• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 183
  • 162
  • 20
  • 15
  • 13
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 463
  • 463
  • 463
  • 164
  • 161
  • 160
  • 106
  • 67
  • 62
  • 45
  • 42
  • 42
  • 40
  • 38
  • 35
  • 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.
31

Equivalent impedance functions for HVDC converters with inverse cosine control

Bieler, Werner, January 1969 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
32

Optimal distribution system horizon planning /

Fletcher, Robert Henry, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 146-155).
33

Shipboard fluid system diagnostics using non-intrusive load monitoring

Mitchell, Gregory R. 06 1900 (has links)
CIVINS / Systems on modern naval vessels are becoming exclusively dependent on electrical power. One example of this is the replacement of distilling and evaporator plants with reverse osmosis units. As the system is in continuous operation, it is critical to have remote real-time monitoring and diagnostic capabilities. The pressure to reduce shipboard manning only adds to the difficulties associated with monitoring such systems. One diagnostic platform that is particularly well suited for use in such an environment is the non-intrusive load monitor (NILM). The primary benefit of the NILM is that it can assess the operational status of multiple electrical loads from a single set of measurements collected at a central point in a ship's power-distribution network. This reduction in sensor count makes the NILM a low cost and highly reliable system. System modeling, laboratory experiments, and field studies have all shown that the NILM can effectively detect and diagnose several critical faults in shipboard fluid systems. For instance, data collected from the reverse osmosis units for two U.S. Coast Guard Medium Endurance Cutters indicate that the NILM can detect micron filter clogging, membrane failures, and several motor-related problems. Field-tested diagnostic indicators have been developed using a combination of physical modeling and laboratory experiments. / CIVINS
34

Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices

Fallier, William F. 06 1900 (has links)
This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an inverter with simulated silicon carbide switches. Theoretically, silicon carbide switches have the advantage of being able to withstand a very large blocking voltage and carry very large forward currents. Silicon carbide switches are also very efficient due to their quick rise and fall times. Since silicon carbide switches can withstand high voltage differentials and switch faster than silicon switches, the switching effects on the electrical distribution system were investigated. The current state of silicon carbide power electronics was also investigated. This research quantifies the current and voltage distortion over various operating conditions. A system model was developed using Matlab, Simulink, and SimPowerSystems. The model consisted of a synchronous generator supplying a rectifier and inverter set driving an induction motor. This induction motor simulates the propulsion motor for a Navy ship. This model had a DC link voltage of 10 kV in order to simulate future Navy IPS systems. The current and voltage distortion were compared to MIL STD 1399 and IEEE STD 519 and 45. / Contract Number: N62271-97-G-0026
35

The level of competitiveness of the South African electricity industry

24 January 2012 (has links)
M.Comm. / South Africa's demand for electricity is expected to outstrip the industry's generation capacity by 2010. If the government wants to avoid this situation, the construction of new plants must commence. At the moment this task has been delayed because the Government is at loggerheads with COSAU and Eskom about restructuring the electricity supply industry. This debate will remain unsolved unless the government can substantiate why exposing the industry to competition will improve its performance. Unfortunately this task is not as simple as it seems. Even though competition is one of the most widely used terms in economics, it still remains an elusive concept. The ambiguity regarding tl1e meaning of competition arises from the failure to divorce the concept of competition from a market structure; as a consequence an operational meaning of what it means to compete \n terms of contemporary business behaviour does not exist. As a result activities associated with industrialisation, such as a changing production function, the development of new products and t~chniqu'::s and business structures are not related to the concept of competition. In order to develop n clear understanding of "what it means to compete", this dissertadon uses a behavioural definition of competition to determine why exposing firms to. competitive pressure improves their performance, reflected in superior static and dynamic efficiency levels. Based on this conceptual framework, Schumpeter' s approach to competition, which emphasises innovation, profits and the entrepreneur as the agent of improvement combined with the idea that it is the uneven development of knowledge that matters in the process of creative destruction", is accepted (Metcalfe & Ramlogan &Uyarra: 2001). Based on the above notion of competition, competitive pressure positively influences firms' performance, improving their static and dynamic efficiency levels. A micro-economic analysis of a C!)IDp.etitive electricity industry is conducted in order to test the abov~ assumption. This case study demonstrates that the competitive process ultimately improves thr: integration of knowledge throughout the supply chain, which is used an input to stimulate innovation within firms and exploit new technologies (Murphy, 2002:21). As a result, firms facing competition will try to retaii1 their market position 2 by exploiting all knowledge and exploring all avenues of technological invention, before selecting the best method (Khan: 1998). In addition, this case study illustrates that stimulating dynamic efficiency goes beyond developing and implementing "hardware" (computers, CCGT plants, fuel cells etc). Although technology plays an important role in shaping industrial organisation, it is not the catalyst that drives innovation and change. Rather organisational innovation changes market participants' schemas, breeding new ideas that become the input to create technology. Therefore organisational innovation has profound efficiency consequences (Williamson, 1994: 183). If technological and organisational inncvation is intertwined, then innovation is a complex evolutionary process, which occurs over time. Furthermore innovation cannot occur in a vacuum, but is interconnected, interwoven and interdependent with an industry's physical and institutional context (Perez, 2000). Based on the stylised facts a competitive market provides the institutional context that stimulates innovation, and therefore it might be worth incurring the transactions costs and short-term losses in order to create these opportunities.
36

Serie injeksie as alternatief tot tapverstelbare transformators in EGAT kragverspreidingsnetwerke

14 October 2015 (has links)
M.Ing. (Electrical and Electronic Engineering) / Please refer to full text to view abstract
37

Power line carrier communication

Razani, Mohammad January 2010 (has links)
Digitized by Kansas Correctional Industries
38

Effects of ancillary service markets on frequency and voltage control performance of deregulated power systems

Roy, Jyotirmoy, January 2007 (has links) (PDF)
Thesis (M.S. in electrical engineering)--Washington State University, December 2007. / Includes bibliographical references (p. 57-58).
39

Reliability and restoration algorithms for electrical distribution systems /

Oka, Ashok A., January 1992 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 274-276). Also available via the Internet.
40

Added CFO voltages from fiberglass poles and its electrical degradation

Li, Xiaoyong. January 2001 (has links)
Thesis (M.S.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.

Page generated in 0.1002 seconds