Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: High-voltage technique.
Дисертації з теми "High-voltage technique"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "High-voltage technique".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Veselova, N. V., Solomon Ojo, and O. E. Vasylieva. "The development of high-voltage technique in NTU "KhPI"." Thesis, Национальный технический университет "Харьковский политехнический институт", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40083.
Повний текст джерела
2
Musabeyoglu, Ahmet Can. "A zero-voltage switching technique for high frequency buck converter ICs." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113122.
Повний текст джерелаАнотація:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 59-60).
This thesis explores a zero-voltage switching (ZVS) method that can be used to decrease the frequency dependent losses in a buck converter. The specific application for this thesis was a buck converter IC with an input voltage of up to 42V. The method utilizes the addition of an auxiliary circuit composed of a helper inductor and two helper power MOSFETs that compliment the switching transition of a conventional synchronous buck converter topology. It is shown in this thesis that by using the described topology, the switching losses of the high-side power MOSFET in a synchronous buck converter can be reduced by up to 45%. Furthermore, it is shown that a similar helper circuit could be used to reduce the gate drive losses for both power MOSFETs in a synchronous buck converter by up to 60%. Since the method requires the use of an additional helper inductor with a small value (10-50 nH), various methods to integrate this inductor into an IC package are investigated. 0.35[mu]m BiCMOS technology was used to simulate and analyze the merits of the described topology and compare it to the LT8697, a hard-switched synchronous buck converter IC.
by Ahmet Can Musabeyoglu.
M. Eng.
3
Liu, Miao. "High-voltage-enabled operational amplifier and active-decoupling technique for wideband balun-LNA." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550551.
Повний текст джерела
4
Zhang, Zhengkao. "Digital technique for on-line measurement of dissipation factor of high voltage apparatus." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23571.pdf.
Повний текст джерела
5
Goh, Swee-Eng. "An exploding foil shockwave technique for magnetic flux compression and high-voltage pulse generation." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/14360.
Повний текст джерелаАнотація:
This thesis describes a novel electromagnetic shockwave technique for use in compressing magnetic flux and to serve as the basis for a new approach to producing fast-rising voltage pulses with amplitudes of several hundred kV. The shockwave is produced by an exploding foil driven electric gun that accelerates a Mylar flyer to impact with a sample of aluminium powder. Both Japanese and Russian researchers have previously published experimental results for shockwave magnetic flux compression using an explosive driver. The present research considers replacing the explosive energy of this driver by the electrostatic energy stored in a capacitor bank, thereby enabling experiments to be performed in a laboratory enviromnent. Differences in performance that arise from the use of explosive and electrical driver are examined. A conventional electric gun system in planar geometry is developed to study the insulator-to-metallic transition in shock-compressed aluminium powder. This provides data on the conducting shock front in powder that can be used for flux compression and high-voltage pulse generation. A prototype cylindrical geometry system is described for proof-of-principle experiments, in which an imploding shockwave compresses flux towards the central axis of a system. A highcvoltage pulse can then be produced by the rapid time-change in the flux linking a suitably situated coil. Design calculation, constructional details and experimental results for the new system are all presented. The experimental programme is augmented by a detailed study of the fundamental shockwave processes. A new mathematical model for an electric gun is developed, that provides detailed description of the foil explosion and flyer acceleration processes. A hydrodynamic code including an equation of _state model for the powder is developed, and is shown to reproduce with reasonable accuracy the shock compression of aluminium powder by flyer impact, including the elastic precursor phenomenon. A magnetohydrodynamic code with an electrical conductivity model for the shockcompressed powder is developed for the study of flux compression and high-voltage pulse generation techniques. This provides a critical insight into the shockwave processes and facilitates a systematic design and performance prediction for future experimentation.
6
Törnqvist, Joacim. "Non-contact High Voltage Measurements: Modeling and On-site Evaluation." Thesis, Umeå universitet, Institutionen för fysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-59934.
Повний текст джерелаАнотація:
In the high voltage grid, voltage measurements are made in dedicated voltage-transformers. These devices are expensive and insulation failures could impact directly on the system, and even cause a power outage. A non-contact measurement technique, on the other hand, does not require a connection to the conductors, and the sensors can therefore be much cheaper by avoiding the need for high voltage insulation. A capacitive coupling between three measurement electrodes, close to ground, and a high voltage three phase conductor system is used to model and measure the electric field and thereby determine the potentials of the conductors. A 2D-model is used for simulations, where the sensors are modeled as ideal, the conductors are modeled in an infinite wire approximation, and the ground plane is approximated as a perfect conductor. For non-ideal sensors a transfer function from the potentials on the measurement equipment to the potentials on the conductors is derived as a lumped-circuit model. The L2-norm errors for the amplitude and the phase in the reconstructed signals are calculated and measured for various sensor distances. Simulations show that the sensor distance should not be larger than the conductor distance to mitigate the erroneous effects from distance uncertainties. The optimal sensor distance depends on the quota between the height from the sensors to the conductors and the conductor distance. Measurements show, in accordance with the theory, that the sensor distance should not be larger than the conductor distance. To reduce the amplitude and phase shift errors the sensors should be placed close to the ground. For applied load resistances there is a tradeoff between amplitude- and phase shift errors. Additionally, higher load resistances attenuate higher frequencies. Measurements have verified that this technique is capable of detecting high harmonics and transients. The relatively low cost and the movability makes this method highly applicable for quick diagnostics on many locations in a grid, where the data can be evaluated on-site using computer based scripts.I kraftnät utförs idag högspänningsmätningar av spänningstransformatorer. Dessa är dyra, och isolationsproblem kan ha en direkt effekt på kraftnätet, och till och med skapa strömavbrott. En beröringsfri mätmetod, å andra sidan, kräver ingen direkt koppling mellan mätutrustningen och ledarna. Sensorerna kan därmed bli billigare eftersom de inte behöver högspänningsisoleras. En kapacitiv koppling mellan tre stycken mätelektroder, placerade nära jordplanet, och ett högspänt trefasledarsystem används för att modellera och mäta det elektriska fältet och därigenom bestämma ledarnas potentialer. En 2D-modell används för simuleringar, där sensorerna modelleras som ideala, ledarna modelleras enligt en raktrådsapproximation (oändligt långa raka ledare), och jordplanet approximeras vara en perfekt ledare med oändlig utsträckning. För icke-ideala sensorer härleds en överföringsfunktion från den uppmätta potentialen på mätutrustningen till ledarnas potentialer som en analog kretsmodell. L2-norm-felen för amplitudfel och fasfel för de rekonstruerade signalerna beräknas och mäts för olika sensoravstånd. Simuleringar visar att sensoravståndet inte bör vara större än ledaravståndet för att dämpa felinverkande effekter från osäkerheter i avståndsuppskattningar. Det optimala sensoravståndet beror på kvoten mellan höjden från sensorerna till ledarna och ledaravståndet. Mätningar visar, i enlighet med teorin, att sensoravståndet inte bör vara större än ledaravståndet. För att reducera amplitud- och fasfel bör sensorerna placeras nära jordplanet. För påkopplade lastresistanser gäller att det är en byteshandel mellan amplitud- och fasfel. För övrigt gäller att högre lastresistanser dämpar högre frekvenser. Mätningar verifierar att denna teknik är kapabel att detektera höga frekvenser och transienter. Den relativt låga kostnaden och metodens rörlighet gör att den kan appliceras för snabbdiagnostik på många punkter i ett kraftnät, där det insamlade datat kan utvärderas på plats med hjälp av datorbaserade skript.
7
Lisenkov, Aleksey. "Electrochemical synthesis of thin oxide films on titanium and aluminium surfaces using high voltage anodisation technique." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22469.
Повний текст джерелаАнотація:
Doutoramento em Ciência e Engenharia de MateriaisA síntese eletroquímica de filmes finos de óxido usando a técnica de oxidação de alta tensão e a investigação da estrutura, propriedades físicas e químicas dos filmes obtidos são os principais objetivos desta tese. A anodização de metais sob a ação de vários kilovolts produz filmes com espessura pequena (até 180 nm) e com propriedades diferentes dos filmes formados usando técnicas eletroquímicas convencionais. As camadas de óxido depositadas desta forma conferem, frequentemente, melhores propriedades de proteção, semicondutoras e fotoeletroquímicas. No âmbito deste trabalho filmes finos sobre titânio e alumínio foram preparados em diferentes eletrólitos, incluindo soluções de ácidos e sais, bem como em água desionizada e peróxido de hidrogénio. Mostra-se que os filmes preparados por oxidação com descarga pulsada de alta tensão têm estrutura superficial e propriedades elétricas mais uniformes em comparação com os obtidos por anodização convencional. Outro objetivo do trabalho é a dopagem dos filmes anódicos com diferentes dopantes, por incorporação de espécies do eletrólito durante a formação do filme. Os filmes preparados por oxidação de descarga pulsada de alta tensão no titânio mostram uma melhor resposta de fotocorrente a comprimentos de onda pequenos e uma concentração mais baixa de dadores ionizados, relativamente aos filmes obtidos por anodização convencional. Os filmes preparados por descarga no alumínio e titânio são formados por uma camada compacta. Estudos sobre o processo de descarga revelaram que o principal fator que influencia a cinética de crescimento do filme de óxido é a concentração de defeitos pontuais, que por sua vez é determinada pela composição do eletrólito. Também se mostrou que as técnicas usando alta tensão permitem preparar filmes anódicos não só em soluções convencionais, mas igualmente em outros meios, tal como água desionizada, água destilada e peroxido de hidrogénio, onde a anodização por métodos convencionais (potenciostático ou galvanostático) é impossível. Além disso é revelado que a técnica da descarga pulsada de alta tensão é um método eficiente para encapsulação de nanocilindros de metal, preliminarmente depositados em nanoporos de titânia e alumina alinhados verticalmente.
