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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.
31

Harmonics on an HVDC transmission line

Welle, Delroy Henry, January 1967 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
32

The voltage dip risk factor for distribution networks

Park, Jeanne 26 February 2009 (has links)
M.Ing. / Electrical quality of supply affects every consumer, from the homeowner to large industry and mining. Customer awareness of poor power quality is increasing due to the more sensitive nature of modern equipment. The positioning of a new plant is therefore very important and cannot only be determined by the availability of resources in the area. To determine the quality of the electricity in a certain network, years of historical data is required. To get enough information regarding a distributions network performance would require voltage dip measurements at a few places in the network for at least three years. For this reason a new method are used in this study. By using the existing information in a network, like: • The amount of lightning strikes per year • The amount of electrocuted birds • The type of protection used • The amount of vandalism incidents on a line per year • The tower footing resistance • The fault level in the network The fuzzy logic principle can be used to determine how susceptible a network is to voltage dips, by determining the favourable and unfavourable conditions for a number of membership functions. Conventional set theory (Boolean) states that an element is either a member of a set or not. Fuzzy logic is an extension of conventional set theory enabling an element to belong to a set degree. This study will look at all the important factors influencing voltage dips, and to use these factors in a fuzzy logic program to determine the voltage dip risk factor for new customers setting up plant in a specific network. The voltage dip risk factor will then determine if it is cost effective for a customer to take on the additional cost in dip proofing his plant.
33

An analytical study of back-to-back HVDC link in weak AC systems /

Hellal, Abdelhafid January 1986 (has links)
No description available.
34

Dynamic power distribution management for all electric aircraft

Xia, Xiuxian 01 1900 (has links)
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.
35

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.
36

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).
37

An investigation of the durability of UK grown softwood distribution poles CCA-treated by sap-displacement

Hainey, Sandra D. January 1992 (has links)
No description available.
38

Limitation of distribution system voltage by decentralised load control

Scott, Nigel Clive January 2000 (has links)
No description available.
39

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
40

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

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