Search results for "converters"

showing 10 items of 140 documents

Evaluation of Gallium Nitride Transistors in Electronic Power Conditioners for TWTAs

2015

The aim of this paper is to evaluate the benefits of replacing Si Mosfets transistors with enhancement mode GaN transistors in a Half-Bridge Zero Voltage and Zero Current Switching Power Switching Converter (ZVZCPS). This converter is usually used as power supply of the travelling-wave tube amplifiers (TWTAs) in aerospace applications. In this paper, firstly the converter is theoretically analyzed, obtaining its operation, losses and efficiency equations, these equations are used to obtain optimizations maps based on the main system parameters. In this way, the ideal design parameters can be visually obtained. These optimization maps are the key to quantify the potential benefits of GaN tra…

Materials sciencebusiness.industryAmplifierTransistorElectrical engineeringGallium nitrideConverterslaw.inventionPower (physics)Reduction (complexity)chemistry.chemical_compoundchemistrylawElectronic engineeringConditionersbusinessAerospace2015 IEEE Aerospace Conference
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Proton exchanged waveguides in LiNbO<inline-formula><sub>3</sub></inline-formula> and LiTaO<inline-formula><sub>3…

1998

Materials sciencebusiness.industryGeneral Engineeringchemistry.chemical_elementNonlinear opticsNonlinear crystalsConvertersLaserNeodymiumAtomic and Molecular Physics and Opticslaw.inventionNonlinear systemOpticschemistrylawbusinessOptical Engineering
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Transconductance Converters Based on Current Mirrors Applied to pH Measurement Using ISFET Sensors

2009

New transconductance circuits (V/I converters) are designed based on current mirrors and operational amplifiers. Their input/output characteristics and the influence of DC parameters are obtained. Experimental results were performed, comparing them with the simulated results. An electronic instrumentation circuit is designed based on one of the transconductance converters analyzed. The purpose of this circuit was to condition the response of an ion-sensitive field-effect transistor (ISFET) to measure pH. In the proposed application, the V/I converter presented provides the stability and accuracy of the ISFET operating point, making an easy characterization procedure and the design of multic…

Materials sciencebusiness.industryTransconductanceTransistorElectrical engineeringConverterslaw.inventionCurrent mirrorlawOperational transconductance amplifierHardware_INTEGRATEDCIRCUITSElectronic engineeringOperational amplifierElectrical and Electronic EngineeringISFETbusinessInstrumentationElectronic circuitIEEE Transactions on Instrumentation and Measurement
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Predictive dead time controller for GaN-based boost converters

2017

A dynamic dead time controller is presented, specifically intended to operate in synchronous boost converters based on GaN field-effect transistor switches. These transistors have a reduced stored charge with respect to silicon metal–oxide–semiconductor field-effect transistors with similar breakdown voltage and series resistance, and can operate at higher frequencies with reduced switching losses. On the other hand, the voltage drop in reverse conduction is typically more than doubled with respect to silicon devices resulting in relevant power losses during the free-wheeling phases. Therefore, dynamic control of dead time can be profitably applied even in converters operating in the tens o…

Materials sciencepredictive control; field effect transistor switches; switching convertors; transient response; predictive dead time controller; dynamic dead time controller; synchronous boost converters; power losses; transient response020209 energypredictive dead time controller02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciSettore ING-INF/01 - Elettronicalaw.inventiondynamic dead time controllerlawControl theorypower losse0202 electrical engineering electronic engineering information engineeringBreakdown voltageElectrical and Electronic EngineeringPredictive controlsynchronous boost converterfield effect transistor switcheswitching convertor020208 electrical & electronic engineeringTransistorConvertersDead timetransient responseBoost converterVoltage dropVoltage
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Detection of Partial Discharges at Square Shaped Voltages

2018

Due to the wide use of electronic converters and the introduction of new powerful power electronics devices, the input waveforms most often used are becoming much different than the traditional power frequent sinusoidal one. In High Voltage (HV) apparatus particularly, this condition can increase the stress on the insulation systems that may lower the reliability of the whole power grid. This type of input voltage, often showing an increased voltage gradient, causes problems in the Partial Discharge (PD) measurement setup and acquisition systems, also due to the increased harmonic content. In this paper, the main aim is to discuss how to suitably approach the measurement technique of PDs at…

Materials scienceunconventional streRenewable Energy Sustainability and the Environmentbusiness.industrypattern recognitionElectrical engineeringEnergy Engineering and Power TechnologyComputer Science Applications1707 Computer Vision and Pattern RecognitionHigh voltageConvertersIndustrial and Manufacturing EngineeringPower (physics)Computer Networks and CommunicationReliability (semiconductor)Artificial IntelligencePartial dischargePower electronicsPartial dischargeHarmonicPWMbusinessInstrumentationVoltage2018 IEEE 4th International Forum on Research and Technology for Society and Industry (RTSI)
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Active snubber network design and implementation on the primary side of an isolated Ćuk converter realizing soft-switching for efficiency …

