Design and experimental characterization of a low-cost, real-time, wireless AC monitoring system based on ATmega 328P-PU microcontroller

This paper describes the development and experimental characterization of a real-time, low-cost, wireless AC monitoring system based on ATmega 328P-PU microcontroller. The proposed system is composed by a main brain for the acquisition and the processing of the data measured by smart meters. From the experimental tests discussed in this work it is demonstrated that the proposed system can monitor, with adequate accuracy, the working cycles of electrical loads in order to evaluate its energy consumption.

Computer-aided analysis and design procedure for rotating induction machine magnetic circuits and windings

The aim of this study is to present a new, accurate, and user-friendly software procedure for the analysis and rapid design of rotating induction machine windings, considering both the electric and the magnetic specifications of the machine itself. This procedure is a valid aid for quick first stage design without the necessity of using finite element method (FEM)-based design procedures. FEM can be used in a second design phase in order to refine the first stage results. The design procedure is hereafter outlined and some examples show its capability.

Ev charging station at university campus

This paper faces the technical and economic challenges related to the design of a green recharge area for electric vehicles at the Campus of Palermo, Italy, with the aim of reduce both costs and pollution connected to the charging process. Based on the behaviour of the student population, the electrical load is identified and two possible solutions are evaluated to manage the peak load: an orientation of the panels increasing the power at defined time and the use of a storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy (LCOE), which reaches 75.3 €/MWh for the orientation of panel and 103 €/MWh for stor…

Physiological compatibility of wireless chargers for electric bicycles

The Inductive Power Transfer represents a viable solution of wireless battery charging for all users of electric mobility. This method brings some benefits to the electric vehicles, being a convenient technique, compared to the conventional wire-based battery charging. Among the electric vehicles, the electric bicycles particularly fit with this innovative method of battery charging. Nevertheless, the physiological effects of the produced magnetic fields need to be taken into account. In this paper, the design of an Inductive Power Transfer system for E-bike wireless battery charging is presented and the measurements concerning the surrounding magnetic field are provided in order to validat…

Comparison between Different Dynamic Reconfigurations of Electrical Connections for partially shaded PV Modules

This paper presents an economical investigation on the benefits related to the employment of reconfiguration systems for photovoltaic plants. More in detail, different structures of reconfigurators are proposed and, in order to evaluate the economical convenience on their installation, the Net Present Value is used as a validation element. Significant results are carried out from the proposed analysis.

A Rotor Flux and Speed Observer for Sensorless Single-Phase Induction Motor Applications

It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring the development of efficient alternatives to improve the operational performance of this machine. Although the rotor flux and rotational speed are essential variables in order to optimize the operation of a SPIM, the use of conventional sensors to measure them is not a viable option. Thus, the adoption of sensorless strategies is the more reasonable proposal for these cases. This paper presents a rotor flux and rotational speed observer for sensorless applications involving SPIMs. Computer simulations and the…

A Low-cost, Real-time Monitoring System for PV Plants based on ATmega 328P-PU Microcontroller

This paper presents a real-time monitoring system for PV power plants based on a microcontroller Atmega328P-PU. The proposed system, whose performances can be relatively close to those achieved with commercial monitoring systems, is simple, low-cost and open source technology-based. In addition, a user interface, capable to communicate through a wireless network by using a standard communication protocol IEEE 802.15.1, is here presented. From the experimental tests described and discussed in this paper it is demonstrated that the proposed monitoring system provides, with adequate accuracy, all the information about the operating status of the PV plant, even during fault conditions.

Performance comparison of tubular linear induction motors with different primary winding connections

This paper presents an experimental characterization and comparison of the performances achieved by a tubular linear induction motor (TLIM) prototype with different typologies of primary winding connections. In particular, three configurations are described: full-pitch star, 5/6 shortened pitch star and 5/6 shortened pitch double star. For this purpose, an experimental test bench at the SDESLAB laboratory (University of Palermo) has been set-up and the results obtained from the tests have allowed to identify which type of winding configuration can be chosen in dependence of the type of application intended for the motor. In addition, this experimental study is suitable for TLIM winding desi…

Experimental Investigation on Magnetic Field Effects of IPT for Electric Bikes

The wireless power transmission (WPT) is increasingly representing a promising technology and an innovative solution, especially for the electric vehicles (EVs) battery charging. The inductive power transfer (IPT) is the standard technology of wireless charging: the energy transfer occurs between two magnetically coupled coils. The IPT-based battery charging is especially convenient for E-bikes and the physiological effects related to the generated magnetic fields should be estimated. In this context, this work presents a 200Â W prototype of wireless battery charger for E-bikes. In addition, the measurements regarding the surrounding magnetic field are given in detail in order to evaluate t…

Novel Energy Modelling and Forecasting Tools for Smart Energy Networks

A novel Energy Modelling and Forecasting Tool (EMFT) has been adopted for use in the VIM SEN (Virtual Microgrids for Smart Energy Networks) project and this paper gives an insight of the techniques used to provide vital support to the energy market, in particular to energy aggregators. A brief description of one of the test sites where data has been collected for validation of the EMFT will be outlined and some examples shown. The information and predictions will then be used by a decision support system to dynamically adjust energy delivery and consumption, by giving advice to users and operators on actions they can take to obtain a better match between energy supply and demand that increa…

