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Dissertations / Theses on the topic 'Electric circuit analysis'
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1
Manthe, Alicia Louise. "Symbolic circuit analysis : DDD optimization and nonlinearity analysis /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/6082.
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Ma, Hong. "Representation of multivariable-controlled MOSFET nonlinearities in transient analysis programs." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30001.
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This thesis deals with the modelling and circuit simulation problems of nonlinear electronic devices. Emphasis has been aimed at MOSFET devices.
A Piecewise Linear (PWL) modelling scheme has been proposed for a general four-terminal nonlinear charge device. The charge functions are all nonlinear and are approximated by PWL functions. If analytical expressions for the nonlinear functions are not available, PWL function approximations can be built from a data table in which discrete data points are recorded.
In the time domain, the critical-damping-adjustment (CDA ) scheme is used as the integration rule in the discretization of dynamic charge devices.
Piecewise linear modelling combined with the CDA integration scheme gives a fast yet adequately accurate simulation algorithm. The algorithm is based on linear analysis because the entire circuit becomes linear with PWL modelling of nonlinear elements. In order to avoid an iterative solution, PWL region extrapolation is permitted when the circuit solution switches PWL regions. The extrapolation approximation will generate an overshoot error in the solution vector. However, with caution in the selection of the integration step size, the error can be limited to an acceptable range.
Two types of MOSFETs have been modelled and simulated with the algorithm introduced in this thesis, and satisfactory results have been obtained as compared to Newton's iteration solutions.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
3
Cakir, Sinan. "Tolerance Based Reliability Of An Analog Electric Circuit." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612929/index.pdf.
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This thesis deals with the reliability analysis of a fuel pump driver circuit (FPDC), which regulates the amount of fuel pumped to a turbojet engine. Reliability analysis in such critical circuits has great importance since unexpected failures may cause serious financial loss and even human death.
In this study, two types of reliability analysis are used: &ldquoWorst Case Circuit Tolerance Analysis&rdquo
(WCCTA) and &ldquo
Failure Modes and Effects Analysis&rdquo
(FMEA). WCCTA involves the analysis of the circuit operation under varying parameters in their tolerance bands. These parameters include the resistances of the resistors, operating temperature and voltage input value. The operation of FPDC is checked and the most critical parameters are determined in the worst case conditions. While performing WCCTA, a method that guarantees the exact worst case conditions is used rather than probabilistic methods like Monte Carlo analysis. The results showed that the parameter variations do not affect the circuit operation unfavorably
operating temperature, voltage input variation and tolerance bands for the resistances are fairly compatible with the circuit operation. FMEA is implemented according to the short circuit and open circuit failures of all the electronic components used in FPDC. The components whose failure has catastrophic effect on the circuit operation have been determined and some preventive actions have been offered for some catastrophic failures.
4
Cooke, Bradly James. "S-parameter VLSI transmission line analysis." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184876.
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This dissertation investigates the implementation of S-parameter based network techniques for the analysis of multiconductor, high speed VLSI integrated circuit and packaging interconnects. The S-parameters can be derived from three categories of input parameters: (1) lossy quasi-static R,L,C and G, (2) lossy frequency dependent (dispersive) R,L,C,G and (3) the propagation constants, Γ, the characteristic impedance, Z(c) and the conductor eigencurrents, I, derived from full wave analysis. The S-parameter network techniques developed allow for: the analysis of periodic waveform excitation, the incorporation of externally measured or calculated scattering parameter data and large system analysis through macro decomposition. The inclusion of non-linear terminations has also been developed.
5
Centeno, Virgilio A. "Mimic circuit simulation in real time." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43745.
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Yoon, Heebyung. "Fault detection and identification techniques for embedded analog circuits." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13041.
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Groves, James O. "Small signal analysis of nonlinear systems with periodic operating trajectories." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-162614/.
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Choi, Pyung. "An equivalent circuit structure macromodel for analog phase locked loops." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/14875.
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9
Jan, Ying-Wei. "A switched-capacitor analysis metal-oxide-silicon circuit simulator." Ohio : Ohio University, 1999. http://www.ohiolink.edu/etd/view.cgi?ohiou1181163717.
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Zhou, Chen. "Design and analysis of an active power factor correction circuit." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53729.
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The design of an active-unity power factor correction circuit with variable-hysteresis
control for off-line dc-to-dc switching power supplies is described. Design
equations relating the boost inductor current ripple to the circuit components selection
and circuit performance arc discussed. A computer-aided design program (CADO) is
developed to give the optimal circuit components selection. A 500 watt, 300 volt experimental
circuit is built to verify the simulation and analysis results.
The control-to-output response of the power factor circuit is verified with the experimental
results. Design guidelines for the low-frequency feedback network are presented.
Small-signal closed-loop responses are measured with an experimental power
factor circuit.Master of Science
11
Buchanan, Brent E. "A mixed-signal CMOS VLSI image convolution circuit using error spectrum shaping." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/15420.
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Fitzpatrick, Justin Jennings. "Analysis and Design of Low-Jitter Oscillators." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd369.pdf.
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Barclay, Daniel Scott. "An automatic test generation method for chip-level circuit descriptions." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/91158.
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An automatic method generates tests for circuits described in a hardware description language (HDL). The input description is in a non-procedural subset of VHDL, with a simplified period-oriented timing model. The fault model, based on previous research, includes micro-operation and control statement faults. The test method uses path-tracing, working directly from the circuit description, not a derived graph or table. Artificial intelligence problem-solving techniques of goals and goal solving are used to represent and manipulate sensitization, justification, and propagation requirements. Backtracking is used to recover from incorrect choices. The method is implemented in ProLog, an artificial intelligence language. Results of this experimental ProLog implementation are summarized and analyzed for strengths and weaknesses of the test method. Suggestions are included to counter the weaknesses. A user's manual is included for the experimental implementation.M.S.
14
Castagno, Scott. "A cascade boost converter design, demonstration, and scaling for future high voltage power conditioning systems." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4564.
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Thesis (M.S.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 17, 2009) Includes bibliographical references.
15
Danielsson, Christer. "Analysis of Synchronous machine dynamics using a novel equivalent circuit model." Licentiate thesis, Stockholm : Skolan för elektro- och systemteknik, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10510.
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Trinkle, Joachim. "Analysis of power ground planes." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0005.
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[Truncated introduction] A major contribution of this thesis is the observation that the N port impedance parameters for the distribution planes can be modelled as simple LC series elements in the frequency range over which the interesting interactions between the loading elements and the planes occur. Loosely speaking, the C represents the inter-plane capacitance and the L is associated with a first order frequency trend of the transfer and input impedances associated with the planes. In the literature, values for L have been obtained for power ground plane structures using curve fitting techniques [38]. In this thesis, formulae are developed for L based on the modal summation expression. As for the impedance case, the approach developed in the thesis that removes the singular behaviour, results in computational efficient expressions. Preliminary results on the simple LC model were presented by the author in [42, 43] The results reported in the thesis extend this work in the light of the new impedance model proposed. The simple LC characterisation enables the development of new low frequency expression for the input and transfer impedance for ports on planes loaded with many decoupling capacitors. The expressions are based on a one off frequency independent decomposition of the inductance matrix associated with the placement of the capacitors. The eigen-mode decomposition eliminates the need for matrix inversion at each frequency point and leads to an efficient computational procedure for calculating the impedance of loaded planes. Furthermore, the interaction between the capacitors and planes is clearly seen in the analytical expressions. This has led to new insights regarding the interaction of multiple capacitors with supply planes in terms of location, resonance mechanisms, pole locations and damping. These insights are beneficial to the understanding and optimisation of printed circuit board power distribution systems.
