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Analysis and implementation of the speaker adaptation techniques : MAP, MLLR, and MLEDFanner, Robert M. 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The topic of this thesis is speaker adaptation, whereby speaker-independent speech models
are adapted to more closely match individual speakers by utilising a small amount of
data from the targeted individual. Speaker adaptation methods - specifically, the MAP,
MLLR and MLED speaker adaptation methods - are critically evaluated and compared.
Two novel extensions of the MLED adaptation method are introduced, derived and
evaluated. The first incorporates the explicit modelling of the mean speaker model in
the speaker-space into the MLED framework. The second extends MLED to use basis
vectors modelling inter-class variance for classes of speech models, instead of basis vectors
modelling inter-speaker variance.
An evaluation of the effect of two different types of feature vector - PLP-cepstra and
LPCCs - on the performance of speaker adaptation is made, to determine which feature
vector is optimal for speaker-independent systems and the adaptation thereof. / AFRIKAANSE OPSOMMING: Die onderwerp van hierdie tesis is spreker-aanpassing, dit wil sê, die verandering van
'n spreker-onafhanklike spraakmodel om nader aan 'n spreker-afhanklike model vir 'n
individu te wees, gegewe 'n klein hoeveelheid spraakdata van die individu. Die volgende
sprekeraanpassing-metodes word geëvalueer: MAP, MLLR en MLED.
Twee nuwe uitbreidings vir die MLED-metode word beskryf, afgelei en geëvalueer.
Die eerste inkorporeer die eksplisiete modellering van die gemiddelde sprekermodel van
die sprekerruimte in die MLED metode. Die tweede uitbreiding maak gebruik van basisvektore
vir MLED wat vanaf die interklas-variansie tussen 'n stel sprekerklasse in plaas
van die interspreker-variansie afgelei is.
Die effek van twee tipes kenmerk-vektore - PLP-kepstra en LPCC's - op die prestasie
van sprekeraanpassings-metodes word ondersoek, sodat die optimale tipe kenmerk-vektor
vir spreker-onafhanklike modelle en hul aanpassing gevind kan word.
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Attitude sensor and actuator interfacing for micro-satellitesDlamini, Zamokwakhe P. (Zamokwakhe Peacemaker) 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The purpose of this thesis was to design and test the interfaces of sensors and actuators. In the
complete Attitude Determination and Control System CADCS) the Interface Control Processor
(ICP) must be interfaced to various sensors and torquers.
The testing of interfaces involves the simulation of sensors and actuators and also two of the
Attitude Control Processor's functions, i.e. sending actuator commands and receiving sensor
data. The tested interfaces are for two actuators and three sensors. Both analog and digital
sensors and actuators are interfaced i.e. reaction wheels, magnetorquers, magnetometer and
horizon /fine sun sensor. The simulated sensors and actuators are to be employed on three axis
controlled, low earth o~biting micro-satellites.
To test the interfaces, a test circuit was developed and the design is presented. Finally the
software to facilitate the testing was developed and is also presented with the analysis based on
protocol implementation and data rates. / AFRIKAANSE OPSOMMING: Die doel van hierdie tesis was om sensor en aktueerder koppelvlakke te ontwerp en te toets. In
die volledige Attitude Determination and Control System CADCS) moet die Interface Control
Processor CICP) aan verskeie sensore en torquers gekoppel word.
Die toets van koppelvlakke behels die simulasie van sensore en aktueerders en ook twee van die
Attitude Control Processor (ACP) se funksies, naamlik die stuur van aktueerder bevele en die
ontvang van sensor data. Die koppelvlakke vir twee aktueerders en drie sen sore is getoets.
Beide analoog en digitale sensore en aktueerders is gekoppel, naamlik die reaksiewiele,
magneetspoele, magnetometer en horison I fyn son sensor. Die gesimuleerde sensore en
aktueerders sal gebruik word op drie-as beheerde, lae aardbaan mikrosatelliete.
Om die koppelvlakke te toets is 'n stroombaan ontwikkel waarvan die ontwerp hier aangebied
word. Sagteware om die toetse te fasiliteer is ontwikkel en word ook hier aangebied tesame met .
analises gebaseer op protokol implementering en data tempo's.
