Contract for the support of household appliances control and monitoring application interworking specification

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.

Development of Innovative Methods for Characterizing, Modeling and Correcting the Non-Ideal Behavior of A/D and D/A Conversion Channels, in Order to Contribute Towards Harmonizing and Upgrading International Standards

Gestione dell’incertezza nelle misurazioni basate su PC

A PC-based wattmeter for accurate measurements in sinusoidal and distorted conditions: Setup and experimental characterization

This paper presents the development of a high-accuracy sampling wattmeter, which can be employed with both sinusoidal and distorted input signals. The proposed personal computer (PC)-based system is a simple, portable, and low-cost solution because it is based on two commercial data acquisition boards connected to a common PC. Owing to this solution, the voltage is sensed directly, avoiding expensive voltage dividers, while the current is sensed by means of a noninductive current shunt. Commercial software is also used for data processing and implementation of the virtual instrument. The setup of the PC-based wattmeter is described, with a detailed description of the correction strategy of …

Valutazione dell’impatto degli ambienti industriali sugli strumenti di misura basati su personal computer

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…

Measurement uncertainty estimation of a virtual instrument

The law of uncertainty propagation is applied to a PC-based virtual instrument. According to the "guide to the expression of uncertainty in measurement", the measuring model and the various sources of uncertainty have been taken into account. The expressions of the combined output uncertainty in various basic digital signal processing blocks, are obtained starting from each input sample absolute accuracy, without taking into account the parameters which regard the overall behavior of an acquisition board, such as the effective number of bits. In order to verify this procedure, the results obtained by means of the theoretical analysis, are compared with the ones obtained from numerical simul…

UNCERTAINTY EVALUATION IN THE LOW-FREQUENCY MAGNETIC FIELD MEASUREMENTS WITH REGARD TO EXPOSURE OF HUMAN BEINGS

The paper deals with low-frequency magnetic field measurements, with regard to exposure of human beings, carried out by using a broadband and isotropic instrument. These measurements are characterized by a very high uncertainty values if compared with the ones usually related to other electrical measurements. These large uncertainty values imply a high risk of wrong decision when there is the need to establish if a site complies or does not comply with a specified emission limits. A reduction of the uncertainty values implies a reduction of the risk. With this aim, in the paper we propose an approach which, in case of fields generated by electric power systems (50 or 60 Hz), allows an effec…

Uncertainty Management in the measurements performed by means of virtual instruments

The uncertainty management is the discipline of optimising the cost of a measurement versus the uncertainty target. In particular, the paper deals with the measurements performed by using a generic virtual instrument. The task is achieved by using the PUMA (procedure for uncertainty management) method that is an iterative technique originally conceived for geometrical and mechanical measurements. The approach is completely based on the "guide to the expression of uncertainty in measurement" rules, but provides a more engineering methodology, since it allows to optimize the cost of the measurements versus the uncertainty target, avoiding the use of inadequate or, on the contrary, too expensi…

Economic benefits of the use of a PV plants reconfiguration systems

This paper shows the economic convenience of the application of a reconfiguration system for photovoltaic plants, considering the incentives system in different Countries. The reconfiguration is an alternative to the Distributed Maximum Power Point Tracking, DMPPT, technique used to overcome the mismatch problem in Photovoltaic, PV, plants. The reconfiguration techniques employ a microprocessor-based system that modifies the layout of the PV plant by physically changing the connections among modules. After having presented the working principle of the PV reconfiguration system allowing the improvement of the efficiency of the same plant and the relevant installation, the main strength and w…

Development of a high-accuracy PC-based wattmeter with commercial data acquisition boards

This paper presents the development of a high accuracy sampling wattmeter, which makes use of two commercial data acquisition boards (DAQs) connected to a common personal computer. Commercial software is also used for data processing and implementation of the virtual instrument. The set up of the PC-based wattmeter is described and a preliminary evaluation of its metrological performances is made by means of two series of experimental tests, which were carried out with an electric power standard and a high performance multifunction calibrator. © 2011 IEEE.

Reduction of the uncertainty in the measurements of magnetic fields

The paper deals with magnetic field measurement, carried out by using a broadband and isotropic instrument. These measurements are characterized by a very high uncertainty values if compared with the ones usually related to other electrical measurements. For these reasons, if the measurements are performed to assess the exposure of human beings, these large uncertainty values imply a high risk of wrong decision when there is the need to establish if a site complies or does not comply with a specified emission limits. A reduction of the uncertainty values implies a reduction of the risk. With this aim, we propose an approach which, in particular but very typical cases, allows an effective re…

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…

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.

