A Sustainable Energy Mix for the Aeolian Islands

The paper examines the current status of the electrical energy production in the Aeolian Islands, an Italian archipelago, composed by small island North of Sicily. Instead the availability of renewable energy sources, like wind, solar, geothermal and sea wave, these islands produce electrical energy using almost entirely fossil fuels. Starting from this initial condition, the paper proposes an energetic mix based on the available resources and focusing the attention on sea wave. An innovative device is presented in order to exploit this energy source.

An inertial system for the production of electricity and hydrogen from sea wave energy

This paper aims at describing a small scale prototype of a complete wave energy converter system for hydrogen production promoting the opportunity of installation in Sicily, in the Mediterranean Sea. The opportunity to produce hydrogen from sea-water identifies ocean wave energy as the most promising solution for electricity generation including hydrogen production and storage. Even if hydrogen is considered one of the most promising secondary sources, criticism arises from both the academic and the industrial world mainly because hydrogen production requires electricity consumption. Furthermore, safety problems concerning hydrogen storage and transport are actually the main hindrance to fu…

Evaluation of the wave energy density on the Sicilian coast

In this article the wave energy density of the northern Sicilian coasts is evaluated and is used to evaluate the producibility of a wave nergy converter to be installed in an area in the north west part of Sicily. In particular, the objective of the study is the evaluation of a potential installation in an area between Trapani and Palermo, which are the largest cities in the north west part of Sicily. In particular in this research, the wave energy density of Sicily has been analyzed by using an analysis of wave data carried out in a 10-year period, using the measurements of buoyant of National Wave measuring System (RON - Rete Ondametrica Nazionale). The analysis shows that the north-weste…

An Experimental Comparison between an Ironless and a Traditional Permanent Magnet Linear Generator for Wave Energy Conversion

Permanent Magnet Linear Generators (PMLGs) are currently being studied for sea wave energy harvesting. Typically, a PMLG consists of an iron-made armature and a moving translator. The permanent magnets adoption produces parasitic effects, such as cogging force, and the machine weight increment. A solution could be the adoption of an ironless configuration, accepting a power density reduction. This paper investigates the use of ironless PMLGs in sea wave energy conversion systems by an experimental comparative analysis between an iron PMLG prototype and an ironless PMLG prototype, which share the same geometry. The main electrical and mechanical parameters (resistance, mass, and magnetic fie…

A Ferrite Tubular Linear Motor (FTLM): Analysis and design

The electromagnetic linear machines have wide applications in the electromagnetic aircraft launch systems [1] and in transportation systems [2]. Additional energy saving and efficiency can be achieved using a linear motor in the refrigeration application [3]. Linear electromagnetic machines are also very suitable for high-speed packaging, manufacturing sectors and precision positioning. There are different linear motor topologies. Tubular permanent-magnets are particularly attractive since they have a high thrust force density and high efficiency, no end windings, and zero net attractive force between stator and armature. There are various tubular motor topologies, in which the armature may…

Assessment of the Operating Temperature of Crystalline PV Modules Based on Real Use Conditions

Determining the operating temperatureTcof photovoltaic panelsPVis important in evaluating the actual performance of these systems. In the literature, different correlations exist, in either explicit or implicit forms, which often do not account for the electrical behaviour of panels; in this way, estimatingTcis based only on the passive behaviour of thePV. In this paper, the authors propose a new implicit correlation that takes into account the standard weather variables and the electricity production regimes of aPVpanel in terms of the proximity to the maximum power points. To validate its reliability, the new correlation was tested on two different PV panels (Sanyo and Kyocera panels) and…

Design and Performance of a High Temperature Superconducting Axial Flux Generator

In this paper, a high temperature axial flux (HTSAF) generator is presented. In this generator the excitation of the generator is obtained by using some high temperature superconducting magnets. In order to reduce the negative effects of vibrations, the excitation is located on the stationary part of the generator. Starting, running and endurance tests of the machine are presented.

Design of a transverse flux machine for power generation from seawaves

Linear electrical generator has been recently studied for the exploitation of sea wave energy, however the definition of the optimum geometry to be used is still debated and due to the fact that seawave energy is characterized by low speed and very high forces, a generator which is able to convert energy at low speed and high force is needed. In this paper we investigate the possibility to use a transverse flux linear generator (TFG) because transverse flux technology presents the highest force density per volume index among the iron based electrical machines. The advantages of TFG topology against the classical longitudinal concept are [1]: (a) the magnetomotive force per pole is independe…

Efficiency Enhancement of Permanent-Magnet Synchronous Motor Drives by Online Loss Minimization Approaches

In this paper, a new loss minimization control algorithm for inverter-fed permanent-magnet synchronous motors (PMSMs), which allows for the reduction of the power losses of the electric drive without penalty on its dynamic performance, is analyzed, experimentally realized, and validated. In particular, after a brief recounting of two loss minimization control strategies, namely, the "search control" and the "loss-model control," both a new modified dynamic model of the PMSM (which takes into account the iron losses) and an innovative "loss-model" control strategy are presented. Experimental tests on a specific PMSM drive employing the proposed loss minimization algorithm have been performed…

The use of sea waves for generation of electrical energy: a linear tubular asynchronous electrical generator

A linear tubular asynchronous generator to be used as generator driven by seawave is presented. The design criteria of a TLIM with hollowed iron induced part as well as the technological processes to be adopted and the materials utilized in the various parts are described. The methodologies for mechanical assembling and electric wiring are considered too. Finally, the prototype with bimetallic induced part that has been designed and built is presented and some experimental results on electrical and mechanical variables are shown.