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Development of a FEM waveguide code, incorporating Fast Frequency Techniques, for numerical synthesisClarke, Samuel R. (Samuel Robert) 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: A computational tool for numerical synthesis via optimization is developed. Only
two port waveguide devices are considered. The Finite Element Method (FEM) is
used for the electromagnetic analysis. Specifically, the frequency domain electric
field FEM is used with vector curl-conforming constant tangential/linear normal
brick-shaped elements. Special boundary conditions are used at the ports.
These boundary conditions only consider dominant mode propagation. The issues
surrounding the implementation of this formulation are discussed. The results generated
using this code compare favorably to examples from independent sources.
A parametric mesher that is used in conjunction with the FEM is developed. This
is done to eliminate the need for human intervention during each iteration of the
synthesis procedure. Fast Frequency (FF) techniques are presented to reduce the
computational requirements of the synthesis. FF techniques reduce the cost of calculating
many frequency samples in a specified band and do not reduce the computational
requirements of computing a FEM solution at a single frequency. The FF
techniques presented are: Asymptotic Waveform Evaluation (AWE), Model Based
Asymptotic Waveform Evaluation (MB-AWE) and Model Based Parameter Estimation
(MBPE) . The results obtained using these techniques are compared and
the most suitable technique for the synthesizer is selected. MBPE is selected as
the most suitable technique for this application. An adaptive sampling algorithm
for Model Based Parameter Estimation is presented. The algorithm relies on the
difference between multiple models generated from the same samples to determine
the sample locations. The use of this algorithm enables a model of a narrow band
filter at X-band to be determined using only fourteen FEM solutions. The difference
between the model- and the FEM solutions is less then -lOOdBacross the
band. A sample synthesis using generalized simulated annealing is presented. A
single pole filter in X-band waveguide is successfully synthesized to illustrate the
usefulness of the code. The use of FF techniques results in a computational cost
saving of a factor of forty times. / AFRIKAANSE OPSOMMING: 'n Rekenaar werktuig vir numeriese sintese deur middel van optimering word ontwikkel.
Slegs twee-poort golfleierkomponente word beskou.
Die Eindige Element-metode (EEM) word vir die elektromagnetiese analise gebruik.
Meer spesifiek, die frekwensiegebied, elektriese-veld EE-formuleering word
gebruik, met eurl-ondersteunende, konstant-tagensiaaljlineêr-normaal, baksteenvormige
vektorelemente. Spesiale grensvoorwaardes word by die poorte gebruik.
Hierdie grensvoorwaardes neem slegs voortplanting van die dominante modus in ag.
Die kwessies rondom die implementering van hierdie EEM word bespreek. Resultate
wat met hierdie kode verkry word, vergelyk goed met dié vanuit onafhanklike
bronne. 'n Parametriese diskretisasie prosedure in ontwikkel, vir gebruik saam
met die genoemde EEM, met die doelom menslike interaksie uit die weg te ruim,
tydens die sintese proses.
Vinnige Frekwensie (VF) tegnieke word beskryf, met die doelom die berekeningskoste
van die sintese te verminder. VF tegnieke verminder die berekeningskoste
verbonde aan 'n reeks EEM oplosings binne 'n gegewe frekwensieband, maar verminder
nie die koste verbonde aan 'n enkel-frekwensie EEM oplossing nie. Die
VF tegnieke wat beskryf word, is die volgende: Asimptotiese Golfvorm Evaluasie
(AGE), Model Gebaseerder Asimptotiese Golfvormevaluasie (MGAGE) en Model-
Gebaseerde Parameterekstraksie (MGPE). Die resultate wat met hierdie metodes
verkry word, word vergelyk om sodoende die mees toepaslike VF tegniek te kies.
MGPE word gekies as die mees toepaslike tegniek.
'n Aanpasbase monsteringsalgoritme vir MGPE word beskryf. Die algoritme berus
op die verskil tussen twee modelle wat vanaf dieselfde stel punte geskep word, om
monsterfrekwensiewaardes te bepaal. Die gebruik van hierdie algoritme lei tot 'n
model van 'n nou-, X-band filter, vanuit slegs veertien EEM oplossings. Die verskil
tussen hierdie model en enige EEM oplossings binne die band, is kleiner as -lOOdB.
