Made available in DSpace on 2014-06-11T19:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-03-30Bitstream added on 2014-06-13T18:21:14Z : No. of bitstreams: 1 oliveira_vjs_me_ilha.pdf: 825294 bytes, checksum: 1231181cf2748d4fec35e435930c317b (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesse trabalho, propõe-se o projeto e implementação de um sintetizador de sinais ortogonais utilizando técnicas de circuito integrado e processo CMOS. O circuito do sintetizador baseia-se em um modelo matemático que utiliza multiplicadores e integradores analógicos, para geração de bases de funções ortogonais, tais como os polinômios de Legendre, as funções de base coseno e seno, a smoothed-cosine basis e os polinômios de Hermite. Funções ortogonais são bastante empregadas em processamento de sinais, e a implementação deste método matemático é capaz de gerar vários tipos de funções em um mesmo circuito integrado. O projeto proposto utiliza blocos analógicos funcionais para implementar o sintetizador. Os blocos que compõem o sintetizador foram projetados utilizando circuitos diferenciais, processamento em modo de corrente e técnicas de low-voltage. Algumas topologias utilizadas estão descritas na literatura, sendo que algumas foram adaptadas e mesmo modificadas, como no caso do multiplicador de corrente. Outras tiveram que ser propostas. As simulações e os resultados experimentais mostraram que o sintetizador é capaz de gerar funções ortogonais com amplitude e distorções satisfatórias. O sintetizador pode ser alimentado em 3V, tal qual foi projetado, tem faixa de entrada de ±20 μA e apresenta DHT (distorção harmônica total) inferior a 4% no quinto e último estágio em cascata. / In this work, a design and implementation of a synthesizer of orthogonal signals using CMOS technology and design technique for integrated circuits is proposed. The synthesizer circuit used analog multipliers and integrators for produce orthogonal functions such as Legendre polynomials, cosine and sine basis of functions, smoothed-cosine basis and Hermite polynomials. Orthogonal functions can be employed in signal processing and the implementation proposed can generate several kinds of functions in the same integrated circuit. In the synthesizer design building blocks was employed. The synthesizer’s blocks were design using differential circuits, low-voltage and current-mode techniques. Some topologies from papers were adapted or modified, as in the case of the current multiplier. Other topologies had to be proposed. The simulation and experimental results have shown that the synthesizer is able to produce orthogonal functions with satisfactory quality in distortions and amplitude. The synthesizer has a 3V supply voltage, a input current range of ±20 μA and it presents less than 4% of THD (Total Harmonic Distortion) in the last output in cascade.

This diploma thesis describes particular parts of power inverter such as gate driver, DSC, LC filter, low power supply, DC/DC converter and four-quadrant bridge and manner of its control by digital signal controller. Inverter is designated for generating of a mobile artificial electric grid (for example in a car).

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The aims of this thesis are to identify all possible modes of operaton for a multi-stage axial flow compressor; then to characterise the performance, attempt to numerically model operation, and determine the main flow field features for each mode. Four quadrant axial flow compressor operation occurs when the direction of flow through the compressor or the sign of the pressure difference across the compressor reverses, or any combination of these. Depending on the direction of rotation of the compressor, six modes of operation are possible in the four quadrants of the performance map. The rotor rotates in the design direction for three modes, and in the opposite direction for the other three. The stationary-rotor pressure characteristic is S-shaped and passes through the second and fourth quadrants. A three-stage axial flow compressor operating in the incompressible flow regime was used for the experimental investigation. Flow through the compressor was reversed or augmented by means of an auxiliary axial flow fan. Compressor performance was measured by means of static pressure tappings, a turbine anemometer calibrated to measure forward and reversed volumetric flow and a load cell for torque measurement. The inter-blade row flow fields were measured with pneumatic probes and 50 μm cylindrical hot film probes. Three dimensional single blade-passage Navier-Stokes simulations were performed using the Numeca FineTurbo package. Steady state simulations used a mixing plane approach. A nonlinear harmonic approximation was used for time-unsteady simulations. Unstalled first quadrant operation was unremarkable, and good agreement was obtained between experimental and numerical data. A single stall cell was detected experimentally during stalled operation, which was not modelled numerically. In the fourth quadrant for positive rotation, (windmilling), the compressor acts as an inefficient turbine. Flow separates from the pressure surface of the blade, rendering