A novel correction method for a low cost sensorless control system of IPMSM electrical drives

In this paper a novel correction method for sensorless Field Oriented Control System of Brushless internal Permanent Magnet Electrical Drives is introduced discussed and experimentally validated. The novelty of this control system is the estimation of rotor speed and angular position is based on the back electromotive force space vector determination, without the aid of voltage probes. Actual voltage signals needed for estimation are replaced with the reference ones given by the current controller. This choice obviously introduces an error that have been vanished by means of a new compensating function or with the aid of data coming from experimental tests. Experimental verifications of the…

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

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

Automazione delle reti elettriche di distribuzione e trasferimento internazionale di know how

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

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

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

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.

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

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

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

Perspective on hydrogen energy carrier and its automotive applications

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

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…

Fault Tolerant Ancillary Function of Power Converters in Distributed Generation Power System within a Microgrid Structure

Distributed generation (DG) is deeply changing the existing distribution networks which become very sophisticated and complex incorporating both active and passive equipment. The simplification of their management can be obtained assuming a structure with small networks, namely, microgrids, reproducing, in a smaller scale, the structure of large networks including production, transmission, and distribution of the electrical energy. Power converters in distributed generation systems carry on some different ancillary functions as, for example, grid synchronization, islanding detection, fault ride through, and so on. In view of an optimal utilization of the generated electrical power, fault to…

Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

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

Comprehensive Modeling and Experimental Testing of Fault Detection and Management of a Nonredundant Fault-Tolerant VSI

This paper presents an investigation and a comprehensive analysis on fault operations in a conventional three-phase voltage source inverter. After an introductory section dealing with power converter reliability and fault analysis issues in power electronics, a generalized switching function accounting for both healthy and faulty conditions and an easy and feasible method to embed fault diagnosis and reconfiguration within the control algorithm are introduced. The proposed system has simple and compact implementation. Experimental results operating both at open- and closed-loop current control, obtained using a test bench realized using a dSPACE system and the fault-tolerant inverter protot…

An exact method for the determination of differential leakage factors in electrical machines with non-symmetrical windings

An exact and simple method for the determination of differential leakage factors in polyphase ac electrical machines with non-symmetrical windings is presented in this paper. The method relies on the properties of Gorges polygons that are used to transform an infinite series expressing the differential leakage factor into a finite sum in order to significantly simplify the calculations. Some examples are shown and discussed in order to practically demonstrate the effectiveness of the proposed method.

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

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

Efficiency Improvement of Permanent-magnet Synchronous Motor Drives for Household Appliances

This paper deals with some aspects of efficiency improvement of PMSMD (Permanent Magnet Synchronous Motor Drives). Particularly two aspects are focused: the control algorithm for the PMSMD, which allows to reduce the power losses of the electric drive without penalty on its dynamic performances and the optimization of an IPMSM (Interior Permanent Magnet Synchronous Motor) rotor configuration capable to increase the performances in terms of shaft torque production, limiting at the same time the rotor leakage flux. The loss minimization algorithm is here briefly analysed, a test bed for experimental validation is presented and the data are analysed. Experimental tests have been performed aimi…

Fuel cell analytical modeling: Solving the trade-off between accuracy and complexity

In this paper, a 5.5 kW Proton Exchange Membrane fuel cell is modeled. The proposed analytical model is described and the parameters identification procedure is further discussed. Simulation results of all three sub-models are compared to test the accuracy of each one. A comparison between simulation and experimental results is provided as well validating the modeling approach.

A measurement setup for electric bicycles powered from renewable energy sources

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

Determination of differential leakage factors in electrical machines with non-symmetrical full and dead-coil windings

In this paper Gorges polygons are used in conjunction with masses geometry to find an easy and affordable way to compute the differential leakage factor of non symmetrical full and dead coil winding. By following the traditional way, the use of the Ossanna's infinite series which has to be obviously truncated under the bound of a predetermined accuracy is mandatory. In the presented method no infinite series is instead required. An example is then shown and discussed to demonstrate practically the effectiveness of the proposed method.