Electrochemical synthesis of thin oxide films by using the high-voltage oxidation technique and investigation of structure, physical and chemical properties of the obtained films are the main objectives of this thesis. Anodisation of metals under action of several kilovolts allow to produce films with rather low thickness (up to 180 nm) and with properties different from the films created by using conventional electrochemical approaches. The oxide layers deposited in this way often confer advanced protective, semiconductor and photoelectrochemical properties. In the frame of this thesis thin films on titanium and aluminium were prepared in several electrolytes, including solutions of acids and salts as well as in deionised water and hydrogen peroxide. It is shown that the films prepared by powerful pulsed discharge oxidation are characterized by more uniform surface structure and electrical properties in comparison to those obtained by conventional anodization. Another aim of the work is doping of the anodic films with different dopants by incorporation of species from the electrolyte during the film formation. Films prepared by powerful pulsed discharge oxidation technique on titanium demonstrate a significantly improved photocurrent response at short wavelengths and an essentially lower concentration of ionized donors as compared with the films obtained by conventional anodization. The discharge-prepared films on both aluminium and titanium are composed by one compact layer. Studies of the discharge processes revealed that the main factor influencing the kinetics of the oxide film growth is the concentration of point defects which, in turn, is determined by the composition of electrolyte. Also, it was shown that the high voltage techniques allow to prepare anodic films not only in conventional solutions, but also in other media such as deionised water, distilled water and hydrogen peroxide, where anodisation by conventional (potentiostatic or galvanostatic) methods is impossible. Furthermore, the powerful pulsed discharge technique is shown as efficient method for encapsulation of metal nanorods preliminarily deposited into the vertically aligned titania and alumina nanopores.
8
Rusek, Bartosz [Verfasser]. "Digital Modeling and Simulations of High Voltage Circuit Breaker Failures for Optimization of Sensor Technique / Bartosz Rusek." Aachen : Shaker, 2007. http://d-nb.info/1166512703/34.
Повний текст джерела
9
Howson, Peter Allen. "Bulk photoconductive high voltage switching techniques." Thesis, University of Brighton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357154.
Повний текст джерела
10
Lambert, Simon. "Voltage equalisation techniques for high capacitance device modules." Thesis, University of Newcastle Upon Tyne, 2013. http://hdl.handle.net/10443/1806.
Повний текст джерелаАнотація:
Traditionally, the electrochemical battery has been the prime medium by which electrical energy is stored for future use. Increasingly, the demands of modern systems such as electric vehicles, renewable energy, distributed generation, smart grid and others has stretched the development of new chemistries, materials and assembly techniques for electrochemical batteries. Additionally, some load profiles in these applications demand extremely high dynamic behaviour which is either undeliverable by conventional electrochemical batteries or is undesirably damaging to these technologies. As such, a family of electrochemical storage, known generally as supercapacitors or ultracapacitors, have been developed and implemented for such applications. In recent years advancements in electrochemical technology has led to hybridisation of high capacitance devices. Lithium-ion capacitors that are used in this work are, with their higher cell voltage and modern packaging, expected to be among the next emerging families of state-of-the-art electrical energy storage devices. The relatively low cell voltage of high capacitance cells requires them to be connected in series to attain a system level voltage. During charging and discharging, manufacturing tolerances between the cells results in voltage mismatch across the stack. Mismatched voltages are an inefficient use of the energy storage medium and can lead to dangerous failures in the cells. Several techniques exist to limit the variance in cell voltages of supercapacitors across a series connected stack. These range from simple systems which discharge the cells at higher voltages through resistors to more complex active converter systems which equalise the cell voltages through charge redistribution via a power electronic converter. Whilst the simpler schemes are effective they are very inefficient and as such are not suitable for use in many applications. A number of active converter voltage equalisation schemes have been proposed in literature, however, each of these equalisation schemes exhibit flaws which either makes them less desirable or less effective for a broad range of applications. Therefore, a new equalisation converter topology is proposed which is designed for greater equalisation effectiveness, modularity and size. The proposed equalisation converter differs from previously published equalisation schemes by allowing energy transfer between any pair of cells without the cumbersome multi-winding transformers employed in existing equalisation converters. The new equalisation scheme uses a bi-directional arrangement of MOSFET switches for galvanostatic isolation allowing the converter to be multiplexed to the stack. This arrangement allows the total size of the equalisation scheme to be reduced whilst maintaining performance.
11
Luo, Jing. "Novel insulation techniques for high voltage pulse transformers." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/13327.
Повний текст джерелаАнотація:
This thesis describes a research investigation into novel designs of high voltage pulse transformers using magnetic insulation, which is the only practicable form of insulation for much of the equipment presently used in ultrahigh voltage pulsed-power work, including transmission lines and plasma opening switches. Although its use in transformers would bring important advantages in both size and weight reductions, a number of seemingly insurmountable problems have however so far prevented this. Two novel arrangements are presented in this thesis: one of these is a 500 kV transformer with self-magnetic insulation, and the other one is a 1 MV 'Tesla' transformer with external magnetic insulation. It is shown that both of these overcome the problems inherent in earlier designs and also offer considerable scope for further development in a number of important areas. It is believed that they represent the first working examples of magnetically-insulated transformers anywhere in the world. Modelling considerations of the transformers developed include both theoretical models and predicted characteristics. The filamentary technique used to describe mathematically the arrangements being investigated involves decomposition of the main conducting components into filamentary elements. The resulting equivalent electrical network includes all the mutual interactions that exist between the different filamentary elements, takes magnetic diffusion fully into account and enables the resistances and self and mutual inductances that are effective under fast transient conditions to be calculated. Theoretical results provided by the resulting mathematical models have been successfully validated by comparison with reliable experimental data. Much of the work detailed in the thesis has already been presented in high quality academic journals and at prestigious international conferences, and a solid theoretical and experimental basis has been laid down for future development and new progress into pulsed power system research.
12
Веселова, Надія Вікторівна. "Становлення і розвиток харківських наукових шкіл у галузі техніки та електрофізика високих напруг (1930–2010 рр.)". Thesis, НТУ "ХПІ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/17177.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата історичних наук за спеціальністю 07.00.07 – історія науки і техніки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2015. У дисертації комплексно досліджується створення та розвиток харківських наукових шкіл у галузі техніки та електрофізики високих напруг у 1930–2010 рр. В роботі визначені харківські наукові школи в цій галузі, а саме: наукова школа високовольтних прискорювачів в УФТІ, яку очолив академік АН УРСР А. К. Вальтер; наукова школа техніки високих напруг ХПІ, засновником якої став академік АН УРСР В. М. Хрущов; наукова школа магнітно-імпульсної обробки металів ХПІ, що була заснована проф. І. В. Білим. Проведено цілісний науково-історичний аналіз процесу виникнення технічних рішень в електрофізиці і створення установок високої напруги в провідних харківських наукових центрах. Розкрито процес формування складу наукових установ і лабораторій, внесок окремих вчених у розвиток техніки і електрофізики високих напруг в м. Харкові. Показана важливість та унікальність створених високовольтних установок, визначено передумови їх створення та досліджено застосування цих пристроїв у вітчизняній науці та промисловості.The thesis for the competition of the academic degree of the candidate of the historical sciences, the speciality 07.00.07 – The history of science and technique. – National Technical University "Kharkiv Polytechnic Institute". – Kharkiv, 2015. The thesis is devoted to the complex research of the establishment and the development of Kharkiv scientific schools in the field of the technique and the electrophysics of the high-voltages in 1930's – 2010's. In this work the Kharkiv scientific schools in this field were identified for the first time. They are: the scientific school of the high-voltage accelerators in the UFTI headed by academician of USSR A.K. Walter; the scientific school of the technique of high-voltages in the KhPI, the founder of which was the acacademician of the Academy of Sciences of USSR V. M. Khrushchev; the scientific school of magnetic-pulse treatment of metals in KhPI which was founded by professor I. V. Belii. A holistic scientific-historical analysis of the process of technical solutions in electrophysics and the creation of high-voltage installations in leading scientific centers of Kharkiv is carried out in this work. The importance and uniqueness of the high-voltage installations is shown here. The importance and the uniqueness of the high-voltage structures, the conditions of their creation usage in home industry and science are shown here.
13
Веселова, Надія Вікторівна. "Становлення і розвиток харківських наукових шкіл у галузі техніки та електрофізика високих напруг (1930–2010 рр.)". Thesis, НТУ "ХПІ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/17176.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата історичних наук за спеціальністю 07.00.07 – історія науки і техніки. – Національний технічний університет "Харківський політехнічний інститут". – Харків, 2015.