17
Goad, Kenneth G. "Integration of an X-Y prober with CAD driven database and test generation software for the testing of printed circuit boards." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45664.
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Guided probe testing of printed circuit boards is a technique that has been well developed by automatic test equipment manufacturers to pinpoint faults. Though the guided probe technique of testing printed circuit boards is a process capable of providing high diagnostic resolution, the technique is inefficient when it is performed manually. The throughput of board testing is bottlenecked because of the time required for an operator to manually move a probe to a specific location on the board under test in order to measure a stimulated response. Integration of a CAD driven X-Y prober is a way to automate guided probe testing of printed circuit boards.
This research integrates a personal computer based automated guided probe testing system. A CAD tool provides geometric and circuit connectivity information. Automatic test generation, CAD information post processing, and automatic guided probe testing software tools are developed to implement the system. The ultimate result is increased circuit board test station throughput. This makes the circuit board manufacturing process more efficient and less expensive while maintaining high quality products through more extensive testing.
Master of Science
18
Shamsi, Mohammad Haris. "Analysis of an electric Equivalent Circuit Model of a Li-Ion battery to develop algorithms for battery states estimation." Thesis, Uppsala universitet, Elektricitetslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-298427.
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Batteries have imparted momentum to the process of transition towards a green future. However, mass application of batteries is obstructed due to their explosive nature, a trait specific to Li-Ion batteries. To cater to an efficient battery utilization, an introduction of a battery management system would provide an ultimate solution. This thesis deals with different aspects crucial in designing a battery management system for high energy as well as high power applications. To build a battery management system capable of predicting battery behavior, it is necessary to analyze the dynamic processes happening inside the battery. Hence, a battery equivalent circuit model is proposed in this thesis as well as proper analysis is done in MATLAB to project a generic structure applicable to all Li-Ion chemistries. The model accounts for all dynamic characteristics of a battery including non-linear open circuit voltage, discharge current and capacity. Effect of temperature is also modeled using a cooling system. The model is validated with test current profiles. Less than 0.1% error between measured and simulated voltage profiles indicates the effectiveness of the proposed model to predict the runtime behavior of the battery. Furthermore, the model is implemented with the energy as well as the power battery pack. State of charge calculations are performed using the proposed model and the coulomb counting method and the results indicate only a 4% variance. Therefore, the proposed model can be applied to develop a real-time battery management system for accurate battery states estimation.
19
Papageorgiou, Vassilios A. "Static two-dimensional calculation of the capacitance and impedance of open microstrip-like structures using variational methods." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08182009-040513/.
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Hasan, Iftekhar Hasan. "Modeling and Analysis of High Torque Density Transverse Flux Machines for Direct-Drive Applications." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1515582377354583.
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Seth, Sachin. "Understanding distortion in silicon-germanium transistors, and its application to RF circuits." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31729.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.Committee Chair: Cressler, John D.; Committee Member: Laskar, Joy; Committee Member: Shen, Shyh-Chiang. Part of the SMARTech Electronic Thesis and Dissertation Collection.
22
Liu, Dong. "Analog and mixed-signal test and fault diagnosis." Ohio : Ohio University, 2003. http://www.ohiolink.edu/etd/view.cgi?ohiou1177701780.
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Yen, Wen-Tsung. "Comparison of SPICE and Network C simulation models using the CAM system." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/4243.
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The performance of SPICE and Network C (NC) circuit simulator when simulating MOS transistor circuits has been investigated and compared. SPICE analog model, NC analog model and NC MOS_PWL model are the three MOS transistor models being used. The comparison between SPICE and NC includes five areas. They are MOS transistor model, circuit analysis and computational methods, limitation on the ability to simulate circuits containing the MOS transistor diode configuration, run time and the ability to build new circuit component models using derived equations.
24
Strohm, Christian. "Circuit Simulation Including Full-Wave Maxwell's Equations." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22544.
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Diese Arbeit widmet sich der Simulation von elektrischen/elektronischen Schaltungen welche um elektromagnetische Bauelemente erweitert werden. Im Fokus stehen unterschiedliche Kopplungen der Schaltungsgleichungen, modelliert mit der modifizierten Knotenanalyse, und den elektromagnetischen Bauelementen mit deren verfeinerten Modell basierend auf den vollen Maxwell-Gleichungen in der Lorenz-geeichten A-V Formulierung welche durch Finite-Integrations-Technik räumlich diskretisiert werden. Eine numerische Analyse erweitert die topologischen Kriterien für den Index der resultierenden differential-algebraischen Gleichungen, wie sie bereits in anderen Arbeiten mit ähnlichen Feld/Schaltkreis-Kopplungen hergeleitet wurden. Für die Simulation werden sowohl ein monolithischer Ansatz als auch Waveform-Relaxationsmethoden untersucht. Im Mittelpunkt stehen dabei Zeitintegration, Skalierungsmethoden, strukturelle Eigenschaften und ein hybride Ansatz zur Lösung der zugrundeliegenden linearen Gleichungssysteme welcher den Einsatz spezialisierter Löser für die jeweiligen Teilsysteme erlaubt. Da die vollen Maxwell-Gleichungen zusätzliche Ableitungen in der Kopplungsstruktur verursachen, sind bisher existierende Konvergenzaussagen für die Waveform-Relaxation von gekoppelten differential-algebraischen Gleichungen nicht anwendbar und motivieren eine neue Konvergenzanalyse. Auf dieser Analyse aufbauend werden hinreichende topologische Kriterien entwickelt, welche eine Konvergenz von Gauß-Seidel- und Jacobi-artigen Waveform-Relaxationen für die gekoppelten Systeme garantieren. Schließlich werden numerische Benchmarks zur Verfügung gestellt, um die eingeführten Methoden und Theoreme dieser Abhandlung zu unterstützen.This work is devoted to the simulation of electrical/electronic circuits incorporating electromagnetic devices. The focus is on different couplings of the circuit equations, modeled with the modified nodal analysis, and the electromagnetic devices with their refined model based on full-wave Maxwell's equations in Lorenz gauged A-V formulation which are spatially discretized by the finite integration technique. A numerical analysis extends the topological criteria for the index of the resulting differential-algebraic equations, as already derived in other works with similar field/circuit couplings. For the simulation, both a monolithic approach and waveform relaxation methods are investigated. The focus is on time integration, scaling methods, structural properties and a hybrid approach to solve the underlying linear systems of equations with the use of specialized solvers for the respective subsystems. Since the full-Maxwell approach causes additional derivatives in the coupling structure, previously existing convergence statements for the waveform relaxation of coupled differential-algebraic equations are not applicable and motivate a new convergence analysis. Based on this analysis, sufficient topological criteria are developed which guarantee convergence of Gauss-Seidel and Jacobi type waveform relaxation schemes for introduced coupled systems. Finally, numerical benchmarks are provided to support the introduced methods and theorems of this treatise.