Figures of merit for analog-to-digital converters: The optimal set for the uncertainty evaluation

ADC based measurements: A common basis for the uncertainty estimation

In the last years, many Authors have dealt with the uncertainty evaluation of the measurement performed by using an analog-to-digital converter, proposing different approaches to analyze the uncertainty propagation. However, in these studies, in order to identify the uncertainty sources, different sets of parameters are used, and, often, it is not considered that the various uncertainty sources have different modalities of propagation. Obviously, this implies that the various proposed approaches are not directly comparable. One of the main reasons which has caused this situation is the coexistent of various Standards concerning the characterization of the analog-to-digital converters. There…

Survey on power increase of power by employment of PV reconfigurator

This paper shows the performance of a PV system under shadow projection on PV panels. The reconfiguration techniques, employing a microprocessor-based system, modifies the layout of the PV plant by physically changing the connections among modules, in order to recover the loss of power due to the shadows. Different cases have been considered to evaluate the increase of power.

Virtual Instruments: Uncertainty Evaluation in the Presence of Electromagnetic Interferences

The electromagnetic interferences can influence the performances of a virtual instrument; consequently, in a generic measurement performed by using these instruments, the related uncertainty values can increase. In the paper, we report the results of various experimental tests performed with the aim to check if and how the radiated and/or conducted disturbances affect the instruments' characteristics and, in particular, the single uncertainty sources. Starting from these results and applying an already proposed method for the uncertainty estimation in the measurements performed by means of virtual instruments, it is possible to take into account and to evaluate the contribute of the electro…

Approaches to evaluate the virtual instrumentation measurement uncertainties

This paper deals with the metrological characterization of virtual instruments. After a brief description of the features, the components and the working principle of the virtual instruments and the various uncertainty sources are analyzed. Then, two methods to evaluate the uncertainty of the measurement results are presented: a numerical method simulating the physical process of the A/D conversion, and an approximated theoretical method applying the "uncertainty propagation law" of the "guide to the expression of uncertainty in measurement." With both methods, the combined standard uncertainty of the measurement result is obtained, starting from the standard uncertainty generated by each s…

PV Reconfiguration Systems: a Technical and Economic Study

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

Selective harmonic mitigation with asymmetrical staircase voltage waveform for a three-phase five-level Cascaded H-Bridge Inverter

Selective harmonics elimination or mitigation strategies are used in all applications where it is necessary to rise the efficiency and reliability of the overall system. This paper presents a simple approach to reduce the low order harmonics amplitude of an asymmetrical staircase voltage waveform for a five-level, three-phase Cascaded H-Bridge Inverter without solving non-linear equations. Through this simple approach, polynomial equations to evaluate the control angels in real-time operations have been found. The effectiveness of the harmonic mitigation method has been tested through the simulation analysis in MatLab/PLECS environment.

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

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

Effects of the electromagnetic disturbances in the DAQ-based measurement instruments and their compensation

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…

Optimal Energy Management of Smart Grids With Plug-In Hybrid Electric Vehicles

In this paper, smart grids based on Renewable Energy Sources are addressed. An Italian case study which has been developed in the frame of the research project i-NEXT (Innovation for green Energy and eXchange in Transportation) is presented. Storage elements are included. Electric and fuel cell powered vehicles' charging stations are here included as local loads. In this paper, power management algorithms and the control logic are described. The control subsystem aims at an efficient management of the involved renewable energy sources avoiding faults in the power system and ensuring a fully functional supply of local loads. A “Service Center” software collecting data from renewable sources,…

Can the effective number of bits be useful to assess the measurement uncertainty?

The effective number of bits (ENOB) is a well know parameter, employed to characterize the overall behavior of an A/D converter. In order to verify if the ENOB can be also used to assess the measurement uncertainty of the A/D conversion based instruments, we use a developed software tool. The results show that using the ENOB can lead to an underestimate of the uncertainties.

Immunity of a Virtual Instrument to conducted electromagnetic disturbances

In the paper the performances of the Virtual Instruments under conducted electromagnetic disturbances are investigated, in order to find out if and how their metrological characteristics change with respect to the ones measured in absence of electromagnetic threats. The analysis is carried out by means of experimental tests, subjecting the AC power port of the systems under test to the conducted disturbances considered by the IEC-61326 standard and following the test procedures prescribed in the IEC-61000-4-series standards. The results show that the tested measurements instruments are sufficiently immune to these disturbances, since no variations of the distinctive parameters have been obs…

A PC-based wattmeter for high accuracy power measurements

This paper proposes the use of a commercial data acquisition board (DAQ) connected to a common personal computer for high accuracy power measurements. In the paper the set up of the PC-based wattmeter is described and an experimental evaluation of its metrological performances is made by means of the comparison with a simultaneous coherent digital sampling wattmeter realized with two high-precision DMMs Hewlett Packard Model 3458 A. In both cases the power source is a Fluke 6100A/E electrical power standard. © 2010 IEEE.

