Accurate, efficient and general computational techniques are developed to evaluate the scattering parameters of passive microstrip components composed of discontinuities in microstrip transmission lines on general two layer substrates with single and two level metallization. An open domain model is used. The Electric Field Integral Equation is examined and the Green's function for single and double layer dielectric substrates on a infinite ground plane are reviewed while emphasizing the important computational details to the model, including singularity of the kernel, evaluation of the Sommerfeld Integrals, and interpolation of the Green's functions. In order to model accurately complex circuit geometries, two dimensional currents are used. Different basis functions for expansion and for testing are chosen in order to make the computation more efficient and allow for structures having general shape in the moment method formulation. A transmission line current source is used to model the parameters are flowing in and circuit evaluated out of structure. Structures excitation and the scattering by calculating the currents each of the N-ports of the such as microstrip bends, microstrip crossovers of arbitrary angle, and coupled microstrip discontinuities are analyzed. To validate the model, results of some elementary structures are compared with published results of other models. / Graduation date: 1992

Thesis, Ph.D., University of Hong Kong, 1979. / Also available in print.

Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). "June 2008." Includes bibliographical references (p. [89]-92). Also available via the World Wide Web.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 1990. / Thesis Advisor(s): Atwater, H.A. Second Reader: Lee, H. M. "March 1990." Description based on signature page as viewed on August 26, 2009. DTIC Descriptor(s): Strip Transmission Lines, Computer Aided Design, Computerized Simulation, Parameters, Microwave Equipment, Radar, Full Wave Rectifiers, Transmittance, Resonant Frequency, Construction, Wave Propagation, Coefficients, Boundary Value Problems, Resonators, Circuits, Discontinuities, Ka Band, Models, Scattering, Equivalent Circuits, Frequency. Author(s) subject terms: Millimeter wave, suspended substrate, design model. Includes bibliographical references (p. 78-79). Also available online.

Fault location for series compensated lines cannot be addressed sufficiently by conventional solutions developed for traditional uncompensated lines. Line-parameters vary with loading and weather conditions, and therefore settings used for fault location are often erroneous. Line-parameter free solutions for fault location are therefore more reliable and accurate than conventional solutions that require such settings. Hence, line-parameter free fault location algorithms for single-circuit and double-circuit series compensated transmission lines were developed during the research project. Single-circuit lines and double-circuit lines both present unique challenges for fault location. They also vary in the number of available measurements that can be used to arrive at a solution for distance to fault. A third algorithm is presented that allows the extension of existing short line algorithms to the case of long lines. This is done by providing a method for incorporating the line shunt admittance into these existing algorithms. The aforementioned three bodies of research work, form the focus of this thesis. The algorithms are derived using two-terminal synchronised current and voltage sampled measurements. Of these, the algorithms for series compensated lines are also derived for asynchronous measurements. Phasors are obtained by carrying out a Fast Fourier Transform, and then appropriate calculations are performed for distance to fault. The thesis covers the mathematical derivations of the algorithms, involving the algebraic reduction of non-linear equations in numerous variables into a single expression for distance to fault. The results for a variety of simulation tests are shown subsequently and discussed. Various fault resistances, fault types, degrees of series compensation, line lengths, fault levels are considered in the tests carried out. The algorithms are largely found to be highly accurate under these various conditions, and where the algorithms perform to a lesser degree of accuracy are highlighted and discussed. Lastly, a detailed chapter discussing future work is also included in the thesis.