the steady-state mixing plane approach unsuitable. The performance characteristic curves for second quadrant for positive rotation, are discontinuous with those of first quadrant operation. The temperature rise in the working fluid is significantly higher than at design point. Periodic flow structures occurring across two blade passages were detected at all flow coefficients investigated, invalidating numerical modelling assumptions. Better agreement was obtained between experimental and numerical data from a case found in literature. If the compressor operates as a compressor in reverse (third quadrant operation), significant separation occurs on the pressure surface of all blades, and flow conditions resemble severe first quadrant stall. Separation becomes less severe at larger flow rates, allowing numerical simulation, though this is sensitive to the initial flow field. In the the part of the second quadrant, where the compressor rotates in reverse, it operates as a turbine. The blade angles and the direction of curvature match the flow angles and turning well, leading to high turbine efficiencies. Numerical simulations yielded good agreement with measured results, but were again sensitive to the initial flow field. Fourth quadrant operation with negative rotation occurs when flow is forced through the compressor in the design direction. Large separation bubbles are attached to the pressure surfaces of rotor and stator blades, so virtually all throughflow occurs near the hub and casing / AFRIKAANSE OPSOMMING: Die doelwitte van hierdie tesis is om al die moontlike werkmodusse vir ’n bestaande multi-stadium aksiaalvloei kompressor uit te ken; om dan die gedrag te gekarakteriseer, ’n poging aan te wend om die werking numeries te modelleer, en die belangrikste vloeiveldkenmerke vir elke modus te bepaal. Vier-kwadrant aksiaalvloei kompressor werking vind plaas as die rigting van die vloei deur die kompressor, of die teken van die drukverskil oor die kompressor omkeer, of enige kombinasie daarvan. Afhangende van die rigting van rotasie van die kompressor is ses operasionele modusse moontlik in die vier kwadrante van die kompressorkaart. Die rotor draai in die ontwerprigting vir drie van die modes, en in die teenoorgestelde rigting vir die ander drie. Die stilstaande-rotor drukkarakteristiek is S-vormig gaan deur die tweede en vierde kwadrante. ’n Drie-stadium onsamedrukbare vloei aksiaalvloei kompressor is vir die eksperimentele ondersoek gebruik. Vloei deur die kompressor is omgekeer of aangehelp deur middel van ’n aksiaalvloei hulpwaaier. Kompressor werking is gemeet deur middel van statiese druk meetpunte in die omhulsel, ’n turbine anemometer wat gekalibreer is om vorentoe en omgekeerde volumetriese vloei te meet, en ’n lassel vir wringmoment meting. Interlemryvloeivelde is opgemeet met pneumatiese sensors en 50-μm silindriese warm film sensors. Drie-dimensionele Navier-Stokes simulasies is uitgevoer vir ’n enkele lem van elke lemry, met behulp van die Numeca FineTurbo sagtewarepakket. ’n Mengvlakbenadering is gebruik vir bestendige toestand simulasies, terwyl ’n nie-linere harmoniese benadering gebruik is vir die tyd-afhanklike simulasies. Ongestaakte eerste kwadrant werking was alledaags, en goeie ooreenkoms is gevind tussen die eksperimentele en numeriese data. ’n Enkele staak-sel is eksperimenteel ontdek tydens gestaakte werking. Gestaakte werking is nie numeries gemodelleer nie. In die vierde kwadrant vir positiewe rotasie, (”windmeulwerking”), werk die kompressor as ’n ondoeltreffende turbine. Vloei-wegbrekinging op die lem drukoppervlaktes maak die bestendige toestand mengvlakbenadering ongeskik. In die kenlyne vir tweede kwadrant positiewe rotasie, is daar ’n diskontinu¨ıteit in die prestasie karakteristiekkrommes vir die eerste en tweede kwadrant werking. Die temperatuurstyging in die werk- vloeistof is beduidend ho¨er as as by die ontwerppunt. Periodiese vloeistrukture wat oor twee lemme plaasvind is gevind by alle vloei ko¨effisi¨ente wat ondersoek is, en dit maak die numeriese modellering aannames ongeldig. Beter ooreenkoms tussen die eksperimentele en numeriese data iss verkry met ’n geval wat uit die literatuur gevind is. Indien die kompressor werk as ’n kompressor in omgekeerde (derde kwadrant weking), vind beduidende wegbreking op die drukoppervlak van al die lemme plaas, wat lyk soos ernstige gestaakte eerste kwadrant werking. Die vloeiskeiding raak minder ernstig by ’n groter vloeitempo, wat numeriese nabootsing toelaat, maar die nabootsings is sensitief vir die aanvanklike vloeiveld. In die tweede kwadrant, by omgekeerde rotasie, werk die kompressor as ’n turbine. Die lemhoeke en die rigting van lemkromming stem ooreen met die vloeihoeke en verwringing, wat lei tot ho¨er turbine doeltreffendheid. Numeriese nabootsings stem goed ooreen met gemete resultate, maar is weereens sensitief vir die keuse van die aanvanklike vloeiveld. Vierde kwadrant werking met negatiewe rotasie vind plaas wanneer die lug gedwing word om deur die kompressor in die ontwerprigting te vloei. Groot skeidingborrels sit vas aan die drukoppervlaktes van alle lemme, sodat meeste deurvloei naby die naaf en die omhulsel plaas vind.