Modeling and simulation of a VCM micromotor and its potential applications

This paper presents the modeling and simulation of a VCM electrostatic micromotor with a new FEM analysis and implementation method, in order to determine the electrical parameters of the model and the generated electrostatic torque. Both the modeling and the simulation have been achieved using several software programs. In particular, the geometric model created with AUTOCAD has been imported to the FEMM program for the finite-element-method analysis. Then, with the LUA and MATLAB simulation programs, the parameters of the model and the related electrostatic torque have been calculated. The results obtained from this work have been compared with those reported in other scientific papers, s…

A Flux and Speed Observer for Sensorless SPIM Applications

It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry appliances, which is become more sophisticated and requires the development of high performance alternatives to drive a SPIM. All proposed strategies to improve the performance SPIM need the evaluation of the rotational speed or position information. Since the use of conventional sensors to measure the rotational speed cannot be justified for SPIM applications, the adoption of a sensorless strategy is a more reasonable option for these cases. This paper presents a flux and speed observer for sensorless applications involving SPIMs. The performance of the proposed observer is verifi…

Experimental Prototyping of a Microgrid with Mechanical Point of Common Coupling

The smartgrid is a key technology for the sustainable and smart utilization of the renewable energies. In this paper, a prototyping of a microgrid, assembled at the Sustainable Development and Energy Saving Laboratory (SDESLAB) of the University of Palermo, is presented and discussed. In detail, the microgrid presents only one mechanical point of common coupling (PCC) with the main grid and it is electrically separated from the main grid. In this way, the voltage variations of the main grid do not affect the microgrid electric quantities behavior. In order to validate the effectiveness of the voltage and frequency control, several experimental tests and analysis have been carried out. In de…

The use of slightly asymmetrical windings for rotating electrical machines

Historically, asymmetrical windings in electrical machines have been rarely used and only for specified needs, because the adoption of symmetrical configurations has always been considered the only solution during the design stage of electrical machines. The aim of this work is to demonstrate with several examples that the use of slightly asymmetrical windings can be a reasonable choice and, in certain cases, a favorable option during the machine design stage, allowing the possibility of selecting a wider range of slot/pole number combinations, without affecting the performances of the machines. More in detail, an interior permanent magnet synchronous machine equipped with a symmetrical 3-p…

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…

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…

Experimental investigation on different rainfall energy harvesting structures

In this paper proposes an experimental comparison between different rainfall harvesting devices and the study of the corresponding electrical rectifying circuit. More in detail, three harvesting structures are considered: the cantilever, the bridge and the floating circle. For each of the proposed structure, different waveforms have been acquired and discussed. The processed data have been compared in order to suggest the best choice for the rectifying circuit, from the simplest one to the most endorsed in the technical literature.

An IPMSM torque/weight and torque/moment of inertia ratio optimization

In this paper, a torque/weight and torque/moment of inertia ratio optimization procedure for interior permanent magnet syncronous motors (IPMSMs) is presented. More in detail, a performance comparison between several IPMSM rotor structures has been carried out in order to determine the optimum geometry that can maximize the torque/weight and torque/moment of inertia ratios. A commercial motor, with known electrical and mechanical characteristics, has been taken as reference. Its rotor structure has been modified several times, obtaining different rotor geometries and, therefore, many IPMSM models with different electrical and mechanical characteristics. The finite element method (FEM) analy…

Speed control of tubular linear induction motors for industrial automated applications

The Tubular Linear Induction Machine (TLIM) has acquired great relevance over the past years for industrial automated applications. For this purpose, the complete modeling, simulation and determination of the parameters of a TLIM is presented in this paper. In addition, the TLIM speed control for this specific application is here described. In order to verify the performances of the proposed system, a test bench has been setup and good agreement is shown from the comparison between measured and simulated results.

A DSP-Based Resolver-To-Digital Converter for High-Performance Electrical Drive Applications

This paper presents a low cost, simple, and highly accurate resolver-to-digital converter (RDC) for electrical drive applications based on an integrated software approach, thus allowing a significant reduction of hardware components count with significant improvements in terms of reliability, reduction of fault rate, and susceptibility to electromagnetic interference (EMI). Particular attention has been addressed to cost which is 25% off over conventional RDC. Simulations and experimental tests confirm the high quality of the proposed system.

Finite-Difference Time-Domain Simulation of Tower and Grounding Subjected to Lightning

In this paper the behavior of a tower and its grounding system, subjected to a lightning, is faced. Finite difference time domain (FDTD) method has been chosen in order to study the non-linear time domain behavior of the system. The electromagnetic problem has been described by using two type of first order time derivative equations: Maxwell's equations and Telegraph equations. Aim of this work is to evaluate the possibility of a flashover between tower and power line, by considering different cases of study.

Experimental investigation on high efficiency real-time control algorithms for IPMSMs

This paper describes an experimental investigation on the power losses variations occurring in an Interior Permanent Magnet Synchronous Motor (IPMSM) with respect to the direct axis current component. Such investigation can be useful to determine a mathematical model accounting for copper, iron and mechanical friction losses, and for the arrangement of a speed control drive system equipped with a real-time power losses minimization algorithm. In particular, a test bench has been set up in order to carry out all measurements and the final power loss identification. The test bed is composed by a IPMSM drive with a field oriented control (FOC) strategy, a power analyzer, a dynamometric brake a…

Design issues for wind farms grid tied Inverter

In this paper the Authors give indications for the design of a grid tied Voltage Source Inverters (VSI) aimed to optimal use in energy conversion from wind source. In particular, the design of the inverter is more focused on the control system planning, with a particular glance on the grid synchronization problem. After the exposition of general issues concerning renewable energies and associated topics, the case of a grid tied inverter is considered and a methodology of design is sketched starting from the consideration of the DC side and also considering the power device losses, the protection issue against over voltages and over-currents, snubber circuits, heat sinks and, finally the con…