25
Cogitore, Bruno. "Recherche de circuits équivalents pour les composants magnétiques haute fréquence." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0059.
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Le travail présenté a deux objectifs. L'élaboration de circuits à constantes localisées représentant le comportement électrique des composants magnétiques du continu jusqu'à quelques mégaHertz, et la compréhension du fonctionnement interne de ces composants pour en déduire des améliorations technologiques. Initialement, cette étude concernait les transformateurs utilisés dans les convertisseurs statiques de quelques centaines de Watts fonctionnant à quelques centaines de kiloHertz, mais la généralité des méthodes employées est telle que la validité des résultats dépasse largement ce cadre initial. Des études macroscopiques sont développées indépendamment du nombre d'enroulements pour les trois aspects physiques fondamentaux : couplage magnétique, couplage électrique, pertes. Les résultats sont confirmés par des essais expérimentaux. Pour le transformateur à deux enroulements, ces études aboutissement à un circuit équivalent caractérisé par une quinzaine de constantes. Une méthode expérimentale indépendante de la constitution du composant permet de calculer toutes ces constantes. Un logiciel basé sur cette méthode permet d'envisager son extension à un nombre quelconque d'enroulements. En complément, des études microscopiques sont développées pour réduire les capacités parasites et les pertes dans les conducteurs voisins d'un entrefer. Des modifications technologiques sont déduites d'études analytique et de simulations. Les améliorations correspondantes sont observées expérimentalement
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Salgado, Danilo Augusto. "Uma abordagem paramétrica do impacto da geração distribuída sobre as correntes de curto-circuito e na proteção de redes de distribuição." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-20062016-083241/.
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Esta dissertação tem por propósito analisar os impactos da geração distribuída sobre as correntes de curto-circuito e sobre a proteção das redes de média tensão das concessionárias de distribuição de energia elétrica usando uma abordagem paramétrica. A principal motivação deste trabalho são os recentes incentivos regulatórios que estão fomentando a geração distribuída no Brasil. Contudo, as redes de distribuição convencionais foram projetadas para serem passivas e a introdução da geração poderá causar problemas de ordem técnica que ainda precisam ser resolvidos. Tais problemas foram pesquisados e aqueles relacionados com os impactos sobre as correntes de curto-circuito foram enfatizados. As normas técnicas das concessionárias também foram investigadas porque seus requisitos, como a ligação dos transformadores de acoplamento, influem nas correntes de curto-circuito. Para se calcular as correntes de curto-circuito, desenvolveu-se uma planilha eletrônica cujos resultados foram validados com programas comerciais de análise de redes elétricas. Esta ferramenta foi utilizada para demonstrar, através de exemplos, o impacto causado pela geração distribuída sobre as correntes de curto-circuito e, posteriormente, para realizar as análises paramétricas nas quais a influência de cada variável foi avaliada. A aplicação do método paramétrico permitiu o estudo de possíveis limites para a potência de um gerador distribuído em função dos impactos admissíveis, de seu ponto de conexão, de seus parâmetros elétricos e dos parâmetros elétricos da rede.The purpose of this thesis is to analyse the impacts of distributed generation on short-circuit currents and protection of the distribution utilities medium voltage networks using a parametric approach. The new regulations that are promoting the distributed generation in Brazil are the main motivation for this work. However, the conventional distribution networks were designed to be passive; therefore the integration of generation may cause some technical problems yet to be solved. Such problems were researched and those related to the impacts on short-circuit currents were emphasized. The utilities technical standards were also explored as their requirements affect the short-circuit currents (e.g. the transformers connections). A spreadsheet was developed in order to calculated the short-circuit currents and it was validated comparing its results to those of a commercial network analysis software. This tool was used to expose the impacts of distributed generation on short-circuit currents through examples and also to carry out parametric analysis in which the influence of every variable was evaluated. The application of a parametric method made it possible to define the maximum installed capacity of a distributed generator as a function of the allowed limits to the impacts on the short-circuit currents, its point of coupling, its electrical parameters and the electrical parameters of the network.
27
Andrade, Fábio José de. "Análise crítica da rota tecnológica adotada no desenvolvimento de equipamento sinalizador de faltas para redes aéreas de distribuição de energia elétrica." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-06062013-171059/.
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Um equipamento sinalizador luminoso de faltas foi desenvolvido pela Companhia Paulista de Força e Luz (CPFL) em parceria com a Escola Politécnica da USP e a empresa Expertise Engenharia Ltda., através de uma série de projetos de pesquisa incluídos no programa de pesquisa e desenvolvimento (P&D) regido pela Agência Nacional de Energia Elétrica (ANEEL) brasileira. Neste trabalho é feita uma análise crítica da rota tecnológica adotada no desenvolvimento do sinalizador de faltas, apontando detalhes e justificativas das escolhas tecnológicas adotadas, além de novas possibilidades de melhoria do equipamento face aos avanços tecnológicos detectados nos últimos anos. Para tanto, é proposto e aplicado um novo método, associado a uma sistematização, para análise comparativa de tecnologias, que considera dados quantitativos, qualitativos e estratégicos diretamente comparáveis entre si. Ao longo do trabalho são analisados as escolhas dos princípios de detecção de faltas e funcionalidades agregadas, o desenvolvimento da eletrônica e dos circuitos integrados do detector de faltas, a fonte de alimentação, a sinalização luminosa e o gabinete do equipamento. Como resultado da linha de pesquisa do sinalizador luminoso de faltas foram obtidos protótipos de prova de conceito, cabeça-de-série e de lote pioneiro, estes últimos prontos e certificados para inserção no mercado. Obtiveram-se também diversas publicações em congressos nacionais, a geração de dois pedidos de patentes e um sistema computacional de alocação otimizada de sinalizadores de faltas em redes de distribuição aérea de energia elétrica.Within the R&D program governed by the National Agency of Electric Energy of Brazil, a luminous faulted circuit indicator equipment (FCI) was developed by the Companhia Paulista de Força e Luz (CPFL) in partnership with the Escola Politécnica da USP and the company Expertise Engenharia Ltda. In this work it is presented a critical analysis of the technological route adopted for development of this new FCI, indicating details and justifications of technological choices adopted, and new detected possibilities for improvements, taken into account the technological advances in recent years. For such purpose, it is proposed a new method, associated to a practical systematization, for comparative analysis of technologies that accounts for quantitative, qualitative and strategic data directly comparable. The work presents analyses on the choices of fault detection principles and related functions, the development of integrated circuits and fault detector electronics, the power supply, the luminous signaling and the equipment case. As results of the research and development of the FCI there were obtained proof of concept, prototype and pilot equipments, the last ones certified and ready for sale. There were also obtained several publications in national conferences, submission of two patent applications and a software for optimization of FCIs allocation on overhead power distribution networks.
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Holmberg, Pär. "Modelling the transient response of windings, laminated steel coresand electromagnetic power devices by means of lumped circuits : With special reference to windings with a coaxial insulation system." Doctoral thesis, Uppsala University, Department of High Voltage Research, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-548.
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Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. This is the case for the explosive magnetic flux compression generator (EMG) and a ferromagnetic actuator.
