Дисертації з теми "Semiconductor invertor"
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Frenzel, Heiko. "ZnO-based metal-semiconductor field-effect transistors." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-61957.
Повний текст джерелаYatim, Abdul Halim bin Mohamed. "A microprocessor controlled three-phase insulated gate transistor PWM inverter drive." Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292639.
Повний текст джерелаBaird, John Malcolm Edward. "A micro processor based A.C. drive with a Mosfet inverter." Thesis, Cape Technikon, 1991. http://hdl.handle.net/20.500.11838/1119.
Повний текст джерелаA detailed study into the development of a three phase motor drive, inverter and microprocessor controller using a scalar control method. No mathematical modelling of the system was done as the drive was built around available technology. The inverter circuit is of a Vo~tage source inverter configuration whicp uses MOSFETs switching at a base frequency of between 1.2 KHz and 2 KHz. Provision has been made for speed control and dynamic braking for special applications, since the drive is not going to be put into a specific application as yet, it was felt that only a basic control should be implemented and space should be left for special requests from prospective customers. The pulses for the inverter are generated from the HEF 4752 I.e. under the control of the micro processor thus giving the processor full control over the inverter and allowing it to change almost any parameter at any time. Although the report might seem to cover a lot of unimportant ground it is imperative that the reader is supplied with the back-ground information in order to understand where A.e. drives failed in the past and where A.e. drives are heading in the future. As well as where this drive seeks to use available technology to the best advantage.
Zhu, Qing. "Semiconductor vertical quantum structures self-formed in inverted pyramids /." Lausanne : EPFL, 2008. http://library.epfl.ch/theses/?nr=4145.
Повний текст джерелаSánchez, López José Guadalupe. "Fabrication, characterization and modeling of high efficiency inverted polymer solar cells." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/664722.
Повний текст джерелаLos avances en tecnologías de energía renovable permiten obtener buenos rendimientos con un costo menor que los precios de los combustibles fósiles. La fotovoltaica es la tecnología de energía solar más desarrollada debido a que convierte directamente la energía de la luz solar en electricidad. Las células solares orgánicas basadas en polímeros: materiales de fullereno (PSC) se consideran una fuente de energía prometedora de bajo costo. Hoy en día, PSC deben exhibir alta eficiencia, larga vida útil, fabricación de bajo costo y cualidades amigables con el medio ambiente para su comercialización a gran escala. Aquí se describió la fabricación,modelado y caracterización de células solares orgánicas basadas en polímeros con arquitectura invertida (iPSCs). La tesis se centra en el estudio de mejoras simultáneas de la eficiencia y estabilidad a largo plazo de iPSCs basados en polímeros: fullerenos. Los polímeros PTB7 y PTB7-Th se usaron como materiales donantes de electrones, mientras que el PC70BM se usó como aceptor de electrones. Se usaron óxido de zinc (ZnO) y titanio (TiOx) como capas de transporte de electrones (ETL), además se usó PFN para propósitos de comparación. Todos los dispositivos iPSC se caracterizaron por métodos ópticos, eléctricos y fotofísicos con el fin de comprender mecanismos de pérdida involucrados en el proceso de degradación. Se usaron modelos de circuitos equivalentes para analizar las características de J-V en oscuridad y se usaron datos de impedancia espectroscópica para identificar el origen de los mecanismos de pérdida. En esta tesis se demostraron células solares orgánicas de alta eficiencia estables basadas en PTB7: PC70BM y PTB7-Th: PC70BM con arquitectura invertida. Además, TiOx utilizado como capa transportadora de electrones crucial para mejorar la eficiencia y la estabilidad de los iPSCs. Finalmente, también se demostró que las capas de ZnO depositadas mediante impresión por chorro de tinta se pueden aplicar con éxito para fabricación de iPSCs de alta eficiencia a escala de laboratorio.
The advances on the renewable energy technologies still allow obtaining good performances with lower cost than fossil fuel prices. Photovoltaics (solar cells) is the most developed solar energy technology due to converts directly the sunlight energy into electricity. The organic solar cells based on polymer:fullerne materials (PSCs) are considered as a promising low-cost energy source. Nowadays, the PSCs must exhibit high efficiency, long lifetime, low-cost fabrication, and environmentally friendly qualities for their large-scale commercialization. Herein the fabrication, modelling and characterization of polymer-based organic solar cells with inverted architecture (iPSCs) were described. The thesis focuses on the study of the simultaneous improvement of efficiency and long-term stability of iPSCs based on polymer:fullerenes. The polymers PTB7 and PTB7-Th were used as electron donor materials, whereas the fullerene PC70BM was used as the electron acceptor. Zinc oxide (ZnO) and titanium oxide (TiOx) were used as electron transport layers (ETL), moreover PFN was used for comparison purposes. All iPSC devices were characterized by optical, electrical and photophysical methods in order to understand the loss mechanisms involved in the degradation process. Equivalent circuit models were used to analyze the J-V characteristics in the dark and impedance spectroscopy data was used to identify the origin of the loss mechanisms. High efficient and stable organic solar cells based on PTB7:PC70BM and PTB7-Th:PC70BM with inverted architecture were demonstrated in this thesis. Moreover, TiOx used as an electron transport layer is crucial for improving the efficiency and the stability of iPSCs. Finally, it was also demonstrated that ZnO layers deposited by inkjet printing can be successfully applied to the fabrication of high efficiency iPSCs at laboratory scale.