A General Mathematical Formulation for the Determination of Differential Leakage Factors in Electrical Machines with Symmetrical and Asymmetrical Full or Dead-Coil Multiphase Windings

This paper presents a simple and general mathematical formulation for the determination of the differential leakage factor for both symmetrical and asymmetrical full and dead-coil windings of electrical machines. The method can be applied to all multiphase windings and considers Gorges polygons in conjunction with masses geometry in order to find an easy and affordable way to compute the differential leakage factor, avoiding the adoption of traditional methods that refer to the Ossanna's infinite series, which has to be obviously truncated under the bound of a predetermined accuracy. Moreover, the method described in this paper allows the easy determination of both the minimum and maximum v…

Experimental Investigation on the Performances of Innovative PV Vertical Structures

The sustainable development of our planet is considerably related to a relevant reduction of CO2 global emissions, with building consumption contributing more than 40%. In this scenario, new technological conceptions, such as building-integrated photovoltaic technology, emerged in order to satisfy the requirements of sustainability imposed by the European Union. Therefore, the aim of this work is to provide a technical and economical comparison of the performances of different vertical-mounted innovative photovoltaic systems, potentially integrated on a building instead of on traditional windows or glass walls. The proposed investigation was carried out by means of experimental tests on thr…

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

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

Efficient contactless power transfer system for EVs

Based on the inductive power transfer (IPT), the contactless approach allows safe and comfortable operations of battery charging for Electric Vehicles (EVs). In this paper, a contactless system particularly suitable for E-bike battery charging is proposed. A practical realization of the system has been carried out, aiming at the system evaluation in terms of working and efficiency. Through a phase shift modulation, a power regulation has been implemented. The target power level is 100 W.

Measuring rain energy with the employment of “Arduino”

This paper presents the performances of rainfall energy harvesting through the use of a piezoelectric transducer and an Arduino-based measuring system. Diverse studies agree on the possibility of generating electricity from rainfall, but to date, a study that can measure the quantity of energy produced during rainfall is still missing. The present study begins with results obtained from laboratory researchers using piezoelectric transducers and oscilloscopes — to measure the energy produced from a single raindrop — and concludes with an ad hoc Arduino-based measuring system, aimed at measuring the actual amount of electrical energy produced by a piezoelectric transducer that is exposed to r…

Differential Leakage Factor in Electrical Machines Equipped with Asymmetrical Multiphase Windings: a General Investigation

This paper presents an investigation in terms of degree of unbalance and leakage factor of electrical machines equipped with multiphase windings. The analysis has been carried out through 4800 combinations between slots/poles/phases/layers, analyzing the variability of the leakage factor for each condition and determining the optimal region for its minimization. The obtained results demonstrate that the leakage factor could be considerably reduced with the adoption of slightly asymmetrical windings, which represent a favorable option during the early design stage of electrical machines.

Analysis, characterization and minimization of IPMSMs cogging torque with different rotor structures

This paper presents the analysis, characterization and comparison of the cogging torque components generated by five different IPMSM rotor structures. More in detail, an IPMSM model (named IPMSM1), which is derived from a commercial geometry, is analyzed by using a Finite Element Method (FEM) approach. Then, four other IPMSM models, which are obtained by modifying the IPMSM1 rotor structure and by maintaining the same stator configuration, are proposed and analyzed. From the obtained simulation results, the cogging torque components for each structure are determined and compared. From this comparison, a significant cogging torque decrease is occurring for the modified geometries, without af…

Nanostructured lead acid battery for electric vehicles applications

This paper presents an innovative lead acid battery, based on nanostructured active materials. Both charging time and specific energy are greatly enhanced in comparison with commercial lead acid battery. Starting from the extremely valuable performances of the nanostructured battery, also a circuital model, for application in electric vehicle traction, has been specifically developed. The circuital model has demonstrated that an enhanced nanostructured battery allows an increase of traveled distance by electric vehicles.

Sensorless variable speed single-phase induction motor drive system

It is usual find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring variable speed drives. Considering the low cost of this machine, the adoption of sensorless speed control is the more reasonable option for SPIM drives. This paper presents a proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques. An observer based on two independent linear close-loop control systems provides the estimation of the rotor flux and speed from the measurements of the stator currents and voltages. These estimatives are used by close-loop systems for speed…

Overview and experimental analysis of MC SPWM techniques for single-phase five level cascaded H-bridge FPGA controller-based

This paper presents an overview and experimental analysis of the MC SPWM techniques for single-phase cascaded H-bridge inverter. The multilevel power converters are an alternative to traditional converters known as “three-level converters”. The voltage waveforms and the related frequency spectra, which have been obtained by simulation analysis in Matlab-Simulink environment, are here reported for all the proposed modulation techniques. The simulation results have been experimentally validated through means of a DC/AC, five-level, single-phase converter prototype with an appropriate test bench.

Contributed Review: Review of thermal methods for space charge measurement.

The space charge accumulation phenomenon has garnered great interest over the last two decades because of the increased use of direct current in high voltage electrical systems. In this context, a significant relevance has been achieved by the thermal methods, used for solid dielectrics. This paper presents a review of this non-destructive measurement system used for the measurement of space charge. The thermal pulse method, the thermal step method, and the laser intensity modulation method are described. For each configuration, the principle of operation, the thicknesses analyzed, and the spatial resolution are described, reporting also the main related applications

Effect of weak magnetic fields on the in vitro propagation of Genista aetnensis (Raf. Ex Biv.) Dc.