Energy and Economic Analysis of Different Buildings Constructed with Environmentally Sustainable and Traditional Materials

Dynamic Preisach Hysteresis Model for Magnetostrictive Materials for Energy Application

In this paper the magnetostrictive material considered is Terfenol-D. Its hysteresis is modeled by applying the DPM whose identification procedure is performed by using a neural network procedure previously publised [. The neural network used is a multiplayer perceptron trained with the Levenberg-Marquadt training algorithm. This allows to obtain the Preisach distribution function, without any special conditioning of the measured data, owing to the filtering capabilities of the neural network interpolators. The model is able to reconstruct both the magnetization relation and the Field-strain relation. The model is validated through comparison and prediction of data collected from a typical …

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Testing a linear ironless generator for the sea wave energy harvesting

Wave energy represents a "new entry"in the renewable energy sector; however, it is believed that in near future sea wave might have a key role for the electrical energy production, thanks its huge energy potential. In this context, the paper suggests an innovative ironless linear generator, that can be used as main component inside a point absorber. In order to exploit the wave energy potential in the Mediterranean Sea, the Engineering Department of Palermo University realized a first small-scale prototype of the electrical linear generator, that is the main component for the energy conversion.

Dynamic Preisach hystersis model for magnetostrictive materials for energy application

Recently Magnetostrictive materials have been proposed as active materials to be used in several energy harvesting technology [1]. In this kind of application, the working condition of the material is highly dynamic and non linear. As a result static models of magnetostrictive materials are usually not very accurate and can be not reliable to develop a sufficiently accurate designof the energy harvesting devices. The presence of hysteresis requires accurate mathematical modeling in order to correctly foresee the behavior of real materials (ferromagnetic or magnetostrictive) used in control systems or in electrical machines and thus simplifying the design of such controllers or predicting wi…

Optimization of Wave Energy Converter: DEIM Point Absorber II

The paper presents a possible solution to optimize a wave energy converter, device able to exploit the wave energy resource. The utilization of this technology shows also positive aspects, thanks to the limited visual and environmental impacts. This system could be also installed in reserved areas, being similar to signal buoys, simplifying the problem of energy supply in small islands. In order to exploit the wave energy potential in the Mediterranean Sea, the department of Energy of Palermo University realized a first prototype of the electrical linear generator, that is the main component of the wave energy converter. This electrical machine can be operated by a two-floating buoys system…

Minimization of detent force in a 1 kW linear permanent magnet generator for the conversion of sea waves energy: Numerical and experimental validation

Linear permanent magnet generators are widely considered for the direct conversion of energy contained in sea waves [1-3]. Both planar and tubular structures have been proposed [4-6] and all these structures present several advantages: relative high efficiency, simplicity of the structures, high sturdiness. However, as all other linear machines they present some drawbacks: oscillations in the movement, distortion in the generated electromotive force (emf), etc. In this paper we focus our attention on the parasitic oscillations of the translator which are caused by the presence of a high detent force. Detent force is generated by the fact that magnetic energy presents a minimum when the leng…

A Magnetohydrodynamic Generator for Marine Energy Harvesting

In this article we present an approach to the description of Magneto-hydrodynamic Marine Energy Harvesting (MHMEH) system. Preliminarly, a general discussion on the principle of operation is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analyses are given.

A New Solution for Sea Wave Energy Harvesting, the Proposal of an Ironless Linear Generator

The paper investigates an innovative ironless linear generator, installable inside a wave energy converter, in order to produce electricity from sea waves. This energy source is considered strategic for the future, especially in small islands

Optimized design of a sea wave energy conversion system

Esperienze di ricerca in un progetto congiunto Università-Impresa per l’automazione delle reti elettriche di distribuzione e il trasferimento internazionale di know how

Optimization of a Sea Wave Energy Harvesting Electromagnetic Device

This paper presents the optimization of a permanent magnet linear generator directly coupled to sea waves. In order to maximize energy extraction, the stochastic features of the energy source is included in the mathematical model of the system in order to satisfactorily tackle the problem. An optimization procedure which includes the stochastic features of the model is presented and a machine built on the basis of the results of this procedure is shown.