Al-Ahdal, Abdulrahman Ghaleb I. "Floating gate ISFET chemical inverters for semiconductor based biomedical applications." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9996.
Повний текст джерелаMoghadam, Mansour Salehi. "Current-source-based low frequency inverter topology." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/12750.
Повний текст джерелаThomschke, Michael. "Inverted Organic Light Emitting Diodes." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-106255.
Повний текст джерелаVrazel, Michael Gerald. "Investigation of InGaAs/InP inverted MSM photodetectors for alignment tolerant photoreceiver applications." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/13849.
Повний текст джерелаQuezada, Novoa Andrés Alberto. "Diseño e implementación de inversor fotovoltaico de bajo costo." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/112523.
Повний текст джерелаEl presente trabajo aborda los conceptos básicos, sobre electrónica, semiconductores de potencia, controladores digitales de señales y software de simulación en electrónica de potencia, para lograr diseñar y construir un inversor MPPT fotovoltaico de 2kW de potencia nominal que sirva como base para desarrollos en esta área. Se presenta una introducción al tema, los objetivos de la memoria y una breve descripción del estado del arte, conocimientos necesarios para desarrollar un equipo de estas características. En función de estos antecedentes se presenta el diseño y simulación de la primera etapa de conversión, correspondiente al módulo Boost, utilizado para realizar un seguimiento de máxima potencia al sistema fotovoltaico. A continuación, se muestra la segunda etapa de conversión, de corriente continua a alterna, mediante un puente inversor completo. Se diseñan los sensores a utilizar, que son de voltaje DC, voltaje AC, corriente y temperatura. Se presenta el diseño de las etapas necesarias de control realimentado, que se programan en un microcontrolador. Esta etapa incluye la determinación de la tensión de máxima transferencia, se sincroniza el inversor con la red y se limita el trabajo del equipo dentro de rangos seguros de operación. Con el software PSim, se simula cada etapa de conversión de potencia, lo que permite realizar un diseño rápido y seguro. Se logra probar los ciclos de control diseñados para el sistema y ver el tipo de comportamiento ante perturbaciones. Se presenta en detalle la fase de construcción de cada uno de los módulos diseñados, reportando los planos, dispositivos y elementos de integración. Se realizan pruebas de potencia para el módulo Boost y el Inversor, ajustando los sensores. Por último se realizan pruebas de control realimentado como seguidor de tensión y seguidor de fase. Se finaliza con los resultados de las características relevantes del equipo, como lo son la eficiencia (80%) y costo de construcción estimado ($1466 US), para luego realizar un análisis de recuperación del capital en base a la energía generada. Como trabajo futuro se requiere de las pruebas de inyección de potencia a la red y de transferencia de máxima potencia conectando un panel fotovoltaico como fuente primaria de energía.
Tang, Zheng. "Studies of Inverted Organic Solar Cells Fabricated by Doctor Blading Technique." Thesis, Linköping University, Department of Physics, Chemistry and Biology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54141.
Повний текст джерелаOver the last few decades, bulk-heterojunction organic photovoltaic devices comprising an intimately mixed donor-acceptor blend have gained serious attention due to their potential for being cheap, light weight, flexible and environmentally friendly. In this thesis, APFO-3/PCBM bulk-heterojunction based organic photovoltaic devices with an inverted layer sequence were investigated systematically. Doctor blade coating is a technique that is roll-to-roll compatible and cost efficient and has been used to fabricate the solar cells.
Initial studies focused on optimization of the electrodes. A thin film of the conductive polymer PEDOT:PSS was chosen to be the transparent anode. Different PEDOT:PSS films with respect to the film thickness and deposition temperature were characterized in terms of conductivity and transmission. Decent conductance and transmittance were obtained in the films deposited with wet film thickness setting of 35 μm, The cathode was fabricated from a metal bilayer comprising Al and Ti with an area about 1 cm2, and the best-working cathodes contained a 70 nm thick Al layer covered by a thin Ti layer of about 10 -15 nm.
Optimized coating temperature and wet film thickness settings for the active layer and PEDOT:PSS layer were experimentally determined. The highest efficiency of the APFO-3/PCBM based inverted solar cells fabricated by doctor blading was 0.69%, which exceeded the efficiency of spin-coated inverted cells.