A procedure to evaluate the electromagnetic immunity degree of a data acquisition system

Uncertainty evaluation in power measurements with commercial data acquisition boards

The paper deals with the metrological characterization of a digital wattmeter developed by using a personal computer, a shunt, two commercial data acquisition boards and commercial software. The uncertainty of the active power measurements is assessed individually characterizing the voltage channel, the current channel and the phase displacement measurement between the two channels. In particular, the uncertainty on the voltage and current rms measurements is evaluated by using an already proposed approach based on the Monte Carlo method and on the usage of five parameters, while the uncertainty on the phase angle is experimentally estimated. In order to validate the proposed approach for t…

Figure di merito di convertitori analogico-digitali: il set ottimale per la valutazione delle incertezze.

Energy Management via Connected Household Appliances

The study reported hereafter provides results based on a campaign of simulations conducted by University of Palermo on the basis of its knowledge in the field Energy Value Chain and in the field of Energy Management (EM) for household appliances. Inputs from CECED Convergence WG has been fundamental to base that study on realistic data and cases. Moreover, the so called EM study, offers also a clear picture about the opportunity to have energy management applications and services in house, being those opportunities strictly related to the cost of in- frastructure needed and to the benefits belonging to different actors in the energy value chain. Energy savings have been considered both in t…

CIGS PV Module Characteristic Curves Under Chemical Composition and Thickness Variations

This paper analyzes how the electrical characteristics of a CIGS photovoltaic module are affected by the chemical composition and by the thickness variations of the CIGS absorber. The electrical characteristics here considered are the short circuit current, the open circuit voltage, the efficiency and the power peak. The chemical composition is varied by tuning the ratio between gallium and indium. This analysis has been performed by means of the wxAMPS software, developed by the University of Illinois. The above variations have been taken into account on a PV module made of 72 cells. This analysis has been carried out employing a PV module mathematical model developed and implemented by th…

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.

Impact of industrial environments on the PC-based measurements

In the paper we present a simple and fast procedure to evaluate the impact of the electromagnetic disturbances, which can be present in the industrial locations, on the measurements performed by a generic PC-based measurement instrument. The method is conceived starting from the data obtained by subjecting the instruments to the disturbances prescribed by the IEC-61326 standard. The results show that, even under heavy disturbances, the common good practices of shielding and grounding allow a correct employment of this kind of instrumentation.

Un wattmetro basato su schede di acquisizione commerciali per misure in regime distorto. Sviluppo dello strumento e prove preliminari

Partial discharges on IGBT modules: Are sinusoidal waveforms sufficient to evaluate behavior?

In recent years, the increasing use of AC-DC converters, especially in the field of renewable energy sources has led to the implementation of new modulation techniques, in particular the ones based on the pulse width modulation. The purpose of the present work is to verify the different behavior that is obtained when the components are subjected to the partial discharge test carried out with a sinusoidal waveform, and when they are subjected to PWM stress-type, similar to the actual signal generated by this type of electronic components. By considering equal rms value of the fundamental sine wave, the comparison has shown different partial discharges patterns.

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.

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.

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…

Applicational Aspects of a New Diagnostic Methodology for Fault Location in MV Networks: Problems, Solutions and Improvements

The electrical energy market liberalization has encouraged utilities to make new investments at distribution level so as to attain higher quality levels. Service continuity is one of the aspects of greater importance in the definition of the quality of the electrical energy, for this reason, the research in the field of faults diagnostic for distribution systems is spreading ever more. The Authors have just developed a new methodology for diagnostic management of automated distribution systems. The technique is based on the use of circuital models of the electrical system resulting from the composition of quadripoles. In this paper, after a brief description of the proposed approach, the is…

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…

Modelling, simulation and characterization of a supercapacitor

In the last decade, the issue of air pollution or the reduction of CO2 emissions has become of extreme interest both for civil society and then for the industrial and scientific research world. For this reason, the scientific research on automotive is called to answer with increasingly innovative solutions. One of the principal subjects are the storage and the utilization of the electric energy for electrical and hybrid vehicles. Nowadays, supercapacitors are getting more and more attention because of their characteristics that allow them to be a bridge between electrolytic capacitors and batteries in several application such as bust-mode energy delivery, regenerative breaks and so on. The …