Over the years, many studies have emphasized the importance of the magnetic fields (MF), used as a safe alternative choice to improve agricultural production. The induction effect of different magnetic fields varies depending on the species, explants typology, intensity of magnetic field and period of exposure. The aim of the present study was to investigate the application of a continuous magnetic field induction, at different exposure times, as a production enhancement for in vitro culture of Genista aetnensis, an endemic shrub commonly named 'Mount Etna broom'. An in vitro protocol has been settled for the conservation of the species. Plantlets cultured onto a solified Murashige and Skoo…

Enhanced Mathematical Modelling of Interior Permanent Magnet Synchronous Machine Considering Saturation, Cross-Coupling and Spatial Harmonics effects

The Interior Permanent Magnet Synchronous machine (IPMSM) conventional mathematical model is generally employed to investigate and simulate the IPMSM control and drive system behaviour. However, magnetic nonlinearities and spatial harmonics have a substantial influence on the IPMSM electromagnetic behaviour and performances. In order to simulate the IPMSM real electromagnetic behaviour, this paper describes an enhanced mathematical model that takes into account the saturation, cross-coupling and spatial harmonics effects. This model has been implemented in Matlab®/Simulink environment where the electric and magnetic parameters are derived from FEA investigations and implemented by the use o…

Experimental Comparison of Efficiency Enhancement Algorithms for Three-Phase Induction Motors

This paper presents an experimental comparison of two efficiency improvement algorithms for three-phase induction motors by adopting Loss Model Algorithms (LMAs). The efficiency enhancement is evaluated starting from several simulations for different conditions of load and speed and, then, validated by comparing the experimental results obtained by applying the two control strategies and the traditional Field Oriented Control (FOC). Significant results in terms of efficiency enhancement are presented and discussed.

Comparison on the use of PV systems in the vertical walls

In this article the preliminary evaluation of the performance of a photovoltaic window is presented. The aim is to trace the behavior of next-generation systems, which favor architectonical integration. Three different systems have been taken into account: a dye sensitized solar cell (DSSC), blue and grey caved silicon panels. The systems can be placed behind a window or behind a wall of glass blocks.

Characterization of Thin Film CIG(S,Se)2 submodules using Laser Beam Induced Current Technique

Nowadays, an important class of thin film solar cells consists of CuInGa(S,Se)2 (CIGSSe) solar cells, i.e., composed of Copper, Indium, Gallium, Sulfur and Selenide. Thanks to their electrical and optical properties and to the technological development, thin film integrated photovoltaic modules have nowadays obtained relatively good values of efficiency. In this work, we have performed the electrical and optical characterization of a CIGSSe sub-module by using both a solar simulator equipment and the Laser Beam Induced Current (LBIC) technique.

Electrical characterization of highefficiency bifacial silicon solar cells

This work presents a preliminary study on the electrical characterization of high efficiency bifacial solar cells. An opening discussion on the state-of-the-art of such advanced technology is initially proposed and the experimental characterization of some prototypes is described. From this analysis, it can be stated that the bifacial silicon solar cells can be a very promising technology with high electrical performances and efficiency.

Parametrical study of multilayer structures for CIGS solar cells

In this paper, a numerical analysis of relevant electrical parameters of multilayer structures for CIGS-based solar cells was carried out, employing the simulation software wxAMPS. In particular, we have focused on thin film cells having a ZnO:Al/ZnO/CdS/CIGS structure with a Molybdenum back contact. The aim of this work is to establish good theoretical reference values for an ongoing experimental activity, where our technology of choice is the single-step electrodeposition. In detail, we have analyzed how the main electrical properties change with the bang gap and the thickness of the absorber layer, for such a type of solar cell structure. Our results show that both efficiency and fill fa…

Recharge stations: A review

Charging equipment for all-Electric Vehicles (EVs) is classified by the rate at which the batteries are charged. Charging times vary based on how depleted the battery is, how much energy it holds, the type of battery, and the type of Electric Vehicle Supply Equipment (EVSE). In this paper, a review of the innovative charging stations is reported.

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.

Stability of Microgrids: An Application of Virtual Synchronous Generator

The objective of this paper is to illustrate an alternative control algorithm for power converters which have the task of introducing the energy generated by systems based on the use of renewable sources such as, photovoltaic or wind power, in to small-sized networks, microgrids. Virtual Synchronous Generator can operate both in parallel to the main network as well as in isolated and autonomous conditions (islanding-mode). The contribute of this work is to drive a consolidate approach, made in time domain, in a more flexible and less time-consuming approach based on Park transformation.

Enhanced loss model algorithm for interior permanent magnet synchronous machines

This paper presents an experimental study on the impact of the parameter variations over the performances of a LMA (Loss Model Algorithm) designed for an IPMSM (Interior Permanent Magnet Synchronous Machine). In a previous work, the characterization was carried out by assessing, for several working conditions, the motor parameters that influence the motor efficiency. The proposed enhanced loss model algorithm is implemented in a rapid prototyping system and its performances, in term of efficiency, are compared with other control systems, obtaining promising results.