У дисертації комплексно досліджується створення та розвиток харківських наукових шкіл у галузі техніки та електрофізики високих напруг у 1930–2010 рр. В роботі визначені харківські наукові школи в цій галузі, а саме: наукова школа високовольтних прискорювачів в УФТІ, яку очолив академік АН УРСР А. К. Вальтер; наукова школа техніки високих напруг ХПІ, засновником якої став академік АН УРСР В. М. Хрущов; наукова школа магнітно-імпульсної обробки металів ХПІ, що була заснована проф. І. В. Білим. Проведено цілісний науково-історичний аналіз процесу виникнення технічних рішень в електрофізиці і створення установок високої напруги в провідних харківських наукових центрах. Розкрито процес формування складу наукових установ і лабораторій, внесок окремих вчених у розвиток техніки і електрофізики високих напруг в м. Харкові. Показана важливість та унікальність створених високовольтних установок, визначено передумови їх створення та досліджено застосування цих пристроїв у вітчизняній науці та промисловості.The thesis for the competition of the academic degree of the candidate of the historical sciences, the speciality 07.00.07 – The history of science and technique. – National Technical University "Kharkiv Polytechnic Institute". – Kharkiv, 2015. The thesis is devoted to the complex research of the establishment and the development of Kharkiv scientific schools in the field of the technique and the electrophysics of the high-voltages in 1930's – 2010's. In this work the Kharkiv scientific schools in this field were identified for the first time. They are: the scientific school of the high-voltage accelerators in the UFTI headed by academician of USSR A.K. Walter; the scientific school of the technique of high-voltages in the KhPI, the founder of which was the acacademician of the Academy of Sciences of USSR V. M. Khrushchev; the scientific school of magnetic-pulse treatment of metals in KhPI which was founded by professor I. V. Belii. A holistic scientific-historical analysis of the process of technical solutions in electrophysics and the creation of high-voltage installations in leading scientific centers of Kharkiv is carried out in this work. The importance and uniqueness of the high-voltage installations is shown here. The importance and the uniqueness of the high-voltage structures, the conditions of their creation usage in home industry and science are shown here.
14
Islas, Michael. "EFFICIENCY IMPROVEMENT TECHNIQUES FOR HIGH VOLTAGE CAPACITOR CHARGING METHODS." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2969.
Повний текст джерелаАнотація:
The goal of this thesis is to design and fabricate a DC-to-DC converter for use in high-voltage capacitor charging applications. The primary objectives include increasing the efficiency and reducing the cost of traditional methods used for this application. Traditional methods were not designed specifically for high-voltage capacitor charging and were thus very primitive and exhibited lower efficiency. Prior methods made use of a high voltage power supply and a current limiting resistor or control scheme. The power supply would often only operate efficiently at a single voltage value and would thus function poorly over a range used in charging a capacitor. The resistor would also dissipate a fair amount of power, also limiting efficiency. This design makes use of a traditional flyback topology utilizing a controller developed specifically for this application, centering the design approach on the LT3750. Hence, taking full advantage of the efficiency improving control scheme it provides. Additionally, through the use of advanced techniques to eliminate noise and power losses, the efficiency may be significantly improved. A detailed theoretical analysis of the charger is also presented. The analysis will then be applied to optimization techniques to select ideal component values to meet specific design specifications. In this research, a specifically designed and developed prototype will be used to experimentally verify the theoretical work and optimization techniques.M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
15
Sun, Jian. "Optimal pulsewidth modulation techniques for high-power voltage source inverters /." Düsseldorf : VDI-Verl, 1995. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=006927196&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Повний текст джерела
16
Robinson, Adrian P. "Automated high voltage cable joint inspection using X-ray techniques." Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427419.
Повний текст джерела
17
Islas, Michael E. "Efficiency improvement techniques for high voltage capacitor carging [sic] methods." Orlando, Fla. : University of Central Florida, 2009. http://purl.fcla.edu/fcla/etd/CFE0002899.
Повний текст джерела
18
Casarin, Jérémy. "Caractérisation et mise en œuvre de composants SiC Haute Tension pour l'application transformateur moyenne fréquence en traction ferroviaire." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0123/document.
Повний текст джерелаАнотація:
L'objectif du projet CONCIGI-HT (CONvertisseur alternatif-continu Compact à Isolement Galvanique Intégré Haute Tension) est d'augmenter le rendement des chaînes de traction tout en réduisant la masse et le volume de la fonction de conversion Alternatif/Continu. Pour cela, l'ensemble transformateur basse fréquence - redresseur est remplacé par une structure multi-convertisseurs, directement connectée à la caténaire haute tension et intégrant des transformateurs fonctionnant en moyenne fréquence (plusieurs kHz). Cette thèse concerne plus particulièrement la caractérisation et la mise en œuvre de composants semi-conducteurs haute tension dans des structures de conversion statiques à étage intermédiaire moyenne fréquence. L'étude est effectuée sur la base d'une chaîne de traction de 2 MW fonctionnant sur un réseau 25 kV/50 Hz. Le premier chapitre présente l'état de l'art de l'Automotrice à Grande Vitesse (AGV) récemment produite par ALSTOM. C'est la chaîne de traction de cet engin qui sert de référence pour l'étude des nouvelles topologies à transformateur moyenne fréquence. Le deuxième chapitre décrit tout d'abord la structure d'une chaîne de traction classique et présente ensuite deux topologies multicellulaires à transformateur moyenne fréquence applicables en traction électrique ferroviaire (la structure indirecte à redresseur de courant MLI et convertisseur DC/DC à résonance ainsi que la topologie directe associant des convertisseurs duaux). Les avantages et inconvénients de ces topologies sont mis en évidence. Le troisième chapitre concerne la mise en œuvre et la caractérisation en commutation douce de composants Silicium 6,5 kV dans les deux topologies présentées précédemment. Deux bancs de test, représentant un étage élémentaire de conversion, ainsi que des allumeurs spécifiques dédiés à la commutation douce, ont été réalisés. Ils permettent l'étude des semi-conducteurs en régime permanent dans des conditions nominales de fonctionnement (3,6 kV / 100 A). Le quatrième chapitre présente la mise en œuvre et la caractérisation de composants en carbure de silicium (SiC). Pour cela des modules de puissance à base de puces 10 kV (MOSFET et Diodes) ont été réalisés. Les résultats expérimentaux, obtenus sur les bancs de test réalisés au chapitre précédent, mettent en évidence une réduction significative des pertes et démontrent la viabilité de la topologie à convertisseurs duaux pour une application en 25 kV/50 Hz. La conclusion présente un premier design d'un bloc élémentaire et les gains en masse et volume ainsi que les économies d'énergies qui pourront être obtenus par rapport à une structure classiqueThe objective of the CONCIGI-HT project (Compact AC/DC converter with Integrated High Voltage Galvanic Insulation) is to increase the efficiency of traction drives while reducing the mass and volume of the AC/DC conversion. To do that, the part low-frequency transformer - rectifier is replaced by a multi-converter topology, directly connected to the high voltage power supply and incorporating medium frequency transformers (several kHz). This thesis relates more particularly to the characterization and implementation of high voltage semiconductors in conversion topologies with intermediate medium frequency link. The study is performed on the basis of a traction drive of 2 MW operating on a 25 kV/50 Hz power supply. The first chapter presents the state of the art of the Automotrice à Grande Vitesse (AGV) recently produced by ALSTOM. The traction drive of this vehicle is used as a reference for the study of new topologies with medium frequency transformer. The second chapter first describes the structure of a conventional traction drive and then presents two multicellular topologies with medium frequency transformer applicable to railway traction (the indirect structure with PWM rectifier and DC/DC resonant converter and the direct topology combining dual converters). The advantages and disadvantages of these topologies are highlighted. The third chapter deals with the implementation and soft switching characterization of 6.5 kV Silicon components in both topologies presented above. Two test benches, representing a basic conversion stage, as well as specific drivers dedicated to the soft switching, has been made. They allow the study of semiconductors in nominal operating conditions (3.6 kV / 100 A). The fourth chapter presents the implementation and characterization of silicon carbide components (SiC). For this, power modules based on 10 kV chips (MOSFET and Diodes) have been achieved. The experimental results obtained on test benches made in the previous chapter, show a significant reduction in losses and demonstrate the viability of the dual converter topology for a 25 kV/50 Hz application. The conclusion presents the first design of an elementary block and gains in mass and volume as well as the energy savings that can be achieved compared to a conventional structure
19
Elayyan, H. S. B. "Protection of high voltage systems against surge voltages : New models and measurement techniques." Thesis, Cardiff University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378453.
Повний текст джерела
20
Wai, Kwok Leung Collin. "Artificial neural network techniques for detecting partial discharges in high voltage power cables." Thesis, University of Brighton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426970.
Повний текст джерела
21
Jamieson, John W. "Signal processing techniques for on-line partial discharge monitoring of high voltage electrical machines." Thesis, Robert Gordon University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260064.
Повний текст джерела
22
Maughan, Steven Ashley. "High efficiency wide-band line drivers in low voltage CMOS using Class-D techniques." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/19570.
Повний текст джерелаАнотація:
In this thesis, the applicability of Class-D amplifiers to integrated wide-band communication line driver applications is studied. While Class-D techniques can address some of the efficiency limitations of linear amplifier structures and have shown promising results in low frequency applications, the low frequency techniques and knowledge need further development in order to improve their practicality for wide band systems. New structures and techniques to extend the application of Class-D to wide-band communication systems, in particular the HomePlug AV wire- line communication standard, will be proposed. Additionally, the digital processing requirements of these wide-band systems drives rapid movement towards nanometer technology nodes and presents new challenges which will be addressed, and new opportunities which will be exploited, for wide-band integrated Class-D line drivers. There are three main contributions of this research. First, a model of Class-D efficiency degradation mechanisms is created, which allows the impact of high-level design choices such as supply voltage, process technology and operating frequency to be assessed. The outcome of this section is a strategy for pushing the high efficiency of Class-D to wide band communication applications, with switching frequencies up to many hundreds of Megahertz. A second part of this research considers the design of efficient, fast and high power Class-D output stages, as these are the major efficiency and bandwidth bottleneck in wide-band applications. A novel NMOS-only totem pole output stage with a fast, integrated drive structure will be proposed. In a third section, a complete wide-band Class-D line driver is designed in a 0.13μm digital CMOS process. The line driver is systematically designed using a rigorous development methodology and the aims are to maximise the achievable signal bandwidth while minimising power dissipation. Novel circuits and circuit structures are proposed as part of this section and the resulting fabricated Class-D line driver test chip shows an efficiency of 15% while driving a 30MHz wide signal with an MTPR of 22dB, at 33mW injected power.