Una procedura per la valutazione del grado di immunità elettromagnetica di strumenti di misura basati su PC

Voltage source inverters: An easy approach for fast fault detection

Fault-tolerant converters have been widely investigated for years and nowadays an extensive technical literature on this field exists. This paper presents a novel fault detection algorithm based on a simple geometrical approach. In the algorithm analysis both the case of faults in single device and the loss of an entire inverter leg have been considered. The proposed methodology is characterized by simplicity, low computational and implementation effort with a consequent fast execution and easy control integration. The suggested algorithm is verified by means of experimental tests and reveals a valid and suitable alternative to the existing state of the art in the field of inverter fault de…

Il metodo PUMA per la stima dell’incertezza

Assessment of virtual instruments measurement uncertainty

Abstract In this paper, two methods to evaluate the measurement uncertainty of a virtual instrument are presented: a numerical method simulating the physical process of the A/D conversion, and an approximated theoretical method applying the “uncertainty propagation law” of the “guide to the expression of uncertainty in measurement”. After a brief description of the features, the constitution and the working principle of the virtual instruments, the various uncertainty sources, are analyzed. With both methods, the combined standard uncertainty of the measurement result is obtained, starting from the standard uncertainty generated by each single source and without taking into account the para…

Compensazione degli effetti di disturbi elettromagnetici in un sistema di acquisizione dati

ADC based measurements: Identification of the parameters for the uncertainty evaluation

In the last years, many Authors have dealt with the uncertainty evaluation of the measurement performed by using an analog-to-digital converter, proposing different approach to analyze the uncertainty propagation. In all these studies, it is clearly pointed out that starting from the manufacturer specifications is the least expensive, the least time consuming and, often, the most accurate way to assess the uncertainties. However, the Authors, which have proposed methodologies for the uncertainty assessment, use different parameters as starting point. One of the main reasons which has caused this situation is the coexistent of various Standards concerning the characterization of the analog-t…

Energy Consumption/Generation Model: Data collected, architecture conceived and scenarios addressed

The paper provides the data collected, the architecture and the conceived scenarios for the development of an Energy Consumptions/Generations Model. This model is suitable for the modeling, processing, analyzing and forecasting of energy consumption and generation at home, building and neighborhood level. Data are from the Census Returns, Electoral Registers & Council of the real town of Loughborough (U.K.). The architecture conceived describes the real distribution system which supplies the Loughborough geographic area. The scenarios considered take into account both traditional dwellings (equipped with dumb appliances) and new dwellings (equipped with smart networked appliances) © 2014 IE…

A/D Conversion Based Measurements: Identification of the Parameters for the Uncertainty Evaluation

Introductory notes for the Acta IMEKO Special Issue on the 24th IMEKO Technical Committee 4 International Symposium and the 22nd International Workshop on Analogue-to-Digital Conversion and Digital-to-Analogue Conversion Modelling and Testing

Measurement has always been a tool by which we can observe the world around us. This concept was once again confirmed during the 24th IMEKO Technical Committee 4 (TC4) International Symposium, which showed how topics related to the world of measurement range across many fields of knowledge. The IMEKO TC4 International Symposium is one of the most important events in the fields concerned with the theoretical and practical aspects of the measurement of electrical quantities and related instrumentation. It involves institutions and academia in a discussion of the state of the art and issues that require a joint approach by engineers, academics and other experts of measurement, instrumentation,…

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 Monte Carlo Method for the Auto-Evaluation of the Uncertainties in the Analog-to-Digital Conversion-Based Measurements

This paper concerns with the measurement uncertainty estimation in the analog‐to‐digital conversion‐based instruments. By using an ad hoc developed software tool, the Monte Carlo method is applied in order to assess the uncertainties associated with the measurement results, overcoming the possible inapplicability of the pure theoretical approach prescribed in the ISO – “Guide to the Expression of Uncertainty in Measurement”. By implementing the software tool in the measurement instruments, the proposed approach can be utilized in order to make the instrument itself able to auto‐estimate the measurement uncertainties.