The manner in which socioeconomic forces direct environmentally unsustainable behaviour is largely unseen and unappreciated. North American cultural beliefs, norms and values reinforce the economic system and constitute significant barriers to large-scale societal ecological behaviour change. Overlooked in the degrowth literature, even by researchers who have examined the importance of socioeconomic barriers (materialism and consumption), is the role occupation plays in dictating the ecological footprint and forming our socioeconomic identities. We have gained some understanding of the motivation of those individuals who have chosen to pursue a low-carbon lifestyle, but are lacking information about those who go one step further and adopt a low-carbon livelihood. Fifteen individuals who successfully adopted low-carbon livelihoods were interviewed to examine socioeconomic barriers they may have experienced and learn how those challenges were met. To assume a low-carbon livelihood at present is likely to require forming a new social status identity, adopting new metrics for judging oneself, and creating a new social network supportive of that identity and its values. A four-quadrant framework was used to examine the systemic nature of emergent themes regarding socioeconomic barriers and how those were overcome. Themes that emerged revealed many similarities to individuals committed to a low-carbon lifestyle with some critical differences in terms of both inhibiting and enabling factors. A core finding was that motivational and personality characteristics of the low-carbon livelihood individuals mimic the attributes of moral exemplars that drive a deep sense of ethical obligation to create a pro- social occupation that can function in a low-carbon manner. Clear values, coupled with a strong sense of personal responsibility, overpowered the socioeconomic barriers participants encountered. Implications regarding interventions for fostering the adoption of low-carbon livelihoods and fortifying the Degrowth movement are examined. / Graduate

Orientador: Nobuo Oki / Banca: Saulo Finco / Banca: Cláudio Kitano / Resumo: Nesse trabalho, propõe-se o projeto e implementação de um sintetizador de sinais ortogonais utilizando técnicas de circuito integrado e processo CMOS. O circuito do sintetizador baseia-se em um modelo matemático que utiliza multiplicadores e integradores analógicos, para geração de bases de funções ortogonais, tais como os polinômios de Legendre, as funções de base coseno e seno, a smoothed-cosine basis e os polinômios de Hermite. Funções ortogonais são bastante empregadas em processamento de sinais, e a implementação deste método matemático é capaz de gerar vários tipos de funções em um mesmo circuito integrado. O projeto proposto utiliza blocos analógicos funcionais para implementar o sintetizador. Os blocos que compõem o sintetizador foram projetados utilizando circuitos diferenciais, processamento em modo de corrente e técnicas de low-voltage. Algumas topologias utilizadas estão descritas na literatura, sendo que algumas foram adaptadas e mesmo modificadas, como no caso do multiplicador de corrente. Outras tiveram que ser propostas. As simulações e os resultados experimentais mostraram que o sintetizador é capaz de gerar funções ortogonais com amplitude e distorções satisfatórias. O sintetizador pode ser alimentado em 3V, tal qual foi projetado, tem faixa de entrada de ±20 μA e apresenta DHT (distorção harmônica total) inferior a 4% no quinto e último estágio em cascata. / Abstract: In this work, a design and implementation of a synthesizer of orthogonal signals using CMOS technology and design technique for integrated circuits is proposed. The synthesizer circuit