Search results for "Energy conversion"

Online optimization of a multi-conversion-level DC home microgrid for system efficiency enhancement

2017

In this paper, an on-line management system for the optimal efficiency operation of a multi-bus DC home distribution system is proposed. The operation of the system is discussed with reference to a distribution system with two conversion stages and three voltage levels. In each of the conversion stages, three paralleled DC/DC converters are implemented. A Genetic Algorithm performs the on-line optimization of the DC network’s global efficiency, generating the optimal current sharing ratios of the concurrent power converters. The overall DC/DC conversion system including the optimization section is modelled using MATLAB/Simulink. Thanks to the implemented online algorithm, considering …

Sustainability of the Renewable Energy Extraction Close to the Mediterranean Islands

2017

The aim of this work is to explore the possibility of transitioning a fuel powered island to a renewable powered one. This transition is analyzed for the real MV/LV distribution system of the island of Pantelleria, in the Mediterranean Sea. Particularly, this work is focused on a renewable source nowadays totally unused: wave energy. Thanks to the innovative generator prototype designed by Department of Energy of University of Palermo (Italy), wave energy is able to represent a primary source for the production of electric energy in the Mediterranean islands. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in di…

On the Efficacy of PCM to Shave Peak Temperature of Crystalline Photovoltaic Panels: An FDM Model and Field Validation

2013

The exploitation of renewable energy sources and specifically photovoltaic (PV) devices have been showing significant growth; however, for a more effective development of this technology it is essential to have higher energy conversion performances. PV producers often declare a higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. In order to improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep the temperature of a PV system lower: a modified crystalline PV system built with a normal PV panel coupled with a Phase Change Material (PCM) heat stor…

A multiphysics approach to the design of a seawave energy conversion system

2008

This paper presents a multiphysics approach to the design of a seawave energy conversion system which consists of a both a permanent magnet linear generator directly coupled to sea waves and the related power electronics conversion system. The thermal, electromagnetic and circuital aspects are included in the proposed approach. In order to maximize energy extraction, the stochastic features of the energy source is considered in the mathematical model of the whole system. An optimization procedures which includes the stochastic features of the model is presented and a machine built on the basis of the results of this procedure is shown.

Finite difference thermal model of a latent heat storage system coupled with a photovoltaic device: Description and experimental validation

2014

Abstract The use of photovoltaic (PV) systems has been showing a significant growth trend but for a more effective development of this technology it is essential to have higher energy conversion performances. Producers of PV often declare an higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. To improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep lower the temperature of a PV system: a modified PV system built with a normal PV panel coupled with a Phase Change Material (PCM) heat storage device. In this paper is described a thermal model ana…

Improving the efficiency of a standard compliant wireless battery charger

2012

In this paper, a wireless charger for portable electronics devices is presented. A power transmitter, also known as the magnetic pad, and a power receiver are magnetically coupled. A receiver architecture which improves the power conversion efficiency is proposed. All advantages brought by the proposed architecture are discussed and standard constraints are presented as well. The receiver is fully standard-compliant. A wireless station for mobile application is designed and tested. Simulation and experimental results are compared. As shown by experimental results, thanks to the proposed architecture the power conversion efficiency of the receiver section is really close to a unit value. Pow…

Electrochemical energy storage mitigating impact of electric vehicle on the electric grid: Two Italian case studies

2017

In the framework of the Italian R&D project i-Next two pilots plants were realized aiming at demonstrate benefits coming from the adoption of electrochemical energy storages (Lithium ion batteries and hydrogen) integrated with renewable energy sources. In the present study the preliminary results coming from the demo sites operations are reported paying attention to the impacts to the grid.

Experimental Test and Simulations on a Linear Generator-Based Prototype of a Wave Energy Conversion System Designed with a Reliability-Oriented Appro…

2017

In this paper, we propose a reliability-oriented design of a linear generator-based prototype of a wave energy conversion (WEC), useful for the production of hydrogen in a sheltered water area like Mediterranean Sea. The hydrogen production has been confirmed by a lot of experimental testing and simulations. The system design is aimed to enhance the robustness and reliability and is based on an analysis of the main WEC failures reported in literature. The results of this analysis led to some improvements that are applied to a WEC system prototype for hydrogen production and storage. The proposed WEC system includes the electrical linear generator, the power conversion system, and a sea-wate…

INNOVATIVE APPLICATIONS OF EXERGY ANALYSIS AND THERMOECONOMICS IN CHEMICAL, THERMAL AND COOLING ENERGY CONVERSION SYSTEMS

Since 70s, the world has been becoming more and more concerned about energy and environmental issues. The need of meeting the current energy demand by guaranteeing the ability of future generation to satisfy theirs have been pushing research not only to exploit alternative energy sources such as renewable energies, but also to improve the efficiency of energy conversion systems. To this regard, developing systems that use efficiently energy is of paramount importance especially in those countries which rely on non-renewable energy sources such as oil, natural gas, and coal. In fact, the reduction of energy consumption will lead not only to the saving of unrestorable and limited energy resou…

Reverse electrodialysis heat engine with multi-effect distillation: Exergy analysis and perspectives

2019

Abstract The increasing worldwide energy demand is rising the interest on alternative power production technologies based on renewable and emission-free energy sources. In this regard, the closed-loop reverse electrodialysis heat engine is a promising technology with the potential to convert low-grade heat into electric power. The reverse electrodialysis technology has been under investigation in the last years to explore the real potentials for energy generation from natural and artificial solutions, and recent works have been addressing also the potential of its coupling with regeneration strategies, looking at medium and large energy supply purposes. In this work, for the first time, a c…