Magnetic Stochastic Resonance in systems described by Dynamic Preisach Model

Stochastic resonance (SR) is generally considered as an enhancement of the system response for certain finite values of the noise strength. In particular the signal to noise ratio (SNR) and the signal amplification show a maximum as a function of the noise intensity. This effect has been experimentally observed in many physical systems and also in magnetic systems. However, as far as magnetic systems are concerned, the dynamic features of the systems have been neglected and it has been assumed that the typical relaxation time is negligible. However this is clearly a rough approximation. In order to clarify this relation, in this paper we numerically study magnetic stochastic resonance in se…

Linear and nonlinear experimental regimes of stochastic resonance

We investigate the stochastic resonance phenomenon in a physical system based on a tunnel diode. The experimental control parameters are set to allow the control of the frequency and amplitude of the deterministic modulating signal over an interval of values spanning several orders of magnitude. We observe both a regime described by the linear response theory and the nonlinear deviation from it. In the nonlinear regime we detect saturation of the power spectral density of the output signal detected at the frequency of the modulating signal and a dip in the noise level of the same spectral density. When these effects are observed we detect a phase and frequency synchronization between the st…

Seawave Power Farm Design:A Case Study

Currentenergycrisisandgeneralconcernsonenvvironmentalissueshavetriggeredaneverincreasingeffortoonharvestingrenewableenergies.Amongstrenewableenergysources,seawaveene ergyisdefinitelytheonethathasbeenlessutilised.Thisisprobablycausedbytworeasons:i)thes strongtechnicalnoveltiesthatarerequiredtoextractthee energythatiscontainedinahighlyandstochasticallyvariablem motion;ii)thedifficultyofindasuitableelectricalsystemabbletoconverttheenergycontainedinthemotionoftheseaintoelectricalenergy.Inthispaperweproposeanapproachtosetupaggeneralmethodologytowardthedesignofaseawavefarm.Thefirststepisexplainedhowtochoosetheconversionsysteem,inthesecondstepisdiscussedtheconnectionschem meamongtheconverters,inth…

A dynamic model for hysteresis in magnetostrictive devices

In this paper, a dynamic model for the description and design of hysteresis in magnetostrictive devices is presented. The model is based on Preisach theory and its dynamic extension. A procedure for determining the Preisach distribution function is given. This procedure is based on neural networks. The model is able to reconstruct both the magnetization relation and the field-strain relation. The model is validated through comparison and prediction of data collected from a typical Terfenol-D sample and a novel experimental technique dedicated to the validation of dynamic models is proposed.

A photovoltaic charging system of an electrically assisted tricycle for touristic purposes

In this paper the design, realization and testing of a photovoltaic charging system suitable for the management of an electrically power assisted tricycle are described. This vehicle uses a photovoltaic module as a source of electric energy for the battery recharging. In this work, an overview on the needs of sustainable mobility and on the commercial electrically power assisted velocipedes is presented. The electrical rickshaw prototype, developed in the SDELab laboratory of the University of Palermo, is presented in detail, underlining the design, implementation and developing phases of the photovoltaic charging system assembled on the velocipede. Moreover, tests oriented on the setting u…

The influence of the stochastic features of the energy source on the design of an electromagnetic generator

The purpose of this paper is to clarify in a general way how the unavoidable randomness of renewable energy sources influences the magnetic design of electric generator. A general model of electro magnetic generator based on the well known d-q axes analysis is given. The energy source is modelled as a stochastic variable and is included in the equations of the system. The equations are solved and, therefore, the energy output of the system is linked to the random characteristic of the energy source. As a result, the magnetic circuit and the parameters of the generator that maximize the energy extraction can be found and generally linked to the stochastic details of the source.

The effect of manufacturing tolerances on a tubular linear ferrite motor

This study presents a numerical and experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor. The statistical distribution of the magnetic characteristic of a set of commercial magnets is obtained experimentally while the performances of a the tubular motor are numerically evaluated. The performances that have been considered are: cogging force, end effect force and generated thrust. It has been shown that: 1)the statistical variability of the magnets modifies the time behavior of the cogging force; 2)the value of both the end effect cogging force and the generated thrust are directly linked to the values of then remanence field o…

A Novel Neural Approach to the Determination of the Distribution Function in Magnetic Preisach Systems

This paper presents a novel method to identify both the functional dependence of the Preisach function as well as its numerical parameters on the basis of some known magnetic behavior. In this paper, the identification of the Preisach function of a material is performed by using a neural network trained by a collection of hysteresis curves, whose Preisach functions are known. When a new hysteresis curve is given as input to this neural network, it is able to give as output both the functional dependence of the Preisach function as well as its numerical parameters.

Experimental Investigation on the Performances of a Multilevel Inverter Using a Field Programmable Gate Array-Based Control System

The Field Programmable Gate Array (FPGA) represents a valid solution for the design of control systems for inverters adopted in many industry applications, because of both its high flexibility of use and its high-performance with respect to other types of digital controllers. In this context, this paper presents an experimental investigation on the harmonic content of the voltages produced by a three-phase, five level cascaded H-Bridge Multilevel inverter with an FPGA-based control board, aiming also to evaluate the performance of the FPGA through the implementation of the main common modulation techniques and the comparison between simulation and experimental results. The control algorithm…

Local DoS applications with micro wind generation systems

In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar-thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind fl…

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.

An electromagnetic generator for MAGLEV transportation systems

The fundamental idea of this paper is to use the distribution theory to analyze linear generators in order to include in the mathematical model both ideal a non ideal features. This paper shows how the use of distribution theory can be used in order to establish a mathematical model able to describe both the ordinary working condition of a linear generator for MAGLEV systems as well the role of the unavoidable irregularities and non-ideal features.