23
Sovar, Robert D. "Novel Analytical Techniques For the Assessment of Degradation of Silicone Elastomers in High Voltage Applications." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16072/.
Повний текст джерелаАнотація:
Over the last 20 years "composite" insulators have been increasingly used in high voltage applications as an alternative traditional materials. More recently, polydimethylsiloxane (PDMS) have been used as weather sheds on these composite insulators. The main attraction with PDMS is that the surface hydrophobicity can be recovered following pollution or surface discharges. Among the possible mechanisms for recovery the most likely is the migration of low molecular weight silicone oil (LMWS) from the bulk to the surface encapsulating pollutant particles. Although it is widely recognised that the migration of LMWS is the cause of this recovery of hydrophobicity, the mechanism of what actually occurs is not well understood. It is also not known for how long this process will continue. The main objective of this study program was to gain improved understanding of the surface hydrophobic recovery process that is unique to polydimethlysiloxane high-voltage insulators. Fundamental knowledge of this mechanism has been increased through the development of the Contact Angle DRIFT Electrostatic Deposition (CADED) novel analytical technique. This technique enabled study of the degradation of silicone elastomers subjected to high voltage environments by closely following LMWS migration from the bulk material to the surface and linking it to the contact angle measurements. The migration rate data showed that the aged material recovered faster that the virgin material. Differences in the rate and maximum surface levels of silicone were seen between materials from different manufacturers. This has significant implications for the life-time of these materials A model system has been developed to examine LMWS diffusion through the bulk material and into the interface of surface and pollutant. This was achieved by examining theoretical and empirically derived equations and using existing experimental data to better understand the mechanism of recovery. This diffusion was Fickian in the initial stages of recovery. X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to substantiate the degree of degradation in in-field silicone insulators by quantifying the levels of the major degradation products: silica and silica-like material and alumina.
24
Kandala, Veera Raghavendra Sai Mallik. "ENERGY EFFICIENT CIRCUIT TECHNIQUES FOR SUCCESSIVE APPROXIMATION REGISTER ADC." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/dissertations/539.
Повний текст джерелаАнотація:
Charge-scaling (CS) successive approximation register (SAR) ADC's are widely used in the design of low power electronics. Significant portions of CS-SAR ADC power are consumed by CS capacitor arrays and comparator circuits. This Dissertation presents circuit techniques to reduce the power consumption of both CS capacitor array and the latch comparator during ADC operations. The impacts of the proposed techniques on ADC accuracies are analyzed and circuit techniques are presented to address the accuracy concerns. The dissertation also presents techniques to cope with capacitor mismatches, which becomes more significant with the use of very small unit capacitors in the CS array. These techniques rely on a novel programmable CS capacitor array that allow optimally grouping the unit capacitors. Based on a 0.13um CMOS technology the proposed techniques are verified with extensive circuit simulation. Post layout simulations are done to evaluate the proposed techniques for energy efficient CS capacitor array.
25
Shim, Ivy Ai Fei. "Signal processing techniques for partial discharge detection and mapping in high voltage underground cable networks." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366884.
Повний текст джерела
26
Mesgarpour, Tousi Maryam. "Electric Field Grading and Electrical Insulation Design for High Voltage, High Power Density Wide Bandgap Power Modules." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/100621.
Повний текст джерелаАнотація:
The trend towards more and all-electric apparatuses and more electrification will lead to higher electrical demand. Increases in electrical power demand can be provided by either higher currents or higher voltages. Due to "weight" and "voltage" drop, a raise in the current is not preferred; so, "higher voltages" are being considered. Another trend is to reduce the size and weight of apparatuses. Combined, these two trends result in the high voltage, high power density concept. It is expected that by 2030, 80% of all electric power will flow through "power electronics systems". In regards to the high voltage, high power density concept described above, "wide bandgap (WBG) power modules" made from materials such as "SiC and GaN (and, soon, Ga2O3 and diamond)", which can endure "higher voltages" and "currents" rather than "Si-based modules", are considered to be the most promising solution to reducing the size and weight of "power conversion systems". In addition to the trend towards higher "blocking voltage", volume reduction has been targeted for WBG devices. The blocking voltage is the breakdown voltage capability of the device, and volume reduction translates into power density increase. This leads to extremely high electric field stress, E, of extremely nonuniform type within the module, leading to a higher possibility of "partial discharge (PD)" and, in turn, insulation degradation and, eventually, breakdown of the module. Unless the discussed high E issue is satisfactorily addressed and solved, realizing next-generation high power density WBG power modules that can properly operate will not be possible. Contributions and innovations of this Ph.D. work are as follows. i) Novel electric field grading techniques including (a) various geometrical techniques, (b) applying "nonlinear field-dependent conductivity (FDC) materials" to high E regions, and (c) combination of (a) and (b), are developed; ii) A criterion for the electric stress intensity based upon accurate dimensions of a power device package and its "PD measurement" is presented; iii) Guidelines for the electrical insulation design of next-generation high voltage (up to 30 kV), high power density "WBG power modules" as both the "one-minute insulation" and PD tests according to the standard IEC 61287-1 are introduced; iv) Influence of temperature up to 250°C and frequency up to 1 MHz on E distribution and electric field grading methods mentioned in i) is studied; and v) A coupled thermal and electrical (electrothermal) model is developed to obtain thermal distribution within the module precisely. All models and simulations are developed and carried out in COMSOL Multiphysics.Doctor of Philosophy
In power engineering, power conversion term means converting electric energy from one form to another such as converting between AC and DC, changing the magnitude or frequency of AC or DC voltage or current, or some combination of these. The main components of a power electronic conversion system are power semiconductor devices acted as switches. A power module provides the physical containment and package for several power semiconductor devices. There is a trend towards the manufacturing of electrification apparatuses with higher power density, which means handling higher power per unit volume, leading to less weight and size of apparatuses for a given power. This is the case for power modules as well. Conventional "silicon (Si)-based semiconductor technology" cannot handle the power levels and switching frequencies required by "next-generation" utility applications. In this regard, "wide bandgap (WBG) semiconductor materials", such as "silicon carbide (SiC)"," gallium nitride (GaN)", and, soon, "gallium oxide" and "diamond" are capable of higher switching frequencies and higher voltages, while providing for lower switching losses, better thermal conductivities, and the ability to withstand higher operating temperatures. Regarding the high power density concept mentioned above, the challenge here, now and in the future, is to design compact WBG-based modules. To this end, the extremely nonuniform high electric field stress within the power module caused by the aforementioned trend and emerging WBG semiconductor switches should be graded and mitigated to prevent partial discharges that can eventually lead to breakdown of the module. In this Ph.D. work, new electric field grading methods including various geometrical techniques combined with applying nonlinear field-dependent conductivity (FDC) materials to high field regions are introduced and developed through simulation results obtained from the models developed in this thesis.
27
Руденко, Сергій Сергійович. "Вдосконалення методів контролю та діагностики заземлювальних пристроїв діючих високовольтних енергооб'єктів України". Thesis, НТУ "ХПІ", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/34461.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.13 – техніка сильних електричних та магнітних полів. Національний технічний університет "Харківський політехнічний інститут", Харків, 2018.
Дисертація присвячена вдосконаленню існуючих методів визначення нормованих параметрів на кожному з етапів електромагнітної діагностики, а також створення якісно нового підходу до видачі рекомендацій з реконструкції заземлювального пристрою для підвищення безпеки експлуатації діючих енергооб'єктів. На основі статистичного аналізу електрофізичних характеристик ґрунту створено вимоги до технічних характеристик приладів для вертикального електричного зондування при проведенні електромагнітної діагностики стану заземлювального пристрою. Розроблено та реалізовано у вигляді програмного комплексу математичну модель нееквіпотенційного заземлювального пристрою довільної конфігурації, розташованого у тришаровому ґрунті. Удосконалено математичну модель для інтерпретації результатів вертикального електричного зондування для багатошарових геоелектричних структур та методику еквівалентування з приведенням їх до вигляду розрахункових моделей. Перевірено адекватність розроблених математичних моделей експериментальним вимірам на понад 70 діючих високовольтних енергооб'єктах України класами напруги 35–150 кВ. Доведено, що реконструкція заземлювального пристрою за вимогами до напруги дотику є найбільш ефективною з точки зору електробезпеки та матеріальних витрат. Створено параметричну модель, яка дозволяє прогнозувати ймовірні матеріально-технічні витрати на реконструкцію.Thesis for granting Candidate of Technical sciences Degree in specialty 05.09.13 – Technics of Strong Electric and Magnetic Fields. – National Technical University "Kharkiv Polytechnic Institute", 2018. The thesis is devoted to the improvement of existing methods of determination of normalized parameters at each of the stages of electromagnetic diagnostics, as well as the creation of a qualitatively new approach to the issuance of recommendations for reconstruction a grounding grids to improve the safety of personnels on energy objects of Ukraine. The statistic of soil electrical properties to evaluate the optimal technical requirements for equipment for vertical electrical soil sounding when performing diagnostics of grounding systems is used. The model of the grounding device was based on the solution of the problem about the electrical field potential of the point current source, located in a three-layer soil. This model allows to determine the field potential at any point in case of the location of the grounding device in any of the layers of soil. Mathematical model and computer program for analyzing and interpreting results of the soil sounding by Wenner configuration was created on the base of the analytical solution for field of current point source located in four-, three- or two-layer structure. The method of equivalenting with bringing the multilayer soil to the form of the calculated models was improved. The adequacy of developed mathematical models for experimental measurements on more than 70 existing high-voltage power facility’s of Ukraine with voltage classes 35-150 kV has been checked. It was proved that the reconstruction of grounding system for requirements of touch voltage both in terms of electrical safety and in terms of material and labor costs is more effectiveness. The parametric model that allows predicting the probable material and technical costs for the reconstruction was created.
