a photovoltaic field are presented. The investigations made possible to identify faulty modules with hot spots by measuring localized superheat due to the presence of concentrated deposits on the exposed surface of the module and the superheating due to the presence of sand/dust deposits distributed on a significant portion of the module surface. The thermographic investigations can be used …

Generatori fotovoltaici dinamici: aspetti tecnici e valutazioni economiche per il loro impiego

La strategia adottata da molte nazioni, europee e non, di affidare la produzione dell’energia elettrica ad un insieme equilibrato di fonti energetiche ha determinato un incremento delle attività di ricerca anche per lo sfruttamento della risorsa solare. Queste attività intraprese dalla comunità scientifica e seguite con attenzione dal mondo imprenditoriale si sono concentrate sulle tecniche e metodologie innovative di conversione della fonte, sulla concentrazione della radiazione solare nel punto di collocazione del dispositivo di conversione o ancora sull’ottimizzazione dell’orientamento del dispositivo rispetto alla direzione della radiazione. Questo lavoro focalizza la sua attenzione su …

A comparison of different one-diode models for the representation of I–V characteristic of a PV cell

Predictive performance tools are an important factor in the success of any new technology because they permit demonstration of whether a system will be efficient and economically feasible. A reliable predictive tool should allow the designer to optimise system performance and to maximise the cost effectiveness of a system prior to installation. This article discusses the five main parametric models for photovoltaic (PV) systems available in the literature. The current–voltage characteristics of a photovoltaic module can be reproduced modelling the PV panel as an equivalent electrical circuit made of linear and non-linear components. The parameters describing such components are directly rel…

Optimization of a thermomagnetic motor

In this paper, an approach towards the optimization of the Curie motor is presented. The approach is based on a thermal-magnetic coupled dynamic model of the motor, which is obtained by assuming the use of a ferromagnetic material working at temperatures near the Curie point. An analytical expression of the generated torque, which links this quantity to the magnetic, thermal, and geometrical parameters of the generated torque, is given. The expressions of speed and torque are derived and related to the thermal properties of the machine and are used as optimization indexes in an optimization procedure. The aim of the optimization process is to obtain a machine able to rotate constantly at th…

Thin Film CIGS Solar Cells, Photovoltaic Modules, and the Problems of Modeling

Starting from the results regarding a nonvacuum technique to fabricate CIGS thin films for solar cells by means of single-step electrodeposition, we focus on the methodological problems of modeling at cell structure and photovoltaic module levels. As a matter of fact, electrodeposition is known as a practical alternative to costly vacuum-based technologies for semiconductor processing in the photovoltaic device sector, but it can lead to quite different structural and electrical properties. For this reason, a greater effort is required to ensure that the perspectives of the electrical engineer and the material scientist are given an opportunity for a closer comparison and a common language.…

Un Sistema di Generazione di Energia Elettrica da Fonte Eolica Mosso da una Nuova Turbina Eolica Modulare del Tipo a Passo Fisso

La generazione distribuita: benefici e problematiche

Il sistema elettrico di potenza di cui fino a ieri eravamo abituati a parlare consentiva di trasportare e distribuire l’energia elettrica prodotta da sorgenti di grande potenza (centrali elettriche) ai centri di consumo grandi e piccoli dislocati su un territorio di grande estensione. In tale accezione il sistema era caratterizzato da presenza di una generazione centralizzata e ciò per ragioni, tra le altre, di economicità, sicurezza e qualità di esercizio. Negli ultimi anni, grazie anche ai processi di liberalizzazione del mercato dell’energia elettrica, si è assistito ad uno sviluppo della cosiddetta generazione distribuita, soprattutto da fonte rinnovabile, il che pone non poche problema…

Guidelines proposal for a good and durable WEC design

In this paper, preliminarily a proposal for design guidelines for a “good” design of wave energy converter is presented and successively a small scale prototype of a wave energy converter including the buoyant electrical generator, the power electronics equipment and a sea water electrolyzer is designed on the basis of these guidelines and presented.

Diagnosi wireless su apparecchiature elettriche affette da scariche parziali di origine interna

Tra le tecniche di rilevazione per apparecchiature elettriche affette da scariche parziali, un metodo innovativo è costituito dalla rilevazione di tipo wireless che produce vantaggi e benefici per gli utenti, i produttori di apparecchiature e le imprese distributrici dell’energia elettrica.

Photovoltaic module characteristics from CIGS solar cell modelling

We describe our approach to the task of modelling, both at single cell structure and complete module levels, during the solar cell technology development process. This can give very helpful indications, in terms of global photovoltaic module characteristics, for the assessment of intermediate research results and planning of further experiments. We make reference specifically to the fabrication of thin film CIGS solar cells by means of single-step electrodeposition, a technique which appears fairly easy and low-cost but, at the same time, can lead to quite different structural and electrical properties.

Misure di incentivazione economica e fiscale per la produzione di energia da impianti fotovoltaici: dal "conto capitale" al "conto energia"

Il settore energetico, settore chiave del sistema economico, attraverso le fonti di energia rinnovabile può ricevere oggi un nuovo slancio e contribuire a uno sviluppo sostenibile ed eco-compatibile. Scopo di questo lavoro è illustrare le differenze tra i vari sistemi di incentivazione economica e fiscale promossi nel tempo in Italia, soffermandosi sul meccanismo di incentivazione in conto energia attualmente vigente, e fornire alcune considerazioni tecniche ed economiche utili a valutare l’investimento.

SPEEDAM 2010 Poster REC0616: An electrochemical route towards the fabrication of nanostructured semiconductor solar cells

Progettazione di impianti fotovoltaici

Automatic detection of thermal anomalies in induction motors

The paper proposes a methodology based on Artificial Intelligence techniques for the automatic detection of abnormal thermal distributions in electric motors, to rapidly identify pre-faults or fault conditions. The proposed approach, applied to induction motors of different sizes, installed in waterworks plants, is based on the execution of Thermographic Non-Destructive Tests, which allow identifying abnormal operating conditions without interrupting the ordinary working conditions of the system. Thermographic images of induction motors are acquired at the installation site and with perspectives visible to the operator, which are sometimes partially obstructed. These thermographic images ar…

A Permanent Magnet Linear Generator for the Enhancement of the Reliability of a Wave Energy Conversion System

In this paper, a linear generator for a highly reliable Wave Energy Conversion system is designed and tested. In order to store energy, the system is able to produce hydrogen The Wave Energy Conversion System consists of an electrical linear generator, a power conversion system and a sea-water electrolyzer. A small scale prototype of the system has been designed and built. The design is oriented to the enhancement of the system robustness and reliability and a Failure Mode and Effects and Criticality Analysis (FMECA) has been used. In order to guarantee an easy extension of the power capability of the marine plant, a modular architecture of the system has been adopted. The design strategy i…

Thermal anomalies detection in a photovoltaic plant using artificial intelligence: Italy case studies

This paper proposes the application of artificial intelligence techniques for the identification of thermal anomalies that occur in a photovoltaic system due to malfunctions or faults, with the aim to limit the energy production losses by detecting faults at an early stage. The proposed approach is based on a Thermographic Non-Destructive Test conducted with Unmanned Aerial Vehicles equipped with a thermal imaging camera, which allows the detection of abnormal operating conditions without interrupting the normal operation of the PV system rapidly and cost-effectively. The thermographic images and videos are automatically inspected using a Convolutional Neural Network, developed by an open-s…

Il dovere di sicurezza:basi legislative e novità introdotte dal D.Lgs. 626/94.