Search results for " Macchine E Azionamenti Elettrici"

Optimization of a thermomagnetic motor

2015

In this paper, an approach towards the optimization of the Curie motor is presented. The approach is based on a thermal-magnetic coupled dynamic model of the motor, which is obtained by assuming the use of a ferromagnetic material working at temperatures near the Curie point. An analytical expression of the generated torque, which links this quantity to the magnetic, thermal, and geometrical parameters of the generated torque, is given. The expressions of speed and torque are derived and related to the thermal properties of the machine and are used as optimization indexes in an optimization procedure. The aim of the optimization process is to obtain a machine able to rotate constantly at th…

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

2022

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

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

2013

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

Experimental results of a low cost weather buoy

2013

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

2022

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

Evaluation of the Potential Energy from Wave Motion on the Sicilian coast

2013

The purpose of this articles is quantitatively evaluate the wave climate variations of the northern Sicilian coasts. In particular, the objective of the study is Castellammare del Golfo, a marine site between Trapani and Palermo. In particular in this research, the wave energy of the Sicily has been studied by an analysis of wave data carried out in a 10- year period, using the measurements of buoyant of RON. The north-western and southern coasts of Sicily have a lower potential with average wave power ranging between 2.5 and 6.5 kW/m.

Pd-Co-Based Electrodes for Hydrogen Production by Water Splitting in Acidic Media

2023

To realize the benefits of a hydrogen economy, hydrogen must be produced cleanly, efficiently and affordably from renewable resources and, preferentially, close to the end-users. The goal is a sustainable cycle of hydrogen production and use: in the first stage of the cycle, hydrogen is produced from renewable resources and then used to feed a fuel cell. This cycle produces no pollution and no greenhouse gases. In this context, the development of electrolyzers producing high-purity hydrogen with a high efficiency and low cost is of great importance. Electrode materials play a fundamental role in influencing electrolyzer performances; consequently, in recent years considerable efforts have b…

Galvanic Deposition of Calcium Phosphate/Bioglass Composite Coating on AISI 316L

2023

Calcium phosphate/Bioglass composite coatings on AISI 316L were investigated with regard to their potential role as a beneficial coating for orthopedic implants. These coatings were realized by the galvanic co-deposition of calcium phosphate compounds and Bioglass particles. A different amount of Bioglass 45S5 was used to study its effect on the performance of the composite coatings. The morphology and chemical composition of the coatings were investigated before and after their aging in simulated body fluid. The coatings uniformly covered the AISI 316L substrate and consisted of a brushite and hydroxyapatite mixture. Both phases were detected using X-ray diffraction and Raman spectroscopy.…

Dynamic reconfiguration of electrical connections for partially shaded PV modules: Technical and economical performances of an Arduino-based prototype

2018

The partial shading phenomenon is a well known problem of photovoltaic plants. Partial shading leads to undesirable effects such the electrical mismatch, the generation of hot spots, and generally the decrease of production of electric energy. To mitigate the last effect, a dynamic reconfiguration of the electrical connections between modules was taken into account. In this paper, starting from an already developed system for a small-scale photovoltaic plant reconfiguration, the study of the economical benefits of the employment of a reconfigurator are traced. Five different incentive policies of diverse Countries have been considered to evaluate the increase of Net Present Value of system …

Experimental investigation on high-efficiency control algorithms for three-phase induction motors

2020

This paper presents an experimental investigation regarding the power losses variations occurring in three-phase induction motors (IMs) as a function of the magnetization level of the machine. More in detail, the power losses identification is obtained by changing in real-time the working operating conditions of the IM drive and the IM reference flux. The sets of measurements are carried out by setting up a test bench and the obtained results confirm that the power losses occurring in induction motors can be minimized by adequately setting the direct axis current component for each IM working condition. This research represents the starting point for the conception of advanced real-time los…