Models are presented that are mainly intended for transients in the millisecond range and faster. Hence, eddy currents and the related skin and proximity effect become significant in windings, magnetic cores and in the armatures of the devices. These effects are important for, e.g., the damping of the transients. Further, the displacement current in the insulation of the winding is significant. It changes the response of the windings dramatically, as it manifests the finite velocity of propagation of the electromagnetic fields. Under such circumstances, reflections and excited resonances can make the transient voltage and current distribution highly irregular.
Induced voltages are modelled with self and mutual inductances or reluctances combined with winding templates. The displacement currents are modelled with capacitances or coefficients of potential. Cauer circuits and their dual form are used to model eddy currents in laminated cores and in conductors. The Cauer circuit enables one to consider hysteresis and the non-linear response of a magnetic core. It is also used to model the eddy currents in the moving armature of an EMG.
A set-up is presented that can be used to study the transient voltage and the current distribution along a coil.
The transient response of coaxially insulated windings is analysed and modelled in detail. A lumped circuit model is developed for a coil, DryformerTM - the new high-voltage transformer - and PowerformerTM, the new high-voltage generator. An alternative model, a combined lumped circuit and FEM model, is presented for a coaxially insulated winding in two slot cores.
29
Lu, Bin. "Energy Usage Evaluation and Condition Monitoring for Electric Machines using Wireless Sensor Networks." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14152.
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Energy usage evaluation and condition monitoring for electric machines are important in industry for overall energy savings. Traditionally these functions are realized only for large motors in wired systems formed by communication cables and various types of sensors. The unique characteristics of the wireless sensor networks (WSN) make them the ideal wireless structure for low-cost energy management in industrial plants.
This work focuses on developing nonintrusive motor-efficiency-estimation methods, which are essential in the wireless motor-energy-management systems in a WSN architecture that is capable of improving overall energy savings in U.S. industry.
This work starts with an investigation of existing motor-efficiency-evaluation methods. Based on the findings, a general approach of developing nonintrusive efficiency-estimation methods is proposed, incorporating sensorless rotor-speed detection, stator-resistance estimation, and loss estimation techniques. Following this approach, two new methods are proposed for estimating the efficiencies of in-service induction motors, using air-gap torque estimation and a modified induction motor equivalent circuit, respectively. The experimental results show that both methods achieve accurate efficiency estimates within ¡À2-3% errors under normal load conditions, using only a few cycles of input voltages and currents. The analytical results obtained from error analysis agree well with the experimental results.
Using the proposed efficiency-estimation methods, a closed-loop motor-energy-management scheme for industrial plants with a WSN architecture is proposed. Besides the energy-usage-evaluation algorithms, this scheme also incorporates various sensorless current-based motor-condition-monitoring algorithms. A uniform data interface is defined to seamlessly integrate these energy-evaluation and condition-monitoring algorithms. Prototype wireless sensor devices are designed and implemented to satisfy the specific needs of motor energy management. A WSN test bed is implemented. The applicability of the proposed scheme is validated from the experimental results using multiple motors with different physical configurations under various load conditions. To demonstrate the validity of the measured and estimated motor efficiencies in the experiments presented in this work, an in-depth error analysis on motor efficiency measurement and estimation is conducted, using maximum error estimation, worst-case error estimation, and realistic error estimation techniques. The conclusions, contributions, and recommendations are summarized at the end.
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Korssell, Christine, and Angelica Waernlund. "Analysis of Disconnection Circuit Breaker Reliability." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214749.
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For the modern human, electricity has become anessential part of life. It is first when the power goes out that societystops and the need of electricity becomes obvious. The largestpower failures have been caused by broken devices in power grids.This project examined different ways to analyze the reliability, lifespan and number of failures over time for the device disconnectingcircuit breaker in power grids.Given data for the circuit breakers has been sorted intodifferent files and the main method used, was linear regression,which were applied on the sorted data. The result showed that thevalues of the circuit breakers deteriorated over time, and this willbe presented in more detail in this report. It can be concluded thatthe disconnecting circuit breakers ages like expected, except forone parameter that gave unexpected result.
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Tessarolo, Alberto. "Modeling and analysis of multiphase machines for high power applications." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421670.
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This doctoral thesis is dedicated to the modeling and analysis of high-power multiphase electric machines.
In the first part, the multiphase technology and variety in the field of high power electric drives and power generation is illustrated by means of some significant industrial realizations which highlight the main design issues and advantages that may lead to choose a high number of phases in large electric machinery.
Subsequently, the attention is focused on the so called split-phase configurations, characterized by stator windings split into *N* three-phase sections. The modeling of these machines is revisited from an analytical viewpoint and an equivalent circuit representation is proposed for them; in particular, it is shown and experimentally proved that, when the number of stator sections *N* exceeds two, a magnetic cross-coupling arises between d-axis and q-axis equivalent circuits.
A different modeling technique, called Vector-Space Decomposition (VSD), is then considered and extended to any kind of multiphase configuration, whether symmetrical or asymmetrical, through suitable geometrical transformations. A special effort is particularly spent on setting forth a general methodology which allows for space harmonics (related to the
non-idealities of air-gap shape and winding distribution) to be included in the machine model through VSD. The result achieved is that some geometry- or design-related machine information which usually require finite-element simulations to be caught, can be successfully incorporated in the VSD lumped-parameter model of the *n*-phase machine, to an extent that is larger
and larger as *n* grows. As an application example, it is shown how space harmonic effects in the operation of a six-phase and a nine-phase salient-pole multiphase machines can be reproduced by time-stepping finite-element analysis and by the proposed lumped-parameter methodology with the same level of accuracy but with a significant time and computational saving in the last mentioned case.
A part of the thesis is also dedicated to model parameter calculation.
Addressing the case of a general number and distribution of stator phases, algorithms are proposed to compute magnetizing parameters through the winding function theory and analytical computation methods are proposed for self and mutual leakage inductance parameters. The accuracy of the proposed
computation method is assessed by comparison with measurements or real machines.
