Search results for "Harmonics"

showing 10 items of 199 documents

Performance Evaluation of a Three- Phase Five-Level Quasi-Z-Source Cascaded H-Bridge for Grid-Connected Applications

2018

In the field of the PV generation, Quasi-Z-source cascaded H-bridge (qZS-CHB) inverters are promising due to their features of modularity and high voltage conversion ratio. Thus, new topology structures and innovative modulation techniques are continuously being developed to improve the performance in terms of voltage stress and harmonic content. This paper proposes an innovative modulation technique that allows reducing the voltage stress and a specially designed grid-connected control strategy is also introduced. Through simulations in MATLAB, it has been validated that the performance of a three-phase five-level qZS-CHB is improved with the proposed solution.

Computer science020209 energyEnergy Engineering and Power TechnologyTopology (electrical circuits)02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciPV systemsmodulation techniquesharmonicharmonics0202 electrical engineering electronic engineering information engineeringElectronic engineeringElectrical and Electronic EngineeringMATLABcomputer.programming_languageQuasi-Z-source cascaded H-Bridge inverters020208 electrical & electronic engineeringHigh voltageH bridgeQuasi-Z-source cascaded H-Bridge inverterSettore ING-IND/31 - ElettrotecnicaThree-phasemodulation techniqueHarmonicsHarmoniccomputerPV systemVoltage
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A chirp-z transform-based synchronizer for power system measurements

2005

In the last few years, increased interest in power and voltage quality has forced international working groups to standardize testing and measurement techniques. IEC 61000-4-30, which defines the characteristics of instrumentation for the measurement of power quality, refers to IEC 61000-4-7 for the evaluation of harmonics and interharmonics. This standard, revised in 2002, requires a synchronous sampling of voltage or current signal, in order to limit errors and to ensure reproducible results even in the presence of nonstationary signals. Therefore, an accurate estimation of the fundamental frequency is required, even in the presence of disturbances. In this paper, an algorithm to detect t…

Computer scienceBluestein's FFT algorithmFast Fourier transformChirp-z transform power quality synchronizationFundamental frequencyPower (physics)Electric power systemSampling (signal processing)SynchronizerHarmonicsElectronic engineeringElectrical and Electronic EngineeringInstrumentationSettore ING-INF/07 - Misure Elettriche E ElettronicheInterpolation
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A Novel Symmetrical Boost Modulation Method for qZS-based CHB Inverters

2020

Quasi-Z-source cascaded H-bridge (qZS-CHB) inverters are arising as an innovation in the field of the electrical conversion for PV applications. This type of converters inherit the advantages of multilevel inverters and single-stage configuration. In this context, this paper proposes a novel symmetrical boost modulation strategy for qZS CHB multilevel inverters to increase the performance in terms of voltage stresses and power quality. The novelty lies in the adoption of a different concept to generate the shoot-through states compared to the traditional methods. Simulation analysis in a grid connected application to evaluate the benefits of this boost method is performed in the MATLAB/PLEC…

Computer scienceContext (language use)02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti Elettrici7. Clean energy01 natural sciencesHarmonic analysisharmonics0103 physical sciences0202 electrical engineering electronic engineering information engineeringElectronic engineeringquasi-Z source cascaded H-Bridge multilevel invertersMATLABcomputer.programming_language010302 applied physics020208 electrical & electronic engineeringConvertersGridboost methodgrid-connected applicationcomputerPhase modulationPulse-width modulationPV systemVoltage2020 IEEE 21st Workshop on Control and Modeling for Power Electronics (COMPEL)
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Comparative Analysis of Modified Modulation Scheme for Three-phase Voltage fed QZS Inverters

2019

Single-stage converters are one promising solution in different field of applications. In particular, quasi-Z-Source VSI topology structure playsan important role because it presents the same advantages of VSI and qZS converters. In addition, it allows increasing the inverter reliability. Moreover, modulation schemes and control strategy are still being developed. For this reason, aim of this paper is to introduce a modified modulation scheme based on the Maximum Constant Boost Control (MCBC) concept and Switching Frequency Optimal (SFO)as reference signals that represents the novelty issue of this work. The analysis has been carried out by comparing the performance of the converter in term…

Computer scienceQuasi-Z-source InverterHarmonicTopology (electrical circuits)Settore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciConvertersModulation techniqueSettore ING-IND/31 - ElettrotecnicaReliability (semiconductor)Three-phaseModulationControl theoryHarmonicsInverterVoltage stressVoltage2019 8th International Conference on Renewable Energy Research and Applications (ICRERA)
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Real filter based on Mellin radial harmonics for scale-invariant pattern recognition.

1994

Several theoretical and experimental studies are developed in order to simplify the construction of filters based on Mellin radial harmonics (MRH) for scale-invariant pattern recognition. A real filter based on MRH is designed. The impulse response of the filter is a hermitic function, obtained by a suitable modification of a MRH component. This real filter has the same scale invariance as the conventional complex MRH filters, with the main advantage of its simplicity. Both computer simulations and optical experiments are presented.