A higher efficiency (0.8 %) was achieved by adding a small amount of high molecular weight polystyrene to the active layer. Morphological changes after adding of the polystyrene were observed by optical microscopy and AFM. A coating temperature dependent phase separation of the APFO-3/PCBM/polystyrene blend was found.
Felgemacher, Christian [Verfasser]. "Investigation of Reliability Aspects of Power Semiconductors in Photovoltaic Central Inverters for Sunbelt Regions / Christian Felgemacher." Kassel : Kassel University Press, 2018. http://d-nb.info/116148308X/34.
Повний текст джерелаKim, Jungbae. "Organic-inorganic hybrid thin film transistors and electronic circuits." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34683.
Повний текст джерелаAkeyo, Oluwaseun M. "ANALYSIS AND SIMULATION OF PHOTOVOLTAIC SYSTEMS INCORPORATING BATTERY ENERGY STORAGE." UKnowledge, 2017. http://uknowledge.uky.edu/ece_etds/107.
Повний текст джерелаErroui, Najoua. "High power conversion chain for hybrid aircraft propulsion." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0106.
Повний текст джерелаRecently, the use of air transport systems has increased considerably. Therefore, the current environmental considerations are pushing to reduce their ecological impact. Projects such as Clean Sky 2 provide an answer to this problem, by proposing a reduction in CO2 emissions and noise pollution. The development of a hybrid-electric aircraft would reduce these emissions by reducing the size and weight of the systems and using more efficient electrical systems. This would reduce fuel consumption and therefore pollutant emissions. This work takes part into HASTECS Clean Sky 2 European project which aims to optimize the complete electrical chain of the hybrid aircraft integrating all aeronautical constraints such as partial discharges for electrical equipment placed in the non-pressurized zone. HASTECS project has set itself the challenge of doubling the specific power of electric machines including their cooling from 5 kW/kg to 10 kW/kg, while the power electronics, with their cooling system, would evolve from 15 kW/kg in 2025 to 25 kW/kg in 2035. To increase the specific power, the cooling system mass should be decreased either by optimizing its components which is done by the 4th work package (WP4) or by reducing power losses. Inverter losses reduction could be achieved by using small voltage rating components, by playing on modulation strategies or by using more performant semiconductors. The first option could be done by using multilevel architectures to avoid the direct series association. Unlike direct series association, the parallel one is easier to manage in terms of switches command so it was allowed in our studies. Several inverter topologies (2-, 3- and 5-level topologies) and modulation strategies (PWM, third harmonic injection, discontinuous PWM and full-wave) were compared using several semiconductors generations to choose the most performant solution in terms of efficiency and specific power. For the considered mission profile, the inverter could be sized for the maximum power point (takeoff) or the most extended flight phase (cruise). A comparative study of modulation strategies was carried out to highlight the structure and modulation presenting the best performance to minimize the losses for the chosen sizing points using most interesting topologies for the studied mission profile using two electrical motor windings configurations proposed by WP1
Senevirathna, Wasana. "Azadipyrromethene-based Metal Complexes as 3D Conjugated Electron Acceptors for Organic Solar Cells." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1402062085.
Повний текст джерелаSaini, Dalvir K. "Gallium Nitride: Analysis of Physical Properties and Performance in High-Frequency Power Electronic Circuits." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1438013888.
Повний текст джерелаHeinzig, André. "Entwicklung und Herstellung rekonfigurierbarer Nanodraht-Transistoren und Schaltungen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-202082.
Повний текст джерелаThe enormous increase in performance of integrated circuits has been driven for more than 50 years, mainly by reducing the device dimensions. This trend cannot continue in the long term due to physical limits being reached. The scope of this thesis is the development and fabrication of novel kinds of transistors and circuits that provide higher functionality compared to the classical devices, thus introducing an alternative approach to scaling. The fabrication of Schottky barrier field effect transistors (SBFETs) based on nominally undoped grown silicon nanowires using established and developed techniques is described. Further the charge carrier injection in the fabricated metal to semiconductor interfaces is analyzed under the influence of electrical fields. Structural modifications are used to optimize the charge injection resulting in increased ambipolar currents and negligible hysteresis of the SBFETs. Moreover, a device has been developed called the reconfigurable field-effect transistor (RFET), in which the electron and hole injection can be independently controlled by up to nine orders of magnitude. This device can be reversibly configured from unipolar electron conducting (ntype) to hole conducting (p-type) by the application of a program voltage to the two individual top gate electrodes at the Schottky junctions. So the RFET merges the functionality of classical FETs into one universal device. Measurements and 3D finite element method simulations are used to analyze the electrical transport and to describe the operation principle. Systematic investigations of changes in the device structure, dimensions and material composition show enhanced characteristics in scaled and low bandgap semiconductor RFET devices. For the realization of novel circuits, a concept is described to use the enhanced functionality of the transistors in order to realize energy efficient complementary circuits (CMOS). The required equal electron and hole current densities are achieved by the modification of charge carrier tunneling due to mechanical stress and are shown for the first time ever on a transistor. An electrically symmetric RFET based on a compressive strained nanowire in <110> crystal direction and 12 nm silicon core diameter exhibits unique electrical symmetry. The circuit concept is demonstrated by the integration of two RFETs on a single nanowire, thus realizing a dopant free CMOS inverter which can be programmed flexibly. The reconfigurable NAND/NOR shows that the RFET technology can lead to a reduction of the transistor count and can increase the system functionality. Additionally, further circuit examples and the challenges of an industrial implementation of the concept are discussed.The enhanced functionality and dopant free RFET technology describes a novel approach to maintain the technological progress in electronics after the expected end of classical device scaling
Krug, Dietmar. "Vergleichende Untersuchungen von Mehrpunkt-Schaltungstopologien mit zentralem Gleichspannungszwischenkreis für Mittelspannungsanwendungen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-216245.