Energy assessment of a wave energy converter in a small island. A case study

The diffusion of technologies supplied by Renewable Energy Sources (RES) is contributing to the challenge of reduction of energy dependence from fossil fuels, avoiding the emission of several polluting substances and greenhouse gases (GHG). Already today, global warming caused by human activity is estimated at around 1∘C; energy consumption attributable to human habits is no longer sustainable. To date, energy production is still heavily dependent on fossil fuels. To reverse the negative trend, it is necessary to invest in new technologies and improve the efficiency of energy production plants in general. In particular, a wave energy converter will be presented, consisting of a buoy connect…

Assessment of the Trend of Albedo: a Case Study of Palermo

In this paper we propose a case study of urban heat island applied to Palermo. The urban heat island (UHI) is the most studied of the climate effects of settlements. The UHI refers to the generally warm urban temperatures compared to those over surrounding, non-urban, areas. The aim of this paper is to find a connection among the average rise in temperature and the modification of albedo.

A small scale prototype of a wave energy conversion system for hydrogen production

In this paper a small scale prototype of sea wave energy converter for hydrogen production and storage is presented. Laboratory prototypes of the wave energy converter device and sea water electrolyzer are presented. Experimental results are shown. A cost-effective and efficient power electronics system is designed. Experimental waveforms of the wave energy converter are imported in the power electronics simulation model to simulate the whole system as closely as possible to its effective behavior. Simulation results are shown to test the efficiency of the proposed solution.

Reduction of cogging force in linear generators for wave energy harvesting

Due to huge energy potential of sea waves, many technologies have been proposed in the last few years. Some concepts have been developed and sometimes also tested in the open sea. Some prototypes use linear generators to directly convert the vertical motion of buoys into electrical energy. This solution minimizes the numbers of energy conversion steps, increasing the energy efficiency. At the same time, the limited numbers of components could also increase the reliability of the wave energy converter. For this reason, the development of linear generators is considered with great interest. This paper investigated the cogging force, a magnetic force due to the interaction between the magnets …

An Innovative Wave Energy Converter in the Mediterranean Sea

The paper proposes a revolutionary device for the utilization of a new entry of renewable energy sources: sea wave. This technology is based on linear generators, able to converts directly a linear motion into electrical output, limiting to minimum the chain of energy conversion. A preliminary feasibility study considers a case study, applied in Lampedusa, a small island in the Mediterranean Sea. Economic and environmental assessments are reported.

Rolling, Pitching and Yawing of a Superconducting Maglev Vehicle

The dynamic characteristics of a Maglev vehicle are influenced by both the translational and the rotational degrees of freedom. As a result, the rolling, pitching and yawing motion modes must be included in a complete description of the dynamic features of a Maglev vehicle. Furthermore, the analysis of this motion modes is also very useful in order to obtain the highest achievable riding comfort.

Electrical Power from seawave energy

Current energy crisis and general concerns on environmental issues have triggered an ever increasing effort on harvesting renewable energies. Amongst renewable energy sources, sea wave energy is definitely the one that has been less utilised. This is probably caused by three reasons: i) the low energy concentration in the sea waves, at least in the sites where it is technically possible to install conversion stations: ii) the strong technical novelties that are required to extract the energy that is contained in a highly and stochastically variable motion; iii) the difficulty to find a suitable electrical system able to convert the energy contained in the motion of the sea into electrical e…

Energy Saving in Public Transport Using Renewable Energy

Hydrogen produced by renewable sources represents an interesting way to reduce the energetic dependence on fossil fuels in the transportation sector. This paper shows a feasibility study for the production, storage and distribution of hydrogen in the western Sicilian context, using three different renewable sources: wind, biomass and sea wave. The objective of this study is the evaluation of the hydrogen demand, needed to replace all diesel supplied buses with electrical buses equipped with fuel cells. An economic analysis is presented with the evaluation of the avoidable greenhouse gas emissions. Four different scenarios correlate the hydrogen demand for urban transport to the renewable en…

An optimum design of the magnetic circuit of a PM linear electrical generator for the exploitation of sea waves

Dynamic behaviour of magnetically levitated systems with hysteresis in the force-position curve

A sliding mass wave energy converter

This paper presents a wave energy converter which is based on a sliding mass coupled to a linear generator. In order to maximize energy extraction, the stochastic features of the energy source has been included in the mathematical model of the system in order to satisfactorily tackle the problem. The results of several simulations are presented.

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.

A Innovative Monitoring Underwater Buoy Systems (MUnBuS) for Marine and Rivers installation with IR-Cam, Instrumental Telemetry and Acoustic Data Acquisition Capability

The proposed low cost systems shows the results obtained in the implementation and testing in marine environment of a Innovative Monitoring Underwater Buoy Systems for Marine and Rivers installation with IR-Cam, Instrumental Telemetry and Acoustic Data Acquisition Capability (MUnBuS). This concerning a innovative Monitoring Underwater Buoy Systems that can be remotely controlled from the ground, air, satellite and sea and from a Center of Supervision Telecontroller And Data Acquisition and Monitoring (Mobile-STADAM Center). The Buoy is hosts for the radio or satellite communication equipment, the downloading and telemetering data equipment and the photovoltaic power supply, board and underw…

Technical and economical comparison between NdFeB and hard ferrites linear electrical generators from sea waves

In this paper the authors perform a technical-economic comparison of two different Tubular Permanent Magnet Linear Machines for sea waves generation by using finite elements analysis. The first configuration includes ferrite rings while the second configuration includes neodymium-iron-boron rings. In order to compare the two types in economic and technical terms, a detailed analysis of the main figures of merit of the two configurations has been carried out. In particular, significant data such as flux distribution, rated voltage and current, axial force, electric power, realization cost and maintenance cost have been compared.

