Dissertations / Theses: 'Power dynamic'

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Demiray, Turhan Hilmi. "Simulation of power system dynamics using dynamic phasor models /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17607.

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Hockenberry, James Richard. "Power system dynamic load modeling." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42594.

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Geitner, Gert-Helge, and Guven Komurgoz. "Power Flow Modelling of Dynamic Systems." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-171305.

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As tools for dynamic system modelling both conventional methods such as transfer function or state space representation and modern power flow based methods are available. The latter methods do not depend on energy domain, are able to preserve physical system structures, visualize power conversion or coupling or split, identify power losses or storage, run on conventional software and emphasize the relevance of energy as basic principle of known physical domains. Nevertheless common control structures as well as analysis and design tools may still be applied. Furthermore the generalization of power flow methods as pseudo-power flow provides with a universal tool for any dynamic modelling. The phenomenon of power flow constitutes an up to date education methodology. Thus the paper summarizes fundamentals of selected power flow oriented modelling methods, presents a Bond Graph block library for teaching power oriented modelling as compact menu-driven freeware, introduces selected examples and discusses special features.

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Bousnane, Kafiha. "Real-time power system dynamic simulation." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6623/.

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The present day digital computing resources are overburdened by the amount of calculation necessary for power system dynamic simulation. Although the hardware has improved significantly, the expansion of the interconnected systems, and the requirement for more detailed models with frequent solutions have increased the need for simulating these systems in real time. To achieve this, more effort has been devoted to developing and improving the application of numerical methods and computational techniques such as sparsity-directed approaches and network decomposition to power system dynamic studies. This project is a modest contribution towards solving this problem. It consists of applying a very efficient sparsity technique to the power system dynamic simulator under a wide range of events. The method used was first developed by Zollenkopf (^117) Following the structure of the linear equations related to power system dynamic simulator models, the original algorithm which was conceived for scalar calculation has been modified to use sets of 2 * 2 sub-matrices for both the dynamic and algebraic equations. The realisation of real-time simulators also requires the simplification of the power system models and the adoption of a few assumptions such as neglecting short time constants. Most of the network components are simulated. The generating units include synchronous generators and their local controllers, and the simulated network is composed of transmission lines and transformers with tap-changing and phase-shifting, non-linear static loads, shunt compensators and simplified protection. The simulator is capable of handling some of the severe events which occur in power systems such as islanding, island re-synchronisation and generator start-up and shut-down. To avoid the stiffness problem and ensure the numerical stability of the system at long time steps at a reasonable accuracy, the implicit trapezoidal rule is used for discretising the dynamic equations. The algebraisation of differential equations requires an iterative process. Also the non-linear network models are generally better solved by the Newton-Raphson iterative method which has an efficient quadratic rate of convergence. This has favoured the adoption of the simultaneous technique over the classical partitioned method. In this case the algebraised differential equations and the non-linear static equations are solved as one set of algebraic equations. Another way of speeding-up centralised simulators is the adoption of distributed techniques. In this case the simulated networks are subdivided into areas which are computed by a multi-task machine (Perkin Elmer PE3230). A coordinating subprogram is necessary to synchronise and control the computation of the different areas, and perform the overall solution of the system. In addition to this decomposed algorithm the developed technique is also implemented in the parallel simulator running on the Array Processor FPS 5205 attached to a Perkin Elmer PE 3230 minicomputer, and a centralised version run on the host computer. Testing these simulators on three networks under a range of events would allow for the assessment of the algorithm and the selection of the best candidate hardware structure to be used as a dedicated machine to support the dynamic simulator. The results obtained from this dynamic simulator are very impressive. Great speed-up is realised, stable solutions under very severe events are obtained showing the robustness of the system, and accurate long-term results are obtained. Therefore, the present simulator provides a realistic test bed to the Energy Management System. It can also be used for other purposes such as operator training.

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Song, Xuefeng. "Dynamic modeling issues for power system applications." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1591.

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Power system dynamics are commonly modeled by parameter dependent nonlinear differential-algebraic equations (DAE) x p y x f ) and 0 = p y x g ) . Due to (,, (,, the algebraic constraints, we cannot directly perform integration based on the DAE. Traditionally, we use implicit function theorem to solve for fast variables y to get a reduced model in terms of slow dynamics locally around x or we compute y numerically at each x . However, it is well known that solving nonlinear algebraic equations analytically is quite difficult and numerical solution methods also face many uncertainties since nonlinear algebraic equations may have many solutions, especially around bifurcation points. In this thesis, we apply the singular perturbation method to model power system dynamics in a singularly perturbed ODE (ordinary-differential equation) form, which makes it easier to observe time responses and trace bifurcations without reduction process. The requirements of introducing the fast dynamics are investigated and the complexities in the procedures are explored. Finally, we propose PTE (Perturb and Taylors expansion) technique to carry out our goal to convert a DAE to an explicit state space form of ODE. A simplified unreduced Jacobian matrix is also introduced. A dynamic voltage stability case shows that the proposed method works well without complicating the applications.

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James, Iain B. "Dynamic characteristics of a split-power IVT." Thesis, University of Bath, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390305.

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McCoy, Timothy J. (Timothy John). "Dynamic simulation of shipboard electric power systems." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12495.

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Singhavilai, Thamvarit. "Identification of electric power system dynamic equivalent." Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=15647.

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Schwingshackl, Christoph Wolfgang. "Dynamic behaviour of inhomogeneous multifunctional power structures." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/52007/.

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Xia, Xiuxian. "Dynamic power distribution management for all electric aircraft." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/6285.

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In recent years, with the rapid development of electric and electronic technology, the All-Electric Aircraft (AEA) concept has attracted more and more attention, which only utilizes the electric power instead of conventional hydraulic and pneumatic power to supply all the airframe systems. To meet the power requirements under various flight stages and operating conditions, the AEA approach has resulted in the current aircraft electrical power generation capacity up to 1.6 MW. To satisfy the power quality and stability requirements, the advanced power electronic interfaces and more efficient power distribution systems must be investigated. Moreover, with the purpose of taking the full advantages of available electrical power, novel dynamic power distribution management research and design for an AEA must be carried out. The main objective of this thesis is to investigate and develop a methodology of more efficient power distribution management with the purpose of minimizing the rated power generating capacity and the mass of the electrical power system (EPS) including the power generation system and the power distribution system in an AEA. It is important to analyse and compare the subsistent electrical power distribution management approaches in current aircraft. Therefore the electrical power systems of A320 and B777, especially the power management system, will be discussed in this thesis. Most importantly the baseline aircraft, the Flying Crane is the outcome of the group design project. The whole project began in March 2008, and ended in September 2010, including three stages: conceptual design, preliminary design and detailed design. The dynamic power distribution management research is based on the power distribution system of the Flying Crane. The main task of the investigation is to analyse and manage the power usage among and inside typical airframe systems by using dynamic power distribution management method. The characteristics and operation process of these systems will be investigated in detail and thoroughly. By using the method of dynamic power distribution management, all the electrical consumers and sub-systems powered by electricity are managed effectively. The performance of an aircraft can be improved by reducing the peak load requirement on board. Furthermore, the electrical system architecture, distributed power distribution system and the dynamic power distribution management system for AEA are presented. Finally, the mass of the whole electrical power system is estimated and analysed carefully.