'n Voorbeeld sintese, wat gebruik maak van veralgemeende, gesimuleerde versmelting,
word beskryf. 'n Enkel-pool filter by X-band word suksesvol gesintetiseer om
die bruikbaarheid van die kode te illustreer. 'n Faktor veertig vermindering III
berekeningskostes word behaal deur gebruik te maak van VF tegnieke.
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Development of a high speed PCI data capture card for the SUNSAT I ground stationVan der Westhuizen, W. J. (Willem Joseas) 03 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The primary payload of the University of Stellenbosch's micro-satellite, SUNSAT I,
was a high quality imager, capable of taking stereoscopic images of the surface of
the earth. Although the orbit of SUNSAT I will have the satellite pass over the whole
earth, contact via the SUNSAT I ground station at the University will only be made for
3% of each day. To be able to photograph any part of the earth onboard memory
was provided on the satellite to store the image until it can be downloaded to the
ground station. A high speed downlink was also added to the satellite to be able to
download a complete image from the onboard memory in one pass and also to take
realtime pictures as the satellite passes over the ground station. At that stage there
was no way to capture the data at the ground station. A high speed digital data
capture mechanism was needed. The thesis discusses the development of a high
speed capture card.
Due to the high speeds needed it provided an excellent opportunity to develop the
card using the PCI bus, the first design to do so at the University, as an interface with
a computer. A prototype card was developed first to do proof of concept. It is shown
that the prototype card fulfilled the functional requirements and it was also used to
capture the first image from the complete satellite during the final tests before launch.
Finally a production card for use in the ground station was designed and assembled. / AFRIKAANSE OPSOMMING: Die hoof loonvrag van die Universtieit van Stellenbosch se eerste mikrosatelliet,
SUNSAT I, is "n hoë kwaliteit kamera wat stereoskopiese fotos van die oppervlak van
die aarde kan neem. Alhoewel die satelliet oor die hele oppervlakte van die aarde
gaan beweeg, is dit vir slegs 3% van die dag sigbaar vanaf die grondstasie by die
Universiteit van Stellenbosch. Om 'n foto van enige plek op aarde te kan neem is
daar aanboord geheue op die satelliet geplaas om die foto te stoor totdat dit by die
grondsatsie afgelaai kan word. "n Hoë spoed skakel is ook daargestelom die data
in die geheue van die satelliet in een verbyvlug te kan aflaai. Dit stel die satelliet ook
in staat om intydse fotos gedurende In verbyvlug van die satelliet te kan neem. Op
daardie stadium het daar nog nie "n manier bestaan om die hoë spoed data vas te
lê nie. In Meganisme om die hoë spoed digitale data te vang was nodig. Hierdie
tesis bespreek die ontwikkeling van so In data vang kaart.
Weens die hoë snelhede wat benodig word, het die PCI bus die ideale oplossing
gebied om die data teen "n hoë spoed op In persoonlike rekenaar te stoor. Dit was
ook die eerste ontwerp aan die Universiteit wat van die PCI bus gebruik gemaak het.
In die eerste instansie is In prototipe ontwikkel om te bewys dat dit wel moontlik is om
die data teen die benodigde tempo te kan stoor. Daar word gewys dat die prototipe
aan die behoefte voldoen en dit is ook gebruik om die eerste beeld vanaf die
volledige satelliet te vang voordat dit gelanseer is.
In die tweede instansie word In produksiekaart ontwikkel en aanmekaar gesit.
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Establishing a process for the fabrication of high-quality HTc SQUIDsRottier, P. A. (Pieter Adriaan) 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: High-temperature (HTc) SQUID magnetometers are used in the biomedical field of magnetocardiography
(MCG). The use of MCG enables a much earlier diagnosis of potentially dangerous
conditions than the use of electrocardiography (EeG). For the use of MCG, high-quality
HTc SQUIDs are necessary. These SQUIDs can only be realised if the design and fabrication
processes are well defined and understood. In this thesis an extensive literature review on the
design process explains all the concepts necessary to understand and design a high-quality HTc
SQUID. Then the fabrication process is redefined and characterised.
The SQUIDs are fabricated with YBCO thin films on MgO substrates. The relevant steps
in the process are the pulsed laser deposition (PLD), UV lithography and argon ion milling.