A Ferrite Tubular Linear Permanent Magnet Generator (FTLPMG) analysis and design

Several linear synchronous generators for the exploitation of sea wave energy have been proposed. Such machines do not require reactive power for the magnetization since they use permanent magnets for the excitation. The use of permanent magnets in a rough environment such as the marine environment may be a very weak point in the application of these kind of devices. In order to overcome this difficulty, the authors in this paper propose a linear synchronous electrical generator. Its excitation uses ferrites as suitable solutions to extract energy from sea waves. This paper describes the analysis and design of an improved axially magnetized tubular permanent-magnet machine in which several …

Experimental validation of a distribution theory based analysis of the effect of manufacturing tolerances on permanent magnet synchronous machines

An experimental study on the effect of permanent magnet tolerances on the performances of a Tubular Linear Ferrite Motor is presented in this paper. The performances that have been investigated are: cogging force, end effect cogging force and generated thrust. It is demonstrated that: 1) the statistical variability of the magnets introduces harmonics in the spectrum of the cogging force; 2) the value of the end effect cogging force is directly linked to the values of then remanence field of the external magnets placed on the slider; 3) the generated thrust and its statistical distribution depend on the remanence field of the magnets placed on the translator.

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.

Analysis a DSP Implementation and Experimental Validation of a Loss Minimization Algorithm Applied to Permanent Magnet Synchronous Motor Drives

In this paper a new loss minimization control algorithm for inverter-fed permanent-magnet synchronous motors (PMSM), which allows to reduce the power losses of the electric drive without penalty on its dynamic performances, is analyzed, experimentally realized and validated. In particular, after a brief recall of two loss minimization control strategies (the "search control" and the "loss-model control"), both a modified dynamic model of the PMSM, which takes into account the iron losses, and a "loss-model" control strategy, are treated. Experimental tests on a specific PMSM drive employing the proposed loss minimization algorithm were performed aiming to validate the actual implementation.…

Dynamic Preisach Hysteresis Model for Magnetostrictive Materials for Energy Application

A new solution for the sea wave exploitation. A linear ironless generator

The exploitation of sea wave represents an important frontier for the energy sustainability in the next future. Despite the proposal of several techniques and solutions, commercial devices are not available. In this context, the Department of Engineering is investigating an innovative solution based on linear energy generators. This machine can be adopted as the main component in a wave energy converter, that is the device for the energy extraction of sea wave. Starting from an existing prototype, the paper examines the replacement of the iron stator with a non-magnetic material, in order to solve several common problems of linear generators, such as the cogging force. Results are reported,…

Study of thermomagnetic energy conversion driven by renewable energy

Magnetic heating, refrigeration and energy conversion have been defined very important challenges for promising environmentally future choices. Recent studies are focused attention on new thermomagnetic systems, devices working through thermomagnetic effect, driven by renewable energies. The aim of this work is a case study presentation of new thermomagnetic energy prototype coupled with renewable technologies or industrial waste heat. The paper is divided into four sections: the first gives a general state of art about magneto-caloric energy conversion systems, the second describes all general thermodynamics and magnetic laws governing the process, the third and fourth sections study in mo…

Design and Experimental Test of a Thermomagnetic Motor

Abstract This paper presents a Thermomagnetic Motor. The design of the motor is based on a thermal-magnetic coupled dynamic model, which is obtained by assuming the use of a ferromagnetic material working at temperatures near the curie point. The motor is modeled in terms of both its magnetic as well thermal properties (magnetic permeability and thermal conductivity) and the thermal processes are supposed to be influenced by the thermal conductivity, the convection and the advection. An analytical expression of the generated torque, which links this quantity to the magnetic, thermal and geometrical parameters of the generated torque is given. A design of a machine, based on this theory is p…

The role of the effect of manufacturing tolerances on a tubular linear ferrite motor

Electric machines are often designed without considering workmanship and materials tolerances. Their manufacturing process involves a series of steps, starting with raw materials and ending with the machine assembly. In each of these steps occur deviations due, for instance, to mistakes in positioning tools or to the tolerances in the electrical and magnetic characteristics of the materials. These deviations may cause unwanted parasitic effects such as torque ripple, losses or acoustic noise. Such effects have to be considered especially in machines used in industrial drives for high performance applications. Moreover the tolerances in the magnetic materials have a considerable effect on th…

Wireless Power Transmission for house appliances: A small-scale resonant coupling prototype

This paper presents a low cost prototype of wireless power transfer system based on resonant coupling. The system here proposed can be useful for house appliances battery charging systems: as a matter of fact, it consists mainly of two copper wire coils or windings, placed one in front of the other on the same axis. By exploiting the coils resonance coupling effect, electric energy can be transferred from the inductor coil to the receiver in order to charge the batteries. Low cost experimental tests demonstrated the effectiveness of the proposed wireless power transfer prototype, being it capable to reach an efficiency of about 80% and more along a distance of 30 cm.