Повний текст джерелаThe thesis deals with a detailed comparison of voltage source converter topologies with a central dc-link energy storage device for medium voltage applications. The Three-Level Neutral Point Clamped Voltage Source Converter (3L-NPC VSC) is compared with multilevel Flying Capacitor (FLC) and Stacked Multicell (SMC) Voltage Source Converters (VSC) for output voltages of 2.3 kV, 4.16 kV and 6.6 kV by using state-of-the-art 6.5 kV, 3.3 kV, 4.5 kV and 1.7kV IGBTs. The fundamental functionality of the investigated converter topologies as well as the design of the power semiconductors and of the energy storage devices (Flying Capacitors and Dc-Link capacitors) is described. The installed switch power, converter losses, the semiconductor loss distribution, modulation strategies and the harmonic spectra are compared in detail
Колотов, Микола Вікторович. "Керування перетворювачами системи орієнтації електронної платформи". Doctoral thesis, 2010. https://ela.kpi.ua/handle/123456789/728.
Повний текст джерелаLin, Yu-Hong, and 林宇宏. "Study of Organic Polymer/Inorganic Semiconductor Hybrid Solar Cells in Inverted Structure." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/05418736293856773860.
Повний текст джерела國立臺灣大學
電子工程學研究所
98
Organic photovoltaic devices are very attractive for their advantages of flexibility, light-weight, and large-area production at a dramatically low cost. In this study, the PV2000 material is used as a photoactive layer, which has a larger relative energy difference between the HOMO level of the electron-donating polymer and the LUMO level of the electron acceptor (energy difference ~1.7 eV) as compared to the standard P3HT:PCBM system, thereby leading to a larger VOC. The better contact in the interface is achieved by the post-annealing process, which corrects the defects between electrode and polymer layer interface. Moreover, the thermally induced morphology modification, crystallization and improved interfacial transportation, thereby leading to better charge collection and reduced series resistance. These results show that the process of post-annealing is very important for our PV2000 inverted device. We used solution process to replace deposition to spin NiO layer on active layer. NiO layer acts as an interfacial electron-blocking layer/hole-transporting layer (EBL/HTL). Utilizing its higher LUMO (lowest unoccupied molecular orbital) could block electron leakage to anode to recombine with hole. The leakage current is reduced to improve the power conversion efficiency of inverted structure devices. When the TiO2 nanorods are introduced, an improvement of light harvest and photocurrent is achieved due to several factors. First, the photoactive layer is thickened and the light path is increased to have more light absorption. Second, the morphology is modified to provide the photoactive layer and inorganic layer a larger contact area for efficient charge collection. Third, the TiO2 nanorods enhance the photoluminescence quenching, indicating improved electron-hole dissociation. In this way, the high PCE of 5.61% from inverted PSCs is achieved. In the second part of this work, our investigation apply the low band gap material (ITRI P47:PC70BM) as the photoactive layer. The light harvest is improved by adjusting the thickness of photoactive layer. In addition, we introduce the solution-process NiO layer between photoactive layer and silver as an electron blocking layer, therefore, the electron is forced to move toward the ITO electrodes, increasing the selectivity of the charge carriers and the shunt resistance of the photovoltaic cell.
Sundholm, Eric Steven. "Amorphous oxide semiconductor thin-film transistor ring oscillators and material assessment." Thesis, 2010. http://hdl.handle.net/1957/16365.
Повний текст джерелаGraduation date: 2010
Murphy, Leanne. "Influence of High Mobility Polymer Semiconductors in Organic Photovoltaics." Thesis, 2013. http://hdl.handle.net/10012/7442.
Повний текст джерелаChu, Ta-Ya, and 朱達雅. "Study of Electronic Structure of Organic Semiconductor Materials and Inverted Bottom-Emission Organic Light-Emitting Devices." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/47000442750120461079.
