Search results for "Fig"

showing 10 items of 1359 documents

Proof of Concept of an Irradiance Estimation System for Reconfigurable Photovoltaic Arrays

2015

In order to reduce the mismatch effect caused by non-uniform shadows in PV arrays, reconfigurable interconnections approaches have been recently proposed in the literature. These systems usually require the knowledge of the solar radiation affecting every solar module. The aim of this work is to evaluate the effectiveness of three irradiance estimation approaches in order to define which can be well suited for reconfigurable PV arrays. It is presented a real-time solar irradiance estimation device (IrradEst), implementing the three different estimation methods. The proposed system is based on mathematical models of PV modules enabling to estimate irradiation values by sensing a combination …

EngineeringControl and OptimizationPyranometerIrradianceEnergy Engineering and Power TechnologyPhotovoltaic arraysSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciSolar irradianceSettore ING-INF/01 - Elettronicalcsh:Technologyjel:Q40jel:Qjel:Q43jel:Q42jel:Q41Electronic engineeringjel:Q48jel:Q47irradiance estimationElectrical and Electronic EngineeringEngineering (miscellaneous)jel:Q49reconfigurable PV arrayMathematical modelRenewable Energy Sustainability and the Environmentbusiness.industrylcsh:Tdynamic reconfiguration systemPhotovoltaic systemjel:Q0jel:Q4Settore ING-IND/33 - Sistemi Elettrici Per L'EnergiaSettore ING-IND/31 - ElettrotecnicamonitoringProof of conceptPhotovoltaic fieldphotovoltaic fields; monitoring; dynamic reconfiguration system; irradiance estimation; reconfigurable PV arraybusinessphotovoltaic fieldsEnergy (miscellaneous)VoltageEnergies
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Optimization of photovoltaic energy production through an efficient switching matrix

2013

This work presents a preliminary study on the implementation of a new system for power output maximization of photovoltaic generators under non-homogeneous conditions. The study evaluates the performance of an efficient switching matrix and the relevant automatic reconfiguration control algorithms. The switching matrix is installed between the PV generator and the inverter, allowing a large number of possible module configurations. PV generator, switching matrix and the intelligent controller have been simulated in Simulink. The proposed reconfiguration system improved the energy extracted by the PV generator under non-uniform solar irradiation conditions. Short calculation times of the pro…

EngineeringMPPTPhotovoltaic modulesEnergy Engineering and Power TechnologyDynamic electrical schemeEnvironmental Science (miscellaneous)lcsh:Technologylcsh:HD72-88Maximum power point trackinglcsh:Economic growth development planningPV systemsGenerator (circuit theory)Matrix (mathematics)Control theoryGrid-connected photovoltaic power systemElectronic engineeringPV systems; Photovoltaic modules; Mismatch; Optimization algorithm; Reconfiguration; MPPT; Dynamic electrical schemeWater Science and Technologylcsh:TRenewable Energy Sustainability and the Environmentbusiness.industryPhotovoltaic systemControl reconfigurationControl engineeringPV systems Photovoltaic modules Mismatch Optimization algorithm Reconfiguration MPPT Dynamic electrical schemeSettore ING-IND/33 - Sistemi Elettrici Per L'EnergiaOptimization algorithmSettore ING-IND/31 - ElettrotecnicaMismatchReconfigurationInverterbusinessJournal of Sustainable Development of Energy, Water and Environment Systems
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Service restoration in compensated distribution networks using a hybrid genetic algorithm

1998

In this paper a genetic algorithm (GA) based approach to the service restoration (SR) problem in automated distribution networks is presented. Normal operation within the network comprises both automatic reconfiguration and compensation so as to reduce power losses, allow load balancing and improve the voltage profile. In the restorative state, the reconfiguration is performed together with compensation, taking mainly into account the load supply requirement and secondarily, the losses reduction requirement. After a general discussion on the restoration problem together with a short review of recent papers on the topic, a solution strategy is proposed. Then, a short account about classical …