A General Mathematical Model for the Simulation of Common Faults in Three‐ phase Voltage Source Inverters

In the last years the fault problem in power electronics has been more and more investigated both from theoretical and practical point of view. This paper analyzes the problem of faults modeling in a three phase voltage source inverter(VSI) and presents a model of a VSI able to simulate both unfaulty and faulty conditions when one or more devices go broken. In the past the fault problem was faced step by step considering the fault on each single device building a model for each case. The model hereafter presented solves this drawback through the introduction of the concept of the Healthy Device Binary Variable (HDBV) and the more general Healthy Leg Binary Variable (HLBV) showing also as th…

Approccio allo Sviluppo di Sistemi Diagnostici per il Funzionamento Fault Tolerant delle Micro-grid

Il progressivo aumento del livello di penetrazione della generazione distribuita(GD) è destinato a provocare un profondo mutamento nelle esistenti reti di distribuzione che non sono più considerate come terminazioni passive del sistema elettrico complessivo. Una soluzione possibile è quella relativa alla realizzazione di piccole reti, le micro-grid, che riproducono, al loro interno, la struttura del sistema di produzione e distribuzione dell’energia elettrica. Per ottenere una adeguata affidabilità della micro-grid risulta importante la individuazione e la gestione dei guasti ai fini del perseguimento dell’esercizio "fault tolerant" della micro-grid stessa. Nel presente lavoro, dopo aver in…

Experimental test on a fuel cell powered brushless synchronous motor for automotive applications

In this paper, a fuel cell powered motor emulator is proposed. The MATLAB/Simulink model including the fuel cell stack, the motor and drive models is described. The Urban Driving Cycle test is performed in MATLAB environment. Effective operating conditions of the whole fuel cell powered motor are accurately emulated according to actual regulations in force. The emulated current profile is used for experimental tests on a 5kW Nuvera PowerFlow stack. Thanks to the proposed approach, the motor and inverter drives are accurately emulated and the provided test-bench is used to evaluate performances of the stack under test for automotive applications. Simulation and experimental results are compa…

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…

A Steady - State Model of a Photo Voltaic Array Directly Coupled to a Voltage Source Inverter and its Graphical Solution Method.

MODELAMIENTO Y SISTEMA DE CONTROL DE UN INVERSOR DIRECTAMENTE ACOPLADO AD UN GENERADOR FOTOVOLTAICO PARA LA REGOLACIÒN DE LA POTENCIA ACTIVA Y REACTIVA ENTREGADA A LA RED.

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…

Efficiency Control for Permanent Magnet Synchronous Generators

In this paper a control algorithm for the efficiency improvement of permanent magnet synchronous generators (PMSG) is presented. The proposed algorithm reduces the losses of the generator without affecting its performances. In details, after a description of a dynamic model of the PMSG, which has been purposely modified in order to take into account the iron losses, the basic equations and the constraints to obtain the loss minimization are presented and discussed. Some simulations of a specific PMSG employing the proposed algorithm are performed. The results of these simulations show that enhancement of the efficiency up to 3 % can be reached in comparison to a PMSG using a traditional con…

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

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

Back EMF Sensorless-Control Algorithm for High-Dynamic Performance PMSM

In this paper, a low-time-consuming and low-cost sensorless-control algorithm for high-dynamic performance permanent-magnet synchronous motors, both surface and internal permanent-magnet mounted for position and speed estimation, is introduced, discussed, and experimentally validated. This control algorithm is based on the estimation of rotor speed and angular position starting from the back electromotive force space-vector determination without voltage sensors by using the reference voltages given by the current controllers instead of the actual ones. This choice obviously introduces some errors that must be vanished by means of a compensating function. The novelties of the proposed estima…

Optimum Performance of Permanent Magnet Synchronous Generators Coupled to Wind Turbines

In this paper a control algorithm for the efficiency improvement of permanent magnet synchronous generators (PMSG) is presented. The proposed algorithm reduces the losses of the generator without affecting its performances. In details, after a description of a dynamic model of the PMSG, which has been purposely modified in order to take into account the iron losses, the basic equations and the constraints to obtain the loss minimization are presented and discussed. Some simulations of a specific PMSG employing the proposed algorithm are performed. The results of these simulations show that enhancement of the efficiency up to 3% can be reached in comparison to a PMSG using a traditional cont…

Generalized PWM-VSI Control Algorithm Based on a Universal Duty-Cycle Expression: Theoretical Analysis, Simulation Results, and Experimental Validations

This paper presents a new approach in realizing various carrier-based pulsewidth-modulation techniques by a generalized control algorithm, which is referred to as the universal control algorithm and is obtained via unequal sharing of null states. The flexibility of such an approach allows one to easily and quickly control two-level inverters. Furthermore, this approach may be also extended with few changes to the control of multilevel inverters. The algorithm that is presented here for two-level voltage-source inverters (VSIs) also obtains efficient detection and management of both the linear and overmodulation ranges. In the overmodulation range, which is treated by using the alpha-beta co…