Повний текст джерела國立交通大學
電子物理系所
95
This research is divided into two parts: [1]Electronic structure of organic semiconductor materials – Study of electronic structure of organic semiconductor materials is based on the density functional theory calculations, which includes organic molecular structure, electronic structure of molecular orbital and energy levels and energy gap. The calculated of IR spectra, singlet and triplet gaps and stokes shift of selected materials are found to be in good agreement with the experimental data. This study contributed to the understanding the characteristics of organic semiconductor and the designing of new materials. [2]Inverted bottom-emission OLED (IBOLED) development - Inverted OLED is best suited for the large n-channel TFT active matrix OLED display technology. We have developed one of the most efficient (22 cd/A) green fluorescent IBOLED which is more efficient than that of the conventional OLED. The efficiency levels of the white OLED achieved 13.0 cd/A and 10.6 lm/W. The projected half-lifetime under an initial luminance of 400 cd/m2 is projected to be over 34,000 hours and the Commission International de l’Eclairage (CIE) coordinates are not affected by aging. The development of IBOLED is useful in fabricating AMOLED with high power efficiency and long device stability and is also expected to impact on the future development of low power solid-state lighting.
Thomschke, Michael. "Inverted Organic Light Emitting Diodes: Optical and Electrical Device Improvement." Doctoral thesis, 2012. https://tud.qucosa.de/id/qucosa%3A26661.
Повний текст джерелаYuan-MingChen and 陳元閔. "Liquid Phase Oxidized InAlAs as Gate Insulator for InAlAs/InGaAs Inverted-type Metal-Oxide-Semiconductor High-Electron-Mobility Transistors Applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/26617651676214625893.
Повний текст джерела國立成功大學
光電科學與工程學系
100
Native InAlAs oxide prepared by liquid phase oxidation (LPO) method as the gate insulator in the fabrication of InAlAs/InGaAs inverted-type metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) ispresented. The liquid phase oxidation system is simple, low-cost, and near temperature (30-70℃) without using extra energy to form a native oxide layer. In this work, we invested an InAlAs/InGaAs HEMT with a thin InAs layer inserted into the InGaAs channel layer to get improved DC and transconductance performance. To further improve HEMT performance, the InAlAs native oxide is used as the gate insulator for MOS-HEMT applications. In the DC measurements, the maximum drain current density is found to be 609 mA/mm at the gate-to-source voltage of 2.5 V, representing an improvement of about 32%. Meanwhile, the extrinsic transconductance is 327 mS/mm, representing an improvement of about 35%. The maximum turn-on voltage is 3.98 V, and the breakdown voltage is -4.62 V. The cut-off frequencies of conventional HEMTs and MOS-HEMTs are 5.7 GHz and 5.62 GHz; the maximum oscillation frequencies are 4.2 GHz and 3.9 GHz, respectively.And the noise figure is improved in MOS-HEMT owing to the reduced surface states.
Heineck, Daniel Philip. "Zinc tin oxide thin-film transistor circuits." Thesis, 2008. http://hdl.handle.net/1957/9975.
Повний текст джерелаGraduation date: 2009
(9581096), Olatunji T. Fulani. "A Heterogeneous Multirate Simulation Approach for Wide-bandgap-based Electric Drive Systems." Thesis, 2021.
Знайти повний текст джерелаRecent developments in semiconductor device technology have seen the advent of wide-bandgap (WBG) based devices that enable operation at high switching frequencies. These devices, such as silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs), are becoming a favored choice in inverters for electric drive systems because of their lower switching losses and higher allowable operating temperature. However, the fast switching of such devices implies increased voltage edge rates (high dv/dt) that give rise to various undesirable effects including large common-mode currents, electromagnetic interference, transient overvoltages, insulation failure due to the overvoltages, and bearing failures due to
microarcs. With increased use of these devices in transportation and industrial applications, it is imperative that accurate models and efficient simulation tools, which can predict these high-frequency effects and accompanying system losses, be established. This research initially focuses on establishing an accurate wideband model of a surface-mount permanent-magnet
ac machine supplied by a WBG-based inverter. A new multirate simulation framework for predicting the transient behavior and estimating the power losses is then set forth. In this approach,
the wideband model is separated into high- and low-frequency models implemented using two different computer programs that are best suited for the respective time scales. Repetitive execution of the high-frequency model yields look-up tables for the switching losses in the semiconductors, electric machine, and interconnecting cable. These look-up tables are then incorporated into the low-frequency model that establishes the conduction
losses. This method is applied to a WBG-based electric drive comprised of a SiC inverter and permanent-magnet ac machine. Comparisons of measured and simulated transients are provided.
Sajadian, Sally. "Energy conversion unit with optimized waveform generation." Thesis, 2014. http://hdl.handle.net/1805/6109.