28
Руденко, Сергій Сергійович. "Вдосконалення методів контролю та діагностики заземлювальних пристроїв діючих високовольтних енергооб'єктів України". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/34463.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.13 – техніка сильних електричних та магнітних полів. Національний технічний університет "Харківський політехнічний інститут", Харків, 2018.
Дисертація присвячена вдосконаленню існуючих методів визначення нормованих параметрів на кожному з етапів електромагнітної діагностики, а також створення якісно нового підходу до видачі рекомендацій з реконструкції заземлювального пристрою для підвищення безпеки експлуатації діючих енергооб'єктів. На основі статистичного аналізу електрофізичних характеристик ґрунту створено вимоги до технічних характеристик приладів для вертикального електричного зондування при проведенні електромагнітної діагностики стану заземлювального пристрою. Розроблено та реалізовано у вигляді програмного комплексу математичну модель нееквіпотенційного заземлювального пристрою довільної конфігурації, розташованого у тришаровому ґрунті. Удосконалено математичну модель для інтерпретації результатів вертикального електричного зондування для багатошарових геоелектричних структур та методику еквівалентування з приведенням їх до вигляду розрахункових моделей. Перевірено адекватність розроблених математичних моделей експериментальним вимірам на понад 70 діючих високовольтних енергооб'єктах України класами напруги 35–150 кВ. Доведено, що реконструкція заземлювального пристрою за вимогами до напруги дотику є найбільш ефективною з точки зору електробезпеки та матеріальних витрат. Створено параметричну модель, яка дозволяє прогнозувати ймовірні матеріально-технічні витрати на реконструкцію.Thesis for granting Candidate of Technical sciences Degree in specialty 05.09.13 – Technics of Strong Electric and Magnetic Fields. – National Technical University "Kharkiv Polytechnic Institute", 2018. The thesis is devoted to the improvement of existing methods of determination of normalized parameters at each of the stages of electromagnetic diagnostics, as well as the creation of a qualitatively new approach to the issuance of recommendations for reconstruction a grounding grids to improve the safety of personnels on energy objects of Ukraine. The statistic of soil electrical properties to evaluate the optimal technical requirements for equipment for vertical electrical soil sounding when performing diagnostics of grounding systems is used. The model of the grounding device was based on the solution of the problem about the electrical field potential of the point current source, located in a three-layer soil. This model allows to determine the field potential at any point in case of the location of the grounding device in any of the layers of soil. Mathematical model and computer program for analyzing and interpreting results of the soil sounding by Wenner configuration was created on the base of the analytical solution for field of current point source located in four-, three- or two-layer structure. The method of equivalenting with bringing the multilayer soil to the form of the calculated models was improved. The adequacy of developed mathematical models for experimental measurements on more than 70 existing high-voltage power facility’s of Ukraine with voltage classes 35-150 kV has been checked. It was proved that the reconstruction of grounding system for requirements of touch voltage both in terms of electrical safety and in terms of material and labor costs is more effectiveness. The parametric model that allows predicting the probable material and technical costs for the reconstruction was created.
29
Diaz, Oscar. "Numerical modelling of positive electrical discharges in long air gaps." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-298355.
Повний текст джерелаАнотація:
This dissertation deals with research on the numerical modelling of electrical discharges in laboratory long air gaps excited with positive switching impulses. It begins with the preliminary work of several scientists during the last decades, making a detailed analysis of different approaches for modelling all the stages in a full discharge. The relations between these models are identified as well as the effect on the outcome when modifying some important input parameters. The general concept describing the discharge phenomenon usually includes three main elements: the streamer inception, the streamer-to-leader transition and the stable leader propagation. These elements are present in many of the analysed models and the main differences between them are the assumptions and simplifications made by each author at a specific point in their methodologies. The models are usually simplified by assigning experimentally determined values to physical constants pertinent to different stages of the full discharge. These constants are the potential gradient in the leader-corona region to sustain the leader propagation, the charge per unit length along the leader channel which depends on the atmospheric conditions and the voltage impulse wave shape; and the leader propagation velocity, which is closely related to the discharge current. The dissertation includes the results of laboratory work related the study of leaders in long gap discharges, electrical parameters and optical records. By reconstructing the three-dimensional leader propagation for the rod-to-plane configuration, it was possible to study the random tortuous path followed by the leader as it propagates. One important element included in the discharge modelling is the representation of the leader-corona region in front of the leader tip as it propagates towards the grounded electrode. For the calculation of the net charge available in the leader-corona region, two new methodologies were pro-posed based on the electrostatic potential distribution obtained from a finite element method solver. This allowed the inclusion of more elements representing different parts of the discharge in the simulation domain. In the final part, all the analysed elements and the new proposed ones were included in a new methodology for the modelling of electrical dis-charges in long air laboratory gaps. The results obtained from this methodology were compared to experimental data. A good agreement was found between the simulation results and the experimental data.
30
Li, Lisha. "High Gain Low Power Operational Amplifier Design and Compensation Techniques." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1701.pdf.
Повний текст джерела
31
Stem, Nair. "Células solares de silício de alto rendimento: otimizações teóricas e implementações experimentais utilizando processos de baixo custo." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-02042008-113959/.
Повний текст джерелаАнотація:
O trabalho realizado nesta tese esteve apoiado em dois objetivos principais. O primeiro centrado na otimização das etapas e processos de fabricação de células solares de silício de alto rendimento envolvendo redução de custos. O segundo objetivo foi direcionado na implementação de células solares eficientes e não dependentes do armadilhamento de impurezas através da difusão de alumínio. Para levar a cabo estes objetivos de forma planejada, o trabalho dividiu-se em otimizações teóricas e implementações experimentais. As otimizações teóricas foram realizadas utilizando dois programas: um programa desenvolvido (simulacell.pas) e implementado no próprio LME (versão 2), e o outro adquirido comercialmente, PC1D. De acordo com os resultados obtidos em estruturas completas n+p e n++n+p foi possível concluir que tanto as estruturas formadas através de emissores homogêneos como as obtidas utilizando emissores duplamente difundidos permitem alcançar eficiências elevadas, 25,5% a 26,0%, respectivamente, em um amplo intervalo de espessuras e concentrações superficiais de dopantes. No que tange aos desenvolvimentos experimentais, este trabalho se inicia com o desenvolvimento de um processo simplificado de baixo custo, em células solares de silício Cz de baixa resistividade com estrutura n+pp+, tipo \"mesa\". Este processo simplificado também está baseado na difusão de fósforo e alumínio (P/Al), utilizando gases industriais e reagentes químicos de grau \"para análise\", como uma transposição do processo de fabricação anteriormente desenvolvido no LME-EPUSP em substratos de silício FZ utilizando tecnologia planar. A célula solar mais representativa do processo implementado, A-16-1, permitiu atingir eficiências no entorno de 17%. As implementações experimentais visaram inicialmente o desenvolvimento de um procedimento visando à qualificação de materiais de partida (silício), utilizando a técnica de decaimento fotocondutivo (PCD) através de dois procedimentos de passivação de superfícies; oxidações térmicas e difusões suaves de fósforo. Posteriormente, utilizando o sistema PCD, novas otimizações dos emissores de tipo n+ homogêneos e regiões de tipo p foram realizadas, seguidos por oxidações térmicas passivadoras hidrogenadas, preservando-se o tempo de vida do volume em valores elevados (aproximadamente 1ms, após a realização de todas as etapas térmicas). Estes resultados qualificam o silício e os materiais de consumo utilizados, assim como, o novo processo de fabricação desenvolvido. Esta técnica também permitiu qualificar os emissores com perfil Gaussianos processados, atingindo valores da ordem de 45fA/cm2 para densidades de recombinação em estruturas n+pn+. Desenvolveram-se também estruturas n+p em materiais Cz de baixa resistividade 2-3W.cm de dois diferentes fabricantes, e silício FZ com 0,5W.cm. Pôde ser comprovada a qualidade das etapas que compõem o processo completo otimizado tendo-se obtido tensões de circuito aberto-implícitas de 652,4mV (Si-Cz fabricante 1) e 662,6mV (Si-Cz fabricante 2), e 670,8mV (FZ). De acordo com simulações realizadas utilizando parâmetros habituais de dispositivos do próprio LME, estas tensões, quando associadas a um conjunto óptico frontal típico das células solares de alto rendimento do LME (texturização química aleatória e filme de SiO2), permitirão atingir valores entre 19% - 20%. Entretanto, utilizando texturização e camada dupla torna-se plausível atingir o marco de 21% de rendimento, ultrapassando assim a barreira dos 17% (recorde nacional), e comprovando a potencialidade da infra-estrutura deste laboratório para o desenvolvimento de células solares não dependentes do efeito do armadilhamento de impurezas através da difusão de alumínio.The work developed at this