Spinodal demixing, percolation and gelation of biostructural polymers

We present a variety of new experiments which concern the self-assembly of a polymeric network from homogeneous solutions of Agarose, a representative biostructural polysaccharide used for previous studies at our laboratories. They allow deriving a semi-quantitative phase diagram in the T, C plane. The diagram includes both the spinodal and gelation lines. Below a value of about 2% w/v, concentration is not sufficient for direct gelation; however, quenching of the sol from high temperatures to below the spinodal line initiates the spinodal demixing. The latter generates two sets of regions having respectively, higher- and lower-than-average polymer concentrations. In the higher-concentratio…

Small Island developing states: Overview about wind, solar and marine energy in Cuba

The current economic, political, and social trends in Cuba indicate that energy sector will change in the future. The energy consumption will increase and Cuba, like most island nations, lacks a large energy resource base and satisfies most of its energy needs with imported fossil fuels. The aim of this work is a summary of renewable energy sources (solar, wind, bioenergy and marine) presented in the island and the development in the next society of the future.

A sustainable energy production: Sea Wave in the small island of Ustica (Italy)

Nowadays the electrical energy production is based on fossil fuels in the greatest part of smaller islands in the Mediterranean Sea. Despite the availability, the renewable energy sources are practically unused, as landscape constraints. So, the paper presents the case of study of Ustica, a small island located at north of Sicily, in the middle of Mediterranean Sea. Starting with the analysis of the electrical energy consumption of public buildings, the paper suggests an energetic scenario, based on solar and sea wave. In particular, in order to use this new resource, the paper presents an innovative wave energy converter. Finally, the energetic and economic evaluations encourage the realiz…

A Preliminary Energy Assessment to Improve the Energy Sustainability in the Small Islands of the Mediterranean Sea

Power plants supplied by renewable energy sources are expanding around the world, in order to reduce the carbon dioxide emissions, limit the global warming and improve the energy sustainability. Despite the relevant achieved results, small islands are heavily reliant on fossil fuels. In this context, renewable energy sources are available but practically unused, due to landscape and economic constraints. This condition is quite common in the Mediterranean Sea. These islands are normally fed by a stand-alone electrical grid and a power plant, equipped with diesel engines. In order to improve the sustainability of the energy sector, the paper considers the case study of Ustica, a small Italia…

A computational magnetohydrodynamic model of a marine propulsion system

In this article we present an approach to the description of Magnetohydrodynamic Propulsion. Preliminarly, an analytical model which includes an electromagnetic model and a thermal model is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analysis are given.

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

Time-Resolved study of network self-organization from a biopolymeric solution

Time-resolved studies of network self-organization from homogeneous solutions of the representative biostructural polymer agarose are presented. Solutions are temperature quenched and observed by several techniques. Consistent with previous suggestions by the authors, experiments at concentrations up to about 1.75% w/v provide direct kinetic evidence for the occurrence of at least two distinct processes, leading, in sequence, to self-assembly. These are as follows: (a) a liquid–liquid phase separation of the solution occurring via spinodal demixing and resulting in two sets of regions that have, respectively, higher and lower than average concentrations of random-coiled polymers; and (b) th…

Dynamic behaviour of controlled permanent magnets for electromagnetic suspension MAGLEV technique

Design and numerical simulation of a magnetostrictive electric power generator.

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…

Mini Wind Plant to Power Telecommunication Systems: a Case Study in Sicily

The ever increasing problems related to air pollution and the difficulties for power lines to reach inaccessible areas are pushing to find new solutions for powering telecommunications equipments (TLC). The renewable energy systems, although relatively expensive, have the required characteristics. The purpose of this work is to find a solution based on a low power wind turbine to serve a real telecommunication site located near Palermo, the main city of Sicily (Italy).

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.

A numerical approach to the description of the role of electromagnetic noise on the iron losses

A innovative semi-immergible USV (SI-USV) drone for marine and lakes operations with instrumental telemetry and acoustic data acquisition capability

The proposed project shows the results obtained in the implementation and testing in lacustrine and marine environment of a nautical remote controlled vehicle with surface navigation and innovative features Semi-Immersible (SI-USV). This vehicle is based on a pending patent belonging to Palermo University (Patent Pending RM2012A000209 and RM2012A000209) concerning innovative semi-immersible vehicles (SI-Drone), that can be remotely controlled from the ground, air, satellite and sea also during the semi-immersible operation. The vehicle with electric power is coupled with a jet propulsion, given the low draft, makes it possible to navigate in shallow waters or coastal shipping or sandbars. T…