The final part of the thesis is devoted to the study of two detailed
phenomena which characterize high-power multiphase machines when supplied by multiple inverters. In the instance of multiple current-source inverters, a model is proposed and validated to describe commutation transients including the mutual interaction effects between different winding sections. In the instance of multiple voltage-source inverters, the low-frequency current
circulation phenomenon is investigated analytically and experimentally showing how it arises due to the internal non-ideal machine structure.Questa tesi di dottorato tratta della modellizzazione ed analisi di machine multiphase di alta potenza. Nella prima parte, si illustra la tecnologia multifase e la varietà delle sue forme progettuali nel campo degli azionamenti elettrici e della generazione di energia elettrica. Nella descrizione, si fa riferimento ad alcune realizzazione industriali significative che mettono in luce le principali problematiche e vantaggi che possono indurre alla scelta di una configurazione multifase in macchie elettriche di grossa taglia. Successivamente, viene trattata una particolare configurazione multifase detta “split-phase”, propria di quelle macchine il cui avvolgimento statorico è suddiviso in *N *sezioni multifase. La modellizzazione di queste macchine è rivisitata da un punto di vista analitico e ne viene fornita una rappresentazione in termini di circuito equivalente; in particolare, si dimostra teoricamente e sperimentalmente che, quando il numero *N* di sezioni statoriche è maggiore di due, si verifica un accoppiamento magnetico tra i circuiti equivalenti di asse diretto e di asse in quadratura. Successivamente, si considera una diversa tecnica di modellizzazione, chiamata Vector-Space Decomposition (VSD), con l’intento di darne una formulazione estesa che si applica trattare ogni tipo di configurazione multifase, sia simmetrica che non, ricorrendo ad opportune trasformazioni geometriche. Particolare attenzione è dedicata alla formulazione di un metodo generale che consente l’inclusione, nel modello della macchina con tecnica VSD, delle armoniche spaziali dovute alla non-idealità della geometria del traferro e della distribuzione degli avvolgimenti. In risultato che ne consegue è la possibilità di incorporare nel modello a parametri concentrati della macchina *n*-fase, realizzato con metodo VSD, alcune informazioni, legate alla geometria e al progetto di dettaglio della macchina, le quali normalmente possono essere tenute in considerazione mediante approcci di simulazione agli elementi finiti. La quantità di informazioni includibile nel modello a parametri concentrati secondo la tecnica proposta si mostra essere tanto maggiore quanto più grande è il numero di fasi *n*. Come esempio di applicazione, si mostra come gli effetti legati alle armoniche spaziali nel funzionamento di una macchina a poli salienti a 6 fasi e a 9 fasi possano essere riprodotti, mediante analisi agli elementi finiti nel dominio del tempo e mediante il metodo a parametri concentrati proposto, con lo stesso livello di accuratezza ma con un significativo risparmio di tempo e di risorse computazionali in quest’ultimo caso. Una parte della tesi è altresì dedicata al calcolo parametrico dei modelli. Riferendosi al caso di numero e distribuzione generici delle fasi di statore, vengono proposti algoritmi di calcolo dei parametri di magnetizzazione basati sulla teoria basata sulle “winding functions” e metodi di calcolo analitici per i parametri di auto e mutua induttanza dispersa. L’accuratezza dei metodi di calcolo proposti è verificata per confronto con misure su macchine reali. La parte finale della tesi è dedicata allo studio di due fenomeni dettagliati che caratterizzando le macchine elettriche multifase alimentate da più invertitori. Con riferimento all’alimentazione da più invertitori a corrente impressa, viene proposto e validato un modello che descrive i transitori di commutazione tenendo conto degli effetti di mutua interazione tra diverse sezioni dell’avvolgimento. Nel caso di alimentazione da più invertitori a tensione impressa, viene indagato analiticamente e sperimentalmente il fenomeno di correnti armoniche di ricircolo tra le fasi a bassa frequenza, dimostrando come esso si verifichi a causa della struttura interna non-ideale della macchina.
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Murray, Cody (Cody Daniel). "Connections between circuit analysis problems and circuit lower bounds." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120467.
Full textAbstract:
Thesis: Ph. D. in Computer Science and Engineering, Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 107-112).
A circuit analysis problem takes a Boolean function f as input (where f is represented either as a logical circuit, or as a truth table) and determines some interesting property of f. Examples of circuit analysis problems include Circuit Satisfiability, Circuit Composition, and the Minimum Size Circuit Problem (MCSP). A circuit lower bound presents an interesting function f and shows that no "easy" family of logical circuits can compute f correctly on all inputs, for some definition of "easy". Lower bounds are infamously hard to prove, but are of significant interest for understanding computation. In this thesis, we derive new connections between circuit analysis problems and circuit lower bounds, to prove new lower bounds for various well-studied circuit classes. We show how faster algorithms for Circuit Satisfiability can imply non-uniform lower bounds for functions in NP and related classes. We prove that MCSP cannot be NP-hard under "local" gadget reductions of the kind that appear in textbooks, and if MCSP proved to be NP-hard in the usual (polynomial-time reduction) sense then we would also prove longstanding lower bounds in other regimes. We also prove that natural versions of the Circuit Composition problem do not have small circuits that are constructible in very small (logarithmic) space.
by Cody Murray.
Ph. D. in Computer Science and Engineering
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Wood, Matthew. "Analysis of near fields and radiation of a printed circuit via hole." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0053.
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Electromagnetic compatibility remains an important topic in the design and manufacturing of printed circuit boards (PCBs). Compatibility of these devices with their surroundings is becoming increasingly difficult as a modern PCB can have hundreds or thousands of parts, operating on many layers, and all at high speed. One such part is a via and its clearance, or via hole, commonly required in multilayer circuits where vertical connections between layers are used. The via hole may be exposed to large electromagnetic fields within the PCB. Although electrically small, the via hole provides a pathway for the fields to excite the exterior, either directly or through coupling to adjacent structures. To quantify this process, the near fields and radiation of an excited via hole are analysed, and are the focus of this thesis. The near fields of the via hole are first decoupled into electric and magnetic fields of the 'static' type. In both cases a series solution for two regions, one outside, and one inside the layers is constructed. The coefficients of the terms of the series are chosen to best satisfy the boundary behaviour of the fields on the conducting surfaces and across the hole. The criteria for assessing quality of the solution is based on the least squares method (LSM). Linear equation systems for both models are derived, and as no numerical integration or discretisation is required, an efficient and robust implementation to find the near fields is developed. Transformation into the far field is then achieved through surface integration of relevant field quantities close to the via hole. The far fields are best viewed as that due to two dipoles, of the magnetic and electric type, with strength and orientation depending on how the via hole is excited. It is shown that the two dipole model is sufficient to find the radiation from a 1mm diameter via hole at a frequency up to 8 GHz. Of further interest is how the choice of via hole dimensions affects the dipole moments and the near fields solved earlier are a key to this understanding.
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Nastov, Ognen J. (Ognen Jovan). "Spectral methods for circuit analysis." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/16718.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 119-124).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Harmonic balance (HB) methods are frequency-domain algorithms used for high accuracy computation of the periodic steady-state of circuits. Matrix-implicit Krylov-subspace techniques have made it possible for these methods to simulate large circuits more efficiently. However, the harmonic balance methods are not so efficient in computing steady-state solutions of strongly nonlinear circuits with rapid transitions. While the time-domain shooting-Newton methods can handle these problems, the low-order integration methods typically used with shooting-Newton methods are inefficient when high solution accuracy is required. We first examine possible enhancements to the standard state-of-the-art preconditioned matrix-implicit Krylovsubspace HB method. We formulate the BDF time-domain preconditioners and show that they can be quite effective for strongly nonlinear circuits, speeding up the HB runtimes by several times compared to using the frequency-domain block-diagonal preconditioner. Also, an approximate Galerkin HB formulation is derived, yielding a small improvement in accuracy over the standard pseudospectral HB formulation, and about a factor of 1.5 runtime speedup in runs reaching identical solution error. Next, we introduce and develop the Time-Mapped Harmonic Balance method (TMHB) as a fast Krylov-subspace spectral method that overcomes the inefficiency of standard harmonic balance for circuits with rapid transitions. TMHB features a non-uniform grid and a time-map function to resolve the sharp features in the signals. At the core of the TMHB method is the notion of pseudo Fourier approximations. The rapid transitions in the solution waveforms are well approximated with pseudo Fourier interpolants, whose building blocks are complex exponential basis functions with smoothly varying frequencies. The TMHB features a matrix-implicit Krylov-subspace solution approach of same complexity as the standard harmonic balance method. As the TMHB solution is computed in a pseudo domain, we give a procedure for computing the real Fourier coefficients of the solution, and we also detail the construction of the time-map function. The convergence properties of TMHB are analyzed and demonstrated on analytic waveforms. The success of TMHB is critically dependent on the selection of a non-uniform grid. Two grid selection strategies, direct and iterative, are introduced and studied. Both strategies are a priori schemes, and are designed to obey accuracy and stability requirements. Practical issues associated with their use are also addressed. Results of applying the TMHB method on several circuit examples demonstrate that the TMHB method achieves up to five orders of magnitude improvement in accuracy compared to the standard harmonic balance method. The solution error in TMHB decays exponentially faster than the standard HB method when the size of the Fourier basis increases linearly. The TMHB method is also up to six times faster than the standard harmonic balance method in reaching identical solution accuracy, and uses up to five times less computer memory. The TMHB runtime speedup factor and storage savings favorably increase for stricter accuracy requirements, making TMHB well suited for high accuracy simulations of large strongly nonlinear circuits with rapid transitions.