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ALBUQUERQUE, MARCOS ANTONIO. "DYNAMIC AGGREGATION OF DUAL-INPUT POWER SYSTEM STABILIZER MODELS TO CALCULATE DYNAMIC EQUIVALENTS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=3278@1.

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FURNAS CENTRAIS ELÉTRICAS S.A
Esta dissertação trata do problema da agregação dinâmica de modelos de estabilizadores com dupla entrada, aplicados em reguladores de tensão de unidades geradoras coerentes, visando o cálculo de equivalentes dinâmicos precisos para estudos de estabilidade transitória de sistemas de energia elétrica. A metodologia utilizada para o cálculo de equivalentes dinâmicos é baseada em coerência de geradores, e apresenta três etapas básicas: a identificação de unidades geradoras coerentes, a redução estática da rede externa, e a agregação dinâmica dos geradores de cada grupo formado. A agregação dinâmica de um grupo de unidades geradoras coerentes permite a formação de uma ou mais unidades geradoras equivalentes. Haverá um modelo equivalente para cada componente da unidade geradora, ou seja, modelos equivalentes de máquina síncrona, sistema de excitação, estabilizador, turbina e regulador de velocidade. O ajuste numérico dos parâmetros lineares da função de transferência equivalente é feito pelo método de Levenberg-Marquardt, de modo a minimizar o erro entre a resposta em freqüência desta função e a da função de transferência agregada, que representa a soma das funções de transferência individuais das unidades de cada grupo. Isto caracteriza um problema de otimização multivariável. As respostas em freqüência são apresentadas em diagramas de Bode (módulo e fase). A avaliação do desempenho dinâmico dos equivalentes é feita no sistema teste New England, comparando-se as curvas de oscilação dos geradores do sistema interno obtidas em simulações com a rede completa e com o equivalente. Os modelos de estabilizadores com dupla entrada utilizados são do banco de dados do sistema elétrico brasileiro.
This dissertation deals with the problem of dynamic aggregation of dualinput stabilizer models applied on voltage regulators of coherent generating units to calculate dynamic equivalents for power system transient stability studies. The methodology used for the calculation of coherency-based dynamic equivalents has three basic steps: the identification of the coherent groups of generating units, the network reduction and the dynamic aggregation of coherent generator models. The dynamic aggregation of a group of coherent generating units attached to a common busbar consists of the representation of this group by one or more equivalent generating units. There will be an equivalent model for each component of the generating unit, i.e., an equivalent model for the synchronous machine, other one for the excitation system, and so on. The linear parameters of the equivalent transfer function are numerically adjusted to match the frequency response of the corresponding aggregated transfer function which represents the sum of the individual transfer functions for each coherent group. This characterises a multivariable optimization problem. The frequency responses are presented in Bode diagrams (magnitude and phase). The dynamic equivalents are evaluated in the New England system. The swing curves of the internal system generators obtained with the complete system are compared with those obtained with the equivalent system. The dual-input power system stabilizer models considered in this work are in the Brazilian system stability database.

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Hakobyan, Aram P. "Severe accident analysis using dynamic accident progression event trees." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1158672136.

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Bystrøm, Vebjørn. "Low power/high performance dynamic reconfigurable filter-design." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8899.

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The main idea behind this thesis was to optimize the multipliers in a finite impulse response (FIR) filter. The project was chosen because digital filters are very common in digital signal processing and is an exciting area to work with. The first part of the text describes some theory behind the digital filter and how to optimize the multipliers that are a part of digital filters. The substantial thing to emphasize here is the use of Canonical Signed Digits (CSD) encoding. CSD representation for FIR filters can reduce the delay and complexity of the hardware implementation. CSD-encoding reduces the amount of non-zero digits and will by this reduce the multiplication process to a few additions/subtractions and shifts. In this thesis it was designed 4 versions of the same filter, that was implemented on an FPGA, where the substantial and most interesting results were the differences between coefficients that was CSD-encoded and coefficients that was represented with 2's complement. It was shown that the filter version that had CSD-encoded coefficients used almost 20% less area then the filter version with 2's complement coefficients. The CSD-encoded filter could run on a maximum frequency of 504,032 MHz compared the other filter that could run on a maximum frequency of 249,123 MHz. One of the filters that was designed was designed using the * operator in VHDL, that proved to be the most efficient when it came to the use of number of slices and speed. The reason for this was because an FPGA has built-in multipliers, so if one has the opportunity to use the multiplier they will give the best result instead of using logic blocks on the FPGA It was also discussed a filter that has the ability to change the coefficients at run-time without starting the design from the beginning. This is an advantage because a constant coefficient multiplier requires the FPGA to be reconfigured and the whole design cycle to be re-implemented. The drawback with the dynamic multiplier is that is uses more hardware resources.

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Caharija, Walter. "Dynamic Bias for RF Class A Power Amplifiers." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9998.

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This thesis focuses on class A radio frequency power amplifiers in dynamic supply modulation architectures (dynamic bias). These are promising efficiency enhancement techniques where the device is driven harder by varying its bias signals. Non linearities that arise are considered as digitally compensated through, for example, digital predistortion (DPD). Bias signals are meant as functions of the PA?s output power level (P out). Therefore, the input power level (P in) as well as the feeding signals are thought as quantities the amplifier need to give a certain P out. The selected set of bias points the device sweeps through is called bias trajectory or bias path. A tool to find a suitable bias trajectory is developed considering the requirements a class A power amplifier should satisfy: high power added efficiency, acceptable gain and output phase variations as P out changes (allowing a DPD algorithm to be effective), low harmonic distortion and not too complicated bias signals patterns. The tool consists of two softwares: ADS and Matlab. ADS simulates the device under test while Matlab allows the user to analyze the data and find a suitable bias path. Once a trajectory is identified, ADS can sweep along it and give more information on linearity and efficiency through, for instance, 2-tone harmonic balance simulations. Note that only static characteristics are evaluated and memory effects disregarded. The path searching algorithm is then applied to a HBT transistor, at a frequency of 1.9GHz and to a complete pHEMT class A PA (frequency of 6Ghz). In both cases a suitable trajectory is identified and analyzed back in ADS. The Matlab plots are qualitatively similar to each other when switching form one device to another. The HBT transistor has then been tested in the laboratory and static measurements have been performed showing good agreement with simulations. Keywords: Bias trajectory, dynamic bias, efficiency, HBT, linearity, pHEMT, power amplifier

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Brynjolfson, Ian. "Dynamic clock management circuits for low power applications." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32954.