2008

This paper describes the process of improving the efficiency of an existing isolated DC/DC converter based on CUK topology with secondary side synchronous rectification, by means of the introduction of an active snubber network on the primary side. The snubber circuit reduces to zero the switching losses during the off-time interval of secondary SR. In particular, the efficiency improvement is due to the elimination of the primary MOSFET Coss output capacitance losses, and mainly of the reverse recovery losses on the secondary SR MOSFET. However, the insertion of the active snubber creates itself additional losses in the circuit, and therefore to measure the really introduced benefit it is …

Network planning and designEngineeringControl theorybusiness.industryElectronic engineeringSnubberĆuk converterTopology (electrical circuits)Power MOSFETConvertersbusinessNetwork topologyCapacitance2008 IEEE Power Electronics Specialists Conference
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H<inf>∞</inf> control of markovian switching systems with time-delays: Applied to DC-DC converters

2011

The DC-DC switching power converters are highly nonlinear systems. Consequently, the conventional linear controls based on averaging and linearization techniques will result in poor dynamic performance or system instability. In order to resolve this problem, in this paper a robust state feedback H∞ control is proposed for these systems under Markovian switching with mixed discrete, neutral and distributed delays. Based on the Lyapunov-Krasovskii functional theory, some required sufficient conditions are established in terms of delay-dependent linear matrix inequalities for the stochastic stability and stabilization of the considered system using some free matrices. The desired control is de…

Nonlinear systemsymbols.namesakeExponential stabilityControl theoryLinearizationConvex optimizationsymbolsMarkov processConvertersRobust controlInstabilityMathematicsIECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society
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A Portable Readout System for Microstrip Silicon Sensors (ALIBAVA)

2009

A readout system for microstrip silicon sensors has been developed. This system is able to measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256. The system can operate either with non-irradiated and irradiated sensors as well as with n-type and p-type microstrip silicon sensors. Heavily irradiated sensors will be used at the Super Large Hadron Collider, so this system can be used to research the performance of microstrip silicon sensors in conditions as similar as possible to the Super Large Hadron Collider operating conditions. The system has two main parts: a hardware part and a software part. The hardware part a…

Nuclear and High Energy PhysicsEngineeringanalog processing circuitsMotherboardPhysics::Instrumentation and DetectorsInterface (computing)Analog-digital conversionFPGAshigh energy physics instrumentationUSBMicrostripChargelaw.inventionCharge sensitive amplifiersData acquisitionmicroprocessorslawlogic designElectrical and Electronic Engineeringdetector instrumentationtime to digitalbusiness.industryReading (computer)electronicsDetectorElectrical engineeringConvertersCollectionsfront-end electronicssemiconductor detectorsNuclear Energy and Engineeringdata acquisition systemsdigital integrated circuitsbusinessDaughterboard
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Analytical and experimental evaluation of a WECS based on a Doubly Fed Induction Generator fed by a matrix converter

2008

In this paper the control of a grid-connected Wind Energy Conversion System (WECS), based on a sensorless vector controlled Doubly-Fed Induction Generator (DFIG) fed by a matrix converter, is presented. The matrix converter is controlled using a space vector modulation algorithm. Stability issues related to the operation of the WECS connected to the grid using a matrix converter are also discussed in this work. The influence of a synchronous rotating filter in the dynamic of the proposed WECS is analysed. A Model Reference Adaptive System (MRAS) observer for sensorless control of the proposed WECS is used in this work. Using the speed estimated by the MRAS observer the electrical torque of …

Operating pointEngineeringObserver (quantum physics)business.industryControl theoryInduction generatorTorqueControl engineeringConvertersbusinessMRASSpace vector modulationMachine control2008 IEEE International Symposium on Industrial Electronics
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Identification of a Hammerstein model for DC/DC converters operating in CCM

2005

This paper deals with a method for identification of a Hammerstein model of DC-DC converters operating in continuous conduction mode (CCM). This model has the duty cycle and the output voltage as input and output, respectively; it consists of a static nonlinearity and a linear and time-invariant model. The aim of the modeling the system by means of a Hammerstein model is due to its capability of describing the converter in a range of steady-state operating points instead of a desired well defined operating point as occurs for the small-signal models which are the more common mathematical description to approach the study of the converters themselves. The nonlinear characteristic of the Hamm…

Operating pointEngineeringbusiness.industryLinear modelSteady-state operating systemConvertersContinuous conduction mode (CCM)Nonlinear systemSettore ING-INF/04 - AutomaticaDuty cycleControl theoryTransient responseTransient (oscillation)businessHammerstein modelPulse-width modulation
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