89 research outputs found
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
Evaluation of the Potential Energy from Wave Motion on the Sicilian coast
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
Assessment of the Operating Temperature of Crystalline PV Modules Based on Real Use Conditions
Determining the operating temperature of photovoltaic panels is important in evaluating the actual performance of these systems. In the literature, different correlations exist, in either explicit or implicit forms, which often do not account for the electrical behaviour of panels; in this way, estimating is based only on the passive behaviour of the . In this paper, the authors propose a new implicit correlation that takes into account the standard weather variables and the electricity production regimes of a panel in terms of the proximity to the maximum power points. To validate its reliability, the new correlation was tested on two different PV panels (Sanyo and Kyocera panels) and the results were compared with values obtained from other common correlations already available in the literature. The data show that the quality of the new correlation drastically improves the estimation of the photovoltaic operating temperature
Dynamic Preisach hystersis model for magnetostrictive materials for energy application
Recently Magnetostrictive materials have been proposed as active materials to be used in several energy harvesting technology [1]. In this kind of application, the working condition of the material is highly dynamic and non linear.
As a result static models of magnetostrictive materials are usually not very accurate and can be not reliable to develop a sufficiently accurate designof the energy harvesting devices. The presence of hysteresis requires accurate
mathematical modeling in order to correctly foresee the behavior of real materials (ferromagnetic or magnetostrictive) used in control systems or in
electrical machines and thus simplifying the design of such controllers or predicting with acceptable accuracy electromagnetic fields in such
devices[2]. In order to overcome this problem, this paper addresses the development of Dynamic Preisach hysteresis model (DPM) for magnetostrictive materials for energy application operating in hysteretic and time varying nonlinear
regimes. DPM is a development of classical Preisach Model which is able to include dynamical features in the mathematical model of hysteresis.
In this paper the magnetostrictive material considered is Terfenol-D. Its hysteresis is modeled by applying the DPM whose identification procedure is performed by using a neural network procedure previously publised [3]. The
neural network used is a multiplayer perceptron trained with the Levenberg-Marquadt training algorithm. This allows to obtain both Everett integrals and the Preisach distribution function, without any special conditioning of the measured data, owing to the filtering capabilities of the neural network interpolators.
The model is able to reconstruct both the magnetization relation and the Field-strain relation. The model is validated through comparison and prediction of data collected from a typical Terfenol-D transducer
A procedure to evaluate the indoor global quality by a sub objective-objective procedure
This paper proposes two complementary procedures for assessing the indoor global
comfort: the first one, prevalently objective, is based on the acquisition of microclimate measured
data and computed subjective values; the second one, that is purely subjective, uses a questionnaire
drawn from the ISO/DP 10551 Recommendation. An application to some lecture-halls is here showe
Design and experimental test of a low costweather buoy
The importance of prevention plans based on realistic inundation scenarios was dramatically highlighted by the Indian Ocean Tsunami of 26 December 2004. But also in the Mediterranean, sea storms basin are a quite common event especially during winter months. These scenarios are generally based on numerical models of tsunami wave propagation that can become more realistic and effective when calibrated with the distribution of true data acquired by special weather buoy. In this paper we present the result of an experimental weather buoy built by DEIM of University of Palermo, that is characterized by small cost and big versatility
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