Повний текст джерелаThe substantial increase demand for electrical energy requires high efficient apparatus dealing with energy conversion. Several technologies have been suggested to implement power supplies with higher efficiency, such as multilevel and interleaved converters. This thesis proposes an energy conversion unit with an optimized number of output voltage levels per number of switches nL=nS. The proposed five-level four-switch per phase converter has nL=nS=5/4 which is by far the best relationship among the converters presented in technical literature. A comprehensive literature review on existing five-level converter topologies is done to compare the proposed topology with conventional multilevel converters. The most important characteristics of the proposed configuration are: (i) reduced number of semiconductor devices, while keeping a high number of levels at the output converter side, (ii) only one DC source without any need to balance capacitor voltages, (iii) high efficiency, (iv) there is no dead-time requirement for the converters operation, (v) leg isolation procedure with lower stress for the DC-link capacitor. Single-phase and three-phase version of the proposed converter is presented in this thesis. Details regarding the operation of the configuration and modulation strategy are presented, as well as the comparison between the proposed converter and the conventional ones. Simulated results are presented to validate the theoretical expectations. In addition a fault tolerant converter based on proposed topology for micro-grid systems is presented. A hybrid pulse-width-modulation for the pre-fault operation and transition from the pre-fault to post-fault operation will be discussed. Selected steady-state and transient results are demonstrated to validate the theoretical modeling.
Heinzig, André. "Entwicklung und Herstellung rekonfigurierbarer Nanodraht-Transistoren und Schaltungen." Doctoral thesis, 2014. https://tud.qucosa.de/id/qucosa%3A29458.
Повний текст джерелаThe enormous increase in performance of integrated circuits has been driven for more than 50 years, mainly by reducing the device dimensions. This trend cannot continue in the long term due to physical limits being reached. The scope of this thesis is the development and fabrication of novel kinds of transistors and circuits that provide higher functionality compared to the classical devices, thus introducing an alternative approach to scaling. The fabrication of Schottky barrier field effect transistors (SBFETs) based on nominally undoped grown silicon nanowires using established and developed techniques is described. Further the charge carrier injection in the fabricated metal to semiconductor interfaces is analyzed under the influence of electrical fields. Structural modifications are used to optimize the charge injection resulting in increased ambipolar currents and negligible hysteresis of the SBFETs. Moreover, a device has been developed called the reconfigurable field-effect transistor (RFET), in which the electron and hole injection can be independently controlled by up to nine orders of magnitude. This device can be reversibly configured from unipolar electron conducting (ntype) to hole conducting (p-type) by the application of a program voltage to the two individual top gate electrodes at the Schottky junctions. So the RFET merges the functionality of classical FETs into one universal device. Measurements and 3D finite element method simulations are used to analyze the electrical transport and to describe the operation principle. Systematic investigations of changes in the device structure, dimensions and material composition show enhanced characteristics in scaled and low bandgap semiconductor RFET devices. For the realization of novel circuits, a concept is described to use the enhanced functionality of the transistors in order to realize energy efficient complementary circuits (CMOS). The required equal electron and hole current densities are achieved by the modification of charge carrier tunneling due to mechanical stress and are shown for the first time ever on a transistor. An electrically symmetric RFET based on a compressive strained nanowire in <110> crystal direction and 12 nm silicon core diameter exhibits unique electrical symmetry. The circuit concept is demonstrated by the integration of two RFETs on a single nanowire, thus realizing a dopant free CMOS inverter which can be programmed flexibly. The reconfigurable NAND/NOR shows that the RFET technology can lead to a reduction of the transistor count and can increase the system functionality. Additionally, further