used analog multipliers and integrators for produce orthogonal functions such as Legendre polynomials, cosine and sine basis of functions, smoothed-cosine basis and Hermite polynomials. Orthogonal functions can be employed in signal processing and the implementation proposed can generate several kinds of functions in the same integrated circuit. In the synthesizer design building blocks was employed. The synthesizer's blocks were design using differential circuits, low-voltage and current-mode techniques. Some topologies from papers were adapted or modified, as in the case of the current multiplier. Other topologies had to be proposed. The simulation and experimental results have shown that the synthesizer is able to produce orthogonal functions with satisfactory quality in distortions and amplitude. The synthesizer has a 3V supply voltage, a input current range of ±20 μA and it presents less than 4% of THD (Total Harmonic Distortion) in the last output in cascade. / Mestre

This thesis deals with method of measuring optical beam intensity, searching for communication system beam using stepper motor movement of the optical head and processing measured signal for displaying on PC. The basic theory of optoelectronics is shown here concerning the problem. There is elaborated main principles of photodetector and stepper motor mainly, which are main part of device. The second part of work is theoretical design of data recorder. All parts are described individually-their characteristics and conditions for correct usage. In the last part setup of device is explained, with the references to blocks of written programs. In the last part, main funcrions of system, its hardware managing and communication are described. At the very end of thesis, examples of measured data are presented.

This works focusesof the propose and realization device for drive four quadrant bridge convertor with transistors IGBT. Final propose include drive unipolar and bipolar, choice between direct or alternative modulation.

This thesis describes the flexible voltage control of a multi-level-voltage-reinjection voltage source converter. The main purposes are to achieve reactive power generation flexibility when applied for HVdc transmission systems, reduce dynamic voltage balancing for direct series connected switches and an improvement of high power converter efficiency and reliability. Waveform shapes and the impact on ac harmonics caused by the modulation process are studied in detail. A configuration is proposed embracing concepts of multi level, soft-switching and harmonic cancellation. For the configuration, the firing sequence, waveform analysis, steady-state and dynamic performances and close-loop control strategies are presented. In order not to severely compromise the original advantages of the converter, the modulated waveforms are proposed based on the restrictions imposed mathematically by the harmonic cancellation concept and practically by the synthesis circuit complexity and high switching losses. The harmonic impact on the ac power system prompted by the modulation process is studied from idealistic and practical aspects. The circuit topology being proposed in this thesis is developed from a 12-pulse bridge and a converter used classically for inverting power from separated dc sources. Switching functions are deduced and current paths through the converter are analysed. Safe and steady-state operating regions of the converter are studied in phasor diagrams to facilitate the design of simple controllers for active power transfer and reactive power generations. An investigation into the application of this topology to the back-to-back VSC HVdc interconnection is preformed via EMTDC simulations.