Computer sciencebusiness.industryMaterials Science (miscellaneous)Pattern recognitionFunction (mathematics)Scale invarianceIndustrial and Manufacturing Engineeringsymbols.namesakeFourier transformFilter (video)HarmonicsPattern recognition (psychology)symbolsArtificial intelligenceBusiness and International ManagementbusinessFrequency modulationImpulse responseApplied optics
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<title>Glass to ferroelectric phase transition induced by ac electric field in PbMg<formula><inf><roman>1/3</roman><…

2003

The nonlinear dielectric response of epitaxial heterostructures of relaxor ferroelectric PbMg1/3Nb2/3O3 thin films was experimentally studied using digital Fourier analysis. The amplitudes and the phase angles of the dielectric harmonics were determined as a function of temperature and the amplitude of the sinusoidal ac field. The response of the films was reconstructed assuming a linear contribution of the film-electrode interface capacitance. In the films at low amplitudes of ac field, a glass-like behavior was identified by a maximum in the third-order nonlinear dielectric permittivity around the freezing temperature, accompanied by a square field dependence of the amplitudes of the odd …

Condensed Matter::Materials SciencePhase transitionMaterials scienceAmplitudeNuclear magnetic resonanceCondensed matter physicsElectric fieldHarmonicsField dependenceDielectricCapacitanceFerroelectricitySPIE Proceedings
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Modified Modulation Techniques for Quasi-Z-Source Cascaded H-Bridge Inverters

2018

Quasi-Z-source cascaded H-bridge (q Z S - C H B) inverters are one promising solution for high power photovoltaic (PV) systems. This type of topologies inherits the advantages of cascaded converters (i.e., multilevel outputs) and impedance-source inverters (i.e., high conversion ratios). In addition, it allows increasing the inverter reliability (with high redundancy). However, the modulation and control of qZS-CHB inverters are challenging to a certain extent. Thus, this paper proposes modified modulation techniques to increase the performances of qZS-CHB converters in terms of voltage gains and stresses. The novelty lies in the use of the switching frequency optimal as reference signals i…

Control and OptimizationComputer science020209 energyEnergy Engineering and Power Technology02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciNetwork topologyIndustrial and Manufacturing EngineeringModulation techniquePV systemsmodulation techniquesharmonicsquasi-z source cascaded h-bridge inverters0202 electrical engineering electronic engineering information engineeringElectronic engineeringRedundancy (engineering)Electrical and Electronic EngineeringQuasi-Z source cascaded H-Bridge inverter020208 electrical & electronic engineeringPhotovoltaic systemHarmonicH bridgeSettore ING-IND/31 - ElettrotecnicaModulationHarmonicsInverterPV systemVoltage
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Experimental study on B-spline-based modulation schemes applied in multilevel inverters for electric drive applications

2019

This work presents the design, simulation, and experimental validation of new B-Spline-based modulation techniques applied to a Multilevel Power Inverter (MPI), particularly focusing the attention on the harmonic content of the output voltages of the inverter. Simulation and experimental results are proposed and discussed, mainly describing the potential benefits, such as the increase of the multi-level operation of the converter, and drawbacks (low-order harmonics) related to the adoption of B-Spline functions for multilevel inverters applied in the field of electrical drives.

Control and OptimizationComputer science020209 energyPower inverterPower conversion harmonicEnergy Engineering and Power Technology02 engineering and technologySettore ING-IND/32 - Convertitori Macchine E Azionamenti Elettricimodular multilevel convertersSettore ING-INF/01 - ElettronicaField (computer science)0202 electrical engineering electronic engineering information engineeringElectronic engineeringElectrical and Electronic EngineeringEngineering (miscellaneous)power conversion harmonicsRenewable Energy Sustainability and the EnvironmentB-spline020208 electrical & electronic engineeringModular multilevel converterPulse width modulation invertersSettore ING-IND/31 - ElettrotecnicaModulationHarmonicsHarmonicInverterEnergy (miscellaneous)Voltage
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A New Software Tool for Design, Optimization, and Complete Analysis of Rotating Electrical Machines Windings

2015

In this paper, a new software tool developed by the authors for ac winding design, optimization, and complete analysis is presented. In particular, this software can be used as a valid aid in design and analysis for a wide variety of motor and generator windings with generic number of phases (including the case of those machines in which some slots are left empty), pole pairs, slot number, and so on. The calculation of winding factors and the evaluation of their harmonic distribution is also accomplished. The software is implemented in the MATLAB programming environment. By means of some examples, covering the most relevant winding types, the capabilities of this software will be shown. In …

Differential leakageTotal harmonic distortionElectromotive forceComputer scienceFluxSettore ING-IND/32 - Convertitori Macchine E Azionamenti ElettriciTopologyElectronic Optical and Magnetic MaterialswindingHarmonic analysisharmonicMagnetomotive forceElectromagnetic coilmagnetomotive force (MMF)Harmonicsflux densityWinding factorwinding factorsElectrical and Electronic Engineeringwinding connectionLeakage (electronics)IEEE Transactions on Magnetics
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Advanced Ultrasonic Structural Monitoring of Waveguides

2008

Ultrasonic Guided Waves (UGWs) are a useful tool in those structural health monitoring applications that can benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes two methods, based on linear and nonlinear acoustics for structural damage detection based on UGWs. The linear method combine the advantages of UGW inspection with the outcomes of the Discrete Wavelet Transform (DWT) that is used for extracting defect-sensitive features that can be combined to perform a multivariate diagnosis of damage. In particular, the DWT is exploited to generate a set of relevant wavelet coefficients to construct a uni-dimensional or m…

Discrete wavelet transformDiscrete Wavelet Transform Feature Extraction Nonlinear Acoustics Ultrasonic Guided WaveMaterials scienceAcousticsSpectral densityNonlinear acousticsWaveletHarmonicsHarmonicElectronic engineeringUltrasonic sensorStructural health monitoringSettore ICAR/08 - Scienza Delle Costruzioni
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