EngineeringMathematical optimizationDistribution networksbusiness.industryControl systemEnergy Engineering and Power TechnologyControl reconfigurationLoad balancing (electrical power)Service restorationElectrical and Electronic EngineeringbusinessAlgorithmVoltageElectric Power Systems Research
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Photovoltaic plant array reconfiguration: Design of a new device

2014

An efficient strategy to improve unequally irradiated PV plants performances is based on the reconfiguration of the connections between the modules. In this paper, an algorithm, for this purpose conceived, is presented. Moreover, the design, realization and finally also the set up of a new reconfiguration system device is fully shown and discussed. The algorithm conceived simulates several possible series-parallel connections under varying irradiation conditions, and determines the optimal modules connection in order to get the maximum output power. In this way, the reconfiguration system may set up the reconfiguration strategy. The reconfiguration system prototype set up, basically consist…

EngineeringMicrocontrollerreconfiguration system devicepower system controlPV power systemSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciTVactuation systemtring PV modules irradiation conditionElectricityArduinounequally irradiated PV plant performanceconditioning systemNew devicehomogeneity conditionmismatch effectOperational amplifiermaximum output powernew device designTransducerpartial shading reconfiguration prototypebusiness.industryreconfiguration system prototype set upPhotovoltaic systemArrayControl reconfigurationControl engineeringoptimal module connectionVoltage measurementeries-parallel connection simulationMicrocontrollerphotovoltaic power systemATmega2560 microcontrollerpower system simulationControl systemacquisition systemmodule connection reconfigurationArduino Mega 2560control systembusinessphotovoltaic plant array reconfigurationreconfiguration strategy
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Full characterization of low-noise HEMTs using only noise figure measurements

1993

A method for the complete characterization of microwave transistors in terms of noise, gain and scattering parameters using a computer-controlled noise figure measuring set-up only is presented. Selection of the optimum measuring conditions, all the steps of the experimental procedure, the data collecting and processing to derive all the parameters, are fully driven by an original (unpublished) software, even without the presence of an (unskilled) operator. Results are presented about the complete characterization of a series of ten pseudomorphicHEMTs in the 8-16 GHz range. The S-parameters are also compared with those measured by an ANA.

EngineeringNoiseNoise measurementNoise-figure meterbusiness.industryAcousticsScattering parametersRange (statistics)Electronic engineeringY-factorNoise figurebusinessLow-noise amplifier41st ARFTG Conference Digest
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Technical and economical evaluation on the use of reconfiguration systems in some EU countries for PV plants

2017

This paper shows the technical and economical evaluation of the application of a reconfiguration system for photovoltaic (PV) plants, considering the incentives system in some European Union countries. The reconfiguration system is an alternative to the distributed maximum power point tracking technique which used to increase the power production in the PV plants under the mismatch phenomenon. The reconfiguration techniques employ a microprocessor-based or field-programmable gate array-based system that modifies the layout of the PV plant through the change of the connections among modules. After having presented the main features working of the PV reconfiguration system allowing the improv…

EngineeringPartial shading (PS)020209 energy02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciIndustrial and Manufacturing EngineeringMaximum power point trackingGate arrayIncentives policie0202 electrical engineering electronic engineering information engineeringProduction (economics)media_common.cataloged_instancePV system topologyElectrical and Electronic EngineeringEuropean unionPhotovoltaic (PV) power systemmedia_commonMismatch lossebusiness.industryMismatch conditionPhotovoltaic systemControl reconfigurationControl engineeringInvestment (macroeconomics)Reliability engineeringSettore ING-IND/31 - ElettrotecnicaIncentiveControl and Systems EngineeringReconstructionbusinessSettore ING-INF/07 - Misure Elettriche E Elettroniche
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An FPGA-Based Software Defined Radio Platform for the 2.4GHz ISM Band

2006

A prototype of a Software Defined Radio (SDR) platform has been successfully designed and tested implementing a reconfigurable IEEE 802.11 and ZigBee receiver. The system exploits the reconfiguration capability of an FPGA for implementing a number of receiver configurations that share the same RF front-end. Configurations can be switched at run time, or can share the available logic and radio resource.