by Ognen J. Nastov.
Ph.D.
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Singh, Sachin. "Analysis of microstrip defected ground structure filters on anisotropic substrates using HFSS /." abstract and full text PDF (free order & download UNR users only), 2005. http://0-wwwlib.umi.com.innopac.library.unr.edu/dissertations/fullcit/3209134.
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Thesis (Ph. D.)--University of Nevada, Reno, 2005."December 2005." Includes bibliographical references (leaves 213-220). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.
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Matoglu, Erdem. "Statistical design, analysis, and diagnosis of digital systems and embedded RF circuits." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-06072004-131249/unrestricted/matoglu%5Ferdem%5F200405%5Fphd.pdf.
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Vishnubhotla, Phanilatha Carleton University Dissertation Engineering Electronics. "Transient thermal analysis of printed circuit boards and electronic packages." Ottawa, 1996.
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Combrink, Frederik Wilhelm. "Analysis and synthesis of an active resonant snubber for high-power IGBT converters." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52090.
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Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: This thesis describes the study of two soft-switching inverter topologies that are well suited to high-power applications. For the first topology, namely an active resonant turn-off snubber, the existing theory is expanded with a detailed study into operation strategies and topology protection. This is followed by an investigation into the second topology, which is a combined snubber that reduces both turn-off and turn-on losses. The investigation involves a detailed analysis of the losses in the snubber components and main devices, as well as a study into the effects of parasitic components and diode reverse recovery on the operation of the snubber. Based on this theory a snubber optimisation procedure is also developed. Possible operation strategies and protection techniques were also evaluated for this topology. Single-phase experimental inverters were used to verify the basic operation theory and switching loss prediction for both topologies. The thesis is concluded by the design and construction of a practical soft-switching threephase inverter. After implementation the experimental inverter is used for theory verification.
AFRIKAANSE OPSOMMING: Hierdie proefskrif beskryf die ondersoek na twee saggeskakelde omsetter topologieë wat veral geskik is vir hoë-drywing toepassings. Die bestaande teorie aangaande die eerste topologie, naamlik 'n aktiewe, resonante, afskakel gapser, word uitgebrei met 'n deeglike-studie oor bedryfstegnieke en beskermingsmetodes. Vervolgens word 'n gekombineerde gapser topologie, wat beide aanskakel- en afskakelverliese verminder, ondersoek. Die studie behels 'n volledige analise van die verliese in die omsetter en gapser komponente en die invloed van parasitêre komponente en diode tru-herstel. Hierdie teorie word ook gebruik om 'n optimale gapser ontwerp prosedure te ontwikkel. Die moontlikke bedryfstegnieke en beskermingsmetodes word ook vir hierdie topologie evalueer. In albei gevalle is eksperimentele, enkelfase omsetters gebruik om die teorie oor basiese werking en skakelverlies vermindering te verifieer. Die ondersoek word afgesluit deur die ontwerp en konstruksie van 'n praktiese, saggeskakelde, drie-fase omsetter te beskryf. Na implimentering van die omsetter word volledige eksperimentele verifikasie uitgevoer.
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Mukherjee, Souvik. "Layout-level Circuit Sizing and Design-for-manufacturability Methods for Embedded RF Passive Circuits." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/16131.
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The emergence of multi-band communications standards, and the fast pace of the consumer electronics markets for wireless/cellular applications emphasize the need for fast design closure. In addition, there is a need for electronic product designers to collaborate with manufacturers, gain essential knowledge regarding the manufacturing facilities and the processes, and apply this knowledge during the design process. In this dissertation, efficient layout-level circuit sizing techniques, and methodologies for design-for-manufacturability have been investigated.
For cost-effective fabrication of RF modules on emerging technologies, there is a clear need for design cycle time reduction of passive and active RF modules. This is important since new technologies lack extensive design libraries and layout-level electromagnetic (EM) optimization of RF circuits become the major bottleneck for reduced design time. In addition, the design of multi-band RF circuits requires precise control of design specifications that are partially satisfied due to manufacturing variations, resulting in yield loss. In this work, a broadband modeling and a layout-level sizing technique for embedded inductors/capacitors in multilayer substrate has been presented. The methodology employs artificial neural networks to develop a neuro-model for the embedded passives. Secondly, a layout-level sizing technique for RF passive circuits with quasi-lumped embedded inductors and capacitors has been demonstrated. The sizing technique is based on the circuit augmentation technique and a linear optimization framework.
In addition, this dissertation presents a layout-level, multi-domain DFM methodology and yield optimization technique for RF circuits for SOP-based wireless applications. The proposed statistical analysis framework is based on layout segmentation, lumped element modeling, sensitivity analysis, and extraction of probability density functions using convolution methods. The statistical analysis takes into account the effect of thermo-mechanical stress and process variations that are incurred in batch fabrication. Yield enhancement and optimization methods based on joint probability functions and constraint-based convex programming has also been presented. The results in this work have been demonstrated to show good correlation with measurement data.
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Salomonsson, Daniel. "Modeling, Control and Protection of Low-Voltage DC Microgrids." Doctoral thesis, Stockholm : Elektriska energisystem, Electric Power Systems, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4666.
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Bocancea, Emanuel. "Data acquisition and analysis system for power electronic circuits." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq22575.pdf.
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Pade, Jonas. "Analysis and waveform relaxation for a differential-algebraic electrical circuit model." Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/23044.
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Die Hauptthemen dieser Arbeit sind einerseits eine tiefgehende Analyse von nichtlinearen differential-algebraischen Gleichungen (DAEs) vom Index 2, die aus der modifizierten Knotenanalyse (MNA) von elektrischen Schaltkreisen hervorgehen, und andererseits die Entwicklung von Konvergenzkriterien für Waveform Relaxationsmethoden zum Lösen gekoppelter Probleme. Ein Schwerpunkt in beiden genannten Themen ist die Beziehung zwischen der Topologie eines Schaltkreises und mathematischen Eigenschaften der zugehörigen DAE.