Η παρούσα διδακτορική διατριβή εστίασε το ενδιαφέρον της στην διερεύνηση των αναλογικών ολοκληρωμένων φίλτρων της κατηγορίας ELIN εξωτερικά γραμμικά, εσωτερικά μη-γραμμικά. Συγκεκριμένα μελετήθηκαν και σχεδιάστηκαν, νέες δομές φίλτρων συμπίεσης-αποσυμπίεσης του προς επεξεργασία σήματος στο πεδίο του υπερβολικού ημιτόνου χαμηλής τάσης τροφοδοσίας. Η γοργή ανάπτυξη της μικροηλεκτρονικής στην υλοποίηση συστημάτων υψηλής αξιοπιστίας και απόδοσης μικρού βάρους και όγκου όπως φορητών ηλεκτρονικών πολυμέσων, επικοινωνιών, βιοϊατρικών συσκευών, ωθεί στην σχεδίαση των ολοκληρωμένων κυκλωμάτων που τα απαρτίζουν με μειωμένη κατανάλωση ισχύος και κατ’ επέκταση χαμηλής τάσης τροφοδοσίας. Σ’ ένα ολοκληρωμένο κύκλωμα η ενσωμάτωση αναλογικών και ψηφιακών κυκλωμάτων σε περιβάλλον χαμηλής τάσης τροφοδοσίας, ώστε το κόστος των διατάξεων να διατηρείται χαμηλό, επηρεάζει άμεσα την απόδοση του αναλογικού τμήματος, προτάσσοντας την ανάγκη για νέες αρχιτεκτονικές σχεδίασης του. Οι διατάξεις των αναλογικών φίλτρων αποτελούν συχνά δομικό στοιχείο των ολοκληρωμένων κυκλωμάτων και η διερεύνηση τους για την επίτευξη μεγάλης δυναμικής περιοχής, ηλεκτρονική ρύθμισης της απόκρισης συχνότητας και ταυτόχρονα χαμηλής κατανάλωσης ισχύος, έχει απασχολήσει αρκετά το ενδιαφέρον της ερευνητικής κοινότητας. Προτείνεται αρχικά η συστηματική σχεδίαση φίλτρων υψηλής τάξης στο πεδίο του υπερβολικού ημιτόνου, αποσκοπώντας στη βελτίωση της διαδικασίας υλοποίησης τους, με χρήση ήδη υπαρχουσών μη-γραμμικών διαγωγών υπερβολικού ημιτόνου, συνημίτονου. Η συμπίεση-αποσυμπίεση του προς επεξεργασία σήματος επιτυγχάνεται με την κατάλληλη τοποθέτηση συμπληρωματικών τελεστών ενώ ταυτόχρονα διατηρείται γραμμική η συνολική συμπεριφορά των διατάξεων. Με γνώμονα την εφαρμογή τους σε βιοϊατρικές συσκευές, εξομοιώνεται με δύο διαφορετικούς τρόπους φίλτρο 3ης τάξης leapfrog με συχνότητα αποκοπής 10Hz και τα αποτελέσματα που προκύπτουν συγκρίνονται με αντίστοιχο γραμμικής συμπεριφοράς. Στην συνέχεια, υλοποιείται η σχεδίαση BiCMOS φίλτρων οποιασδήποτε τάξης, δομημένα από μη-γραμμικούς διαγωγούς υπερβολικού ημιτόνου με δυνατότητα λειτουργίας σε υψηλές συχνότητες και σε χαμηλή τάση τροφοδοσίας. Επιλέγονται οι μέθοδοι του γραμμικού μετασχηματισμού, λειτουργικής και τοπολογικής εξομοίωσης ενός πρωτότυπου ελλειπτικού βαθυπερατού 3ης τάξης με συχνότητα αποκοπής 0.5 kHz και κυμάτωση στην ζώνη διέλευσης 0.5dB. Ακολουθεί ανάλυση και σύγκριση των αποτελεσμάτων που προκύπτουν στο περιβάλλον Analog Virtuoso της Cadence Software, της τεχνολογίας AMS CMOS S35 0.35μm, μεταξύ των φίλτρων στο πεδίο του υπερβολικού ημιτόνου καθώς και με αντίστοιχες διατάξεις στο πεδίο του λογαρίθμου τάξης-ΑΒ και (OTA)-C στο γραμμικό χώρο. Προτείνεται ακόμη, η BiCMOS σχεδίαση γενικευμένων φίλτρων 2ης τάξης απλής εισόδου-πολλαπλών εξόδων και πολλαπλής εισόδου-απλής εξόδου, με δυνατότητα λειτουργίας σε περιβάλλον χαμηλής τάσης τροφοδοσίας, ηλεκτρονικής ρύθμισης της συχνότητας αποκοπής ω0 του συντελεστή ποιότητας Q και της ορθογώνιας μεταβολής μεταξύ των. Από την εξομοίωση τους πρόκυψε ότι είναι ενεργειακά αποδοτικότερη η υλοποίηση τους συγκρινόμενα με αντίστοιχα στο πεδίο του λογαρίθμου. Τέλος, στα πλαίσια υλοποίησης βιοϊατρικών εφαρμογών προτείνεται η σχεδίαση ενός μη-γραμμικού τελεστή ενέργειας στο πεδίο του υπερβολικού ημιτόνου για την ανίχνευση αιχμών δραστηριότητας σε νευρωνικά δίκτυα με τάση τροφοδοσίας 0.5V. Ο μη-γραμμικός διαγωγός υπερβολικού ημιτόνου, του οποίου ο διαγραμμικός βρόγχος αποτελείται από (pMOS) τρανζίστορ δομεί τους διαφοριστές και πολλαπλασιαστές τεσσάρων τεταρτημορίων τάξης-ΑΒ που απαρτίζουν την διάταξη. Εξομοιώνεται, κάνοντας χρήση CMOS τρανζίστορ της τεχνολογίας TSMC 130 nm, στο περιβάλλον Analog Virtuoso της Cadence Software και συγκρινόμενος με ήδη υπάρχουσες διατάξεις, παρουσιάζει την μικρότερη κατανάλωση ισχύος. / This present Ph.D dissertation is focused its interest on the design of low voltage analog integrated circuits. Companding (compressing-expanding) systems are Externally Linear, Internally Non-linear (ELIN) processors with potential for low-voltage operation capability. In this direction novel topologies of companding filters in the Sinh-Domain are introduced. Τhe radical technological