The characterisation of the fabrication process is based on a statistical method called Design
of Experiment (DOE). This enables more information to be obtained about the fabrication
process than before. For the PLO process the important parameters are determined and an
initial optimisation is done. During the characterisation process it is proven that the use of
ozone during PLO has a positive effect on the quality of the YBCO thin film. On the PLD
apparatus the substrate heater and laser-beam profile is improved. The UV lithography process
is analysed and a DOE is proposed for optimisation. A temperature bath is added to the process
to enable better reproducibility. An rf multicusp ion mill is built for argon-ion milling, this
device is tested and shown to provide the required etching capability. / AFRIKAANSE OPSOMMING: Hoë-temperatuur (HTc) SQUID magnetometers word in die biomediese rigting vir magnetokardiografie
(MKG) gebruik. Met MKG kan 'n mens potensieel gevaarlike toestande heelwat
vroeër diagnoseer as wat moontlik is met elektrokardiografie (EKG). HTc SQUIDs van hoë
kwaliteit word benodig vir MKG. Sulke SQUIDs kan slegs vervaardig word as die vervaardiging
en ontwerpsprosesse goed gedefinieer en verstaan word. In hierdie tesis verduidelik 'n omvattende
literatuurstudie oor die ontwerpsproses al die konsepte wat nodig is om 'n SQUID van
hoë kwaliteit te verstaan en te ontwerp. Verder word die vervaardigingsproses geherdefinieer
en gekarakteriseer.
Die SQUIDs word vervaardig met YBCO-dunfilm op MgO-substrate. Die relevante stappe
tydens die vervaardiging is: gepulseerde laser deposisie (PLO), UV-litografie en argon-ioonstraling.
Die karakterisering van die vervaardigingsproses is gebaseer op 'n statistiese metode
genaamd "Design of Experiment" (DOE). Hierdie metode laat 'n mens toe om meer inligting
oor die proses te verkry as wat voorheen moontlik was. Gedurende die karakterisering
word bewys dat die gebruik van osoon gedurende die PLO-proses 'n positiewe invloed op die
kwaliteit van die YBCO-dunfilm het. Die PLO-apparaat se substraatverwarmer en laserstraalprofiel
word verbeter. Die UV-litografieproses word geanaliseer en 'n DOE word voorgestel
vir die optimisering daarvan. Daar word 'n temperatuurbad by die proses gevoeg om die herhaalbaarheid
te verbeter. 'n "Rf multicusp ion mill" word gebou, die toestel word getoets en
daar word aangetoon dat dit die nodige etsvermoë het.
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Structure from motion estimation using a nonlinear Kalman filterVenter, Chris (Christian Johannes) 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Structure from Motion is defined as the problem of extracting the 3d motion of a camera
moving through a scene, as well as the 3d structure of the scene, from the image sequence
produced by the camera over time. Several methods based on the Kalman filter have
been proposed in the past, mostly based on the Extended Kalman filter. We propose
an algorithm based on the dual Unscented Kalman filter to estimate the structure and
motion of an object under perspective projection. It is shown that the algorithm is stable
and accurate under synthetic as well as real-world conditions. / AFRIKAANSE OPSOMMING: Struktuur vanuit Beweging is 'n rekenaar-visie probleem waarin die 3d beweging van 'n
kamera deur 'n ruimte, asook die 3d struktuur van die ruimte, bepaal moet word slegs
vanuit die 2d beelde in die beeldreeks wat deur die kamera geneem word. 'n Verskeie reeks
oplossings, gebaseer op die Kalman filter, is reeds voorgestelom die probleem op te los.
Meeste van die oplossings implementeer die "Extended Kalman filter", of EKF. Ons stel
'n algoritme voor, gebaseer op 'n nuwe nie-lineêre benadering tot die Kalman filter, die
sogenaamde "Unscented Kalman filter", of UKF. Hierdie algoritme bepaal die struktuur
en beweging onder 'n perspektief-projeksie kamera. Daar word getoon dat die algoritme
stabiel en akkuraat funskioneer onder sintetiese sowel as reële toevoer.
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The design of a coupled co-axial resonator filter for low earth orbit satellites working at microwave frequenciesSam, Lwazi 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Keywords: Coupled resonator filters, Co-axial line resonators, Basic Coupling
Design, Co-axial resonator filter
The study of the basic dynamics of filters, with the emphasis on coupled resonator
filters, is presented. Special attention is paid to the synthesis of doubly terminated
coupling matrices using the Darlington method. Due to restrictions placed on the
filter by the equivalent circuit used, a coupling matrix reduction is applied to the
resulting coupling matrix.