Experimental study on efficiency enhancement in Interior Permanent Magnet Synchronous machines

This paper presents an experimental study on the efficiency variation occurring in an IPMSM (Interior Permanent Magnet Synchronous Motor) with respect to the direct axis current component and for several working conditions. Such investigation is the starting point for the arrangement of a speed control drive system equipped with a real-time power losses minimization algorithm. More in detail, a test bench is set up to carry out the measurements needed for the final power loss identification. The experimental investigation is developed by performing tests at different speed, magnetization and load conditions. From the obtained results, it can be stated that the IPMSM efficiency can be maximi…

A cogging torque minimization procedure for IPMSMs based on different laminate geometry

This paper presents a possible minimization procedure of the cogging torque generated by an IPMSM (Interior Permanent Magnet Synchronous Machine) with a progressive modification of a basic geometrical structure of rotor laminates. More in detail, an IPMSM model is analyzed by using a Finite Element Method (FEM) approach. Then, other IPMSM models, which are obtained by modifying the geometry of the IPMSM rotor laminates and by maintaining the same stator configuration, are proposed and discussed. From the obtained simulation results, the cogging torque components for each structure are determined by means of FEM and compared to each other. From this comparison, it can be stated that the cogg…

Characterization of thin film CIG(S,SE)2 submodules using solar simulator and laser beam induced current techniques (Versione estesa)

In this work, the electrical and optical characterization of CIG(S, Se)2 sub-modules using both a solar simulator equipment and the Laser Beam Induced Current (LBIC) technique is presented. By using the solar simulator and a proper set-up, the electrical parameters of the modules at varying irradiance and temperatures are determined. In addition, the LBIC measurements are carried out to analyze the 2D photocurrent uniformity of the modules at two different wavelengths. Dispersion values of extracted parameters can be very useful for practically tuning the modelling stage at device/module level.

Interior permanent magnet synchronous motors: Impact of the variability of the parameters on their efficiency

In the scientific literature, various authors presented different control strategies aimed to increase the efficiency of the interior permanent magnet synchronous motors. These strategies, starting from a well-known mathematical model of the dynamic behaviour of the motor, are able to reduce the power losses acting on the magnetizing component of the stator current. However, none of the proposed approaches takes into account that, varying the working conditions of the motor, also the values of the parameters, which have an impact on the power losses, can vary. In this paper, therefore, starting from an accurate measurement of the motor characteristics for various values of speed and load, w…

ANALISI DELLE PRESTAZIONI E MIGLIORAMENTO DI MICROMOTORI ELETTRICI E DI MOTORI ELETTRICI A POTENZA FRAZIONARIA

Experimental characterization and comparison of TLIM performances with different primary winding connections

Abstract This paper presents an experimental characterization and comparison of the performances achieved by a Tubular Linear Induction Motor (TLIM) prototype with different typologies of primary winding connections. More in detail, three different configurations have been considered, analyzed and discussed: full-pitch star, 5/6 shortened pitch star and 5/6 shortened pitch double star. For this purpose, an experimental test bench at the Sustainable Development and Energy Saving Laboratory (SDESLab), University of Palermo, Italy, has been set-up. The obtained results have allowed the identification of the best winding configuration for different applications intended for the motor. Moreover,…

Economic evaluation on the use of reconfiguration systems for increase of energy production in PV plants

This paper presents an economic analysis of the effectiveness of Dynamic Reconfiguration Systems (DRS) for PV plants in dependence of the incentive policies offered by several countries of the European Community. This evaluation has been achieved by means of the NPV (Net Present Value) and through the comparison between Bulgaria, Romania, Greece and Croatia. From the obtained results, it can be stated that the adoption of reconfiguration systems, in certain cases, can be a convenient solution.

Design, Microfabrication and Characterization of a Power Delivery System for new Biomedical Applications

This paper presents the design, microfabrication and characterization of a wireless power delivery system capable of driving a surface acoustic wave sensor (SAW) for biomedical applications. The system consists of two planar, spiral-square microcoils, which have been geometrically optimized in order to maximize the quality factor Q. The integration of the SAW - microcoil system into artificial implant sites will allow a real-time biofilm growth monitoring and treatment, providing countless advantages to the related medical applications.

Design of a grid connected inverter for sustainable small wind farms

The actual definition of sustainability is nowadays widely accepted. It provides a very general indication on what it is, but it reveals unable to assert how it should be reached. However, if one considers the multiplicity of human activities that have led to talk of real process of human settlement on the environment, it is then understood how it is close to the particular mankind activities. Then the task of providing a guidance on what to do within the sustainability concept is delegated case by case. In this paper, with reference to wind renewable source, The Authors give some indications in the design of a voltage source inverters aimed to optimal use of the wind source. In particular …

Simple and Flexible Power Loss Minimizer With Low-Cost MCU Implementation for High-Efficiency Three-Phase Induction Motor Drives

This paper presents a simple, practical and low-cost implementation of a power losses minimization algorithm for three-phase induction motors taking also into account both iron core losses and magnetic saturation. The algorithm evaluates, in real-time, the optimal direct axis magnetizing flux component for efficiency enhancement of the drive. A further advantage of the proposed technique is represented by a flexible and low-cost implementation by means of an ATMEL ATSAM3X8E microcontroller. The power loss minimization algorithm is tested preliminarily by means of several simulations, then, experimentally validated by applying the proposed control strategy on a 5.5 kW Field Oriented Control …

A General and Accurate Measurement Procedure for the Detection of Power Losses Variations in Permanent Magnet Synchronous Motor Drives

The research of innovative solutions to improve the efficiency of electric drives is of considerable interest to challenges related to energy savings and sustainable development. In order to successfully validate the adoption of new and innovative software or hardware solutions in the field of electric drives, accurate measurement procedures for either efficiency or power losses are needed. Moreover, high accuracy and expensive measurement equipment are required to satisfy international standard prescriptions. In this scenario, this paper describes an accurate measurement procedure, which is independent of the accuracy of the adopted instrumentation, for the power losses variations involved…

A general procedure for the construction of Gorges polygons for multi-phase windings of electrical machines

This paper presents a simple and effective procedure for the determination of the Gorges polygon, suitable for all possible winding configurations in electrical machines. This methodology takes into account the determination of a Winding Distribution Table (WDT), in which all the information about the distribution of the currents along the stator periphery is computed and from which the Görges polygon are easily derived. The proposed method can be applied to both symmetrical and asymmetrical multi-phase windings, including concentrated, fractional, reduced and dead-coil ones. The examples provided in this paper demonstrate the versatility of the proposed method.