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Low power methods employing dynamically controlled clock rates offer potentially powerful energy saving capabilities. Dynamic clock management is a system level technique that benefits from the relationship between operating frequency and power consumption through the variation of clock speeds based on demand. This thesis provides robust and scalable clock management circuits for dynamic clock control. A complete Programmable Clock Manager (PCM) has been designed, implemented, integrated into a Systems-on-a-Chip and tested. The PCM incorporates two novel circuits who enable dynamic clock management, the Range Shifting Phase-Locked Loop (RSPLL) and the Dynamic Programmable Clock Divider (DPCD). The self-calibrating RSPLL extends operating bandwidth while reducing jitter. Such a Phase-Locked Loop design also provides easier system-level integration and range-independent usage. The design is scalable to the higher bandwidths and lower voltages, associated with future technologies. The DPCD is capable of dynamic clock division without exhibiting glitches. Both of these robust circuits are easier to use for all clock managment purposes.

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Medina, Juan Felipe Miranda. "Dynamic biasing for linear power amplifier efficiency enhancement." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20045.

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Spectrum is an indispensable and scarce resource in modern communication systems. Reduced hardware complexity is therefore traded for bandwidth-efficient modulation that increases the signal’s peak-to-average power ratio (PAPR). For applications requiring high linearity amplification at microwave frequencies, class-A and -AB power amplifiers have been the traditional choice. However, due to the large PAPR of the modulated signals, they must be operated at several decibels back-off to comply with linearity requirements. Though class-A/AB amplifiers offer descent efficiency at peak envelope power, efficiency decays rapidly with input power back-off. The designer is seemingly left with an inevitable linearity– efficiency trade-off. Though there are several alternatives around the problem, in the context of point-to-point radios the challenge is to find low-cost, reliable solutions that are independent of carrier frequency and manage large bandwidths (e.g., 40 MHz) for moderate output powers (i.e., not larger than 10 W). It is therefore that dynamic biasing—the joint variation of input and output biases following envelope power—is attractive. Following envelope power instead of envelope amplitude and varying also the input bias makes DB substantially different from envelope tracking (ET). Varying the output and input biases as first and second order polynomials of the input power, the bias bandwidth can be controlled to be only twice and four times the RF bandwidth, respectively. Bias bandwidth in a typical ET system would be at least twice as large. This dissertation specifically addresses the problem finding the polynomial coefficients for bias variation, first through simulation methods, and then through direct measurement on different technologies (an MMIC HBT transistor, a discrete GaAs amplifier, and a discrete GaN amplifier). The dynamic biasing problem is formulated mathematically and solved using random search optimization, for which a multi-objective cost function and a linearity measure—different from least square error—are introduced. The effect of output matching on the linearity of the amplifier, and the inclusion of digital predistortion without affecting bias bandwidth are also considered. The results from this research study show that dynamic variation of the input bias alone can significantly improve linearity—a low-complexity, low-cost solution due to the low current levels at the input—. The largest benefits in efficiency are certainly obtained from output bias variation. Though it may adversely affect linearity if used alone, in many cases full dynamic bias (both at input and output)is a win–win combination both in regards to linearity and efficiency. The technique is also attractive because the transistor can be biased higher at peak power if the PAPR of the signal is large, and hence higher average output power can be obtained than with static biasing.

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Crawford, Paul M. "Dynamic study of factors impacting on combat power/." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23187.

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This thesis extends the development of the Generalized Value System (GVS), used in the Airland Advanced Research Model (ALARM), as an on-going research effort at the Naval Postgraduate School. Specifically, the problem of determining the multidimensional mapping of the state variables that represent the condition of an entity into the power function is addressed. The methods described provide a means of acquiring this mapping function by the use of a Degraded Power Function (DPF). The DPF provides a basis for estimating the future state of an entity based on the state (condition) of the entity, virtually eliminating the exponential decay function presently in use. Keywords: Inherent power. (Theses)

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SIQUEIRA, MAGDA SAMPAIO DIOGO DE. "HIERARCHICAL DYNAMIC STATE ESTIMATION FOR ELECTRIC POWER SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1985. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9464@1.

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Em muitos países, redes elétricas de grande porte são formadas pela interconexão de companhias de energia elétrica cada qual possuindo seu próprio centro de controle. Para supervisionar eficientemente tais sistemas de potência, técnicas de estimação hierarquizada de estado devem ser consideradas. Esta tese apresenta um novo algoritmo que utiliza conceitos hierárquicos para resolver o problema da estimação dinâmica de estado para sistemas de potência de grande porte em regime quase-permanente de operação. O processo de estimação é feito em dois níveis de cálculo de modo a se obter uma solução satisfatória do ponto de vista computacional para as etapas usuais da estimação dinâmica de estado: estimação dos parâmetros do modelo, previsão do estado e filtragem do estado. A nível local, algoritmos convencionais de estimação dinâmica de estado são executados simultanea e independentemente para todos os subsistemas. A coordenação dessas estimativas locais é obtida em um centro nacional de supervisão e controle, operacionalmente de hierarquia superior no sistema elétrico interligado. Resultados numéricos mostram o desempenho do algoritmo proposto em diferentes condições de operação: normal, mudança brusca do estado e presença de erros grosseiros.
In many countries, huge power networks are formed from the interconnection of electric power companies each one having its own supervisory control center. In order to supervise efficiently such power systems, hierarchical state estimation techniques have to be considered. This dissertation presents a new algorithm using hierarchical concepts to solve the dynamic state estimation problem for large-scale electric power systems operating under quasi-static conditions. A two-level calculation is performed to give a satisfactory solution from the computational point of view for the usual steps of the dynamic state estimation procedure: model parameter estimation, state prediction and state filtering. At the local level, conventional dynamic state estimation algorithms are carried out simultaneously and independently for all subsystems. The coordination of these local estimations is obtained at a national center for supervision and control, which is at the top of operational hierarchy in the interconnected electrical system. Numerical results show the performance of the proposed algorithm under different operational conditions: normal, sudden variation of states and occurrence of bad data.

