Search results for "electric [charge]"
showing 10 items of 729 documents
Design of a power conditioning unit for a Stirling generator in space applications
2012
The Free-Piston Stirling Generator (FPSG) is a thermal to electrical energy conversion system, based upon the thermal engine of the same name. Intensive research concerning the feasibility of the engine for its application in deep space and planetary missions has been conducted, primarily due to the potential increase in efficiency (−30%) over the currently used Radio-isotope Generators (RTGs). On the other hand, less attention has been paid to the power conditioning requirements and alternatives. The present work has investigated on the dynamics governing the FPSGs in order to assess the design requirements for the subsequent power-conditioning unit (PCU). Thereafter, two alternatives of A…
Thermo acoustic - MHD electrical Generator
2011
Abstract The thermo-acoustic generators offer a unique means of converting thermal energy into mechanical energy without any moving parts and without fluid circulation. They are comparable to the Stirling engine with the advantage of much greater simplicity. They are therefore natural candidates for special uses where interventions are limited. The problem to solve is transforming the mechanical energy into electrical energy. MHD generators offer excellent opportunities in this area, particularly by using the mechanisms of induction. The work concerns the combination of a thermo-acoustic generator with an induction generator of a new concept for obtaining electric current with adjustable vo…
Optimization of a thermoelectric system for power generation realized by ‘‘hidden’’ components
2014
Abstract Today the utilization of renewable energy sources is very important to support the traditional ones, and also in order to reach the objectives fixed by the Kyoto Protocol. In this context, also well-known technologies related to the electric energy production, formerly not suitable – due to the poor technological level of the components or due to the high costs linked to the system efficiency – may now find a suitable collocation. Among these technologies, the thermoelectric effect may be very advantageous in some particular applications of small power. A power generation system utilizing this technology has been studied by the authors. This system utilizes the thermal difference b…
Efficiency Maximization of Permanent Magnet Synchronous Generators Coupled to Wind Turbines
2007
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…
Local DoS applications with micro wind generation systems
2015
In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar-thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind fl…
Environmental benefits through new distributed on site control actions inside European apartments
2008
Energy management control actions inside apartments and detached houses have to be carried out in order to reduce CO2 emissions. In this work, new control actions turned to the reduction of both electrical energy losses and electrical energy consumptions inside typical European (Italian, French, German and United Kingdom) apartments are proposed. These actions are of the ldquoLoad Shiftingrdquo type, that makes the apartment daily load profile as flat as possible, and of the ldquoDistributed on Site (DoS)rdquo type consisting in heating the water needed by dishwashers and washing machines inside instantaneous gas water heaters (IGWHs) instead of inside the household appliances themselves. T…
Vibration signature analysis for rotor broken bar diagnosis in double cage induction motor drives
2013
The paper investigates the diagnosis of rotor broken bars in field oriented controlled (FOC) double cage induction motor drives, using current and vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. The proposed diagnosis approach is based on optimized use of wavelet analysis by a pre-processing of phase current or axial/radial vibration signals. Thus, the time evolution of the tracked rotor fault components can be effectively analyzed. This paper shows also the relevance of the fault components computed from axial vibration sign…
Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis
2017
This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard…
The use of sea waves for generation of electrical energy and Hydrogen
2009
Recently linear synchronous generator for the exploitation of sea wave energy has been proposed. That solution does not require reactive power to magnetize but needs permanent magnets to assure the excitation. The electrical energy generated by such a device must be converted and conditioned in order to match the instantaneous utility requirements and a power link from the sea to an interconnection is needed. In this paper in order to overcome that difficulty, the authors propose the use of the electrical energy generated to generate “in situ” hydrogen. As a result the output of the generation would be hydrogen that can be stored and used when needed The proposed electrical generator is a P…
Magnetic Tunnel Junction (MTJ) Sensors for Integrated Circuits (IC) Electric Current Measurement
2013
We report on MgO Magnetic Tunnel Junction (MTJ) devices focusing on their potential application in the measurement of electrical current at the integrated circuit level. Single devices and full bridges have been specifically developed for this purpose. A sort of different designs regarding their geometry arrangement as well as the number of constitutive elements have been tested. Experimental characterization has been performed and results including impedance and sensitivity measurements are given.