Efficiency Improvement of Inverter-Fed Permanent Magnet Synchronous Motors

In this paper a control algorithm for the efficiency improvement of inverter-fed permanent magnet synchronous motors (PMSMs) is presented. The proposed algorithm allows reducing the losses of the drive without reduction of its dynamic performances. In details, after recalling a dynamic model of the PMSM, which has been purposely modified and that takes into account the iron losses, the basic equations and the constraints to obtain the loss minimization are presented and discussed. Some simulations of a specific PMSM drive employing the proposed algorithm are performed. The results of these simulations show that the dynamic performances are maintained, and enhancement of the efficiency up to…

A security and surveillance application of the innovative Monitoring Underwater Buoy Systems (MUnBuS) on the Protected Marine Area (AMP) of capo gallo (PA-IT)

The proposed low cost systems shows the results obtained in the implementation and testing on real security application to Protected Marine Area surface and submarine environment of a innovative Monitoring Underwater Buoy Systems (MUnBuS) for installation with IR-CCTV-Cam, ultrasonic dolphin warning system and Green Laser Perimeter Detection. This concerning innovative Monitoring Underwater Buoy Systems that can be remotely controlled from the ground, air, satellite and sea and from a Center of Supervision Telecontroller And Data Acquisition and Monitoring (Mobile- STADAM Center). The Buoy is hosts for the radio or satellite communication equipment, the downloading and telemetering data equ…

Wave Energy Assessment and Performance evaluation in Mediterranean Sea

The paper proposes a revolutionary device for the utilization of a new entry of renewable energy sources: sea wave. This technology is based on linear generators, able to converts directly a linear motion into electrical output, limiting to minimum the chain of energy conversion. A preliminary feasibility assessment considers a case study applied in Lampedusa, a small island in the Mediterranean Sea. Economic and environmental evaluations are here reported.

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.

Design and Test of a Thermomagnetic Motor Using a Gadolinium Rotor

The purpose of this paper is to show that a Thermomagnetic (Curie) Motor [1-3], which can rotate continuously and has useful mechanical characteristics, is feasible. A thermomagnetic motor can directly converts thermal energy into kinetic energy. In this type of motor force is generated by a thermally induced permeability difference in two areas of the rotor, which can generate a force if the rotor is placed in a magnetic field. This force can be enhanced if the hot side temperature of the rotor is above the Curie’s temperature of the magnetic material and the cold side under this temperature Unfortunately, the traditional ferromagnetic materials have very high Curie’s temperature and there…

A Magnetohydrodynamic Auxiliary Propulsion system for docking assistance of autonomous vehicle

In this article we present an approach to the description of Magnetohydrodynamic Auxiliary Propulsion system for docking assistance of autonomous vehicle. Preliminarily, an analytical model which includes an electromagnetic model and a thermal model is presented. Successively, in order to move beyond the analytical model, a 3-D MHD modeling tool and a Runge Kutta method based solver are presented and they are used to investigate an alternative MHD solutions. Some numerical analysis are given

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.

Experimental study on B-spline-based modulation schemes applied in multilevel inverters for electric drive applications

This work presents the design, simulation, and experimental validation of new B-Spline-based modulation techniques applied to a Multilevel Power Inverter (MPI), particularly focusing the attention on the harmonic content of the output voltages of the inverter. Simulation and experimental results are proposed and discussed, mainly describing the potential benefits, such as the increase of the multi-level operation of the converter, and drawbacks (low-order harmonics) related to the adoption of B-Spline functions for multilevel inverters applied in the field of electrical drives.

State of art and economic evaluation of wave energy converters. A case study

The even increasing energy demand in the world is a relevant problem for the modern society. The energy supply from fossil fuels has become a critical aspect due to the progressive reduction of reserves and political instability among the Countries. For these reasons, the exploitation of renewable energy sources is looked with a great interest. In this context, solar, wind, geothermal, hydropower, and biomass can be successfully used through commercial technologies. Other potential renewable energy sources could have potential applications in the next future. Among these, sea wave is considered a very promising energy source, especially for small islands. In this context, the paper propones…

Nexus Water & Energy: A Case Study of Wave Energy Converters (WECs) to Desalination Applications in Sicily

The recent studies about interactions among energy and water are considered as a new field of research. As almost all energy generation processes require significant amounts of water, and water requires energy for treatment and transport, so these two resources are inextricably linked. The main aim of this work is a presentation of the use of renewable energy for desalination plants in Sicily: in particular exploitation of wave energy into electrical energy necessary for water treatment. Desalination is the most energy intensive water treatment technology but it could be solution for many problems in water supply for areas with chronic debt of water. In this study we find three section: in …

Sea water desalination and energy consumption: A case study of wave energy converters (WEC) to desalination applications in sicily

Recent studies about interactions among energy and water are considered as a new field of research. As almost all energy generation processes require significant amounts of water, and water requires energy for treatment and transport, so these two resources are inextricably linked. The main aim of this work is a presentation of the use of renewable energy for desalination plants in Sicily: in particular exploitation of wave energy into electrical energy necessary for water treatment. Desalination is the most energy intensive water treatment technology but it could be solution for many problems in water supply for areas with chronic debt of water. The aim of this work is a description of a s…

An Approach to the conversion of the power generated by an offshore wind power farm connected into seawave power generator

Generazione di energia elettrica dal moto ondoso del mare mediante l'utilizzo di generatori elettrici lineari

In questo brevetto è illustrato un dispositivo innovativo per la produzione di energia elettrica dalle onde del mare. Il dispositivo è basato sull'utilizzo di un generatore lineare a magneti permanenti che sfrutta il moto verticale dell'onda marina per generare una forza elettromotrice.