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Στόχος της παρούσας εργασίας είναι η συμβολή στην διαδικασία εκτίμησης του αριθμού των αναμενόμενων σφαλμάτων των γραμμών μεταφοράς στο Ελληνικό Δίκτυο με στόχο τον καλύτερο σχεδιασμό των γραμμών μεταφοράς. Λαμβάνοντας τα στοιχεία του αριθμού των σφαλμάτων για τα έτη 2007 και 2008, στο παρόν έργο, συγκρίνονται τα πραγματικά σφάλματα με τα αναμενόμενα (εκτιμηθέντα με τη βελτιωμένη μέθοδο ANACOM) και εξάγονται συμπεράσματα για την ικανότητα της μεθόδου να συμβάλλει στον επαρκή σχεδιασμό των γραμμών μεταφοράς στον Ελλαδικό χώρο. Συγκεκριμένα μελετήθηκαν δεκαπέντε (15) γραμμές μεταφοράς 150kV και 400kV αρχικά υπολογίζοντας τα αναμενόμενα σφάλματα με την προαναφερθείσα μέθοδο και στη συνέχεια συγκρίνοντας τα σφάλματα αυτά με τα πραγματικά. Παρατηρήθηκε ότι, ενώ στις περισσότερες περιπτώσεις ο αριθμός των πραγματικών σφαλμάτων ήταν σημαντικά μικρότερος από τον αριθμό των αναμενόμενων, υπήρξαν τέσσερις (4) γραμμές για τις οποίες η μέθοδος ANACOM είχε ως αποτέλεσμα σοβαρή υποεκτίμηση. Τα αποτελέσματα της παρούσας μελέτης συγκρίθηκαν με αποτελέσματα προγενέστερων σχετικών μελετών και συμπεράσματα εξήχθησαν με στόχο την αξιολόγηση της επάρκειας της μεθόδου ως μοναδικό κριτήριο για τον σχεδιασμό των γραμμών μεταφοράς. / The aim of this paper is to contribute to the process of estimating the number of expected errors of transmission lines in Greek Network in order to better design of transmission lines. Taking the figures of the number of errors for the years 2007 and 2008, in this work, comparing actual to expected errors (evaluated with the improved method ANACOM) and draws conclusions about the ability of the process to assist in the design of adequate transmission lines to Greece. Specifically studied fifteen (15) transmission lines 150kV and 400kV initially calculating the expected errors to the aforementioned method and then comparing these errors with the actual. Observed that, while in most cases the number of factual errors were significantly smaller than the number expected, there were four (4) lines for which the method ANACOM resulted serious understatement. The results of this study were compared with results of previous related studies and conclusions were reached in order to assess the adequacy of the method as the sole criterion for the design of transmission lines.

In modern power transmission systems, the double-circuit line structure is increasingly adopted. However, due to the mutual coupling between the parallel lines it is quite challenging to design accurate fault location algorithms. Moreover, the widely used series compensator and its protective device introduce harmonics and non-linearities to the transmission lines, which make fault location more difficult. To tackle these problems, this dissertation is committed to developing advanced fault location methods for double-circuit and series-compensated transmission lines. Algorithms utilizing sparse measurements for pinpointing the location of short-circuit faults on double-circuit lines are proposed. By decomposing the original network into three sequence networks, the bus impedance matrix for each network with the addition of the fictitious fault bus can be formulated. It is a function of the unknown fault location. With the augmented bus impedance matrices the sequence voltage change during the fault at any bus can be expressed in terms of the corresponding sequence fault current and the transfer impedance between the fault bus and the measured bus. Resorting to VCR the superimposed sequence current at any branch can be expressed with respect to the pertaining sequence fault current and transfer impedance terms. Obeying boundary conditions of different fault types, four different classes of fault location algorithms utilizing either voltage phasors, or phase voltage magnitudes, or current phasors, or phase current magnitudes are derived. The distinguishing charactristic of the proposed method is that the data measurements need not stem from the faulted section itself. Quite satisfactory results have been obtained using EMTP simulation studies. A fault location algorithm for series-compensated transmission lines that employs two-terminal unsynchronized voltage and current measurements has been implemented. For the distinct cases that the fault occurs either on the left or on the right side of the series compensator, two subroutines are developed. In additon, the procedure to identify the correct fault location estimate is described in this work. Simulation studies carried out with Matlab SimPowerSystems show that the fault location results are very accurate.

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 26, 2007) Includes bibliographical references (p. 112-113).

Thesis (M. Eng.)--Carleton University, 2001. / Includes bibliographical references (p. 189-193). Also available in electronic format on the Internet.