Review of acoustic methods for space charge measurement

In the last decade, due to the increased use of direct current, the space charge accumulation phenomenon has reached more interest. In this regard, several non-destructive measurement systems were used. In particular, for solid dielectrics, the acoustic methods have had greater success. This review presents a brief historical evolution of the Pulse Electro- Acoustic (PEA) method, describing the working operation, the thicknesses analyzed and the spatial resolution for the different configurations of the PEA cell. The Pressure Wave Propagation (PWP) method in both configurations Piezo-PWP and Laser Induced Pressure Pulse (LIPP) is also described.

Sensorless variable speed single-phase induction motor drive system based on direct rotor flux orientation

The single-phase induction motor (SPIM) is one of the electrical machines more used in the World, and can be found in several fractional and sub-fractional horsepower applications in houses, offices, shoppings, farms, and industries. The introduction of more sophisticated applications has required the use of variable speed drives for SPIM, where the adoption of sensorless techniques is the more reasonable option for speed control due to the low cost of this electrical machine. A proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques is presented in this paper. None transformation is used in order to eliminate the asymmetry of the stator windings…

Simulation of parasitic effects on Silicon Carbide devices for automotive electric traction

Wide Band Gap (WBG) semiconductors are increasingly addressed towards Electric Vehicle (EV) applications, due to their significant advantages in terms of high-voltage and low-losses performances, suitable for high power applications. Nevertheless, the packaging in WBG devices represents a challenge for designers due to the notable impact that inductive and capacitive parasitic components can bring in high switching frequency regime in terms of noise and power losses. In this paper, a comparison between conventional Silicon (Si) and emerging Silicon-Carbide (SiC) power switching devices is presented. The effects of inductive parasitic effects and switching frequency are investigated in simul…

A General Design Procedure for Symmetrical Windings of Electrical Machines

Winding design methods have been a subject of research for many years of the past century. Many methods have been developed, each one characterized by some advantages and some drawbacks. Nowadays, the star of slots is the most widespread design tool for electrical machine windings. In this context, this paper presents a simple and effective procedure to determine the distribution of the EMF stars and of the winding configuration in all possible typologies of electrical machines equipped with symmetrical windings. Moreover, this procedure can also be easily implemented in a computer program in order to perform automated winding designs for rotating electrical machines. Several examples are p…

Photovoltaic facade: Comparison of actual technologies

This article aims to establish the economic contribution of a photovoltaic system placed on a façade of a building, replacing traditional elements such as windows and glass-cement walls with active elements. The aim is to compare the behavior of next-generation systems, which favor architectonical integration, with traditional ones. Two novel systems have been taken into account: a dye sensitized solar cell (DSSC) and blue and grey thin film silicon panels. Different generation systems have been tested and compared in terms of efficiency and fill factor.

A Cogging Torque Minimization Procedure for Interior Permanent Magnet Synchronous Motors Based on a Progressive Modification of the Rotor Lamination Geometry

This article describes a simple cogging torque minimization procedure for interior permanent magnet synchronous machines (IPMSMs), consisting of a progressive modification of the rotor lamination geometry. This procedure can be generalized for the main topologies of PMSM, independently of the number of stator slots or the location of the permanent magnets. For this purpose, a basic IPMSM structure is analyzed by means of the FEM (finite element method) approach, and then, several other IPMSM geometries, obtained by adequately modifying the rotor lamination geometry of the basic IPMSM model without changing its stator configuration, are proposed and discussed. The trends of the cogging torqu…

FOC with Resolver Implementation for PMSM Drives by Using a Low Cost Atmel SAM3X8E Microcontroller

The aim of this paper is the low-cost experimental implementation of a field oriented control strategy for a Permanent Magnet Synchronous Motor (PMSM) by using an Atmel SAM3X8E microcontroller, mounted on an Arduino DUE board. In this electrical drive for PMSM, a resolver is used in order to measure the rotor position and speed: Therefore, the low-cost Arduino DUE performs not only FOC algorithm and phase currents data acquisition, but also a resolver-To-digital converter process, rotor position and speed data acquisition, and resolver signals management. The code has been implemented in the open source Arduino IDE, using C language, whereas the control and plot visualization interfaces hav…

Economic evaluation of PV system for EV charging stations: Comparison between matching maximum orientation and storage system employment

This article addresses the problem of the choice of a generation system to be implemented to reduce the impact of charging electric vehicles at University. Based on the behaviour of the student population, it is identified the electrical load. Two possible solutions are evaluated in order to manage the peak load: an orientation of the panels in order to increase the power at defined time and the use of storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy.

Maximum Torque Per Ampere control algorithm for low saliency ratio interior permanent magnet synchronous motors

This paper presents an investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs). In particular, this study was carried out on a small-power IPMSM with low salience ratio. Both control algorithms have been implemented in the Matlab/Simulink environment, obtaining promising results.

