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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.
171

Design procedures for self-supporting transmission towers.

Hanna, Albert William Ghabbour. January 1971 (has links)
No description available.
172

Scattering by interconnected straight wires

Hassan, Mohamed Abdel Aziz Ibrahim January 1974 (has links)
No description available.
173

Strategic placement of distribution network operator owned wind turbines by using market-based optimal power flow

Mokryani, Geev, Siano, P. January 2014 (has links)
No / In this study, a new methodology to optimally allocate wind turbines (WTs) in distribution networks is proposed. A market-based optimal power flow is used to determine the optimal numbers and capacities of WTs in a way that maximises the social welfare. The method is conceived for distribution network operators to strategically allocate WTs in distribution networks. The proposed method by yielding location-specific WTs capacity settlement both in terms of cost reduction and consumers' benefits is consistent with distribution network topology and constraints. The method is solved by using step-controlled primal dual interior point method considering network constraints. The effectiveness of the proposed method is demonstrated with two radial distribution systems including an 84-bus 11.4 kV and a 69-bus 11 kV network.
174

Analysis and Comparison of Power Loss and Voltage Drop of 15 kV and 20 kV Medium Voltage Levels in the North Substation of the Kabul Power Distribution System by CYMDIST

Mehryoon, Shah M. January 2009 (has links)
No description available.
175

Power Line Communications over Power Distribution Networks of Microprocessors - Feasibility Study, Channel Modeling, and a Circuit Design Approach

Thirugnanam, Rajesh 24 January 2008 (has links)
Power line communications (PLC) has been considered by utility companies for over a half century and for home networking in recent years. However, PLC at the IC level, or even at the PCB level, has not been investigated outside Dr. Ha's research group. This thesis investigates the feasibility of PLC over power distribution networks (PDNs) of advanced microprocessors. A PDN in an integrated circuit (IC) is ubiquitous as seen by the internal logic, i.e., a power line is accessible to any internal node. This suggests the possibility of monitoring or controlling the logic value of any internal node through a power line by attaching a simple sensing/control circuit to the node. Routing the data through a power line avoids the necessity of preplanning the routing of a data path between the node and an external data pin. PLC over microprocessor PDNs also provide a viable means for "run-time testing" as well as for monitoring the so called "large time-constant errors" resulting from aging and temperature variations. In this thesis, we considered impulse-based ultra wideband (I-UWB) communication technology for PLC over PDNs of microprocessors. I-UWB has several advantages for PLC over PDNs due to its robustness to multipath effects, simple hardware for transmission and reception of pulses and, more importantly, reduced interference to the normal operation of microprocessors. A microprocessor PDN is heavily decoupled to damp the resonances in the power supply impedance as well as to reduce the slew rate of current variations by locally supplying (sinking) currents to (from) the switching nodes. Consequently, a PDN behaves like a bulky lowpass filter for high frequency signals. However, the inductance component of decoupling capacitors becomes more significant beyond the self resonant frequency (SRF) of the capacitors. So, a PDN becomes essentially a distributed circuit beyond the SRF and is no longer a lowpass filter. Indeed, high frequency PDN models developed earlier at Dr. Ha's group show that there exist multiple frequency bands where high frequency signals can propagate through the PDN with relatively low attenuation [3] [4]. The major contributions of our research lie in three areas. First, we verified existence of passbands on PDN's transfer characteristics through measurements. We carried out high frequency measurements on the PDN of Intel's 65 nm Pentium processor and 45 nm Core 2 Duo processor. We measured PDN transfer characteristics up to several GHz from a core power pin on a tester board to an on-chip power node for both active and cold microprocessor dies. The measurements show the existence of narrow, sporadic and migratory passbands i.e. location of passbands change from one generation of processor to the next. The migratory nature of passbands requires the I-UWB receiver and a transmitter to cover a wide range of frequencies rather than a specific passband. Second, we have developed a PDN communication channel model for system level study. To develop the channel model, we also performed noise measurements on Intel microprocessors. The link budget was calculated based on the channel model and appropriate modulation schemes were suggested through the system level study. Third, we investigated design of an I-UWB receiver and a transmitter, which cover a wide bandwidth. The proposed receiver and transmitter designs were evaluated through simulations in TSMC 0.18 μm CMOS process. Our simulation indicates that the PLC over a PDN is feasible with a relatively simple digital-process friendly I-UWB receiver and a transmitter. / Ph. D.
176

