84,544 research outputs found
Author, Geraldine Brooks at the National Library of Australia for the 2009 Ray Mathew Lecture, Canberra, 23 October 2009 [picture] /
No full textTitle from acquisitions documentation.; Part of the collection: Portraits of author, Geraldine Brooks during her visit to the National Library of Australia for the 2009 Ray Mathew Lecture, Canberra, 23 October 2009.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Photographed by a staff member of the National Library of Australia
Portrait of Robert Dessaix in the National Library of Australia bookshop, Canberra, 10 October 2008, 1 [picture] /
No full textTitle from acquisitions documentation.; Part of the collection: Portraits of author Robert Dessaix in the National Library of Australia bookshop, Canberra, 10 October 2008.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Photographed by a staff member of the National Library of Australia
Portrait of Robert Dessaix in the National Library of Australia bookshop, Canberra, 10 October 2008, 2 [picture] /
No full textTitle from acquisitions documentation.; Part of the collection: Portraits of author Robert Dessaix in the National Library of Australia bookshop, Canberra, 10 October 2008.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Photographed by a staff member of the National Library of Australia
Design metrics for evaluating the propulsive efficiency of future ships
No full textThere is an increasing need for the ship design process to take account of environmental issues such as the emission of greenhouse gases and the likely extension of a carbon dioxide charging mechanism to international shipping. These issues, together with the need for economic viability, provide further incentives to improve the efficiency of propulsion of ships. The main components of powering are firstly reviewed. Individual components and other power saving devices are identified which should contribute to improvements in the overall efficiency of propulsion. Suitable design metrics and procedures, taking into account economic and environmental factors, are recommended for the design of future ships
Battery Storage System as Power Unbalance Redistributor in Distribution Grids Based on Three Legs Four Wire Voltage Source Converter
No full textThis article discusses the application of battery energy storage systems (BESSs) as power redistributors in three-phase distribution grids as an add-on functionality to typical BESS applications, such as congestion management and energy arbitrage. Combining those ancillary services into a single power unit is not yet performed in practice but may constitute an emerging business opportunity to increase the BESS revenues. The unbalanced operation of the BESS voltage source converter (VSC) leads to the circulation of low-frequency current harmonics in the dc-link through the capacitors and the battery cells. Therefore, it is particularly interesting whether relatively large 50- and 100-Hz currents can safely circulate within these components. Analytical modeling and design guidelines for the dc-link of a three-leg four-wire two-level VSC operating under unbalanced loads are detailed. Furthermore, a low-power VSC prototype is used to demonstrate the working principle of the BESS, providing power unbalance redistribution and symmetric power exchange. Additionally, the ICR18650-26F Lithium-ion cells are cycled to reach end-of-life with different current profiles and C-ratings. The analysis shows that charging with a 100 Hz ripple superimposed to the dc current leads to a 10% increment in degradation
Effects of power electronic compensation on distribution network thermal and voltage violations
No full textThis paper is concerned with the use of medium-voltage power electronics in providing active compensation to distribution networks. The primary purpose of using active compensation is to allow for network growth in the form of distributed generation or customer demand increases. With continuing growth, network thermal and voltage constraints would eventually be violated at some point, even with the use of power electronic compensation. Through the study of increasing generation on several hundred distribution network datasets, trends in the type and location of these constraint breaches are identified for both uncompensated and compensated networks. In comparing the initial types of constraint breaches in uncompensated and compensated networks, the use of power electronics is seen to eliminate overvoltage issues as the primary concern in many cases. In addition, while power electronic compensation is seen to make a significant change in the growth accommodated before constraint breach, the location of these initial breaches is not altered appreciably
Benefits of distribution-level power electronics for supporting distributed generation growth
No full textIt is expected that distribution networks will be required to accommodate large amounts of distributed generation (DG). Keeping power flows and voltages within their limits will require either traditional infrastructure upgrades or active compensation. The form of active compensation (e.g., series, shunt, back to back, multiterminal), quantity, and rating of the compensator should be chosen to realize the best cost-benefit ratio. Distributed-generator and compensator placement algorithms are used with a power-flow and constraint satisfaction algorithm to analyze a large number of case studies (using real U.K. network data). From these cases, assessments of compensator performance are made and summarized statistically. When considering incremental deployment across all networks, with the site of greatest benefit chosen at each increment, it is found that static synchronous compensators provide the most favorable cost-benefit ratio. In contrast, multiterminal voltage-source converters tend to provide the greatest flexibility when considering uniform deployment across all networks. It is also observed that traditional reinforcement enhances the benefits provided by active compensation
Peter Macinnis conducting a teachers' workshop at the National Library of Australia, Canberra, 22 October 2009 [picture] /
No full textTitle from acquisitions documentation.; Part of the collection: Teachers' workshop for the book Australian backyard explorer by author Peter Macinnis at the National Library of Australia, Canberra, 22 October 2009.; Acquired in digital format; access copy available online.; Mode of access: Internet via World Wide Web.; Photographed by a staff member of the National Library of Australia
Author-reader relationship at the site of the work
No full textWithin the format of a critical exegesis and four original works of extended prose fiction, this thesis explores the interaction between the author and reader and argues that literary meaning is the outcome of shifts of power between these two entities. It concludes that because these shifts in power are orchestrated by the author, the author is relevant to understanding how meaning is produced
Power system analysis / John J. Grainger, William D. Stevenson, Jr.
No full textBased on: Elements of power system analysis, by William D. Stevenson.sventeenth reprint 2011.Includes index.xix, 787 pages. :Covering such topics as power flow, power-system stability and transmission lines, this senior/graduate text teaches the fundamental topics of power system analysis accompanied by discussions and numerous examples
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