Energy and Economic Comparison of Different Conditioning System among Traditional and Eco-Sustainable Building

The use of bioclimatic principles can reduce energy demands and CO2 emissions in the building sector [1-. Costs are one of the most important barriers to a widespread adoption of the green architecture technologies [4-. The aim of this study is to compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the bioclimatic building but built by conventional building materials. The tools used for this study were TRNSYS and HOMER

An optimum design of the magnetic circuit of a PM linear electrical generator for the exploitation of sea waves.

In this paper an approach to the optimization of the magnetic design of a Permanent Magnet (PM) linear generator for the exploitation of the energy contained in sea waves is presented. This approach consists of a two step procedure: the first one takes into account the stochastic features of the sea wave motion and describe the working condition of the machine under this motion by adopting a lumped parameter model. In this step the objective function is the energy production. The second step optimizes the generator by using the results obtained in the first step as the constraints that must be fulfilled by a design based on a Finite Element Method (FEM) analysis. Furthermore, the approach i…

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.

Design and performances of a high temperature superconducting axial flux generator

An important quality index of electric machine is the power density: it is known that axial flux machine tends to have a higher power density than the radial machines. As a result they are becoming more and more used in applications where the power density is a critical issues. However, the best way to enhance the power density is to increase the value of the airgap field and this could be achieved by using a superconducting excitation. Many projects have been developed in the world in order to develop both superconducting generator and superconducting motor, but in most of these programs the geometry of the machine has been based on radial machines [1]. All of these approaches show the fea…

Desalination in small islands: the case study of Lampedusa (Italy)

Desalination represents a common solution to overcome the water scarcity in small island. A case study is presented, considering the island of Lampedusa, located at south of Sicily (Italy). As many small islands in the middle of the Mediterranean Sea, Lampedusa presents a small standalone electrical grid, entrusted to old diesel engines. For more, the renewable energy sources are extremely underdeveloped in this territory. Lampedusa is regularly affected by water scarcity, so freshwater is produced by desalination plant and sometimes transported by boat from Sicily. As sustainable solution, the paper firstly analyses the energy demand for desalination and then proposes the installation of a…

Analysis of interconnection substations for sewave 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.

A Renewable Energy mix to Supply the Balearic Islands: Sea Wave, Wind and Solar

The paper investigates the status of the electrical energy sector in the Balearic Islands (Spain). In order to improve the energetic sustainability, this work analysis the availability of renewable energy sources, focusing the attention on sea wave, wind and solar. For the utilization of sea wave source, an innovative device is proposed.

Wind turbines to power telecommunication Systems: A case study in Sicily

Design Criteria and Experimental Tests of a PM Linear Electrical Generator for the Exploitation of Sea Waves Energy

First Life Cycle Impact Considerations of Two Wave Energy Converters

The work presents two different revolutionary devices for the utilization of a new entry of renewable energy sources: sea wave. The first technology is based on linear generators, able to directly converts a linear motion into electrical output, limiting to minimum the chain of energy conversion. The other solution is based on a mechanical motion converter, coupled with alternators. The scope of this paper is to compare the two different systems designed by University of Palermo, through Life Cycle Assessment, in order to evaluate the global effects of the two systems to the environment.

A Power Law Behavior in the Incentivized Italian Photovoltaic Market

The Italian photovoltaic (PV) marketis analyzed by using the data contained in the database that describes all PV Plants installed in Italy under the incentive program called “2nd Conto Energia”. It is shown that the cumulative probability distribution of the size of the installed PV plants has a broken power tail. An approach to partially quantify the effect of the economic, juridical and technical rules is introduced in order to show how the regulatory body influences the power tail of the cumulative probability curve.

Identification of the inertial model for innovative semi-immergible USV (SI-USV) drone for marine and lakes operations

The proposed project shows the results obtained in the implementation and testing in lacustrine and marine environment of a nautical remote controlled vehicle with surface navigation and innovative features Semi-Immergible (SI-USV). This vehicle is based on a pending patent belonging to Palermo University (Patent Pending RM2012A000209 and Patent RM2014Z000060) concerning innovative semi-immersible vehicles (SI-Drone), that can be remotely controlled from the ground, air, satellite and sea also during the semi-immersible operation. Given its low draft, the electric powered vehicle, coupled with jet propulsion, makes it possible to navigate in shallow waters, coastal shipping or sandbars.

Experimental Evidence on the Thermal Performance of Opaque Surfaces in Mediterranean Climate

The thermal insulation of buildings, intended as wrap feature which determines the dispersion of heat, the reference parameter is necessary to contain the thermal losses during the winter season. The transmittance of the opaque components, used as an indicator of the energy quality of a casing, together with the overall coefficient of dispersion, represents a proper descriptor of the behavior during the heating season. However, if a strong insulation in winter conditions brings only positive effects, the same cannot be said for the summer conditions. A high value of the insulation in the casing is convenient only when the gains free, either in the form of solar contribution that of endogeno…