Uncertainty evaluation in the measurements for the electric power quality analysis

The paper deals with the uncertainty estimation in the measurements performed to assess the electric power quality. In a first steps, according to the 'ISO - Guide to Expression of the Uncertainty in Measurements' all the error sources, which give a significant contribution to the combined uncertainty associated to the measurement results, are identified. Successively, in order to analyze how the errors propagate through the measurement chain, a Monte Carlo based approach is proposed. The method exploits an ad-hoc developed simulator of the measurement process, which takes into account the particular way of propagation of all the identified error sources. Eventually, with the aim of validat…

Technical and economical evaluation on the use of reconfiguration systems in some EU countries for PV plants

This paper shows the technical and economical evaluation of the application of a reconfiguration system for photovoltaic (PV) plants, considering the incentives system in some European Union countries. The reconfiguration system is an alternative to the distributed maximum power point tracking technique which used to increase the power production in the PV plants under the mismatch phenomenon. The reconfiguration techniques employ a microprocessor-based or field-programmable gate array-based system that modifies the layout of the PV plant through the change of the connections among modules. After having presented the main features working of the PV reconfiguration system allowing the improv…

Site-to-Site reproducibility of Conducted immunity tests on PC-Based Data Acquisition Systems

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.

MISURE BASATE SULLA CONVERSIONE ANALOGICO-DIGITALE:IDENTIFICAZIONE DEI PARAMETRI PER LA VALUTAZIONE DELL’ INCERTEZZA

The PUMA method applied to the measures carried out by using a PC-based measurement instrument

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…

Uncertainty management in the measurements for the electric power quality analysis

The paper deals with the uncertainty estimation in the measurements performed to assess the electric power quality. In a first steps, all the error sources, which give a significant contribution to the combined uncertainty associated to the measurement results, are identified. Successively, in order to analyze how the errors combine and propagate through the measurement chain, four approaches are proposed and validated. These approaches entail a greater and greater uncertainty overestimation, but, at the same time, require less and less time and resources. Therefore, the four methodologies are perfectly adequate for the implementation of the PUMA (Procedure for Uncertainty Management) metho…

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.

PV systems in the vertical walls: A comparison of innovative structures

This paper presents the performance comparison of PV windows with the purpose of tracing the behavior of next-generation systems, which could favor architectonical integration. More in detail, a dye sensitized solar cell (DSSC) and blue and grey thin film silicon panels have been analyzed. The systems can be placed behind a window or behind a wall of glass blocks. The three generation systems are then compared in terms of both efficiency and Fill Factor.

Electric Power Quality Evaluation in the Presence of Electromagnetic Emissions

The measurements for the assessment of the electric power quality are often carried out in hostile electromagnetic environments. The aim of the paper is analyzing if and how both radiated and conducted electromagnetic emissions can disturb the measurement system used to quantify these disturbances. To achieve the target, an experimental approach is proposed, which, by means of a simple and fast test, allows establishing if the real electromagnetic environment, where power quality analysis is performed, can alter the measurements. © 2013 IEEE.

Caratterizzazione di un sistema di acquisizione dati in presenza di disturbi elettromagnetici condotti

Assisted software design of a wide variety of windings in rotating electrical machinery

In this paper a software developed by the Authors for winding design is presented. In particular, this software can be used as a valid aid in design and analysis for a wide variety of windings with generic number of phases, pole pairs, slot number, etc.. The calculation of winding factors and the evaluation of their harmonic distribution is also accomplished. The software is implemented in MATLAB® environment. By means of some examples, covering the most relevant winding types, the capabilities of this software will be shown. Particularly, integer and fractional slot, single and double layer winding, concentrated windings, imbrication, belt widening and belt shifting techniques can be treat…

Rotor bar pre-fault detection in the squirrel cage induction motors

The paper deals with a diagnosis technique to detect and monitor incipient faults in the rotor bars of squirrel gage induction motors. The failure mode analysis is performed monitoring the motor axial vibrations. To accomplish the task, the authors present a mathematical model that allows relating the occurrence and the severity of the faults to the presence and the magnitude of some frequency components of the axial vibration spectrum. To validate the proposed approach, the results obtained by applying the mathematical model are compared with the ones obtained by experimental tests done on both healthy and faulty motors.

Battery Models for Battery Powered Applications: A Comparative Study

Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are…

Behavior of the virtual instruments in presence of conductede lectromagnetic disturbances

Virtual instruments: Uncertainty evaluation in the presence of unknown electromagnetic interferences

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.

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…

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Piezoelectric model of rainfall energy harvester

In this paper a model to predict the harvest of the energy contained in rainfall by means of piezoelectric transducers is presented. Different studies agree on the level of suitable generated voltage on the electrodes of a piezoelectric transducer subjected to rainfall, but a complete characterization on the supplied power is still missing. This work, in order to limit optimistic forecasts, compares the behavior of the transducers subjected to real and artificial rainfall, a condition that has shown promising behavior in laboratory.