A General Mathematical Formulation for Winding Layout Arrangement of Electrical Machines

Winding design methods have been a subject of research for many years of the past century. Many methods have been developed, each one characterized by some advantages and drawbacks. Nowadays, the star of slots is the most widespread design tool for electrical machine windings. In this context, this paper presents a simple and effective procedure to determine the distribution of the slot EMFs over the phases and of the winding configuration in all possible typologies of electrical machines equipped with symmetrical windings. The result of this procedure gives a Winding Distribution Table (WDT), which can be used to define coils and coil groups connections and also to simply implement winding…

A prototypal PCB board for the EMI characterization of SiC-based innovative switching devices

In this paper, a preliminary PCB board for the electromagnetic interference (EMI) characterization of innovative silicon-carbide (SiC) based switching devices is presented. Packaging technological issues can determine hurdles in the high-frequency switching and high power regime where wide band gap semiconductors are intended today for Electric Vehicle (EV) applications. In particular, the parasitic inductances that emerge in such devices, must be assessed, by using e.g. EMI techniques. In this specific case, the EMI characterization is supposed to be carried out in a semi-anechoic chamber, available at the University of Palermo (UNIPA), to assess the electromagnetic disturbances according …

Finite-element performance comparison of IPMSMs with unsymmetrical double-layer windings

This paper presents a comparison of the performances between IPMSMs (Interior Permanent Magnet Synchronous Machine) with a symmetrical and with two different types of unsymmetrical windings. The aim is to demonstrate that the adoption of slightly unsymmetrical windings does not significantly affect the performances of the machines, both in terms of cogging torque and torque/load angle characteristics, providing also the advantage of a higher possibility of choice in terms of slot number/poles ratio. More in particular, an IPMSM model (named IPMSM-1) derived from a commercial geometry equipped with a symmetrical winding is analyzed by using a Finite Element Method (FEM) approach. The simulat…

Uncertainty evaluation in the differential measurements of power losses in a power drive system

Abstract In order to guarantee a correct classification in the standardized energy efficiency classes, the current standards concerning the power drive systems prescribe that their power losses must be evaluated with great accuracy. This circumstance involves the usage of expensive measurement systems, since accurate instrumentation, skilled personnel and controlled environments are required. During the design stage of a power drive system, however, the measurement of the absolute value of its power losses is not always needed. Often, in fact, it is enough to assess the power losses variations caused by a modification of either hardware or software sections of the power drive system. In the…

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.

Performance Comparison of Electrical Motors equipped with slightly Asymmetrical Windings

This paper presents a comparison between the performances of electrical machines equipped with slightly asymmetrical windings. More in detail, by modifying the stator geometry of an Interior Permanent Magnet Synchronous Machine equipped with a symmetrical winding configuration, other two slightly asymmetrical winding topologies are obtained. The three models are, then, analyzed by means of a finite element method (FEM) and the related results are compared in terms of cogging torque, static characteristics and leakage factor. The obtained results demonstrate that the adoption of slightly asymmetrical windings could be an interesting alternative solution during the design stage of electrical …

Electrical characterization of low power CIGSSe photovoltaic modules

This paper presents the electrical characterization of low power CIGSSe photovoltaic (PV) modules. Such investigation is achieved to perform a comparison of their performances with conventional silicon PV modules. For this purpose, a test bench, suitable for the characterization of both traditional and innovative low power modules, has been set-up and experimental results are accurately described and discussed.

Characterization of Thin Film Cig(S,Se)2 Submodules Using Solar Simulator and Laser Beam Induced Current Techniques

In this work, the electrical and optical characterization of CIG(S,Se)2 sub-modules using both a solar simulator equipment and the Laser Beam Induced Current (LBIC) technique is presented. By using the solar simulator and a proper set-up, the electrical parameters of the modules at varying irradiance and temperatures are determined. In addition, the LBIC measurements are carried out to analyze the 2D photocurrent uniformity of the modules at two different wavelengths. Dispersion values of extracted parameters can be very useful for practically tuning the modelling stage at device/module level.

Experimental comparison of two control algorithms for low-saliency ratio interior permanent magnet synchronous motors

In this paper, an experimental investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs) is described, analyzed and discussed. This investigation was carried out on a small-power IPMSM with low saliency ratio. More in detail, after a previous simulation study, the control techniques have been experimentally implemented and validated through means of a dSPACE® rapid prototyping system. The performances of the two algorithms have been evaluated and compared, obtaining interesting results.

Electrical characterization of CIGSSe photovoltaic modules

This work describes the electrical characterization of CIG(S,Se) 2 sub-modules in order to compare the related performances with those obtained from traditional silicon photovoltaic modules. This characterization has been performed through means of a test bench, mainly composed by a solar simulator equipment, allowing the determination of the parameters of the prototypes under test at different irradiances and temperatures.

A General Investigation on the Differential Leakage Factor for Symmetrical and Asymmetrical Multiphase Winding Design

This work provides an investigation based on a fast estimation of the degree of unbalance (D.U.%) and the differential leakage factor (&sigma

Experimental Implementation of an Enhanced Field Oriented Control Strategy for Induction Motors Using a Low-Cost ATSAM3X8E Microcontroller

This paper presents a low-cost Micro Controller Unit (MCU) implementation of an enhanced Field Oriented Control (FOC) technique that takes into account the non-linearity of the ferromagnetic material. The algorithm is applied to a three-phase 5.5 kW Induction Motor (IM) and experimentally carried out by means of an ATMEL ATSAM3X8E microcontroller. The effectiveness of the enhanced control strategy is verified by comparing the dynamic performances of the electric drive with those obtained by means of a traditional FOC technique. For this purpose, an experimental test bench is set up for the implementation of the enhanced FOC technique. Finally, the technical and economic features of the simp…

