Search results for "conductor"
showing 10 items of 1270 documents
Finite-element Discretizations of Semiconductor Energy-transport Equations
2003
Energy-transport models describe the flow of electrons in a semiconductor crystal. Several formulations of these models, in the primal or dual entropy variables or in the drift-diffusion-type variables, are reviewed. A numerical discretization of the steady-state drift-diffusion-type formulation using mixed-hybrid finite elements introduced by Marini and Pietra is presented. The scheme is first applied to the simulation of a one-dimensional ballistic diode with non-parabolic band diagrams. Then a two-dimensional deep submicron MOSFET device with parabolic bands is simulated, using an adaptively refined mesh.
Research Toward The Optical Equipment For An Autonomous Robot For TviV Environment
1989
The paper consists of three major parts: basic technical problems in very high power/megavolt environment, signal processing and mechanical equipment for this environment, construction of a sensor equipped robot for this environment. The first part contains mainly metrological confinements and reliability considerations for the optical, optoelectronic and electronic part of a system. The second part contains mechanics and robotics problems. The result of these two parts is a choice of a system to be realized.
Test bench for coupling and shielding magnetic field
2016
This paper describes a test bench for training purposes, which uses a magnetic field generator to couple this magnetic field to a victim circuit. It can be very useful to test for magnetic susceptibility as well. The magnetic field generator consists of a board, which generates a variable current that flows into a printed circuit board with spiral tracks (noise generator). The victim circuit consists of a coaxial cable concentric with the spiral tracks and its generated magnetic field. The coaxial cable is part of a circuit which conducts a signal produced by a signal generator and a resistive load. In the paper three cases are studied. First, the transmitted signal from the signal generato…
Design, fabrication, and analysis of a spin-valve based current sensor
2004
Abstract In this work, we suggest a novel current sensor design, based on spin valve technology, with a full Wheatstone bridge configuration. The principal characteristic is that the four magnetoresistance sensing elements, fully active, are deposited and patterned at the same time. This way, differences among them should be insignificant, so improving voltage offset and drift temperature parameters. The complete IC fabrication process involves only three lithography steps, making the process cheaper and faster. In order to get a balanced bridge, the measured current must be properly driven, by means of an auxiliary PCB. Some prototypes, with different input impedances, have been fabricated…
Charge measurement using an array of Faraday’s Cups on a printed circuit board
2014
Abstract An absolute method of measuring charge is to use a Faraday Cup (FC) principle. This study relates to a novel method of measuring charge on a flat substrate, which is coated with charged powder particles. The substrate consists of an array of FC with different dimensions. The sensor is manufactured using flame-retardant printed circuit board (PCB) technology. The objective of this work is to reduce the charge sharing by developing a grounded shield cup around each conductive cup in the array and accordingly increase cup-to-ground capacitance. The results have confirmed that the improved well shielding would provide a more accurate quantitative charge measurement.
A comparison of two innovative customer power devices for Smart Micro-Grids
2015
The paper presents a comparison of two prototypes of innovative Customer Power Devices designed for applications in Smart Micro-Grids. The devices are both equipped with Energy Storage Systems, consisting in Lithium batteries and have been assembled, independently, by the DIAEE of the University of Rome 'La Sapienza' and the DEIM of the University of Palermo in collaboration with the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In the paper, the characteristics and the operating modes of the devices are examined and some consideration on their application in Low Voltage Smart Micro-Grids are provided. © 2015 IEEE.
A review of multiple faults diagnosis methods in Voltage Source Inverters
2015
This paper examines, as in short review, the methods of diagnosis of simple and multiple faults on Voltage Source Inverter (VSI). The methods examined here are essentially based on the inspection of the load currents. Some of these diagnosis methods are characterized by low computational effort, other for a better reliability avoiding faultless positive tests. Some solutions are characterized by a share of these benefits while others prefer an enforcement of trustworthiness, in spite of the lower calculation amount. The analysis of the technical literature, certainly, offers a glimpse about the creation of new algorithms and significant advances for the future.
UPS fuel cell based: An innovative back-up system
2007
The aim of the paper is to evaluate the technical feasibility and aspects related to the use, in an Uninterruptible Power Supply (UPS), of fuel cells instead of traditional electrochemical batteries. The proposed system, named UPS-FCB (Fuel Cell Based) presents a modular and versatile system configuration; particularly it is possible to integrate it with traditional UPS. Moreover the system features can be modified in terms of power, reliability, back-up time, etc., by changing the power devices. A detailed experimental analysis has been carried out on a passive stand-by UPS integrated with a FCB; experimental results can be easily extended to the other possible system architectures. © 2007…
Electrical-optical characterization of multijunction solar cells under 2000X concentration
2014
In the framework of the FAE "Fotovoltaico ad Alta Efficienza" ("High Efficiency Photovoltaic") Research Project (PO FESR Sicilia 2007/2013 4.1.1.1), we have performed electrical and optical characterizations of commercial InGaP/InGaAs/Ge triple-junction solar cells (1 cm2) mounted on a prototype HCPV module, installed in Palermo (Italy). This system uses a reflective optics based on rectangular off-axis parabolic mirror with aperture 45×45 cm2 leading to a geometrical concentration ratio of 2025. In this study, we report the I-V curve measured under incident power of about 700 W/m2 resulting in an electrical power at maximum point (PMP) of 41.4 W. We also investigated the optical properties…
Uprating an Overhead Line. Italian TSO Applications for Integration of RES
2013
The increase of Renewable Energy Sources (RES) production units has caused significant changes in the electrical system configuration. The existing structural asset isn't adequate to dispatch these new power flows that, at same time, should be favorite by various TSOs in order to obtain incentives. The outage of primary substations on the grid and the increase of consumptions have caused growing load currents on existing overhead line. This paper, after introducing thermal resistant conductors and Dynamic Rating (DR) solutions, reports an applications used by TERNA Group S.p.A. (Italian TSO). These systems are already installed on lines and they are contributing to increase power flows than…