Der Analyse-Teil umfasst eine detaillierte Beschreibung einer Normalform für Schaltkreis DAEs vom Index 2 und Abschätzungen, die für die Sensitivität des Schaltkreises bezüglich seiner Input-Quellen folgen. Es wird gezeigt, wie diese Abschätzungen wesentlich von der topologischen Position der Input-Quellen im Schaltkreis abhängen.
Die zunehmend komplexen Schaltkreise in technologischen Geräten erfordern oftmals eine Modellierung als gekoppeltes System. Waveform relaxation (WR) empfiehlt sich zur Lösung solch gekoppelter Probleme, da sie auf die Subprobleme angepasste Lösungsmethoden und Schrittweiten ermöglicht. Es ist bekannt, dass WR zwar bei Anwendung auf gewöhnliche Differentialgleichungen konvergiert, falls diese eine Lipschitz-Bedingung erfüllen, selbiges jedoch bei DAEs nicht ohne Hinzunahme eines Kontraktivitätskriteriums sichergestellt werden kann. Wir beschreiben allgemeine Konvergenzkriterien für WR auf DAEs vom Index 2. Für den Fall von Schaltkreisen, die entweder mit anderen Schaltkreisen oder mit elektromagnetischen Feldern verkoppelt sind, leiten wir außerdem hinreichende topologische Konvergenzkriterien her, die anhand von Beispielen veranschaulicht werden. Weiterhin werden die Konvergenzraten des Jacobi WR Verfahrens und des Gauss-Seidel WR Verfahrens verglichen. Simulationen von einfachen Beispielsystemen zeigen drastische Unterschiede des WR-Konvergenzverhaltens, abhängig davon, ob die Konvergenzbedingungen erfüllt sind oder nicht.The main topics of this thesis are firstly a thorough analysis of nonlinear differential-algebraic equations (DAEs) of index 2 which arise from the modified nodal analysis (MNA) for electrical circuits and secondly the derivation of convergence criteria for waveform relaxation (WR) methods on coupled problems. In both topics, a particular focus is put on the relations between a circuit's topology and the mathematical properties of the corresponding DAE. The analysis encompasses a detailed description of a normal form for circuit DAEs of index 2 and consequences for the sensitivity of the circuit with respect to its input source terms. More precisely, we provide bounds which describe how strongly changes in the input sources of the circuit affect its behaviour. Crucial constants in these bounds are determined in terms of the topological position of the input sources in the circuit. The increasingly complex electrical circuits in technological devices often call for coupled systems modelling. Allowing for each subsystem to be solved by dedicated numerical solvers and time scales, WR is an adequate method in this setting. It is well-known that while WR converges on ordinary differential equations if a Lipschitz condition is satisfied, an additional convergence criterion is required to guarantee convergence on DAEs. We present general convergence criteria for WR on higher index DAEs. Furthermore, based on our results of the analysis part, we derive topological convergence criteria for coupled circuit/circuit problems and field/circuit problems. Examples illustrate how to practically check if the criteria are satisfied. If a sufficient convergence criterion holds, we specify at which rate of convergence the Jacobi and Gauss-Seidel WR methods converge. Simulations of simple benchmark systems illustrate the drastically different convergence behaviour of WR depending on whether or not the circuit topological convergence conditions are satisfied.
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SCHULZE, TOBIAS. "NATURAL VENTILATION OF HIGH-RISE BUILDINGS - A Methodology for Planning With Different Analysis Tools and Case-Study Integration." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2637369.
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Natural ventilation of buildings has the potential to significantly reduce energy consumption related to cooling and fanning. This can be achieved by providing good indoor air quality without any electricity demand and improving thermal comfort in the summer through increased daytime airspeed and high night ventilation rates. In high-rise buildings, however, natural ventilation is still not a widely preferred means of ventilation.
The main reason is the lack of information on the required system design. Evaluation tools and instruments are not suitable for complex flow path design. Only few results are available on the performance of naturally ventilated high-rise buildings, especially where energy conservation is considered.
The current thesis is predicated on this research gap. The existing barriers for implementing passive technologies can be lowered by creating a quantifiable framework that accounts for all the relevant input parameters in the design process. In order to reach this goal, a planning and simulation approach is developed. Simulations results are compared to those of a reference case-study.
The 28-floor ‘Kanyon’ office tower, situated in Istanbul, is selected to demonstrate the applicability. From the energy metering, it is concluded that mechanical cooling and ventilation result in significant electricity consumption. Detailed information on the building and its operation has been made available by the building management. In addition, the impact of different moderate climates is analysed.
The primary objectives of the thesis can be stated as the development of a design approach, and the investigation of the feasibility of the proposed design, based on an existing case-study building virtually adapted. The approach is developed in three steps, including conceptual design considerations, the development of a preliminary design tool, and a detailed design development.
In the first step, an architectural concept is developed for wide-shaped high-rise buildings where it is impossible to realise simple cross or single-sided ventilation. Conceptual adaptations addressing the flow-path design are a central chimney strategy in respect to the building width, isolated, modular segments in respect to the building height and opposed, wind adapting openings. Other solutions proposed for passive cooling are improved shading devices and activation of the structural mass for night-time ventilation.
In the second step, the originally developed ‘HighVent’ planning tool is introduced. Simple electrical circuit analogies, for both ventilation and thermal models, are found to be suitable in supporting the passive system planning. As classic design day conditions are too strict for passive system design, meaningful boundary conditions are provided. Openings can be sized automatically including an optimization process. The program first calculates the flow-path for a given airflow rate with unchanging boundary conditions. These values are then provided to the thermal module, which calculates the dynamic thermal comfort. The procedure is repeated till the system size is sufficient for passive cooling.
In the third step, the annual performance is exemplarily modelled with EnergyPlus building energy simulations including airflow networks and controls. This includes the ‘HighVent’ tool preliminary design outputs, the conceptual adaptations made, and the remaining features of the as-built Kanyon building.
The design approach is then further evaluated by comparing mechanical operation with an operation based on passive and hybrid control. Indicators proposed to evaluate the functionality are the energy consumption compared to that of mechanical ventilation and cooling systems, and compliance with the thermal comfort limits; additional aspects are the ventilation rates and the indoor air quality reached.
Simulation results indicate that properly designed and controlled natural ventilation shows a good functionality. Control over the openings is crucial, as otherwise ventilation rates can get too high and the rooms tend to cool down too much even during summer. It is shown that the ‘Adaptive Temperature Amplifier’ control algorithm developed is very robust. Differences in climate have a varying impact. For example, in the climate of Stuttgart, further adaptations to the preliminary design are not necessary, whereas in Istanbul adaptations might be reasonable. However, to satisfy the comfort expectations in Turin, there is a necessity for adaptations or a hybrid cooling concept. That humidity values meet comfort expectations must be discussed and accepted by all project stakeholders, else hybrid operation might be a good alternative.
To systematically study the possible energy conservation while maintaining thermal comfort, the energy consumption of identical buildings with different variants (passive/hybrid/active) is benchmarked against the as-built scenario. Results show that the Kanyon’s primary energy input can be reduced by approximately 30% to 40% for passive operation and by 28% to 34% for hybrid operation. This verifies the initial assumption that energy conservation of passively cooled and ventilated office spaces is significant, especially when compared to highly energy consuming state-of-the-art office towers.
