Thesis--University of Missouri, School of Mines and Metallurgy, 1894. / The entire thesis text is included in file. Holograph [Handwritten and illustrated in entirety by author]. Title from title screen of thesis/dissertation PDF file (viewed September 3, 2008)

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 70).

Thesis (M. Phil.)--University of Hong Kong, 1990.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Ronald Harley; Committee Member: Dr. John Buck; Committee Member: Dr. Miroslav Begovic; Committee Member: Dr. Nigel Hampton; Committee Member: Dr. Rhett Mayor. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Cesar Luongo, Florida State University, FAMU-FSU College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed July 28, 2006). Document formatted into pages; contains xiii, 126 pages. Includes bibliographical references.

Thesis (M.S.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 91-93)

Thesis (Ph. D.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 1, 2007) Includes bibliographical references.

Thesis (M.S.C.I.T.)--Regis University, Denver, Colo., 2006. / Title from PDF title page (viewed on May 25, 2007). Includes bibliographical references.

This thesis describes the development of an accurate method of fault location in transmission lines and cables. While the presence of a high frequency transient superimposed on the 50 Hz f a u l t voltage and current waveforms must be removed for most of the transmission line protection methods, the method presented in this thesis, which draws from travelling wave principles, locates the fault position using recordings from the fault waveform independent of the frequency components present. Using the telegraph equations as a line model, voltage and current samples taken at one end of a line within the first 5 ms of fault inception were used to generate instantaneous voltage and current profiles for the rest of the transmission line. The voltage and current estimation were based on the solution of the equations of the line model by the method of characteristics. Different criteria functions, involving the computed variables were applied to determine the fault positions. The basic functions involve any one of the square of the voltage, the square of the current or the product of the two. Fault position is determined by the turning or inflexionary point in the functions. In a further development the variation of the tangent to the functions described was considered and the fault position was found to be indicated by the peak of the scatter diagram produced. This latter function finds special application for resistive faults and faults in teed networks where the turning point given by the earlier functions are not usually well defined. The algorithm has been tested both with laboratory simulations and digital computer simulated data on typical 33 kV, 132 kV and 400 kV systems. Fault location accuracies of between 0.1% to 3.3% were achieved. Following the success with laboratory tests on models, a proposal has been put forward for an on-line fault locator.

The object of this research is to develop a satisfactory method for locating high-impedance faults in underground cables. Most methods of locating faults require that the fault-impedance be reduced to a low value before the measurement can be made. After a careful investigation of the available literature, it was decided that the most desirable method would be one utilizing the traveling-wave. Of the traveling-wave methods, the fault-generated surge method appeared to have the greatest possibilities; yet, according to the author's knowledge, this method has not been applied to power cables. In this method, the cable itself may be considered as the network that generates the required surges. The cable is initially charged to a voltage sufficiently high to establish an arc at the fault. The sudden collapse of the high voltage at the fault generates a surge which travels along the cable to the monitoring end, where it Initiates a timing device and is reflected back along the cable toward the fault. The arc which is still conducting reflects the surge back to the station. The time interval between the first and second arrival of the fault-surge at the station is recorded by the timing device and is proportional to the distance to the fault. In mathematically analyzing the surge phenomena in cables, the La Place operational method of analysis is used. The calculations for the transient produced by the discharge of a distortionless cable are worked out in full detail. The wave-form calculated is plotted and substantiated with experimental results. The transient produced is a rectangular wave that is exponentially attenuated and whose period is 4δ, where δ is the one-way transmission time of the cable in seconds. It is this wave-form generated by the cable itself that is used to locate the fault. Basically, the fault-locator developed consists of, a high-voltage low-current power pack, a triggering unit, a timing-pip generator, two uniform delay lines, and a double-beam oscilloscope. The block diagram of the fault-locator and the circuit diagrams of the triggering unit and timing-pip generator are given. The operation of the circuits and the procedure for measuring cable faults are fully explained. The fault-locator was tested on coaxial cable only, since no power cables were available. The results obtained were very satisfactory. The oscilloscope traces obtained were photographed and the experimental results discussed. It is concluded that the fault-locator can be used without modification for locating low and medium-impedance faults, as well as high-impedance faults in power cables. If the timing-pip interval is increased, the fault-locator can also be used for locating faults on overhead transmission lines. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate