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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Modelling, simulation and control of photovoltaic converter systems

Gow, John A. January 1998 (has links)
The thesis follows the development of an advanced solar photovoltaic power conversion system from first principles. It is divided into five parts. The first section shows the development of a circuit-based simulation model of a photovoltaic (PV) cell within the 'SABER' simulator environment. Although simulation models for photovoltaic cells are available these are usually application specific, mathematically intensive and not suited to the development of power electronics. The model derived within the thesis is a circuit-based model that makes use of a series of current/voltage data sets taken from an actual cell in order to define the relationships between the cell double-exponential model parameters and the environmental parameters of temperature and irradiance. Resulting expressions define a 'black box' model, and the power electronics designer may simply specify values of temperature and irradiance to the model, and the simulated electrical connections to the cell provide the appropriate I/V characteristic. The second section deals with the development of a simulation model of an advanced PVaware DC-DC converter system. This differs from the conventional in that by using an embedded maximum power tracking system within a conventional linear feedback control arrangement it addresses the problem of loads which may not require the level of power available at the maximum power point, but is also able to drive loads which consistently require a maximum power feed such as a grid-coupled inverter. The third section details a low-power implementation of the above system in hardware. This shows the viability of the new, fast embedded maximum power tracking system and also the advantages of the system in terms of speed and response time over conventional systems. The fourth section builds upon the simulation model developed in the second section by adding an inverter allowing AC loads (including a utility) to be driven. The complete system is simulated and a set of results obtained showing that the system is a usable one. The final section describes the construction and analysis of a complete system in hardware (c. 500W) and identifies the suitability of the system to appropriate applications.
72

Distribution system operation and planning in the presence of distributed generation technology

Jones, Gavin Wesley, January 2007 (has links) (PDF)
Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 16, 2007) Includes bibliographical references (p. 71-74).
73

Modeling and simulations of diphasic composites for development of high energy density dielectrics

Patil, Sandeep Kesharsingh, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2008) Includes bibliographical references.
74

Problems of the fossil-energy economy and the possible implications of alternative energy sources for planning future Australian settlements /

Hume, David Edward. January 1978 (has links) (PDF)
Thesis (M.U.R.P. 1979) from the Department of Architecture, University of Adelaide. / Includes bibliographical references (p. 165-188).
75

Three essays on the electricity spot and financial derivative prices at the Nordic Power Exchange

Deng, Daniel. January 2006 (has links)
Thesis (doctoral)--Göteborgs Universitet, 2006. / Added t.p. with thesis statement inserted.
76

Essays on restructured electricity markets

Nicholson, Emma Leah. January 2008 (has links)
Thesis (Ph.D.)--Georgetown University, 2008. / Includes bibliographical references.
77

Power and energy geopolitical aspects of the transnational natural gas pipelines from the Caspian Sea basin to Europe /

Benke, Ildiko. January 2010 (has links) (PDF)
Thesis (M.S. in Defense Analysis)--Naval Postgraduate School, June 2010. / Thesis Advisor(s): Tsypkin, Mikhail ; Second Reader: Lober, George. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Natural gas, transportation routes, pipelines, power rivalry, energy demand, energy resources, energy policy, energy security, post-Cold war era, Caspian Sea basin, Russian periphery, geopolitical, littoral states, political instability. Includes bibliographical references (p. 53-56). Also available in print.
78

Three essays on the electricity spot and financial derivative prices at the Nordic Power Exchange /

Deng, Daniel. January 2006 (has links)
Thesis (doctoral)--Göteborgs Universitet, 2006. / Added t.p. with thesis statement inserted. Includes bibliographical references.
79

Physics-Based Modeling of Power System Components for the Evaluation of Low-Frequency Radiated Electromagnetic Fields

Barzegaran, Mohammadreza 07 March 2014 (has links)
The low-frequency electromagnetic compatibility (EMC) is an increasingly important aspect in the design of practical systems to ensure the functional safety and reliability of complex products. The opportunities for using numerical techniques to predict and analyze system’s EMC are therefore of considerable interest in many industries. As the first phase of study, a proper model, including all the details of the component, was required. Therefore, the advances in EMC modeling were studied with classifying analytical and numerical models. The selected model was finite element (FE) modeling, coupled with the distributed network method, to generate the model of the converter’s components and obtain the frequency behavioral model of the converter. The method has the ability to reveal the behavior of parasitic elements and higher resonances, which have critical impacts in studying EMI problems. For the EMC and signature studies of the machine drives, the equivalent source modeling was studied. Considering the details of the multi-machine environment, including actual models, some innovation in equivalent source modeling was performed to decrease the simulation time dramatically. Several models were designed in this study and the voltage current cube model and wire model have the best result. The GA-based PSO method is used as the optimization process. Superposition and suppression of the fields in coupling the components were also studied and verified. The simulation time of the equivalent model is 80-100 times lower than the detailed model. All tests were verified experimentally. As the application of EMC and signature study, the fault diagnosis and condition monitoring of an induction motor drive was developed using radiated fields. In addition to experimental tests, the 3DFE analysis was coupled with circuit-based software to implement the incipient fault cases. The identification was implemented using ANN for seventy various faulty cases. The simulation results were verified experimentally. Finally, the identification of the types of power components were implemented. The results show that it is possible to identify the type of components, as well as the faulty components, by comparing the amplitudes of their stray field harmonics. The identification using the stray fields is nondestructive and can be used for the setups that cannot go offline and be dismantled
80

Measuring energy consumption characteristics in mobile data communication

Thomasson, Anton January 2011 (has links)
This report looks at the modern cellular wireless network environment and the factors of energy consumption therein. The consumption of connectivity re- lated hardware is gradually becoming a larger part of the power consumption of virtually any mobile device. This report studies measurements of a mobile broadband module energy usage due to data transfer. It is found that switch- ing between technologies is still beneficial and savings are very feasible when using technologies with different traits if done correctly. Further the possibility of energy savings within a single high-bandwidth technology (3G) are assessed considering variations on response time and throughput. This is relevant as the need to handle highly dynamic loads becomes more and more important in the modern connectivity landscape. By gauging the savings available from schedul- ing link accesses and switching technology this is put in context by sampling a few common services namely Skype, Spotify and normal web browsing for their energy footprints. We will also look briefly at the background traffic generated by two common operating systems, Windows 7 and Ubuntu GNU/Linux.

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