circuit examples and the challenges of an industrial implementation of the concept are discussed.The enhanced functionality and dopant free RFET technology describes a novel approach to maintain the technological progress in electronics after the expected end of classical device scaling.:Kurzzusammenfassung Abstract 1 Einleitung 2 Nanodrähte als aktivesGebiet fürFeldeffekttransistoren 2.1 Elektrisches Potential und Ladungsträgertransport in Transistoren 2.1.1 Potentialverlauf 2.1.2 Ladungsträgerfluss und Steuerung 2.2 Der Metall-Halbleiter-Kontakt 2.2.1 Ladungsträgertransport über den Schottky-Kontakt 2.2.2 Thermionische Emission 2.2.3 Ladungsträgertunneln 2.2.4 Methoden zur Beschreibung der Gesamtinjektion 2.3 Der Schottkybarrieren-Feldeffekttransistor 2.4 Stand der Technik 2.4.1 Elektronische Bauelemente auf Basis von Nanoröhren und Nanodrähten 2.4.2 Rekonfigurierbare Transistoren und Schaltungen 2.5 Zusammenfassung 3 TechnologienzurHerstellung vonNanodraht-Transistoren 3.1 Herstellung von SB-Nanodraht-Transistoren mit Rückseitengatelektrode 3.1.1 Nanodraht-Strukturbildung durch VLS-Wachstum 3.1.2 Drahttransfer 3.1.3 Herstellung von Kontaktelektroden 3.1.4 Herstellung von Schottky-Kontakten innerhalb eines Nanodrahtes 3.2 Strukturerzeugung mittels Elektronenstrahllithographie 3.2.1 Schichtstrukturierung mittels Elektronenstrahllithographie 3.2.2 Strukturierung mittels ungerichteter Elektronenstrahllithographie 3.2.3 Justierte Strukturierung mittels Elektronenstrahllithographie 3.2.4 Justierte Strukturierung mittels feinangepasster Elektronenstrahllithographie 3.2.5 Justierte Strukturierung mittels kombinierter optischer und Elektronenstrahllithographie 3.3 Zusammenfassung 4 Realisierung und Optimierung siliziumbasierter Schottkybarrieren- Nanodraht-Transistoren 4.1 Nanodraht-Transistor mit einlegierten Silizidkontakten 4.1.1 Transistoren auf Basis von Nanodrähten in <112>-Richtung 4.1.2 Transistoren mit veränderten Abmessungen 4.2 Analyse und Optimierung der Gatepotentialverteilung im Drahtquerschnitt in Kontaktnähe 4.3 Si/SiO2 - Core/Shell Nanodrähte als Basis für elektrisch optimierte Transistoren 4.3.1 Si-Oxidation im Volumenmaterial 4.3.2 Si-Oxidation am Draht 4.3.3 Silizidierung innerhalb der Oxidhülle 4.3.4 Core/Shell-Nanodraht-Transistoren mit Rückseitengate 4.4 Analyse der Gatepotentialwirkung in Abhängigkeit des Abstands zur Barriere 4.5 Zusammenfassung 5 RFET - Der Rekonfigurierbare Feldeffekttransistor 5.1 Realisierung des RFET 5.2 Elektrische Charakteristik 5.2.1 Elektrische Beschaltung und Funktionsprinzip 5.2.2 Elektrische Messungen 5.2.3 Auswertung 5.3 Transporteigenschaften des rekonfigurierbaren Transistors 5.3.1 Tunnel- und thermionische Ströme im RFET 5.3.2 Analyse der Transportvorgänge mit Hilfe der numerischen Simulation 5.3.3 Schaltzustände des RFET 5.3.4 On-zu-Off Verhältnisse des RFET 5.3.5 Einfluss der Bandlücke auf das On- zu Off-Verhältnis 5.3.6 Abhängigkeiten von geometrischen, materialspezifischen und physikalischen Parametern 5.3.7 Skalierung des RFET 5.3.8 Längenskalierung des aktiven Gebietes 5.4 Vergleich verschiedener Konzepte zur Rekonfigurierbarkeit 5.5 Zusammenfassung 6 Schaltungen aus rekonfigurierbaren Bauelementen 6.1 Komplementäre Schaltkreise 6.1.1 Inverter 6.1.2 Universelle Gatter 6.1.3 Anforderungen an komplementäre Bauelemente 6.1.4 Individuelle Symmetrieanpassung statischer Transistoren 6.2 Rekonfigurierbare Transistoren als Bauelemente für komplementäre Elektronik 6.2.1 Analyse des RFET als komplementäres Bauelement 6.2.2 Bauelementbedingungen für eine rekonfigurierbare komplementäre Elektronik 6.3 Erzeugung eines RFETs für rekonfigurierbare komplementäre Schaltkreise 6.3.1 Möglichkeiten der Symmetrieanpassung 6.3.2 Erzeugung eines RFET mit elektrischer Symmetrie 6.3.3 Erzeugung und Aufbau des symmetrischen RFET 6.3.4 Elektrische Eigenschaften des symmetrischen RFET 6.4 Realisierung von komplementären rekonfigurierbaren Schaltungen 6.4.1 Integration identischer RFETs 6.4.2 RFET-basierter komplementärer Inverter 6.4.3 Rekonfigurierbarer CMOS-Inverter 6.4.4 PMOS/NMOS-Inverter 6.4.5 Zusammenfassung zur RFET-Inverterschaltung 6.4.6 Rekonfigurierbarer NAND/NOR-Schaltkreis 6.5 Zusammenfassung und Diskussion 7 Zusammenfassung und Ausblick 7.1 Zusammenfassung 7.2 Ausblick Anhang Symbol- und Abkürzungsverzeichnis Literaturverzeichnis Publikations- und Vortragsliste Danksagung Eidesstattliche Erklärung
Krug, Dietmar. "Vergleichende Untersuchungen von Mehrpunkt-Schaltungstopologien mit zentralem Gleichspannungszwischenkreis für Mittelspannungsanwendungen." Doctoral thesis, 2015. https://tud.qucosa.de/id/qucosa%3A30069.