thesis has been based on two main objectives. First, it was focused on the optimization of the steps and processes for the fabrication of high efficiency solar cells, reducing production costs. The latter objective was directed to develop solar cells that were efficient and non-dependent on impurities gettering performed through the aluminum diffusion. In order to attend the planned objectives the work was divided into the theoretical objectives and experimental developments. The theoretical optimizations were performed using two different program codes: one was developed at LME (simulacell.pas), being upgraded afterwards (version 2); and the other was acquired commercially, the PC1D. According to the obtained results in complete structures n+p and n++n+p, it was possible to conclude that the homogeneous and double diffused emitter structures can provide high efficiencies, from 25,5% to 26,0%, respectively, for a wide range of thicknesses and surface doping levels. Concerning the experimental developments, this work starts with a low cost simplified process, using Cz silicon solar cells with low base resistivity and the structure n+pp+, \"mesa\" type. This simplified process was also based on the phosphorus/ aluminum diffusion (P/Al), using industrial gases and for analysis grade chemical reagents, as a fabrication process transposition of the process previously developed at LME-EPUSP using silicon substrates with planar technology. The most representative solar cells of the implemented process, A-16-1, provided about a 17% efficiency. The experimental implementations aimed the development of procedure for starting material (silicon) qualification, by using the photoconductive decay technique (PCD) with two surface passivation procedures: thermal oxidation and light phosphorus diffusion. Later, using PCD system, new optimizations of n+ homogeneous emitters and p-type region were performed, followed by passivating thermal oxidations with hydrogenation, maintaining the volume lifetime at high values (approximately 1ms, after each thermal step). These results qualified the used silicon and the consumer materials, as well the new fabrication process developed. This technique has also allowed qualifying the processed Gaussian profile emitters, providing values about 45fA/cm2 for the recombination current density in n+pp+ structures. N+p structures were also developed using Cz silicon with low resistivity 2- 3W.cm of two different manufacturers and FZ with 0.5W.cm. It could be proved the quality of the steps of a complete optimized process resulting implicit open circuit voltages of 652.4mV (Cz silicon - manufacturer type 1), 662.6mV (Cz silicon - manufacturer type 2), and 670.8mV (FZ silicon). According to the theoretical simulations performed using the usual parameters of devices processed at LME (random chemical texturization and SiO2 film), efficiencies between 19%-20% can be reached. However, using a random texturization and a double layer anti-reflection system, a 21% efficiency becomes possible, surpassing the 17% barrier (national record), and proving the potentiality of this laboratory facility for the development of solar cells non-dependent on impurity gettering through the aluminum diffusion.
32
Tezenas, du Montcel Benoît. "Étude expérimentale et modélisation d’un plasma de vapeurs métalliques dans une ampoule à vide pour le développement de disjoncteurs Haute-Tension." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0110.
Повний текст джерелаАнотація:
Dans le cadre d’un projet étudiant la possibilité de remplacer le SF6 par du vide comme milieu de coupure dans les disjoncteurs Haute-Tension, un travail ayant pour objet d’acquérir une meilleure compréhension du comportement d’un arc de vapeurs métalliques à grandes distances inter-électrodes (> 10 mm) et contrôlé par un champ magnétique axial (AMF) a été entrepris. Ce travail a premièrement donné lieu à l’élaboration d’une expérience au cours de laquelle des arcs, créés entre deux contacts en CuCr25 fixes, ont été visualisés par vidéo rapide dans une maquette démontable d’ampoule à vide. Différents types de régime d’arc ont été observés. En outre, à l’aide d’une méthode numérique de détection des spots cathodiques, nous avons pu étudier l’évolution de la distribution spatiale des spots cathodiques, mesurer l’intensité moyenne du courant porté par un spot et déterminer le profil radial moyen de la densité de courant cathodique. Cette thèse a aussi eu pour objet le développement d’un modèle magnétohydrodynamique à 2 fluides, 2D-axysimétrique et quasi-stationnaire, de la zone d’écoulement hydrodynamique de l’arc, permettant de traiter le cas des régimes d’arc diffus supersonique et diffus subsonique. Ce modèle a permis d’étudier le comportement du plasma d’arc en fonction des intensités du courant d’arc et de l’AMF et de la distance inter-électrodesIn the frame of a project investigating the possibility to replace SF6 by vacuum as a breaking medium in High-Voltage circuit breakers, a study that focusses on acquiring a better understanding of the behavior of a metal vapor arc at long contact gap (> 10 mm) and controlled by an axial magnetic field (AMF) has been undertaken. The study involves first the building of an experimental setup where arcs, created between two fixed CuCr25 contacts, were visualized using a high-speed camera in a vacuum demountable chamber. Various types of arc regime have been observed. Moreover, by means of a numerical method of detection of the cathode spots, we were able to study the evolution of the spatial distribution of the cathode spots, to measure the average current carried by a spot and to determine the average radial profile of the current density at the cathode surface. This study had also for object the development of a 2D-axisymetric and quasi-steady magnetohydrodynamic model of the hydrodynamic flow region of the arc based on a two-fluid approach. The model allows to simulate the supersonic and the subsonic diffuse arc regimes. It is used to study the arc behavior as a function of to the arc current, the AMF intensity and the contact gap
33
Messali, Amir. "Contribution to Rotor Position and Speed Estimation for Synchronous Machine Drive Using High Frequency Voltage Injection : Application to EV/HEV Powertrains." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0048.
Повний текст джерелаАнотація:
Cette thèse s’inscrit dans le cadre de la chaire Renault/Centrale Nantes sur l’amélioration des performances des véhicules électriques (EV/HEV). Elle est dédiée à la problématique de l’estimation de la position/vitesse des moteurs synchrones à aimants permanents (MSAP) sans capteur mécanique, en utilisant les techniques d’injection de signaux haute fréquence (HF) sur toute la plage de vitesse des MSAP. Dans ce cadre, plusieurs contributions ont été proposées dans les parties de démodulation/traitement du signal et d’algorithmes de poursuite des techniques d’injection HF, afin d’améliorer l’estimation de la position/vitesse des MSAP par rapport aux méthodes existantes. Dans la partie démodulation/traitement du signal des techniques d’injection HF, les contributions ont consisté à proposer des solutions originales permettant de réduire les effets de filtrage dans la chaine d’estimation et de rendre cette dernière indépendante des paramètres (électriques) de la machine. Dans la partie poursuite, les contributions portent essentiellement sur l’exploitation de la fonction signe de l’erreur de position (à la place de l’erreur de position) comme information de mesure, pour estimer la position, la vitesse et l’accélération des MSAP sans capteurs mécaniques avec des observateurs par modes glissants d’ordre 1 (classiques, étapes par étapes et adaptatifs). Les contributions proposées dans les deux parties ont pour avantages d’une part, de robustifier la chaine d’estimation en la rendant indépendante des paramètres électriques et mécaniques. Et d’autre part, d’améliorer la précision et les performances de la chaine d’estimation, et par conséquent du contrôle des MSAP sans capteurs mécaniques, dans les phases transitoires et en régimes permanents avec une méthode de réglage aisée. Les méthodes d’estimation développées ont été testées en simulation et en expérimentation sur un banc d’essai de machines électriques. Les résultats obtenus ont permis de mettre en évidence les performances de ces méthodes en terme de suivi de trajectoire et de robustesse sur toute la plage de fonctionnement des MSAP sans capteurs mécaniquesThis thesis is part of the Renault / Centrale Nantes Chair on improving the performance of electric vehicles (EV / HEV). It is dedicated to the problem of estimating the position / speed of self-sensing permanent magnet synchronous motors (PMSM) without mechanical sensors, using high frequency (HF) signal injection techniques over the full speed range of PMSM. In this context, several contributions have been proposed in the demodulation / signal processing and tracking algorithms parts of HF injection techniques, in order to improve the estimation of the position / speed of the MSAP compared to the existing methods. In the demodulation / signal processing part of the HF injection techniques, the contributions consisted of proposing original solutions making it possible to reduce the filtering effects in the estimation chain and to make the latter independent of the electrical machine parameters. In the tracking part, the contributions mainly concern the use of the function sign of the position error (instead of the position error) as measurement information, to estimate the position, the speed and the acceleration of self-sensing PMSM with firstorder sliding mode observers (conventional, step-by-step and adaptive). The contributions proposed in both parts have the advantages of robustifying the estimation chain by making it independent of electrical and mechanical parameters on the one hand. On the other hand, they allow improving the accuracy and performance of the estimation chain, and therefore the control of self-sensing PMSM, in transient and steady-state phases with an easy tuning method. The estimation methods developed were tested in simulation and experimentation on a test bench of electrical machines. The results obtained made it possible to highlight the performances of these methods in terms of trajectory tracking and robustness over the entire operating range of PMSM self-sensing control
34
Novotná, Veronika. "Analýza elektrických a tepelných jevů při elektroporaci." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-409362.
