Search results for "Rectifier"

Partial discharge behavior under single phase half and full-bridge rectifier

2017

The aim of the present work is to simulate partial discharges (PDs) phenomena under voltage stress close to the Direct Current (DC) waveform. The employed waveforms have been realized by using a full-wave and a half-wave rectifiers. After that, in order to generate a steadier voltage supply, a capacitive filter has been inserted in the output of the half-wave rectifier. Simulations have been carried out by modifying a previous software used in the case of Alternating Current (AC). Finally, experimental tests have been carried out in order to validate simulation results.

On the use of front-end cascode rectifiers based on normally on SiC JFET and Si MOSFET

2014

The new wide band-gap semiconductor devices provide new properties to be explored. Normally on silicon carbide (SiC) JFET power devices have several advantages, in particular low switching losses and the potential capabilities of high temperature and high reverse blocking voltage. Looking for improving the overall efficiency in power converters, new structures based on these power devices might be studied. In this paper, a cascode rectifier based on normally on SiC JFET is presented and analyzed. This rectification structure can be applied as front-end rectifier stage for ac-dc power converters, increasing the overall efficiency of these topologies. A second cascode rectifier based on silic…

Design and analysis of filament power supply method for increasing life time of thermal emission tubes

2017

This paper has reviewed power supply methods for thermal electron tubes and proposes a method for purpose of increasing its lifetime, with reducing complexity of circuit and, improvement in power efficiency. In this work, the filament is operated with a decreased voltage level while maintaining the output anode power at the same level as required for the filament's operation at nominal voltage. The supply circuit is designed to avoid the reduction of filament voltage below a minimum level. A power converter made of thyristors and rectification diodes is designed to supply the filament voltage. Converter is carefully monitored and controlled by an algorithm embedded in a contemporary Digital…

Asymmetric nanopore rectification for ion pumping, electrical power generation, and information processing applications

2011

Single-track, asymmetric nanopores can currently be functionalised with a spatially inhomogeneous distribution of fixed charges and a variety of pore tip shapes. Optimising the asymmetric nanopore characteristics is crucial for practical applications in nanofluidics. We have addressed here this question for three cases based on different input/output chemical and electrical signals: (i) ion pumping up a concentration gradient by means of a periodic, time-dependent bias potential, (ii) information processing with a single nanopore acting as the nanofluidic diode of a logic gate, and (iii) electrical energy harvesting using a nanopore that separates two solutions of different salt concentrati…

Biomolecular conjugation inside synthetic polymer nanopores via glycoprotein-lectin interactions

2011

We demonstrate the supramolecular bioconjugation of concanavalin A (Con A) protein with glycoenzyme horseradish peroxidase (HRP) inside single nanopores, fabricated in heavy ion tracked polymer membranes. Firstly, the HRP-enzyme was covalently immobilized on the inner wall of the pores using carbodiimide coupling chemistry. The immobilized HRP-enzyme molecules bear sugar (mannose) groups available for the binding of Con A protein. Secondly, the bioconjugation of Con A on the pore wall was achieved through its biospecific interactions with the mannose residues of the HRP enzyme. The immobilization of biomolecules inside the nanopore leads to the reduction of the available area for ionic tran…

Electrical network of nanofluidic diodes in electrolyte solutions: Connectivity and coupling to electronic elements

2016

[EN] We consider a nanopore network with simple connectivity, demonstrating a two-dimensional circuit (full-wave rectifier) with ensembles of conical pores acting as nanofluidic diodes. When the bridge nanopore network is fed with an input potential signal of fluctuating polarity, a fixed output polarity is obtained. The full-wave rectification characteristics are demonstrated with square, sinusoidal, and white noise input waveforms. The charging of a load capacitor located between the two legs of the bridge demonstrates that the nanofluidic network is effectively coupled to this electronic element. These results can be relevant for energy transduction and storage procedures with nanopores …

Innovative systems based on optical nanoantennas for energy harvesting application

The purpose of this study is to outline the main guidelines for the design of arrays of optical rectennas aiming to harvest energy and for the optimization of the power transfer to an external load. In particular, the novelty of this study consists in introducing the concept of the integrated design between the array of optical rectennas and the harvesting circuit able to exploit the available energy. The design of the array represents the crucial point in order to optimize the power transfer between the antenna and the load and can influence the rectenna design. On the other hand, the maximum power transfer to the load has to be obtained under matching conditions between the array and the …

Dynamic behavior analysis and characterization of a cascode rectifier based on a normally-on SiC JFET

2014

Spin-valve current sensor for industrial applications

2003

This work presents an industrial application of a new spin-valve current sensor based on the giant magnetoresistance effect (GMR) and provides a comparison between this sensor and the typical sensor used in these applications, the hall sensor. Experimental results derived from the application of this two sensors in a power application (a bi-directional three-phase rectifier) are shown.

Control of ultra-high switching frequency power converters using virtual flux-based direct power control

2017

This paper presents a control technique for ultra-high switching frequency rectifiers known as virtual flux-based direct power control (VF-DPC). This method utilizes AC voltage sensors to provide better power quality at the input and output of power converters. Performance of an ultra-high switching frequency converter using the extended and conventional VF-DPC method is analyzed. The analysis has shown that the extended VF-DPC method can reduce better the total harmonic distortion (THD) of input currents and the ripples of the output DC voltage as compared to conventional VF-DPC. Finally, the effect of switching frequency and inductance size on rectifier operation is investigated in this s…