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Kitimbo, Andrew. "Rating of Power Cables for Dynamic Load Situations." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195113.

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Huvudsyftet med detta projekt var att utvärdera möjligheten att använda metoder för ”dynamic rating” för att dimensionera (trekärniga) strömkablar som ansluter havsbaserade vindkraftparker. Flera publikationer från kabelindustrin visar att de metoder för att beräkna armeringsförluster som föreslås av IEC för (trekärniga) strömkablar är väldigt konservativa. Målet med projektet var att utveckla mer precisa modeller för att uppskatta armeringsförluster på ett mindre konservativt sätt. Kabelmodeller utvecklades och simulerades under vanliga installations- och miljövillkor. Modeller validerades med hjälp av mätningar från strömkabeln som ansluter den havsbaserade vindkraftparken Eegmond aan Zee belägen i Nordsjön. De validerade modellerna användes vidare för att dimensionera kabeln som kommer att ansluta vindkraftparken East Anglia. Effektprofilerna från denna vindkraftpark användes som parametrar i modellerna för att utföra ”rating analysis”. En del av modelleringsprocessen var att jämföra beräkningsförmågan av Cymcap och Comsol Multiphysics. Cymcap är en kommersiell mjukvara som använder sig av metoder för att beräkna armeringsförluster som föreslås av IEC. Å andra sidan, Comsol Multiphysics baseras på den finita elementmetoden. En litteraturstudie utfördes för att förstå armeringsförluster hos undervattenskablar samt förstå på vilket sätt IEC metoderna anses vara konservativa. Två koncepter identifierades som viktigaste för att beräkna armeringsförluster. Förluster förekommer på grund av komponent av det magnetiska fält som är parallell med kabelarmeringen. Storleken av förlusterna påverkas av den ”crossing pitch” mellan ledaren och armeringen. För precisa armeringsförluster uppskattningar, 3D FEM modeller behövs för hela kabelgeometrin, men det var omöjligt med datakraften som var tillgänglig för projektet. Ungefärliga uttryck för komponenten av det magnetiska fält som är parallell med kabelarmeringen användes i 3D och 2D FEM modeller av enskilda kablar för att beräkna armeringsförluster. Resultat från 3D FEM och från 2D FEM var liknande. Däremot, armeringsförluster och förhållanden med ”crossing pitch” som beräknades var olika för två olika uttryck för det magnetiska fältet. Det var därför svårt att dra fullständiga slutsatser angående det exakta förhållandet mellan ”crossing pitch” och armeringsförluster. Utöver det, information om ”crossing pitch” mellan effektkärnor och kabelarmeringar saknades. Det var därför också svårt att dra några definitiva slutsatser. Armeringsförlusterna som användes för ratingberäkningar var estimerade värde var baserade på 3D FEM simulerade resultat (publicerade) för liknande kabelstorlek som presenterades i ett papper. Validering visar att modellerna för nedgrävda elkablar hade simuleringsresultat nära mätvärdena. Däremot 2D modellerna lyckades inte fånga konvektiv värmeöverföring för ”J tubes” kablar, vilket resulterade i stora skillnader mellan simulerade resultat och mättningar. Kabelratinganalyser visade att ledningstemperatur under dynamisk belastning var lägre än det som observerades för stabilt tillstånd belastning. Detta indikerade att det var möjligt att använda ledningar av mindre tvärsektionsstorlek för dynamisk belastning än det som behövs för stabilt tillstånd belastning för havsbaserade vindkraftkablar.
The overall objective of the project was to evaluate the viability of applying dynamic rating to the dimensioning of offshore wind farm power export cables, usually three core armoured cables. Following various publications in the cable industry indicating that the armour loss estimation methods proposed by IEC for three core armoured cables are overly conservative, the project aimed to develop models for more accurate estimation of the armour losses of three core armoured cables so as to realise less conservative cable rating calculations. Models were developed for offshore wind farm export cables for the typical installation conditions in which these cables are applied. The models were then validated with measurements of cable temperature evolution with loading taken for the power export cable of Eegmond aan Zee offshore wind farm located in the North Sea. The validated models for power cables in the different installation environments relevant for offshore wind farm power export cables were then used to perform cable rating calculations for the power export cable circuits of one of the proposed East Anglia offshore wind farms. The power profile with time as expected to be generated from the wind farm was applied to the models for the cable rating analyses. As part of the modelling process, the capabilities of Cymcap, a commercially available software tool for the rating of power cables were compared with those of Comsol Multiphysics, a finite element tool, for steady state and dynamic cable rating calculations. For purposes of achieving less conservative cable rating results than would have been obtained with IEC methods, a good understanding of the behaviour of the armour losses in submarine cables was obtained from various publications. Two concepts understood to be important in the estimation of the armour losses were that the losses are due to the magnetic field component parallel to the armour wires and that their magnitude is influenced by the crossing pitch between the power cores and the armour wires of the cable. For accurate estimation of the armour losses, 3D FEM models are required for the entire complex cable geometry which was not possible with the available computing resources. Approximate expressions for the magnetic field parallel to the armour wires were obtained and applied to 3D and 2D FEM models of individual armour wires to compute the armour losses. The results with 3D FEM were similar to those obtained with 2D FEM. However, a comparison of the armour loss estimates obtained with two different expressions for the magnetic field gave varying results for the armour losses and their dependence on the crossing pitch making it difficult to draw any conclusions on the exact relationship between the armour losses and the crossing pitch. Secondly, the unavailability of any information on the crossing pitch between the power cores and the armour wires of the cables used in the study also made it difficult to draw conclusions on the armour losses of these cables from the models. The armour losses eventually used in the cable rating calculations were estimates based on the armour losses obtained from published results of 3D FEM simulations of a cable of similar dimensions. In the validation of the models, the results from the models of buried cables showed close agreement with the measurements. However, for cables in J tubes, the inability of 2D models to capture convective heat transfer resulted in large deviations between the results from the models and the measurements. From the cable rating analyses, the conductor temperature attained with dynamic loading was observed to be less than that from steady state loading for the same cable dimensions. This indicated that it was possible to use smaller conductor cross sections when using dynamic rating than with steady state rating of offshore wind farm power export cables.

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Perez-Davis, Marla Esther. "Heat receivers for solar dynamic space power systems." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055525095.

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Das, Debrup. "Dynamic control of grid power flow using controllable network transformers." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43739.

