Search results for "Voltage"
showing 10 items of 934 documents
Electrodynamic Control of the Combustion Characteristics and Heat Energy Production
2015
ABSTRACTElectric field effects (EFE) on combustion characteristics, heat energy production, and composition of polluting emissions have been investigated experimentally for different types of fuels (natural gas, biomass) providing experimental study of the EFE in a district heating boiler and complex modeling experiments in a small-scale pilot device. The DC field-induced variations of the produced heat energy, efficiency of heat energy production, flame characteristics, and the composition of polluting emissions have been studied for a positively biased axially inserted electrode and negatively biased (grounded) heat surfaces by varying the applied DC voltage, net current, and consumed ele…
Novel voltage-controlled conditioning circuit applied to the ISFETs temporary drift and thermal dependency
2003
This paper describes a novel conditioning circuit applied to ion-sensitive field-effect transistors/membrane-ion-sensitive field-effect transistors (ISFETs/MEMFETs) sensors. The novel conditioning circuit allows the sensor polarization with the needed either voltage or current required in each application, thanks to two completely independent voltage-controlled blocks (current and voltage blocks). The control of the voltage block is the most critical point in our design because the voltage block maintains the sensor feedback stable, avoiding the thermal and temporary drifts of the sensor feedback.
Novel Three-Phase Multilevel Inverter With Reduced Components for Low- and High-Voltage Applications
2021
In this article, a novel multilevel topology for three-phase applications, having three-level and hybrid N -level modular configurations, enabling low-, medium-, and high-voltage operations, is presented. The proposed topology has several attractive features, namely reduced component count, being capacitor-, inductor-, and diode-free, lowering cost, control-complexity, and size, and can operate in a wide range of voltages and powers. Selected simulation and experimental results are presented to verify the performance of the proposed topology. Further, the overall efficiency of the topology and loss distribution in switches are studied. Finally, the key features of the proposed topology in t…
Preliminary test on a cascode switch for high-frequency applications
2020
Nowadays, an increasing electrification level is being addressed towards different sectors, such as transportation and industrial electronics. To bear that, high speed electrical machines represent a mature technology in different application fields, e.g. avionics, automotive, compressors and spindles. In order to guarantee high speed while keeping high power quality without adopting bulky filtering circuits, DC-AC converters shall be controlled by means of high Pulse Width Modulation (PWM) frequencies. In addition to the emerging switching device technologies, such as those based on Silicon-Carbide (SiC) and Gallium-Nitride (GaN), alternative circuital topologies are crucial in order to co…
Overview and experimental analysis of MC SPWM techniques for single-phase five level cascaded H-bridge FPGA controller-based
2016
This paper presents an overview and experimental analysis of the MC SPWM techniques for single-phase cascaded H-bridge inverter. The multilevel power converters are an alternative to traditional converters known as “three-level converters”. The voltage waveforms and the related frequency spectra, which have been obtained by simulation analysis in Matlab-Simulink environment, are here reported for all the proposed modulation techniques. The simulation results have been experimentally validated through means of a DC/AC, five-level, single-phase converter prototype with an appropriate test bench.
Four Quadrant Switch Based Multiple-Input DC-DC Converter
2021
In this paper, a novel non-isolated multiple input dc-dc converter (MIC) is proposed. The MIC uses four-quadrant switches, only one inductor and capacitor. It is capable of bidirectional operation in non-inverting buck-boost configuration and can accommodate the simultaneous transfer of energy from more than one source of different voltage levels to the DC bus. This MIC is analysed for two inputs in this paper. As compared to existing MICs in literature, the proposed converter utilizes less number of inductors and requires only one switch to integrate any extra energy storage. Different operation modes of the proposed MIC are numerically verified and validated on a high-fidelity hardware-in…
Novel zero-current-transition circuit for three-phase buck rectifiers
2002
ZCT circuits have already been proposed in the past and are becoming more and more popular in high power rectifiers and inverters where bipolar devices have to be used (IGBTs or even BJTs). Although ZCT techniques have already been applied to three-phase boost type topologies, no ZCT circuits have been proposed for three-phase buck-type topologies. The authors propose a new load independent ZCT circuit for a three-phase buck-type rectifier which achieves high noise reduction, voltage stress reduction and zero current transitions to almost all transitions of the rectifier's switches including the additional auxiliary switches.
On the de-energization of over-head low-voltage lines under high-impedance fault conditions
2018
Downed distribution conductors in overhead distribution systems, may not be a concern for equipment, but greatly challenge the safety of persons, as well as the integrity of properties. Upstream overcurrent protective devices may not be able to detect the magnitudes of fault currents resulting from these high-impedance faults. Even though protective devices capable to detect such faults have been available on the market, not all the utilities have equipped their stations with these products, likely due to the costs. In this paper, the authors formalize the problem, and propose a possible cost-effective solution for the low-voltage over-head lines with neutral wire. Such solution includes a …
Implementation and Experimental Tests of a Management System for MV/LV Distribution Grids
2019
The continuous monitoring of network power flows and the remote control of Distributed Generators and Energy Storage Systems are the essential elements to allow a full exploitation of Renewable Energy Sources and their real integration in distribution networks. Thus in the paper a management system is presented for load flow monitoring in MV/LV distribution network. Moreover, on the basis of calculated power flows, the management system is able to send control commands to DGs and ESSs, to vary their power production or power factor or eventually to disconnect them in order to maintain the network stability. The proposed solution was really implemented in the MV network of Ustica Island, dev…
Novel constant current driver for ISFET/MEMFETs characterization
2001
Abstract In the present work a new constant current driver for ISFETs and MEMFETs sensors has been developed. The proposed circuit maintains the ISFET/MEMFET operation point at constant drain–source current and voltage. The combination of some programmable current sources and an appropriate selection of a simple precision resistor allow a good ISFET/MEMFET polarization. The use of operational amplifiers with low offset and drift are required to provide the buffering function needed by the sensor.