developments of microelectronics in the systems implementation with high reliability and performance, such as portable electronic devices for multimedia, communications and biomedical systems, demand the design of integrated circuits with reduced power consumption and thus low voltage supply. Integration of analog and digital circuits of systems-on-chip – (SoC) in order to be kept the low cost, directly affects the performance of the analog section, pointing forward the need for novel architectural design. One of the basic building blocks for circuit design is analog filters and their investigation in order to achieved large dynamic range, electronic tuning capability of their frequency characteristics which has gained a significant research effort toward these goals. At first, a new systematic method for designing Sinh-Domain filters is introduced. The proposed method offers the benefits of facilitating the design procedure of high-order Sinh-Domain filters using already introduced building blocks and of the absence of any restriction concerning the type and/or the order of the realized filter function. This is achieved by employing an appropriate set of complementary operators, in order to transpose the conventional functional block diagram representation of each linear operation to the corresponding one into the Sinh-Domain. In order to demonstrate the validity of the proposed systematic method, 3rd order leapfrog low-pass filter with a cut-off frequency at 10Hz which is typical for biomedical applications, has been realized following two alternative approaches and, also, a comparison has been performed among them and a conventional linear filter where the most important performance factors have been taken into account. Continuing, novel BiCMOS sinh-domain filter topologies, derived according to operational emulation, component substitution techniques and Linear Transformation of the corresponding 3rd-order passive prototype filters, with a cut-off frequency at 0.5 kHz and pass-band ripple 0.5dB, is proposed. This has been achieved by utilizing BiCMOS nonlinear ransconductor cells into the sinh domain. An attractive benefit of the proposed filter topologies is their capability for operating in high frequencies and a low-voltage environment. The performance of a leapfrog sinh-domain filter has been compared, using the Analog Design Environment of the Cadence software using AMS CMOS S35 0.35μm, with those of the corresponding log-domain and operational ransconductance amplifier (OTA)-C filters. Furthermore, the design of a family of Sinh-Domain universal biquad filters are introduced offering the benefits of low-voltage operation and, simultaneously, power efficient realizations in comparison with the corresponding already proposed biquads. Also, they have the capability for orthogonal adjustment between the resonance frequency and Q factor of the filter and these parameters could be also electronically adjusted through appropriate dc currents. Thus, they could be considered as attractive blocks for realizing high-performance analog signal processing systems. Finally, a Sinh-Domain topology for realizing the Non Linear Energy Operator (NEO) is introduced. For this purpose, a novel Sinh-Domain differentiator is proposed which offers the benefits of ultra low-voltage operation capability and electronic tuning of the realized time-constant. The whole system is also constructed from a four-quadrant current multiplier, realized by employing appropriately configured non-linear transconductors. Considering a single power supply voltage of 0.5V, the behavior of the proposed Sinh-Domain NEO realization has been simulated using the Analog Design Environment of the Cadence software using TSMC 130 nm design hit.

This thesis deal with design of multi-quadrant power supply in linear and switching mode. In the case of the switching mode energy recuparation is also considered as well as optimalization of change of load response over time. Power supplies are designed as general purpose laboratory and process power supplies. Power supplies are designed so that they can be connected via galvanic insulated USB interface with a PC