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The objective of the research is to develop a cost-effective, dynamic grid controller called the controllable network transformer (CNT) that can be implemented by augmenting existing load tap changing (LTC) transformers with an AC-AC converter. The concept is based on using a fractionally rated direct AC-AC converter to control the power through an existing passive LTC. By using a modulation strategy based on virtual quadrature sources (VQS), it is possible to control both the magnitude and the phase angle of the output voltage of the CNT without having any inter-phase connections. The CNT architecture has many advantages over existing power flow controllers, like absence of low frequency storage, fractional converter rating, retro-fitting existing assets and independent per-phase operation making it potentially attractive for utility applications. The independent control of the magnitude and the phase angle of the output voltage allow independent real and reactive power flow control through the CNT-controlled line. In a meshed network with asymmetric network stresses this functionality can be used to redirect power from critically loaded assets to other relatively under-utilized parallel paths. The power flow controllability of CNT can thus be used to lower the overall cost of generation of power. The solid state switches in the CNT with fast response capability enable incorporation of various additional critical functionalities like grid fault ride through, bypassing internal faults and dynamic damping. This bouquet of features makes the CNT useful under both steady state and transient conditions without compromising the grid reliability.

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Deaton, Juan D. "Evaluation of Dynamic Channel and Power Assignment Techniques for Cognitive Dynamic Spectrum Access Networks." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/42165.

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This thesis provides three main contributions with respect to the Dynamic Channel and Power Assignment (DCPA) problem. DCPA refers to the allocation of transmit power and frequency channels to links in a cognitive dynamic spectrum network so as to maximize the total number of feasible links while minimizing the aggregate transmit power. In order to provide a method to compare related, yet disparate, work, the first contribution of this thesis is a unifying optimization formulation to describe the DCPA problem. This optimization problem is based on maximizing the number of feasible links and minimizing transmit power of a set of communications links in a given communications network. Using this optimization formulation, this thesis develops its second contribution: a evaluation method for comparing DCPA algorithms. The evaluation method is applied to five DPCA algorithms representative of the DCPA literature . These five algorithms are selected to illustrate the tradeoffs between control modes (centralized versus distributed) and channel/power assignment techniques. Initial algorithm comparisons are done by analyzing channel and power assignment techniques and algorithmic complexity of five different DCPA algorithms. Through simulations, algorithm performance is evaluated by the metrics of feasibility ratio and average power per link. Results show that the centralized algorithm Minimum Power Increase Assignment (MPIA) has the overall best feasibility ratio and the lowest average power per link of the five algorithms we investigated. Through assignment by the least change in transmit power, MPIA minimizes interference and increases the number of feasible links. However, implementation of this algorithm requires calculating the inverse of near singular matrices, which could lead to inaccurate results. The third contribution of this thesis is a proposed distributed channel assignment algorithm, Least Interfering Channel and Iterative Power Assignment (LICIPA). This distributed algorithm has the best feasibility ratio and lowest average power per link of the distributed algorithms. In some cases, LICIPA achieves 90% of the feasibility ratio of MPIA, while having lower complexity and overall lower average run time.
Master of Science

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Rousseau, Jean-Pierre. "Dynamic evaluation of the solar chimney." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1184.

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Smith, Mark Allen. "Improved dynamic stability using FACTS devices with phasor measurement feedback /." This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-05022009-040702/.

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Krishnan, Venkat Kumar. "Coordinated static and dynamic reactive power planning against power system voltage stability related problems." [Ames, Iowa : Iowa State University], 2007.

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Blood, Ellery A. "From Static to Dynamic Electric Power Network State Estimation: The Role of Bus Component Dynamics." Research Showcase @ CMU, 2011. http://repository.cmu.edu/dissertations/57.

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This thesis addresses the challenge of accurately and robustly estimating the network state on an electric power network despite its large size, infrequent measurement updates, and high likelihood of corrupted data. This is especially important as electrical transmission operators are increasingly being asked to operate the networks at their maximum allowable capacity. Accurate knowledge of the state is necessary to ensure adequate margin to these operating limits should a fault occur. This thesis provides the following contributions. 1. Models describing the dynamics of slow machinery attached to and coupled via the electric power network were used to allow dynamic state estimation. 2. The detail of the coupled dynamic network model was evaluated to determine the level of modeling complexity required to achieve significant state estimation performance gains. 3. Improvements to bad data detection and identification by using information from the dynamic state estimator were demonstrated and evaluated. 4. The improvements to network static observability were discussed and evaluated.

27

Shaaban, Mohamed Mohamed Abdel Moneim. "Calculation of available transfer capability of transmission networks including static and dynamic security." Thesis, Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576817.

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Li, Bo. "Modeling and Runtime Systems for Coordinated Power-Performance Management." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/87064.

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Emergent systems in high-performance computing (HPC) expect maximal efficiency to achieve the goal of power budget under 20-40 megawatts for 1 exaflop set by the Department of Energy. To optimize efficiency, emergent systems provide multiple power-performance control techniques to throttle different system components and scale of concurrency. In this dissertation, we focus on three throttling techniques: CPU dynamic voltage and frequency scaling (DVFS), dynamic memory throttling (DMT), and dynamic concurrency throttling (DCT). We first conduct an empirical analysis of the performance and energy trade-offs of different architectures under the throttling techniques. We show the impact on performance and energy consumption on Intel x86 systems with accelerators of Intel Xeon Phi and a Nvidia general-purpose graphics processing unit (GPGPU). We show the trade-offs and potentials for improving efficiency. Furthermore, we propose a parallel performance model for coordinating DVFS, DMT, and DCT simultaneously. We present a multivariate linear regression-based approach to approximate the impact of DVFS, DMT, and DCT on performance for performance prediction. Validation using 19 HPC applications/kernels on two architectures (i.e., Intel x86 and IBM BG/Q) shows up to 7% and 17% prediction error correspondingly. Thereafter, we develop the metrics for capturing the performance impact of DVFS, DMT, and DCT. We apply the artificial neural network model to approximate the nonlinear effects on performance impact and present a runtime control strategy accordingly for power capping. Our validation using 37 HPC applications/kernels shows up to a 20% performance improvement under a given power budget compared with the Intel RAPL-based method.
Ph. D.
System efficiency on high-performance computing (HPC) systems is the key to achieving the goal of power budget for exascale supercomputers. Techniques for adjusting the performance of different system components can help accomplish this goal by dynamically controlling system performance according to application behaviors. In this dissertation, we focus on three techniques: adjusting CPU performance, memory performance, and the number of threads for running parallel applications. First, we profile the performance and energy consumption of different HPC applications on both Intel systems with accelerators and IBM BG/Q systems. We explore the trade-offs of performance and energy under these techniques and provide optimization insights. Furthermore, we propose a parallel performance model that can accurately capture the impact of these techniques on performance in terms of job completion time. We present an approximation approach for performance prediction. The approximation has up to 7% and 17% prediction error on Intel x86 and IBM BG/Q systems respectively under 19 HPC applications. Thereafter, we apply the performance model in a runtime system design for improving performance under a given power budget. Our runtime strategy achieves up to 20% performance improvement to the baseline method.