Повний текст джерелаАнотація:
This dissertation thesis describes a phenomenon called electroporation. It is about its theoretical aspects as well as about modeling of processes in the tissue during electroporation. Further, it describes the technical design of two developed unique experimental generators of DC and AC pulses for electroporation purposes. It also includes a description of experiments which were done using discussed generators.
35
Ke, Heng-Hsi, and 柯恆熙. "Adjustable Forward Voltage Technique in LED Driver for High Efficiency." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/69985002095267363227.
Повний текст джерелаАнотація:
碩士國立交通大學
電機學院電子與光電學程
102
In recent year, light emitting diodes (LEDs) are widely used for display of various products, such as television, cellular phones, NB, tablet computer, etc. The advantages of LED backlight liquid are listed below. Firstly, it is more energy saving. LED backlight products save 40% energy, comparing with products with CCFL backlight in civilian industry. LED backlight technology, LED backlight display will be more energy saving in the future. Secondly, it is green and environment-friendly. Mercury in CCFL backlight is considerable damage to the environment, but LED backlight does not contain it. If LED backlight displays are popular in the future, it will be very helpful to improve the global environment. Thirdly, it has a wider color gamut. LED backlight module has a more pure white light and a wider color gamut, comparing with conventional CCFL backlight module. LED backlight display can display more vivid color and make a better color representation.Fourthly, it has a longer serving time. Theoretically, LED backlight has a long serving time and a longer brightness decreasing cycle, comparing with CCFL backlight. And it still can extend the serving time with the development of the technology. Fifthly, it is lighter and thinner. LED backlight products are much lighter and thinner than CCFL backlight products. The selling point of LED backlight displays in the market is ultra-thin which meets the fashion needs of consumers. This thesis proposes a LED driver with adjustable forward voltage technique in LED driver for High efficiency, and it was suitable for the LED backlight. This LED driver utilized a constant current regulator to support the LED string a stable current without color shift and a PWM dimming circuit to adjust the illuminate. Because the LED forward voltage variation occurred by time and manufacture, this driver utilized an adjustable forward voltage to overcome this problem. Then use a reference voltage tracking circuit with soft start to avoid the inrushing current issue. This LED driver circuit was simulated by TSMC 0.6um BCD 40 V process.
36
Zhang, Zhengkao. "Digital technique for on-line measurement of dissipation factor of high voltage apparatus." 1997. http://hdl.handle.net/1993/1015.
Повний текст джерелаАнотація:
To ensure the reliability of power supply it becomes necessary to periodically monitor the condition of power apparatus. Conventionally this may be achieved by carrying out tests such as the partial discharge and dissipation factor tests in a laboratory. This method, however, requires that the apparatus in question be disconnected from service and transported to the testing location. In the last few years on-line diagnostic tests have found favour not only because they are cost effective but also do not involve service interruption and furthermore offer the possibility of continuous monitoring. The reported methods measure the phase difference between voltage and current digitally by converting the signals to rectangular waveforms while preserving zero crossings. The method discussed in this paper uses a different technique. The Discrete Fourier Transform (DFT) is performed on the acquired analog signals; the phase difference is found from phase information of the fundamental quantities. This procedure effectively eliminates errors due to harmonics. It has an additional advantage in that the error introduced due to noisy data is smaller than that present in a method which relies on detection of zero crossings. The suggested method has been validated by comparison with the results obtained by a conventional bridge measurement. The effects of sampling rate and system frequency fluctuation on the measurement have also been studied.
37
Hau-ChengLee and 李浩正. "Novel High Step-Up DC-DC Converter Using Coupled Inductor and Voltage Doubler Technique." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/11551171824134232477.
Повний текст джерелаАнотація:
碩士國立成功大學
電機工程學系碩博士班
98
In this thesis, a novel high step-up DC-DC converter is presented. The coupled-inductor and voltage-doubler circuit are integrated in the proposed converter to achieve high step-up voltage gain without extremely high duty ratio. The energy stored in the leakage-inductor of the coupled-inductor can be recycled into the output and the voltage-stress on the power switches is half of the output voltage such that low voltage rating power devices are used in the proposed converter. Thus, the overall system efficiency can be improved. The operating principles and the steady-state analyses of continuous and discontinuos conduction modes are described in detail. Also, the boundary operating condition is discussed. Finally, a laboratory prototype circuit with 24 V input voltage and 200 V/250 W output is implementerd to verify the performance of the proposed converter.
38
Fan, Chung-Kai, and 范仲凱. "High Gain Low Voltage CMOS UWB LNA Employing Noise Cancellation and Current-Reused Technique." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/63619620906029327759.
Повний текст джерелаАнотація:
碩士國立雲林科技大學
電子工程系
104
This thesis presents the research and implement on low noise amplifier for wireless communication system. The chips were fabricated by TSMC commercial 0.18-μm 1P6M CMOS technology. The efficiency of the circuit was demonstrated by measurement at National Chip Implementation Center (CIC). This work presents two chips, the chips are for front-end in wireless communication system, low noise amplifier, the frequency range of the two chips are 3.1-10.6GHz. The first ultra-wideband low noise amplifier using common-source configuration (CS-Stage) and Two sets of series and parallel resonant LC to achieve broadband input matching, resistive feedback architecture and Cascode configuration to increase the gain of the circuit and gain flatness, the output of a resistive feedback is also used to form a dual feedback circuit architecture to improve the circuit stability. The second ultra-wideband low noise amplifiers design in high-gain applications, but also has low power consumption, using a common-source configuration (CS-Stage) and noise cancellation technology, the input can achieve impedance matching and low noise simultaneously, in the gain stage, using Current-Reused Technique and Cascode architecture, can achieve overall circuit of high gain and low power consumption, using the output of a resistive feedback, to extend the bandwidth effect.
39
Lu, Yu-Ju, and 盧郁如. "A Low Voltage High Speed Pipelined Analog-to-Digital Converter Using Hybrid OPAMP-Reset Switching-Technique and Switched-RC Technique." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/28041458929691782108.
Повний текст джерелаАнотація:
碩士國立成功大學
電機工程學系碩博士班
97
A low supply voltage, high resolution, and high speed pipelined analog-to-digital data convertor (ADC) is designed in this thesis. In order to solve the floating switch problem, hybrid OPAMP-reset switching-technique and switched-RC technique is used to implement the feedback capacitor reset and charge transfer functions for high resolution requirement. To meet low supply voltage requirement, a gain-boosting folded-cascode operational amplifier (OPAMP) and a switched-capacitor comparator are designed. For stability, a switchable common mode feedback (CMFB) circuit is designed to generate different output common mode voltages in each phase. This pipelined ADC with 1-V supply voltage has been design in 0.18-μm CMOS process without low threshold MOS devices. The SNDR is 50.3 dB with the input frequency of 2 MHz and sample frequency of 50 MHz. The total power consumption is 33 mW.
40
Shen, Meng-Jie, and 沈盟傑. "Implementation of a Novel Interleaved High Step-Up DC-DC Converter with Voltage Stacking Technique." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/87823762051005312093.
Повний текст джерела
41
Tien, Yu-Jen, and 田佑仁. "Implementation and Study of High Step-up Power Converter by Coupled Inductor and Voltage-lift Technique." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/86838492223837519471.
Повний текст джерелаАнотація:
碩士建國科技大學
電機工程系暨研究所
99
Abstract This thesis presents a high step-up ratio power converter with coupled inductors and voltage-lift technique. By adjusting the turns ratio of coupled inductors and utilizing voltage-lift technique and voltage double circuits, high voltage gain ratio is achieved. Furthermore, the energy of the leakage inductor of coupled inductors can be recycled during switching off period, effective voltage clamping on the power switch can be achieved, and therefore enhances the power conversion efficiency. The steady state operation of the proposed converter is first analyzed; and, the voltage gain of the converter is further deduced. Finally, the high step-up ratio power converter with the combination of coupled inductors and voltage-lift technique is completed and experimental results prove the characteristics of high voltage gain ratio, high efficiency conversion and low voltage stress of power switches. The maximum efficiency of the circuit presents 99.0% and the full load efficiency reaches 90.1% that it is considered suitable for the applications of converting low voltage into high voltage.
42
徐華志. "An Edge Termination Technique for High-Voltage Devices in 4H-SiC-Counter-Doped Junction Termination Extension." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/939v84.
Повний текст джерела
43
Yeh, Chih-Pu, and 葉之樸. "Primary-Side Regulator with Self-Calibration Knee Voltage Detection (KVD) Technique for High Efficiency and Low Cost." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/dtx9s8.
Повний текст джерелаАнотація:
碩士國立交通大學
電控工程研究所
101
Nowadays portable devices have been considered a necessity by a lot of people and have become an essential part of everyday life. With the rapid growth in the consumer electronics, rechargeable mobile battery bank has proved to be the most compatible and satisfactory solution for portable devices. Therefore, it will be an important task for us to create a fast and efficient battery charging method with safe delivery of energy to the battery. Since universal serial bus (USB) charging method is a common trend now, most of the portable devices are charged via alternating current (AC) supply combine with USB. Primary-side regulator (PSR) is a high efficiency and low cost solution for power applications. It is a high-input voltage isolated charger compatible with the AC supply. To stabilize and to smoothly transit between the constant voltage and the constant current modes, the constant voltage and constant current loops are connected in parallel in the proposed PSR charger. However, the prominent difference between the PSR and conventional regulators is that the PSR does not have direct feedback loop to obtain the output information. Hence, it is a major challenge to precisely detect knee voltage from the auxiliary winding and thus to accurately control the entire system. This thesis introduces the PSR with self-calibration knee voltage detection (KVD) technique, which it can perform self-calibration based on the detection period for error checking and correction. Moreover, the new detection method not only can precisely get the knee voltage without any external components, but also can have all control paths stabilized. The transition smoothly changes between the constant voltage and the constant current modes. Valley switching with a dynamic frequency switching is applied in the constant voltage mode in order to enhance its efficiency and performance.