An investigation is performed on A/2 co-axial line resonators, with the emphasis on
rectangular co-axial line resonators with a round center conductor. The basic
definition of the coupling coefficient is revisited and it is calculated using the method
based on Bethe's theory and Cohn's experimental work.
A 4th-order co-axial resonator filter operating at 3 GHz is designed using the theory
outlined in this thesis. The measured response is in good agreement with the theory in
terms of the center frequency, but disagree in terms of the coupling coefficient,
bandwidth and Q-factor. The reasons for this, as well as suggestions for improving
the accuracy of the parameters mentioned, are given. / AFRIKAANSE OPSOMMING: Sleutelwoorde: Gekoppelde resoneerder filters, Ko-aksiale lyn resoneerders,
Basiese Koppeling Ontwerp, Ko-aksiale resoneerder filter
Die studie van die basies dinamika van filters, met die klem op gekoppelde
resoneerder filters, is voorgelê. Spesiale aandag is gegee aan die sintese van
dubbelbelaste koppel matrikse met die gebruik van die Darlington metode. As gevolg
van die beperkings wat op die filter geplaas word deur die gebruik van die ekwivalent
stroombaan, word 'n koppel matriks vermindering gebruik.
'n Ondersoek is gedoen op A/2 ko-aksiale lyn resoneerders, met die klem op
reghoekige ko-aksiale lyn resoneerders met 'n ronde binnegeleier. Die basiese
definisie van die koppel koëffisiënt is hersien en dit is bereken met die gebruik van
die metode wat baseer is op Bethe se teorie en Cohn se experimentele werk.
'n 4de-orde ko-aksiale resoneerder filter wat opereer by 3 GHz is ontwerp met die
gebruik van die teorie wat in hierdie tesis gaskets word. Die gemete weergawe is in
goeie ooreenkoms met die teorie in terme van die senter frekwensie, maar verskil in
terme van die koppel koëffisiënt, bandwydte en Q-faktor. Die rede hiervoor, as ook
voorstelle vir die verbetering van die akkuraatheid van die parameters wat genoem is,
IS gegee.
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Feature tracking and pattern registrationWagener, Dirk Wolfram 11 1900 (has links)
Thesis (MScEng) -- Stellenbosch University, 2003. / ENGLISH ABSTRACT: The video-based computer vision patient positioning system that is being developed at iThemba Laboratories, relies on the accurate, robust location, identification and tracking of a number of markers on the patient's mask. The precision requirements are demanding - a small error in the location of the markers leads to an inaccurate positioning of the patient, which could have fatal consequences. In this thesis we discuss the contsruction of suitable markers, their identification with subpixel accuracy, as well as a robust tracking algorithm. The algorithms were implemented and tested on real data. We also note and give examples of other applications, most notably 2D human face tracking and the 3D tracking of a moving person. / AFRIKAANSE OPSOMMING: Die video-gebaseerde rekenaarvisie pasiënt posisionerings stelsel wat by iThemba Laboratoriums ontwikkel word, maak staat op die akkurate opsporing, identifikasie en volging van 'n stel merkers op die pasiënt se masker. Die akkuraatheids voorwaardes is besonders streng - selfs 'n klein fout in die lokasie vandie merkers sal lei tot die onakkurate posisionering van die pasiënt, wat dodelike gevolge kan hê. In hierdie tesis bespreek ons die konstruksie van geskikte merkers, die identifikasie van die merkers tot op subbeeldingselement vlak en ook die akkurate volging van die merkers. Die algoritmes is op regte data getoets. Ander toepassings soos 2D en 3D menlike gesigs-volging word ook kortliks bespreek.