The results of this research work are intended, on the one hand, to support building planners in better understanding and implementing passive cooling measures and, on the other hand, to contribute to further development of sustainable building practices.
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Li, Harry W. "A noniterative DC analysis program for analog integrated circuits." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/15977.
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Sarvar, Farhad. "Determination and simulation of the heat transfer characteristics of electronic assemblies." Thesis, University of South Wales, 1992. https://pure.southwales.ac.uk/en/studentthesis/determination-and-simulation-of-the-heat-transfer-characteristics-of-electronic-assemblies(55c0f76d-ca94-4344-a268-f8817df44ccf).html.
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This research project has developed a computer-assisted methodology whereby the temporal and spatial distribution of temperature in thick film circuits fabricated on ceramic substrates may be predicted. The analogy between thermal and electrical systems is used to define a thermal structure in electrical format which is then simulated using ASTEC3 electronic analysis package. Procedures have been developed whereby the three heat transfer mechanisms namely conduction, convection and radiation may be modelled. Models have also been proposed which allow the more important sections of a thermal structure to be analysed in finer detail. These procedures have been used hi the solution of some standard heat flow problems whose solutions have also been obtained by other more conventional techniques for comparison. Programs have been developed which facilitate the presentation of the results in the form of contour-maps or 3-D temperature distribution plots. Software has also been developed which can generate the electrical equivalent description of a device in ASTEC3 syntax. Estimates of the computing times required to carry out electro-thermal simulations of hybrid and VLSI devices have been made. The predicted computation times are feasible. Confirmatory experiments have been carried out in large scale using partially heated samples prepared from printed circuit boards. These were heated electrically and temperature measurements were made using an infrared thermometer. These structures were modelled and simulated using ASTEC3 for comparison. It was found that for an accurate thermal analysis there was a need for reliable data for the thermal conductivity of the glass-fibre laminate and the heat transfer coefficients of convection. Experiments were designed to measure the thermal conductivity of the laminates tangential to the plane of the boards. A standard Lees' disc apparatus was also used to measure this parameter in a direction normal to the boards. A Schlieren optics apparatus was used to study the convection plumes over the surface of the plates in a horizontal position with the heated side facing upwards which provided a significant insight into the flow regime over such surfaces. Values were subsequently determined for the convection coefficients from the boards. Using the measured thermal conductivities of FR4 boards and the estimated convection coefficients, excellent agreement was achieved between the measured and simulated results. Temperature measurements were also conducted at reduced dimensional scale on especially designed thick film resistor samples. The samples were fabricated by R.S.R.E and temperature measurements were carried out using a thermal imaging equipment manufactured by AGEMA. Again the Schlieren apparatus was used to observe the convection plumes forming over the devices which led to a better understanding of the heat transfer mechanism from such devices. These observations were then used to estimate the natural convection coefficients from the surface of horizontally positioned resistor samples which were then included in the ASTEC3 model of the devices. The subsequent ASTEC3 thermal simulation showed an excellent agreement with the measured temperature profile.
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Garg, Nitin Kumar 1967. "Analysis domain truncation of interconnections in multilayer packaging structures." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277078.
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Interconnect lines, which connect components on a chip, can exhibit transmission line properties. Several factors like decrease in size of components, and decrease in spacing between interconnect lines, have contributed to the increase in importance of interconnect lines. A circuit-analysis approach that does not include the effect of these lines may be useless for highly dense chips. The presence of an active line does not require the analysis of all the other lines in a transmission-line system. In this thesis, a numerical experimental approach based on several industry-typical geometries is used to discuss analysis domain truncation of parallel conductors lying on a horizontal plane. It is found that "The maximum analysis domain between parallel conductors lying on a horizontal plane can be deduced from the analysis of the case of several similar, and parallel conductors of smallest possible width lying on a horizontal plane." UAC (University of Arizona Capacitance Calculator) is used as the TEM parameter extractor, while UACSL (University of Arizona Coupled Line Simulator With Linear Terminations) is used to calculate the voltages on the transmission lines.
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Tannir, Dani A. "Efficient nonlinear distortion analysis of RF circuits." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99541.
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The third order intercept point (IP3) is an important figure of merit which gives a measure of the linearity of communication circuits. There are two classes of methods for calculating the IP3 of a circuit. The first is analytical and is usually based on Volterra series. This approach is cumbersome and is difficult to apply to arbitrary circuits with arbitrary non-linearities. The second class of methods is based on multi-tone simulations and is general and flexible but requires significant CPU cost. In this thesis a new method based on the computation of the circuit moments is proposed. The new approach uses the circuit moments in order to numerically compute the Volterra kernels. This automates the process of numerically obtaining such kernels for any circuit and results in an efficient approach for the computation of IP3 for arbitrary circuits. The proposed approach is simple to apply and presents a significant improvement in CPU cost over existing methods.
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Chan, Na-Han. "Rapid current analysis for CMOS digital circuits." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26380.
Full textAbstract:
A versatile and efficient computer-aided analysis tool, CUREST, has been developed for the analysis of supply currents in CMOS digital circuits. It is based on Nabavi-Lishi's semi-analytical model for computing the current and delay in a CMOS logic gate which, when compared to HSPICE running the level-3 MOSFET model, is more than three orders of magnitude faster, and accurate to within 10%. CUREST is built on top of the timing analyser TAMIA and, in particular, uses its circuit parser and its data structure to store the circuit topology and primary input pattern.Extension tests on benchmark circuits containing up to 555 gates, which were analysed with CUREST using thousands of primary input patterns, demonstrate that the current analysis time is in the range of 1ms per gate per input pattern, using a SUN4/490 workstation with 32 Mb of main memory, running the SUN OS 4.103 operating system. The peak value of the total supply current, the current rise-time, and the time at which the peak occurs are usually computed to within 10% of HSPICE. However, appreciable errors often occur in the average current. This is because at the moment we do not have a good model for dealing with incomplete transitions associated with glitches in a CMOS gate.
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Ozgun, Recep. "Design and timing analysis of wave pipelined circuits." Thesis, Wichita State University, 2006. http://hdl.handle.net/10057/383.
Full textAbstract:
In conventional pipelined circuits there is only one data wave active in any pipeline stage at any time; therefore, the clock speed of the circuit is limited by the maximum stage delay in the circuit. In wave pipelining, the clock speed depends mostly on the difference between the longest and shortest path delays. In some circuit designs there are redundant elements to make the circuit less sensitive to noise, to provide higher signal driving capability, or other purposes. Also, some circuit designs include logic to detect the early completion of a computation, or to guarantee that the worst physical path delay does not equate to the worst computational delay. Prior tools for wave-pipelined circuits do not account for such design features. This research develops a computer-aided design tool to determine the maximum clock speed for wave pipelined circuits with redundant logic or where otherwise the internal circuit timing depends on the input signal values. Moreover, alternative design techniques are proposed to improve the performance of wave pipelined circuits.Includes bibliographic references (leaves 39-41)
Thesis (M.S.)--Wichita State University, Dept. of Electrical and Computer Engineering.
"May 2006."
Includes bibliographic references (leaves 39-41)
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Eberhardt, Friedemann. "Symbolic tolerance and sensitivity analysis of large scale electronic circuits." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301578.
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