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Newham, Nikki. "Power System Investment Planning using Stochastic Dual Dynamic Programming." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/1975.

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Generation and transmission investment planning in deregulated markets faces new challenges particularly as deregulation has introduced more uncertainty to the planning problem. Tradi- tional planning techniques and processes cannot be applied to the deregulated planning problem as generation investments are profit driven and competitive. Transmission investments must facilitate generation access rather than servicing generation choices. The new investment plan- ning environment requires the development of new planning techniques and processes that can remain flexible as uncertainty within the system is revealed. The optimisation technique of Stochastic Dual Dynamic Programming (SDDP) has been success- fully used to optimise continuous stochastic dynamic planning problems such as hydrothermal scheduling. SDDP is extended in this thesis to optimise the stochastic, dynamic, mixed integer power system investment planning problem. The extensions to SDDP allow for optimisation of large integer variables that represent generation and transmission investment options while still utilising the computational benefits of SDDP. The thesis also details the development of a math- ematical representation of a general power system investment planning problem and applies it to a case study involving investment in New Zealand’s HVDC link. The HVDC link optimisation problem is successfully solved using the extended SDDP algorithm and the output data of the optimisation can be used to better understand risk associated with capital investment in power systems. The extended SDDP algorithm offers a new planning and optimisation technique for deregulated power systems that provides a flexible optimal solution and informs the planner about investment risk associated with uncertainty in the power system.

30

Forsén, Rikard. "Dynamic pressure measurements in high power impulse magnetron sputtering." Thesis, Linköping University, Department of Physics, Chemistry and Biology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52551.

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A microphone has been used to measure the dynamic pressure inside a vacuum chamber during high power impulse magnetron sputtering with high enough time-resolution (~µs) to track the pressure change during the discharge pulse. An experimental measurement of the dynamic pressure is of interest since it would give information about gas depletion, which is believed to dramatically alter the plasma discharge characteristics. This investigation has shown that the magnitude of the pressure wave, which arises due to the gas depletion, corresponds to a 0.4 - 0.7Pa (3 - 5.5mTorr) pressure difference at a distance of 15cm from the target, with base pressures of 2 - 6mTorr for a peak current of 110A. It has also been shown that another pressure wave, about 250µs later, can be detected. Its explanation is suggested to be that the initial pressure wave is bouncing against the chamber walls and thereby causing another peak.

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Kramer, Joshua. "A dynamic power optimization methodology for gigabit electrical links." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 134 p, 2007. http://proquest.umi.com/pqdweb?did=1397913001&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Domeij, Martin. "Dynamic avalanche in Si and 4H-SiC power diodes /." Stockholm, 1999. http://www.lib.kth.se/abs99/dome0604.pdf.

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Hu, Fei. "Process variation-resistant dynamic power optimization of VLSI circuits." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Fall/Dissertation/HU_FEI_35.pdf.

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Liu, Xiaopeng. "Power system dynamic vulnerability under extreme transmission line contingencies." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18782.

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Power systems around the world may be under the threat of extreme conditions such as natural disasters and terrorist attacks. To find the most severe condition in the static sense, systematic methods based on optimization have been developed. However, until now, there is no systematic way to find the most severe contingency in the dynamic sense. The thesis proposes such a systematic approach. The method adopts a two-step “screening-and-ranking” procedure similar to the one employed in conventional dynamic security analysis. In the “screening” step, transmission lines are screened using two criteria. The first criterion is based on critical eigen-sensitivity with respect to single line outages. A transmission line is selected only if one of the critical eigenvalues has a large sensitivity to the outage of this line. The second criterion is based on a topology analysis searching for cut-sets in the system. A transmission line is selected if it is a member of a system cut-set with high power imbalance ratio. In the “ranking” step, time-domain analysis is performed on all the combinations of the lines screened by the first step, to determine their real dynamic impact on the system. Relays for generators, loads, and transmission lines are set-up so as to capture possible cascading events after the initial disturbance. Test results on the One Area IEEE96 system show that the set of critical lines selected by the proposed screening scheme is dependent on the system operating conditions. The screening step can reduce the contingency number significantly, which will alleviate the computation burden in the ranking step by a large margin. The most severe contingencies in term of load shedding were in most cases identified by the proposed method. The merit of the method is its simplicity, which makes it applicable to the analysis of N-2 and N-3 transmission line contingencies. Limitations of the method, such as the possibility of missing the more disruptive c
Les réseaux électriques peuvent être sous la menace de conditions extrêmes, tels que désastres naturels et attentats terroristes. Pour déterminer la condition la plus sévère en état stationnaire, des méthodes systématiques utilisant des techniques d'optimisations ont été développées. Jusqu'à présent il n'existe cependant pas de méthodes systématiques pour déterminer quel défaut est le plus sévère en régime dynamique. Cette thèse propose une telle méthode. Elle utilise une approche en deux étapes, « triage et classement », similaire à celle utilisée dans une analyse de sécurité dynamique conventionnelle. Dans l'étape de triage, les lignes de transport d'électricité sont sélectionnées selon deux critères. Le premier est basé sur la sensibilité critique des valeurs propres par rapport à la perte d'une seule ligne. Une ligne de transport est sélectionnée seulement si une des valeurs propres critiques a une sensibilité élevée à la perte de cette ligne. Le second critère est basé sur une analyse topologique et recherche des ensembles de coupure dans le système. Une ligne de transport est sélectionnée si elle appartient à un ensemble de coupure avec un déséquilibre de puissance élevé. Dans l'étape de classement, une analyse temporelle est effectuée sur toutes les combinaisons possibles des lignes de transport sélectionnées dans la première étape, afin de déterminer leurs véritables impacts dynamiques sur le réseau électrique. Les relais de protection sont représentés. Les résultats des simulations sur le système test IEEE96 démontrent que l'étape de triage peut réduire le nombre de défauts de manière significative, ce qui peut alléger considérablement le fardeau de calcul dans l'étape de classement. Les défauts les plus sévères en termes de délestage étaient identifiés dans la plupart des cas par la méthode proposée. L'intérêt de la méthode réside dans sa simplicité,$

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Roa-Sepulveda, C. A. "Dynamic simulation of voltage instability phenomena in power systems." Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390456.