Повний текст джерелаThe thesis deals with a detailed comparison of voltage source converter topologies with a central dc-link energy storage device for medium voltage applications. The Three-Level Neutral Point Clamped Voltage Source Converter (3L-NPC VSC) is compared with multilevel Flying Capacitor (FLC) and Stacked Multicell (SMC) Voltage Source Converters (VSC) for output voltages of 2.3 kV, 4.16 kV and 6.6 kV by using state-of-the-art 6.5 kV, 3.3 kV, 4.5 kV and 1.7kV IGBTs. The fundamental functionality of the investigated converter topologies as well as the design of the power semiconductors and of the energy storage devices (Flying Capacitors and Dc-Link capacitors) is described. The installed switch power, converter losses, the semiconductor loss distribution, modulation strategies and the harmonic spectra are compared in detail.:Inhaltsverzeichnis Liste der Variablen i Liste der Abkürzungen v 1 Einleitung 1 2 Überblick von Mittelspannungsstromrichtertopologien und Leistungshalbleitern 3 2.1 Mittelspannungsumrichtertopologien 3 2.2 Leistungshalbleiter 8 3 Aufbau und Funktion von Mittelspannungsstromrichtertopologien 10 3.1 Neutral Point Clamped Stromrichter (NPC) 10 3.1.1 3-Level Neutral Point Clamped Stromrichter (3L-NPC) 10 3.1.2 Mehrstufige NPC-Umrichter 21 3.2 Flying Capacitor Stromrichter (FLC) 23 3.2.1 3-Level Flying Capacitor Stromrichter (3L-FLC) 23 3.2.2 4-Level Flying Capacitor-Stromrichter (4L-FLC) 33 3.2.3 Mehrstufige Flying Capacitor-Stromrichter (NL-FLC) 39 3.3 Stacked Multicell Stromrichter (SMC) 43 3.3.1 5L-Stacked Multicell Stromrichter (5L-SMC) 43 3.3.2 N-Level Stacked Multicell Umrichter (NL-SMC) 51 4 Modellierung und Auslegung der Stromrichter 59 4.1 Verlustmodell 59 4.1.1 Sperrschichttemperaturen 64 4.2 Auslegung der Leistungshalbleiter 65 4.2.1 Stromauslegung 67 4.2.2 Worst-Case Arbeitspunkte 69 4.3 Auslegung der Zwischenkreiskondensatoren 75 4.3.1 Spannungszwischenkreis 76 4.3.2 Lastseitige Strombelastung und resultierende Spannungswelligkeit im Spannungszwischenkreis 77 4.3.3 Abhängigkeit der Strombelastung und der Spannungswelligkeit im Spannungszwischenkreis vom Frequenzverhältnis mf 95 4.3.4 Netzseitige Zwischenkreiseinspeisung 97 4.3.4.1 Zwischenkreiseinspeisung mit idealisiertem Transformatormodell 98 4.3.4.2 Zwischenkreiseinspeisung mit erweitertem Transformatormodell 101 4.3.5 Simulation des Gesamtsystems 104 4.4 Auslegung der Flying Capacitors 107 4.4.1 Strombelastung der Flying Capacitors 109 4.4.2 Spannungswelligkeit über den Flying Capacitors 113 4.4.3 Abhängigkeit der Spannungswelligkeit der Flying Capacitors vom Frequenzverhältnis mf 124 4.4.4 Auswirkung der Spannungswelligkeit der Flying Capacitors auf die Ausgangsspannungen 126 5 Vergleich der Stromrichtertopologien 129 5.1 Daten für den Stromrichtervergleich 129 5.2 Basis des Vergleiches 132 5.3 Vergleich für einen 2,3 kV Mittelspannungsstromrichter 134 5.3.1 Vergleich bei verschiedenen Schaltfrequenzen 134 5.3.2 Vergleich bei maximaler Trägerfrequenz 142 5.4 Vergleich für einen 4,16 kV Mittelspannungsstromrichter 146 5.4.1 Vergleich bei verschiedenen Schaltfrequenzen 146 5.4.2 Vergleich bei maximaler Trägerfrequenz 153 5.5 Vergleich für einen 6,6 kV Mittelspannungsstromrichter 156 5.5.1 Vergleich bei verschiedenen Schaltfrequenzen 156 5.5.2 Vergleich bei maximaler Trägerfrequenz 162 5.6 Vergleich von 2,3 kV, 4,16 kV und 6,6 kV Mittelspannungsstromrichtern 165 5.6.1 Vergleich bei identischer installierter Schalterleistung SS 165 5.6.2 Vergleich bei einer identischen Ausgangsleistung 167 6 Zusammenfassung und Bewertung 171 Anhang 175 A. Halbleiterverlustmodell 175 Referenzen 177