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Thesis (Ph. D.)--Washington State University, May 2009. / Title from PDF title page (viewed on Apr. 2, 2009). "School of Electrical Engineering & Computer Science." Includes bibliographical references (p. 433-454).

Thesis (M.S.)--Rochester Institute of Technology, 1995. / Typescript. Includes bibliographical references (leaves 97-99).

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 76.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007. / Tentzeris, Manos, Committee Member ; Wollack, Edward, Committee Member ; Cressler, John, Committee Member ; Papapolymerou, Ioannis, Committee Chair ; Laskar, Joy, Committee Co-Chair ; Ayazi, Farrokh, Committee Member.

To design high frequency complex electromagnetic structures with TLM is not trivial in spite of the simplicity of the fundamental TLM algorithm. This is because TLM is a time and space discretization method in which the entire computational domain must be filled with nodes. In three-dimensional cases, the computational effort to solve realistic problems would soon become intractable unless special techniques are used. To be attractive to the design engineer, field simulation tools must include these advanced techniques automatically in the models. New TLM features and computational techniques have been developed in this thesis to overcome the above mentioned problems. An experimental multi-purpose electromagnetic field simulation tool has also been created to demonstrate the features and techniques developed in this thesis can be easily integrated into a well designed tool. / Graduate

M.Ing. / This study investigates the limits to which distortion can be compensated in electrical distribution networks. Many factors hinder the "ideal" compensation of the line current to a perfect sinusoidal, in phase, scaled replica of the supply voltage. The different power theories that can be used to derive the reference compensation current, is one of the fundamental limits. The differences and correspondences between the FBD and Czarnecki theories are investigated in detail. Furthermore, it is shown by simulation and practical results, that the effectivity of compensation by the instantaneous power theory is load dependent. The compensation strategy and topology also impose limits on the effectivity of compensation. The position and strategy of a compensator determine whether the consumer is able to isolate his distortion from the rest of the network, or isolate himself from the distortion of other consumers. Distortion frequencies and system impedances are chosen specifically to visually show the effect of the different topologies and strategies, by means of simulation. One of the most important limits brought about by new technology, is the lagging of the reference compensation current, due to the use of signal processing in determining the reference signals. The effect of this lagging reference is clearly shown by means of simulation and practical compensation systems. An effectivity index for this phenomenon is defined for steady state systems. The dynamic limitations of this lagging reference compensation current is investigated thoroughly. A method is derived by which the maximum fault, due to the sampling time and signal processing time, can be calculated when a high f-region occurs in the line current. The dynamic response of the compensation system is also limited by the ' di-ability of the converter. Therefore, a method is developed to calculate the individual fault contribution of the lagging reference as well as the converter. This method enables designers to determine the parameters of the signal processing system and the converter in the planning phase. The use of a maximum sampling frequency is stressed. In the experimental work, a 10kVA, PWM-switched IGBT inverter is used as a parallel voltage fed compensator. It compensates for two non-linear loads : a three phase diode rectifier with an inductive load, and a three phase diode rectifier with a capacitive load. The practical compensation according to the instantaneous power theory of these two loads, confirms that the result of this compensation is load dependent. The effect of the lagging reference compensation current in a practical system is also shown.

The determination of the amplitude-response characteristic is an important means of checking a network design. However, this measurement is usually a time-consuming procedure and at best does not yield a continuous curve. A device which would produce a continuous curve corresponding to the amplitude-response characteristic would be extremely useful in network design and development. It is shown that the system response to a frequency-modulated signal can be made to approximate the amplitude-response characteristic if the frequency is varied slowly enough so that the "quasi-stationary" conditions exist. The physical realization of this slowly varying frequency requires an oscillator with an extremely large frequency range, controllable by one circuit parameter. The greatest difficulties involved in the design of this oscillator were the development of a simple and stable subtractor and the synthesis of the frequency-determining networks. A mathematical analysis was made to determine the characteristics of the network necessary to produce a logarithmic relation between the oscillator frequency and the control position. The audio-frequency sweep generator was constructed using networks designed to approximate the required characteristics and when tested proved to have a satisfactory output waveform. Any improvement in the oscillator performance would require a better approximation to the specified network characteristics. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment Of the requirements for the degree of Master of Science in Engineering. Johannesburg, 1993 / Renewal is the extraction of the intellectual content (algorithms, data structures) from an existing program, and then puilding a new more maiatainable program using more modem progra1Tlming methods and languages. A survey of software structure on maintenance. highlighted the different hierarchies produced by functional and object-oriented design methods. Elecsim, a linear circuit sL~ulator written in Pascal, was chosen as the existing program to be renewed, The new version follows the approach of decoupling the user interface and introducing an explicit scheduler. The object-oriented design technique is used extensively. Other issues addressed include online-help and. documentation for the program. Conclusions are drawn which are generally applicable from the specificlessons learnt from the Elecsim/Elector case study. / MT2017