The Dual Use of Power Distribution Networks for Data Communications in High Speed Integrated Circuits

Chung, Woo Cheol 17 February 2006 (has links)
This thesis investigates a new data communication method in high speed integrated circuits using power distribution networks (PDNs). The conventional purpose of PDNs in integrated circuits (ICs) is to deliver power to internal nodes of an IC while meeting a level of power integrity. As the power consumption increases for very large scale integration (VLSI) systems, the number of power/ground pins increases as well. In this thesis, we propose to use PDNs for dual purposes, delivery of power and one-/two-way data communications, which is highly beneficial for pin-limited high performance ICs. To this end, we investigate signaling methods for a microscopic communication channel. Impulse-based ultra wideband (UWB) signaling is selected due to its robustness to noise and wideband characteristics. Next, we study a planar structure IC package based on the cavity resonator model (CRM) as a communication channel. Impedance characteristics of a planar structure IC package and other relevant components of an IC are important, and they are investigated for data transmission over power distribution networks. Another important aspect of the study is data transmission and reception, which we investigate through simulations. Finally, we study one possible application for one way communications, massive parallel scan design, which greatly shortens the testing time at moderate overhead. The performance is measured with eye diagrams and bit error rates (BERs) under the presence of voltage drop, simultaneous switching noise, and thermal noise. / Ph. D.
177

A computer-aided fault analysis of the VPI electric service power distribution system

Hogshead, George Leonard 09 November 2012 (has links)
In this thesis, a general-purpose digital computer program to perform fault analyses is developed and discussed in detail. The program is utilized to perform a complete fault study of the distribution system of the VPI Electric Service, as an example test case. Equations are gathered and a computer program is written to calculate the fault current magnitudes on a distribution system when three phase, phase to phase, phase to phase to ground, or phase to ground faults occur. The program is written to include basic circuit types that are in use in the utility industry today. The program provides results that are in tabular form for easy use. The VPI Electric Service system is discussed and results are included for the major distribution circuits in the system. System maps have been prepared for the circuits and are available at the Electric Service. A user's guide is included so that the program can be used whenever system changes demand a new study. / Master of Science
178

An alternating direction search algorithm for low dimensional optimization: an application to power flow

Burrell, Tinal R. 16 December 2009 (has links)
Presented in this paper is a scheme for minimizing the cost function of a three-source technique to arrive at an approximation point (I,J) that is within one unit of the true minimum. The Line-Step algorithm is applied to several systems and is also compared to other minimization techniques, including the Equal Incremental Loss Algorithm. Variations are made on the Line-Step Algorithm for faster convergence and also to handle inequality constraints. / Master of Science
179

Internet Peer-to-Peer Communication Based Distribution Loop Control System

Depablos, Juancarlo 13 June 2003 (has links)
This thesis describes the application of microprocessor based relays with internet communication capabilities in distribution protection systems. The traditional distribution protection system (recloser, sectionalizers) was configured to automatically isolate faulted circuits as well as to reenergize unfaulted loads after a certain number of reclosing operations. Internet Peer-to-Peer communication enables distribution relays to communicate with others connected to the communication network without having a master device. According to the results, the addition of peer-to-peer communication to a traditional distribution protection system significantly enhances its general performance eliminating undesired losses of unfaulted load. Additionally, it reduces outage duration as well as thermal and mechanical stress due to successive re-energizations under faults condition. / Master of Science
180

Modeling, Detection, and Localization of High-Impedance Faults In Low-Voltage Distribution Feeders

Uriarte, Fabian 05 February 2004 (has links)
High-impedance faults (HIFs) on distribution feeders are abnormal electrical conditions that cannot be detected by conventional protection schemes. These faults pose a threat on human lives when neighboring objects become in contact with the line's bare and energized conductors. An accurate electrical model for a HIF is implemented to investigate typical patterns in the line's current that allow for the detection of these faults. The occurrence of HIFs is detected with harmonic-current phase analysis and localized with recloser-sectionalizer technology as presented in this work. A sectionalizer algorithm is then presented showing the decision criteria for HIF declaration and shown to discriminate against nominal behavior in distribution feeders of similar harmonic content. Finally, it is shown that the algorithm will not produce a misreading when a current transformer enters saturation. / Master of Science

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