Search results for "Generator"

An Experimental Comparison between an Ironless and a Traditional Permanent Magnet Linear Generator for Wave Energy Conversion

2022

Permanent Magnet Linear Generators (PMLGs) are currently being studied for sea wave energy harvesting. Typically, a PMLG consists of an iron-made armature and a moving translator. The permanent magnets adoption produces parasitic effects, such as cogging force, and the machine weight increment. A solution could be the adoption of an ironless configuration, accepting a power density reduction. This paper investigates the use of ironless PMLGs in sea wave energy conversion systems by an experimental comparative analysis between an iron PMLG prototype and an ironless PMLG prototype, which share the same geometry. The main electrical and mechanical parameters (resistance, mass, and magnetic fie…

DESALINATION AND SEA WAVE TO PRODUCE FRESHWATER AND ENERGY FROM THE SEA. THE PROPOSAL OF A LINEAR GENERATOR FOR A WAVE ENERGY CONVERTER AND EVALUATIO…

2020

Testing a linear ironless generator for the sea wave energy harvesting

2022

Wave energy represents a "new entry"in the renewable energy sector; however, it is believed that in near future sea wave might have a key role for the electrical energy production, thanks its huge energy potential. In this context, the paper suggests an innovative ironless linear generator, that can be used as main component inside a point absorber. In order to exploit the wave energy potential in the Mediterranean Sea, the Engineering Department of Palermo University realized a first small-scale prototype of the electrical linear generator, that is the main component for the energy conversion.

Reduction of cogging force in linear generators for wave energy harvesting

2022

Due to huge energy potential of sea waves, many technologies have been proposed in the last few years. Some concepts have been developed and sometimes also tested in the open sea. Some prototypes use linear generators to directly convert the vertical motion of buoys into electrical energy. This solution minimizes the numbers of energy conversion steps, increasing the energy efficiency. At the same time, the limited numbers of components could also increase the reliability of the wave energy converter. For this reason, the development of linear generators is considered with great interest. This paper investigated the cogging force, a magnetic force due to the interaction between the magnets …

Stability of Microgrids: An Application of Virtual Synchronous Generator

2022

The objective of this paper is to illustrate an alternative control algorithm for power converters which have the task of introducing the energy generated by systems based on the use of renewable sources such as, photovoltaic or wind power, in to small-sized networks, microgrids. Virtual Synchronous Generator can operate both in parallel to the main network as well as in isolated and autonomous conditions (islanding-mode). The contribute of this work is to drive a consolidate approach, made in time domain, in a more flexible and less time-consuming approach based on Park transformation.

INVERTER-BASED DISTRIBUTED GENERATORS, MODELING AND CONTROL

In the last few years, electrical power generation is moving from a centralized generation towards distributed generation including on-site Renewable Energy Sources (RESs). In order to overcome RES related issues, as intermittent and fluctuating power, storage elements are included in the on-site generation system. The interaction between distributed generator (DG) units including RES, storage and front-end power converters should be carefully modeled in order to analyze the power system stability. An accurate modeling of DGs is required. In this thesis, a new modeling approach has been proposed for the inverter-based DGs based on the concept of electrostatic synchronous machines. Detailed …

Economic analysis on dynamic photovoltaic systems in new Italian "feed in tariffs" context

2013

Dynamic photovoltaic generators, based on the application of solar-trackers, are able to give an increment to the electric energy production from solar source. Their realization and maintenance costs are certainly higher than those of fixed ones. In this paper the Authors propose a method to estimate the increment of electrical energy generation that must be guaranteed by a dynamic photovoltaic generator, so as its realization could be more favorable with respect to that of a fixed generator one with the same rated power. This method, developed by means of classical economic indexes like the Pay-Back-Period and the Net Present Value, takes in to account the economic incentives for the PV sy…

A Technical Approach to the Energy Blockchain in Microgrids

2018

The present paper considers some technical issues related to the “energy blockchain” paradigm applied to microgrids. In particular, what appears from the study is that the superposition of energy transactions in a microgrid creates a variation of the power losses in all the branches of the microgrid. Traditional power losses allocation in distribution systems takes into account only generators while, in this paper, a real-time attribution of power losses to each transaction involving one generator and one load node is done by defining some suitable indices. Besides, the presence of P–V nodes increases the level of reactive flows and provides a more complex technical perspective. For this re…

Secure random number generation in wireless sensor networks

2011

The increasing adoption of wireless sensor networks as a flexible and inexpensive tool for the most diverseapplications, ranging from environmental monitoring to home automation, has raised more and more atten-tion to the issues related to the design of specifically customized security mechanisms. The scarcity ofcomputational, storage, and bandwidth resources cannot definitely be disregarded in such context, and thismakes the implementation of security algorithms particularly challenging. This paper proposes a securityframework for the generation of true random numbers, which are paramount as the core building blockfor many security algorithms; the intrinsic nature of wireless sensor nodes …

A TRNG Exploiting Multi-Source Physical Data

2010

In recent years, the considerable progress of miniaturization and the consequent increase of the efficiency of digital circuits has allowed a great diffusion of the wireless sensor network technology. This has led to the growth of applications and protocols for applying these networks to several scenarios, such as the military one, where it is essential to deploy security protocols in order to prevent opponents from accessing the information exchanged among sensor nodes. This paper analyzes security issues of data processed by the WSN and describes a system able to generate sequences of random numbers, which can be used by security algorithms and protocols. The proposed True Random Number G…