Experimental analysis with FPGA controller-based of MC PWM techniques for three-phase five level cascaded H-bridge for PV applications

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

Sensorless Speed Control for Double-Sided Linear Induction Motor Applications

In this work, a flux and speed observer for double-sided linear induction motor applications is presented and experimentally validated. More in detail, from a Double-Sided Linear Induction Motor (DLIM) prototype, the complete modelling and the determination of the related parameters are here reported. Furthermore, the equations for a d-flux and q-flux observer are conceived and several simulation tests are performed. From the good agreements between the trends over time of the speed estimated by the observer and the simulated one, it can be stated that the observer is well designed. Moreover, in order to experimentally validate the proposed observer, a test bench is set-up for the DLIM/obse…

Influenza di campi magnetici a bassa frequenza (ELF-MFS) sull'accrescimento in vitro di callo di Salvia officinalis "Maxima"

La presente ricerca ha avuto lo scopo di valutare la risposta di una coltura cellulare di Salvia officinalis sottoposta ad un flusso magnetico della densità di 50 milliTesla per la durata di 0, 1, 2, 3, 4, o 5 minuti. Il callo è stato allevato su substrato agarizzato di Murashige e Skoog addizionato con 0,5 mg L-1 2,4-D e 0,5 mg L-1 chinetina. Dopo il trattamento le colture sono state poste in camera di crescita ad una temperatura di 24˚C ed in presenza di 16 ore di luce. Il tasso di crescita relativo, parametro indicativo del ritmo di accrescimento della coltura di cellule indifferenziate, è risultato crescente all’aumentare del periodo di esposizione al campo magnetico, raggiungendo dopo …

Speed Control of a two-Degrees of Freedom Induction Motor with Rotor Helical Motion for Industrial Applications

This paper describes the realization of a two-degrees of freedom induction motor prototype with rotor helical motion, suitable for several industrial applications as grinders, augers, drilling and milling spindles, robotic arms and drives for medical tools and prostheses. This prototype was realized by combining a three-phase tubular linear induction motor (TLIM) with the stator of a three-phase rotary induction motor, resulting in a THMIM (Tubular Helical Motion Induction Motor). Moreover, a possible simple electrical drive, capable to control the helical motion, is proposed, simulated and analyzed. In particular, the mathematical model of the THMIM has been initially developed and, then, …

Piezoelectric Rainfall Energy Harvester Performance by an Advanced Arduino-Based Measuring System

This paper presents the performances of rainfall energy harvesting through the use of a piezoelectric transducer and an Arduino-based measuring system. Different studies agree on the possibility of generating electricity from rainfall, but to date, a study on measuring the quantity of energy produced during rainfall is still missing. The present study begins with results obtained from laboratory researchers using piezoelectric transducers and oscilloscopes, finalized to measure the energy produced from a single raindrop, and concludes with an ad hoc Arduino-based measuring system, aimed to measure the actual amount of electrical energy produced by a piezoelectric transducer that is exposed …

Experimental characterization of a wind generator prototype for sustainable small wind farms

This paper presents the experimental characterization of a wind turbine prototype used for micro wind farms. The proposed prototype, whose advantages can be summarized in versatility of application, low noise and compactness, can generate 1 kW of rated power for a wind speed equal to 4 m/s. The tests here reported and carried out by means of an experimental test bench confirm that the prototype is well designed and adequate for the purpose of its application.

Switching Capacitors Transformerless Bidirectional DC-DC Converter

This paper presents an innovative converter topology that better connects the needs of the battery pack and the electric motor towards the validation of an eco-sustainable electric mobility model. More in particular, the components of the proposed converter change their connection state during both the charging and discharging time of the battery, leading to a higher performance with respect to traditional step-down or step-up converters. The simulations carried out by means of the PLECS® environment have demonstrated the early feasibility of the proposed system.

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

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

Interior Permanent Magnet Synchronous Machine Drive Powered by Fuel Cell for Automotive Applications

Electric vehicles represent an optimal solution for the reduction of pollution in urban areas. In particular, the Fuel Cell (FC) technology is a promising solution especially for its charging times and zero CO2 direct emissions. The paper addresses the design and performance study of an Interior Permanent Magnet Synchronous Machine (IPMSM) drive powered by fuel cell for automotive applications. The IPMSM drive is powered by the use of 5,5 kW FC unit and it is composed of two DC-DC power converters and one inverter. In detail, a test bench has been carried out for the evaluation of the performances of each IPMSM drive conversion stage. Moreover, in order to simulate automotive working condit…

An inductive charger for automotive applications

The inductive charging represents a valid solution for the power transfer in automotive applications. Due to the Inductive Power Transfer (IPT), the wireless battery charging of Electric Vehicles (EVs) provides several benefits. In this paper, an inductive charger which is particularly suitable for electrical bicycles is proposed. A practical realization of the system has been carried out, and the system has been tested in terms of working and efficiency. Through a Phase Shift Modulation (PSM), a power regulation has been implemented. The target power is 100 W.

Algorithmic Approach for Slot Filling Factors Determination in Electrical Machines

In several industrial sectors, such as electric and hybrid traction, the demand for increasingly efficient and high power density electrical machines has grown considerably over the last few years. The improvement of slot filling factor of the electrical machines is an useful provision to satisfy this request. In particular, this topic has been the subject of interest for the industrial sector in recent years, since the technology of winding processes have evolved and allow an economically sustainable realization of windings with an ordered structure rather than randomly. The winding phase must be supported by an accurate design process in which it is possible to evaluate the maximum slot f…