Marco Trapanese

Stochastic resonance in magnetic systems described by Preisach hysteresis model

We present a numerical study of stochastic resonance in magnetic systems described by Preisach hysteresis model. It is shown that stochastic resonance occurs in these systems. Specifically, the signal-to-noise ratio (SNR) and the signal amplification (SA) present a maximum as a function of noise intensity. We also found that the hysteresis loops, dynamically described by the system, are strongly modified near the maxima of SNR and of SA.

Preisach function identification by neural networks

This paper presents a novel technique for the identification of the Preisach density function which is based on a neural-network approach and which requires a relatively limited amount of experimental parameters. The fundamental idea of this method is to identify Preisach function of the material by training a neural network with a set of loops whose identification function is known. In the final section of the paper, the method is verified on several cases.

Linear and nonlinear experimental regimes of stochastic resonance.

We investigate the stochastic resonance phenomenon in a physical system based on a tunnel diode. The experimental control parameters are set to allow the control of the frequency and amplitude of the deterministic modulating signal over an interval of values spanning several orders of magnitude. We observe both a regime described by the linear-response theory and the nonlinear deviation from it. In the nonlinear regime we detect saturation of the power spectral density of the output signal detected at the frequency of the modulating signal and a dip in the noise level of the same spectral density. When these effects are observed we detect a phase and frequency synchronization between the stochastic output and the deterministic input.

Energy and Economic Comparison of Different Conditioning System among Traditional and Eco-Sustainable Building

The use of bioclimatic principles can reduce energy demands and CO2 emissions in the building sector [1-. Costs are one of the most important barriers to a widespread adoption of the green architecture technologies [4-. The aim of this study is to compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the bioclimatic building but built by conventional building materials. The tools used for this study were TRNSYS and HOMER

Noise enhanced stability in magnetic systems

In this paper noise enhanced stability in magnetic systems is studied by both an Ising-type model and a Preisach–Arrhenius model as well as a dynamic Preisach model. It is shown that in one nonequilibrium Ising system noise enhanced stability occurs and that dynamic Preisach model has the capability to predict the occurrence of noise enhanced stability in magnetic systems. On the contrary, in a Preisach–Arrhenius model of a single quadrant magnetic material, noise enhanced stability is not detected.

Design of Bilateral Switched Reluctance Linear Generator to Convert Wave Energy: Case Study in Sicily

The aim of this work is a case study of the adaptation bilateral switched reluctance linear generator to the exploitation of energy of the sea. This type of generator can be used to convert wave energy in electrical energy. In this paper we present an analytical sizing and FEM simulation. As for the results, analysis of the data extracted through the simulations it was possible to calculate the emf. The emf was calculated in two cases of motion of the slider: first hypothesis has set the constant speed while the second is a variable speed according to the law of an oscillatory motion of the sea.

Design and Performance of a High Temperature Superconducting Axial Flux Generator

In this paper, a high temperature axial flux (HTSAF) generator is presented. In this generator the excitation of the generator is obtained by using some high temperature superconducting magnets. In order to reduce the negative effects of vibrations, the excitation is located on the stationary part of the generator. Starting, running and endurance tests of the machine are presented.

Efficiency Maximization of Permanent Magnet Synchronous Generators Coupled Coupled to Wind Turbines

In this paper a control algorithm for the efficiency improvement of permanent magnet synchronous generators (PMSG), the relative simulations and their results are 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 modified in order to take into account the iron losses, the basic methodologies to obtain the loss minimization are presented and discussed. Many simulations of a specific PMSG employing the proposed algorithm were carried out and are presented. The results of these simulations show that enhancement of the efficiency up to 3% and more can be reached in comparison to a PMSG using a traditional control strategy. The control algorithm has been tested through simulations in order to demonstrate its validity when the generator is coupled to wind turbines.

The Jiles Atherton model for description of hysteresis in lithium battery

In this paper Jiles Atherton (JA) Model is used to obtain a mathematical model of the hysteresis in lithium battery. JA Model allows to describe both the hysteresis and the dynamical features of charging and discharging cycles in a lithium battery. The identification of the model is obtained by using a neural network technique developed for magnetic systems. The model is validated on some experimental tests on commercial batteries.

Energy Savings through Integration of the Illumination Natural and Artificial, Using a System of Automatic Dimming: Case Study

The reduction of electrical energy consumption in buildings is a subject of great interest in the international scientific community. In buildings with a lot of available natural light, designed with large glazed surfaces, the artificial lighting system is often oversized and cannot be divided into segments to meet lighting demands during daylight hours.This article presents an experimental study, conducted in a university lecture hall that has a glazed surface covering the whole wall at one end, which provides a level of internal illumination that is only sufficient for the area next to the window itself, even when the outside lighting conditions are very bright. It is therefore necessary to turn on the artificial lighting system.The mathematical approach used in this paper has been successfully applied by the authors in other fields of science [1-2].Using an automatic dimmer system, the calibration of which is based on experimental measurements, the lighting is arranged in such a way as to illuminate the most disadvantaged areas of the room, and then to extend itself gradually to the whole of the room, over the period of time that the lecture hall is in use.