44
CHOU, YING-WEI, and 周盈瑋. "A Dynamic Bootstrap Voltage Technique for High Efficiency Buck Converter in Universal Serial Bus Power Delivery Device." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/76pmef.
Повний текст джерелаАнотація:
碩士國立交通大學
電機工程學系
103
The dynamic bootstrap voltage (DBV) technique is proposed to keep high efficiency over a wide load range for high power universal serial bus (USB) devices. Silicon area of embedded power management (PM) with the DBV technique in system-on-a-chip (Soc) can be effectively reduced to 50% of conventional design with P-type high-side power MOSFET. Test chip fabricated in 0.25μm CMOSFET process shows 92% peak efficiency from 1mA to 1A. Maximum driving current is higher than 3A with 88 % efficiency. Compared to that without the DBV technique, the efficiency is improved about 28%.
45
Liu, Yu-Hsuan, and 劉宇軒. "A Novel High-Performance Current-Voltage Dual-Mode DC-DC Buck Converter with Adaptive Clock Control Technique." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/p86t4z.
Повний текст джерелаАнотація:
碩士國立交通大學
電機工程學系
105
This thesis presents a novel high-efficiency, fast-transient, and low-cost current-voltage dual-mode (CVDM) dc-dc buck converter using adaptive clock controller (ACC). The proposed CVDM control can switch the control method between current mode and voltage mode to improve the performance according to different situations. By using the ACC technique, the circuit can dynamically and smoothly adjust the switching frequency during the transient response to improve the undershoot, overshoot voltage, and recovery time. Moreover, the proposed on-chip soft-start circuit can eliminate the excess large current during the startup of the regulator. In this work, only an output inductor, capacitor, and feedback resistors are outside the system on chip (SoC), so the chip area and the cost can be reduced effectively. The circuit was implemented by TSMC 0.35-μm CMOS process. The input voltage is 2.7~4.2V and the output voltage is 0.9~2.7V accordingly, which is suitable for portable devices. The transient recovery time and undershoot voltage are less than 5μs and 94mV, respectively, for the load current change from 50mA to 500mA. As compared with the traditional structure without any fast transient technique, the performance of transient recovery time and undershoot voltage can be reduced by 83% and 36%, respectively. The maximum conversion efficiency is 95.784% at 100mA load current. Above 90% conversion efficiency can be achieved for load current from 30mA to 600mA. With the proposed techniques, the performance of the dc-dc converter is improved significantly.
46
Hsu, Yi-Chieh, and 許益捷. "Area-Saving and High Efficiency RGB-LED Driver with Adaptive Driving Voltage and Energy-Saving Control Technique." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/z62pru.
Повний текст джерелаАнотація:
博士國立臺灣大學
電子工程學研究所
107
The red-green-blue light-emitting diode (RGBLED) driver with adaptive driving voltage and energy-saving (ADVE) technique is presented in this paper. To obtain the proper driving voltage, an ADVE control circuit is proposed. This approach tracks the reference voltage of a boost converter to achieve the appropriate output voltage of the boost converter. Hence, the power loss of the linear current regulator is reduced to improve the efficiency of whole system. Moreover, the occupied area of the linear current regulator is saved about 10% by the proposed switching linear current regulator. This chip was fabricated using TSMC 0.35 µm 2P4M complementary metal-oxide-semiconductor (CMOS) technology. The active chip area is 0.3 mm2. The maximum driving current and operating frequency are 200 mA and 100 kHz, respectively. Compared with a conventional LED driver with fixed output voltage, the experimental results demonstrate that the power loss of the proposed LED driver with ADVE technique is reduced by over 58%.
47
Lin, Ching-Hua, and 林慶樺. "Design Techniques for Low Voltage and High Performance SoC." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/30217489350766800175.
Повний текст джерелаАнотація:
碩士國立中正大學
電機工程所
97
Recently, integrated circuit, there are several important design considerations, power consumption, energy consumption, performance, leakage current, energy-delay product ... and so on, especially into the nanometer process, leakage current is a major focus. The thrust of this paper is to set out a wide range of circuit design methods, and its purpose, and the paper will propose a design method to achieve multi-level circuit design applications. Content is divided into two parts, one for the analysis of how to design multi-level circuit technology, and the other for the operation in the subthreshold voltage standard cell library design. At present, foundry generally will provide multi-threshold voltage device for use. In this paper will study what the threshold voltage device adapted to what the application and its shortcomings. Some suitable for high-performance, but there are some problem in leakage current. Some suitable for low energy consumption, and low leakage current, but it can not achieve high-performance applications. This paper presents a strategy, the use of high-performance modules, and dynamic voltage scaling, Self Super Cut-Off Power-gating design techniques[1], and the proposed subthreshold voltage standard cell library design in this paper to achieve wide range applications.
48
Li, Jipeng. "Accuracy enhancement techniques in low-voltage high-speed pipelined ADC design." Thesis, 2003. http://hdl.handle.net/1957/28872.
Повний текст джерелаАнотація:
Pipelined analog to digital converters (ADCs) are very important building
blocks in many electronic systems such as high quality video systems, high
performance digital communication systems and high speed data acquisition systems.
The rapid development of these applications is driving the design of pipeline ADCs
towards higher speed, higher dynamic range, lower power consumption and lower
power supply voltage with the CMOS technology scaling. This trend poses great
challenges to conventional pipelined ADC designs which rely on high-gain
operational amplifiers (opamps) and well matched capacitors to achieve high accuracy. In this thesis, two novel accuracy improvement techniques to overcome the
accuracy limit set by analog building blocks (opamps and capacitors) in the context of
low-voltage and high-speed pipelined ADC design are presented. One is the time-shifted
correlated double sampling (CDS) technique which addresses the finite opamp
gain effect and the other is the radix-based background digital calibration technique
which can take care of both finite opamp gain and capacitor mismatch. These methods
are simple, easy to implement and power efficient. The effectiveness of the proposed
techniques is demonstrated in simulation as well as in experiment.
Two prototype ADCs have been designed and fabricated in 0.18μm CMOS
technology as the experimental verification of the proposed techniques. The first ADC
is a 1.8V 10-bit pipeline ADC which incorporated the time-shifted CDS technique to
boost the effective gain of the amplifiers. Much better gain-bandwidth tradeoff in
amplifier design is achieved with this gain boosting. Measurement results show total
power consumption of 67mW at 1.8V when operating at 100MSPS. The SNR, SNDR
and SFDR are 55dB, 54dB and 65dB respectively given a 1MHz input signal. The
second one is a 0.9V 12-bit two-stage cyclic ADC which employed a novel
correlation-based background calibration to enhance the linearity. The linearity limit
set by the capacitor mismatches, finite opamp gain effects is exceeded. After
calibration, the SFDR is improved by about 33dB and exceeds 80dB. The power
consumption is 12mW from 0.9V supply when operating at 2MSPS.Graduation date: 2004
49
Beig, Abdul Rahiman. "Application Of Three Level Voltage Source Inverters To Voltage Fed And Current Fed High Power Induction Motor Drives." Thesis, 2004. http://etd.iisc.ernet.in/handle/2005/1163.
Повний текст джерела
50
CHEN, YU-HUA, and 陳郁樺. "Design and Implementation of a Novel Interleaved High Step-Up DC-DC Converter with Voltage-Lifting and Voltage-Stacking Techniques." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s4ypcn.
Повний текст джерелаАнотація:
碩士崑山科技大學
電機工程研究所
106
A novel interleaved high step-up DC-DC converter is proposed in the thesis. The circuit configuration is based on an interleaved boost converter and introduces three-winding coupled inductors, lift capacitors, switched capacitors and diodes to consist voltage-lift cell and voltage-stack cell. The converter meets the requirements of high voltage gain and high power applications to become suitable for the power conversion of renewable energy power systems. The operating principle of the converter, guidelines of component design and selection, and design of driving circuit and closed-loop controller are presented in detail. The controller is designed to eliminate the effect of the variations of input voltage and output load on the output voltage such that the well output voltage regulation is achieved. The advantages of the proposed converter are as follows. The converter can achieve high voltage gain without extreme duty ratio operation. The voltage stresses on the power switches and diodes are greatly lower than the output voltage such that the low-voltage-rated MOSFETs with low on-resistances and low-voltage-rated schottky diodes with low forward voltage drop can be used to reduce the conduction losses. The switches achieve zero-current switching in the turn-on state to reduce switching losses. The parallel-input configuration can share the input current and is suitable for large input current applications. The input current ripple is reduced due to the interleaved PWM operation. The diode reverse-recovery problem can be alleviated by the leakage inductances of the coupled inductors. The leakage energy is recycled by the clamp circuit to improve efficiency and to suppress that the voltage spikes on the switches in the turn-off state. Finally, a 1000W prototype converter with 28 V input and 380 V output voltages is implemented and tested. The experimental result are provided to validate the effectiveness of the proposed converter. The maximum efficiency can be up to 98.07% at output power 100 W, and the efficiency at full load is 91.08%.