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Handwritten signature verification using hidden Markov modelsSindle, Colin 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Handwritten signatures are provided extensively to verify identity for all types of transactions
and documents. However, they are very rarely actually verified. This is because of
the high cost of training and employing enough human operators (who are still fallible) to
cope with the demand. They are a very well known, yet under-utilised biometric currently
performing far below their potential. We present an on-line/dynamic handwritten signature
verification system based on Hidden Markov Models, that far out performs human
operators in both accuracy and speed. It uses only the local signature features-sampled
from an electronic writing tablet-after some novel preprocessing steps, and is a fully
automated system in that there are no parameters that need to be manually fine-tuned
for different users. Novel verifiers are investigated which attain best equal error rates of
between 2% and 5% for different types of high quality deliberate forgeries, and take a
fraction of a second to accept or reject an identity claim on a 700 MHz computer. / AFRIKAANSE OPSOMMING: Geskrewe handtekeninge word gereeld gebruik om die identiteit van dokumente en transaksies
te bevestig. Aangesien dit duur is in terme van menslike hulpbronne, word die integrit
eit daarvan selde nagegaan. Om handtekeninge deur menslike operateurs te verifieër.
is ook feilbaar-lOO% akkurate identifikasie is onrealisties. Handtekeninge is uiters
akkurate en unieke identifikasie patrone wat in die praktyk nie naastenby tot hul volle
potensiaal gebruik word nie. In hierdie navorsing gebruik ons verskuilde Markov modelle
om dinamiese handtekeningherkenningstelsels te ontwikkel wat, in terme van spoed en
akkuraatheid heelwat meer effektief as operateurs is. Die stelsel maak gebruik van slegs
lokale handtekening eienskappe (en verwerkings daarvan) soos wat dit verkry word vanaf
'n elektroniese skryftablet. Die stelsel is ten volle outomaties en geen parameters hoef
aangepas te word vir verskillende gebruikers nie. 'n Paar tipes nuwe handtekeningverifieërders
word ondersoek en die resulterende gelykbreekpunt vir vals-aanvaardings- en
vals-verwerpingsfoute lê tussen 2% en 5% vir verskillende tipes hoë kwaliteit vervalsde
handtekeninge. Op 'n tipiese 700 MHz verwerker word die identiteit van 'n persoon ill
minder as i sekonde bevestig.
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Shunt active power filtering algorithms for unbalanced, non-linear loadsGous, Marthinus Gerhardus Faculin 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: This thesis presents the design and implementation of shunt active power filtering algorithms for
unbalanced, non-linear loads.
A three-phase four-wire topology is developed in the dqO space. Based on this development an accurate
dynamic system model, taking into account the effect of the neutral inductor is developed.
The synchronous reference frame technique is expanded to enable the isolation of the zero sequence
current component into its instantaneous active and reactive current components. Additionally a
prediction method is proposed that will enable the proper prediction of the reference currents in a threephase
four-wire system.
Two categories of reference current signal tracking algorithms are investigated; namely the predictive
current controller and the sliding mode current controller. A compensating technique is proposed to
compensate for the effects that sampling and computational time delay have on the performance of the
system. Additionally, an investigation is done into the effect that dead-time has on the performance of the
system, and based on this investigation a dead-time compensating strategy is proposed.
Finally simulation and practical results are provided to validate the discussed theories. / AFRIKAANSE OPSOMMING: Hierdie verhandeling ondersoek die ontwerp en implementering van parralel gekoppelde aktiewe filter
algoritmes vir ongebalenseerde, nie-lineêre laste.
'n Drie-fase vier-draad topologie, asook 'n korrekte model van die dinamiese sisteem, wat die effek van
die neutraal induktor insluit, is ontwikkel in die dqO ruimte. Die sinchroon verwysing vlak tegniek is
uitgebrei om die isolering van die nul sekwensie stroom in onderskeidelik die oombliklike aktiewe en
reaktiewe stroom komponente te verdeel. Addisioneel is a vooruitskatting tegniek aanbeveel wat die
beheerder in staat sal stelom voldoende die verwysing strome vooruit te skat in 'n drie-fase vier-draad
stelsel.
Twee katagoriee van verwysing stroom volging algoritmes is ondersoek, naamlik die afskatting stroom
beheerder en die gleiende modus stroom beheerder. 'n Effektiewe kompensasie tegniek is voorgestel
om die effek van tydvertraging as gevolg van monstering en verwerking te elimineer. Addisioneel is die
effek van dooie-tyd ondersoek en gebasseer op hierdie ondersoek is 'n effektiewe dooie-tyd
kompensasie tegniek voorgestel.
Laastens is simulasies en praktiese resultate verskaf om die werking van die voorgestelde teorie te
bevestig.
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