EngineeringRF front endRadio receiver designExploitbusiness.industrySoftware radioComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSFrequency shift keyingControl reconfigurationSoftware-defined radioRemote radio headEmbedded systemField-programmable gate arraybusinessISM bandreceived signal
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HEMT for low-noise microwaves: CAD-oriented performance evaluation

1995

This paper shows how a graphic processing of low-noise HEMT's small signal parameters, allows evaluating and comparing the actual performance obtainable in front-end applications. HEMT's tradeoff charts which solve tradeoffs among the basic low-noise amplifier performance are reported. Figures of merit for microwave low-noise HEMT which represent a fast way of evaluating HEMT in actual working conditions and of selecting the proper transistor, are defined. As an example, the tradeoff charts and the figures of merit of two HEMT's (Fujitsu FHR02FH, Sony 2SK677) and a pseudomorphic-HEMT (Celeritek CFB001-03) are reported and compared with the data sheets. © 1995, IEEE. All rights reserved.

EngineeringRadiationbusiness.industryAmplifierTransistorElectrical engineeringCADCondensed Matter PhysicHigh-electron-mobility transistorCondensed Matter Physicscomputer.software_genreSettore ING-INF/01 - ElettronicaSignallaw.inventionlawElectronic engineeringFigure of meritComputer Aided DesignElectrical and Electronic EngineeringbusinesscomputerMicrowaveIEEE Transactions on Microwave Theory and Techniques
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Reconfigurable dualband antenna module with integrated high voltage charge pump and digital analog converter

2014

Integration of a reconfigurable antenna module for handheld applications employing a set of novel technologies is demonstrated. A low profile dualband hybrid dielectric resonator antenna (DRA) based on glass-ceramics and a tunable matching network (TMN) based on ferroelectric varactors with a maximum biasing of 90V form a reconfigurable antenna module. The control of the antenna module is performed by a 120V CMOS high voltage (HV) charge pump with an 8-bit digital analog (D/A) converter generated from a 3.7V battery. Adaptive impedance matching at the lower band of 1.9 GHz is carried out by the TMN when the dualband antenna is exposed to different operation scenarios. Meanwhile, the upper b…

EngineeringReconfigurable antennaDielectric resonator antennaDirectional antennabusiness.industryElectrical engineeringImpedance matchingSlot antennalaw.inventionCMOSlawCharge pumpAntenna (radio)businessThe 8th European Conference on Antennas and Propagation (EuCAP 2014)
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Economic benefits of the use of a PV plants reconfiguration systems

2015

This paper shows the economic convenience of the application of a reconfiguration system for photovoltaic plants, considering the incentives system in different Countries. The reconfiguration is an alternative to the Distributed Maximum Power Point Tracking, DMPPT, technique used to overcome the mismatch problem in Photovoltaic, PV, plants. The reconfiguration techniques employ a microprocessor-based system that modifies the layout of the PV plant by physically changing the connections among modules. After having presented the working principle of the PV reconfiguration system allowing the improvement of the efficiency of the same plant and the relevant installation, the main strength and w…

EngineeringRelation (database)business.industryPhotovoltaic systemControl reconfigurationSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciEnvironmental economicsInvestment (macroeconomics)Economic benefitsMaximum power point trackingSettore ING-IND/31 - ElettrotecnicaIncentivePv plantReconfiguration photovoltaic incentives policiesbusinessSettore ING-INF/07 - Misure Elettriche E Elettroniche2015 International Conference on Renewable Energy Research and Applications (ICRERA)
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