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Wu, I. Hsuan, and 吳怡萱. "Online Dynamic Power Management." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/96202739734085858463.

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37

SRIVASTAVA, MAYANK. "LOW POWER PSEUDO DYNAMIC BUFFER WITH DYNAMIC LOGIC." Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/14506.

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Dynamic logic circuit is the main digital circuits, with a clock as a controlling signal. Comparing with the complementary logic circuit which is having both Pull-up and Pull-down network, dynamic logic circuit has only one network. Dynamic logic circuits consume nearly half of the transistor count as well as the layout area. Parasitic capacitances are used to stored the voltage at the output of the dynamic node, which is typically buffered before it is sent to the next stage. This voltage is affected by the charge sharing. Advantage of dynamic logic circuit is having smaller area and higher speed. According to the theory, the dynamic logic circuit will uses precharge and evaluation phases of the clock cycle. During the precharge phase, a lot of extra noise are introduced into the system compared with the static logic circuit. A noticeable amount of power is waisted due to these periodic precharge phases. Here we propose a Low power pseudo dynamic buffer structure for the dynamic logic circuit. Using this dynamic buffer structure, the precharge pulse is obstructed at the input of the dynamic buffer and is supress from being propagated to the output of the dynamic gate. As a result, power typically consumed during the precharge phase is saved. According to the proposed structure will dramatically reduce the output noise as well as considerable power consumption compared to the traditional dynamic buffer circuits.

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Falahi, Milad. "Dynamic Reactive Power Control of Isolated Power Systems." Thesis, 2012. http://hdl.handle.net/1969.1/148126.

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This dissertation presents dynamic reactive power control of isolated power systems. Isolated systems include MicroGrids in islanded mode, shipboard power systems operating offshore, or any other power system operating in islanded mode intentionally or due to a fault. Isolated power systems experience fast transients due to lack of an infinite bus capable of dictating the voltage and frequency reference. This dissertation only focuses on reactive control of islanded MicroGrids and AC/DC shipboard power systems. The problem is tackled using a Model Predictive Control (MPC) method, which uses a simplified model of the system to predict the voltage behavior of the system in future. The MPC method minimizes the voltage deviation of the predicted bus voltage; therefore, it is inherently robust and stable. In other words, this method can easily predict the behavior of the system and take necessary control actions to avoid instability. Further, this method is capable of reaching a smooth voltage profile and rejecting possible disturbances in the system. The studied MicroGrids in this dissertation integrate intermittent distributed energy resources such as wind and solar generators. These non-dispatchable sources add to the uncertainty of the system and make voltage and reactive control more challenging. The model predictive controller uses the capability of these sources and coordinates them dynamically to achieve the voltage goals of the controller. The MPC controller is implemented online in a closed control loop, which means it is self-correcting with the feedback it receives from the system.

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"Nonlinear dynamic maximum power theorem." Massachusetts Institute of Technology, Research Laboratory of Electronics, 1987. http://hdl.handle.net/1721.1/4218.

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John L. Wyatt, Jr.
Bibliography: p. 12-13.
Supported in part by the National Science Foundation ECS-83-10941 Supported in part by the Defense Advanced Research Projects Agency under contract no. N00014-80-C-0622

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Steven and 蔡志昇. "Power Minimization for Dynamic PLAs." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/76450333169387645831.

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碩士
國立清華大學
資訊工程學系
91
Dynamic PLAs which are built of the NOR-NOR structure have been very popular in high performance design because of their high speed and predictable routing delay. However, the NOR-NOR structure incurs high switching activity in product lines and thus results in large power consumption. In this paper, we propose a new dynamic PLA structure which incorporates super product lines. A super product line adds the NAND functionality on top of the NOR structure, thus lowering the switching activities in the product lines as well as power consumption. Since there are many candidates for the super product lines, we have developed a CAD algorithm based on the maximum weighted matching to find optimal solution. In addition, the line reordering method is applied to further reduce the power consumption. We have performed experiments on a large set of MCNC benchmark circuits. Our experimental results not only show significant reduction in power but also the delay. On the average, the power consumption can be saved 54.86% and the delay can be improved 17.12%.

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Senapati, Prasanta Kumar. "Low power dynamic comparator design." Thesis, 2014. http://ethesis.nitrkl.ac.in/6386/1/E-21.pdf.

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In many applications there is a growing demand for the development of low voltage and low power circuits and systems. Low power consumption is of great interest because it increases the battery lifetime. One of the main building blocks in many applications is the analogue-to-digital converter (ADC) which serves as an interface between the analogue world and the digital processing unit. In all these designs the comparator of the ADC, which is one the most power hungry blocks, is always on. In order to reduce the power consumption of the ADC it is possible to turn the comparator off when the decision is made and the comparator is not needed until the next clock cycle. This work provides a comprehensive review about a variety of comparator designs - in terms of performance, power and delay. The initial part of the work was working with static comparators architectures with different pre-amplifier modifications .Later part deals with two dynamic comparator architectures. The main components of such comparators are the preamplifier and latch circuit. Preamplifier is used for removing the kickback noise and the dc offset voltage while the latch is required for the comparison. The proposed architectures operate on three phases which are non-overlapping and dissipate 7ìW power when operated on a single 1V supply voltage. The latch is basically a back to back connected inverter circuit which inactivated only during the second phase.

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Wu, Shang-Wei, and 吳尚瑋. "Effects of Large Power Plant on Power System Dynamic Stability." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/51793288745215208727.

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碩士
國立臺灣海洋大學
電機工程學系
96
The main objective of this thesis is to study the dynamic stability characteristics of a power system with a large power plant installed for operation. The method of frequency domain analysis is utilized for the study with which the eigenstructure (eigenvalues with associated eigenvectors and participation factors) of each electromechanical oscillation mode can be computed for the analysis of system dynamic stability. Electromechanical oscillations include inter-area mode and intra-area (local and intra-plant) mode of oscillations. The inter-area mode often has lower frequency and damping ratio and affects relatively more numbers of generators. In this thesis, the eigenstructures of all electromechanical oscillation mode of the studied power system, with longitudinal structure and four geographic (northern, central, southern, and eastern) areas, are first computed. The results show that the system damping conforms to the criterion of dynamic stability under both peak load and light load operations. There is relatively more power imbalance between areas under light load since a net power is transferred from the northern area to the central area due to the operation of pumped storage units, and thus the damping ratio of the system under light load is lower than that under peak load. It is recommended that the inter-area oscillation mode be the focus of dynamic stability study for the studied system.

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Singh, Mohit 1982. "Dynamic models for wind power plants." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-3809.

