0000000000004081
AUTHOR
V. Cecconi
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…
New solutions for prefabricated secondary substations in the view of sustainability
The secondary substations will assume an important role as “smart nodes” of the smart grid. So in few years there will be a widespread dissemination on the territory of this apparatus. Consequently, great care have to be taken not only on safety issues, but also on the constructive methodology, in order to determine low environmental impact and decommissioning cost. This paper focuses on innovative solutions for the realization of prefabricated secondary substations, in the direction of sustainability. Innovative layout and enclosure topologies have been here taken into account. In particular, by considering that the substation concrete box is, at the same time, uneconomical and with strong…
Wind Electrical energy generating systems EMC. A dedicated experimental simulator for tests
In wind electrical energy generating systems, due to fast voltage and current fluctuations, the power converter represents a source of electromagnetic disturbances. EMI problems of stand alone wind generators are here analysed in order to take into account many different power quality problems which result in voltage fluctuations and harmonics in the net. This paper, moreover, presents a wind turbine experimental simulator (WTES) that moves a wind electrical energy generating system (WEEGS) to carry out EMI measurements and the relative experimental results. The WEEGS here taken into account comprises a wound rotor induction generator (WRIG) in which the frequency transformation from the ro…
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…
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…
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…
New circuital models of grounding systems and PDS for EMI analysis during a lightning strike
In this paper circuital models of a Power Drive System (PDS) and of grounding systems are proposed in order to analyse Electromagnetic Interferences (EMI) induced in a PDS when a lightning current flows in the grounding system. The models have been developed adopting the network approach with lumped parameters and have been implemented using the software MATLAB. A High Frequency (HF) model suitable to simulate the impulse response of a PDS is described and a generalized method in order to calculate the lumped parameters values of grounding system models is presented. The new method takes into account the burial depth of electrodes as regards their length. The validation results of this new …
A Phase-Shift Full Bridge Converter for the Energy Management of Electrolyzer Systems
The purpose of this work has been the development of the supplying system for an industrial electrolyzer. The hydrogen generating device is part of a complex system constituted by a supplying photovoltaic plant, the grid and a fuel cell battery. The main aim of this electrical system is the hydrogen storage devoted to the suitable load supplying in order to obtain an optimum load profile in case of domestic consumers. The converter is linked to a maximum power point tracking (MPPT) algorithm which enables a converter to extract the maximum power from the photovoltaic plant. The energy is supplied to the electrolyzer or the storage system according to the load profile. A phase-shift control …
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…
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 laser cavity-solitons for metrological applications
Laser cavity-solitons can appear in systems comprised of a nonlinear microcavity nested within an amplifying fiber loop. These states are robust and self-emergent and constitute an attractive class of solitons that are highly suitable for microcomb generation. Here, we present a detailed study of the free-running stability properties of the carrier frequency and repetition rate of single solitons, which are the most suitable states for developing robust ultrafast and high repetition rate comb sources. We achieve free-running fractional stability on both optical carrier and repetition rate (i.e., 48.9 GHz) frequencies on the order of [Formula: see text] for a 1 s gate time. The repetition r…
Test Bench Realization and Application of Specific Working Cycles for the Characterization of Wheelchair Electrical Drives
The life quality of motion disabled people is increased by the use of more and more sophisticated electrical wheelchairs. Despite the diffusion of such aid tools, specific technical standards for the determination of characteristic parameters of their electric drives are not so developed as the ones available for urban electric vehicles. In this paper, in order to define new technical standards for wheelchairs electrical drives, a wheelchair test bench has been purposely carried out. Moreover two specific working cycles, previously conceived and defined by some of the Authors to characterize the performances of the propulsion systems suitable for electrical wheelchair applications, have bee…
A Contribution to Tests Standardization for Inverter-Fed Asynchronous Machines
Losses of inverter-fed asynchronous motors and their experimental evaluation are considered. The formal expressions of iron and copper losses are first recalled, and it is shown as they are influenced by the harmonic content of inverter output voltages. Theoretical and experimental values of these losses are then given together with the presentation of the experimental tests used for their determination. A suitable set of tests is then suggested for the determination of the conventional efficiency of inverter-fed asynchronous motors. The content cannot be considered exhaustive on the matter. It represents only a first contributive approach to the standardization of inverter-fed asynchronous…
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…
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 …
Active power maximizing for Wind Electrical Energy Generating Systems moved by a Modular Multiple Blade Fixed Pitch Wind Turbine
This paper proposes a new solution for wind electrical energy generating system (WEEGS). The system here taken into account is moved by a modular multiple blade fixed pitch wind turbine (MMBFPWT) and foresees a new MPPT algorithm whose main characteristics are low cost, low noise, buildings simplicity and modularity. The mathematical model of the entire WEEGS has been here developed taking into account all the components starting from the wind turbine and ending with the electrical grid. The WEEGS mathematical model has been implemented in Matlab-Simulink in order to carry out the simulations needed to test the effectiveness of the proposed WEEGS. The simulations results show the effectiven…
An optimum design of the magnetic circuit of a PM linear electrical generator for the exploitation of sea waves.
In this paper an approach to the optimization of the magnetic design of a Permanent Magnet (PM) linear generator for the exploitation of the energy contained in sea waves is presented. This approach consists of a two step procedure: the first one takes into account the stochastic features of the sea wave motion and describe the working condition of the machine under this motion by adopting a lumped parameter model. In this step the objective function is the energy production. The second step optimizes the generator by using the results obtained in the first step as the constraints that must be fulfilled by a design based on a Finite Element Method (FEM) analysis. Furthermore, the approach i…
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, …