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Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. In order to determine how realistic model performance is, the performance of the one of the models (doubly fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.
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Kumar, Amit 1978. "Dynamic power reduction using data gating." Thesis, 2006. http://hdl.handle.net/2152/30338.

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There has been a constant need for low power techniques to achieve high performance at the lowest possible power dissipation. Lots of works have been done to achieve this target. These works have focused on the different aspects of power reduction. One of these aspects of power saving is Dynamic power reduction. This thesis work is focused on this aspect of power saving by reducing the unnecessary transitioning in the circuit. To achieve this, new method called data gating, is proposed here which stops unnecessary toggling in the circuit using different forms of gating mechanisms. This thesis is organized as follows; first chapter is about the low power design of CMOS circuits. That chapter covers the sources of power dissipation in ICs as well as the techniques that have been used to minimize the power consumption. Second chapter talks more about dynamic power consumption. Techniques used for reducing dynamic power consumption through reduction in switching activities are mentioned in that chapter. Also the new technique, Data Gating, to reduce dynamic power is proposed in second chapter. Third chapter talks about simulation setup, tools used for simulation. Results obtained from different simulations are presented in that chapter. Fourth Chapter is about the analysis of simulation results. It also outlines some possible limitations of the proposed method as well as certain points that need to be considered before applying new technique. Fifth and final chapter summarizes the conclusion and possible future work that can be done to enhance the proposed technique, Data Gating.
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Lin, Kuo Chi, and 林國基. "Dynamic Power Control in Fading Channel." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/49969734335246694483.

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HUANG, ZHONG-GING, and 黃鐘慶. "Long-term power system dynamic analysis." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/32645466904050563900.

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WANG, LI, and 王醴. "Analysis of power system dynamic stability." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/45625016847724142637.

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Gonçalves, Mário Rui Adrião. "Dynamic response of WC-Ni power." Master's thesis, 2016. http://hdl.handle.net/10316/37018.

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Dynamic behavior of WC-Ni system powder, containing 9 wt.% Ni, was investigated. From medium strain rates, the Spilt Hopkinson Pressure Bar (SHPB) method was selected. The design of the Hopkinson bar experiment was modified in order to study the stress and strain states as well as the sound speed in the powder during the dynamic loading. The powder specimen was confined in a sleeve and was loaded by mean of Hopkinson bars in order to get the axial stress and the strain in the sample. Hoop strain gauge was glued in a confining sleeve allowing the deduction of the radial stress in the specimen. To investigate the WC-9Ni powder behavior at high strain rates a multiple target setup was designed. In this case, the Hugoniot properties were measured under a planar shock wave by using a gas-gun. The multiple target was specially designed to hold 3 specimens. From the SHPB compression tests a particular behavior was observed during the dynamic compaction, wherein two phases were identified but the effects were not well recognized.
Este trabalho teve principal objetivo estudar o comportamento dinâmico do sistema WC-Ni, Ni = 9%pd, sob a forma de pó. Para taxas médias de deformação utilizou-se a técnica experimental Split Hopkinson Pressure Bar (SHPB). Os resultados obtidos, no que concerne os estados de tensão e de deformação, assim como a velocidade do som no pó durante a ação de uma carga dinâmica, foram conseguidos por modificação da conceção da SHPB. Após colocação da amostra em pó num tubo, este foi comprimido por ação das barras de Hopkinson. Conseguiu obter-se a tensão e a deformação axial na amostra WC-9Ni. Foi ainda necessário colocar um extensómetro na direção circunferencial do tubo contendo o material de forma a estimar-se o valor de tensão radial na amostra. Para taxas elevadas de deformação, as propriedades de Hugoniot do material em pó foram avaliadas por onda de choque plana utilizando um canhão de gás. Para tal projetou-se uma configuração de alvos múltiplos de modo a conter três grupos de amostras. A partir dos ensaios de compressão SHPB observou-se um comportamento dinâmico particular do sistema WC-9Ni, tendo sido identificadas duas fases. As causas para tal comportamento permanecem por esclarecer.

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Cheng, Tung-Shuan, and 鄭東栓. "Dynamic Body-Biasing and Power-Gating Techniques for Low Power Design." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/w37uu9.

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碩士
國立交通大學
電子工程系所
92
The low-power circuit designs using dynamic body-biasing and power-gating techniques are realized in this thesis. For the flexibility and reusability in System-on-Chip designs, an on-chip configurable body-bias generator that produces various voltage levels is proposed and simulated in TSMC 100nm technology. The output voltage can be controlled through digital input signals. A dual-level on-chip body-bias generator is presented and combined with SRAM cell arrays to observe the effectiveness in leakage suppression. Simulation results in TSMC 0.13um technology show that 75% and 64% net cell leakage reductions are achieved for 64-bit and 32-bit wordlines, respectively. The physical layout is implemented in TSMC 0.13um technology and triple-well structure is necessary for separating body nodes of transistors. A column/row co-controlled SRAM cell arrays scheme is also proposed and simulations and layout are implemented in TSMC 0.13um technology. The cells on the same wordline are divided into blocks and each block has a dedicated gating device. The gating devices are controlled by signals from both column and row decoders. Simulation results show a great amount of active and standby power saving and power-delay product demonstrates that the induced performance overhead is insignificant. Moreover, the area overheads for 8-bit block and 16-bit block conditions are 20.7% and 12.1%, respectively, and only 8.1% is for 32-bit block condition. This technique can be applied to SRAM, register file, CAM, DRAM, flash memory, cache, or other similar memory and logic circuits.

50

Chen, Jin-jia, and 陳晉嘉. "Transmission Power Dynamic Adjust Algorithms:Adjust MN’s Transmission Power in AdHoc Network." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/36847292329695274426.

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Abstract:

碩士
國立臺灣科技大學
電子工程系
96
The Nodes of Ad Hoc network may run in a noisy environment. This will degrade the quality of the channel. When the level of noise is increased, the throughput of the network will be decreased. Since the nodes in Ad Hoc network use IEEE 802.11 DCF protocol and send frames with max power, the interference from other nodes will create noisy environment and the throughput will be decreased and collision probability will be increased. In this paper, we present a protocol named Transmission Power Dynamic Adjust Algorithms (TPDAA) for Ad Hoc network. When a node needs to sends data, its MAC layer calculates the changed noise level of the past. In this way, the sender can calculate the needed power level under present noise level. The collision probability will be decreased and SNR of channel will be more stable under this scheme. For a specific routing protocol, a node can adjust the number of neighbors with this power control scheme and achieve better performance for Ad Hoc network.

Dissertations / Theses on the topic 'Power dynamic'

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