Thesis (M.S.)--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 April 22, 2009) Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2004. / Printout. Includes bibliographical references (leaves 41-43). Also available on the World Wide Web.

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007. / Committee Chair: Adibi, Ali; Committee Member: Chang, Gee-Kung; Committee Member: Ralph, Stephen.

Thesis (M.S.)--Michigan State University. Electrical Engineering, 2008. / Title from PDF t.p. (viewed on Aug. 5, 2009) Includes bibliographical references (p. 230-231). Also issued in print.

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 130-131). Also available on the World Wide Web.

Abstract not available

Bibliography: p. 114-117.

The development of a simple efficient Pulse Width Modulation (PWM) modulator has been a goal for many research workers. In general three techniques have been used, namely; the analogue triangular wave technique; the use of look-up tables, and the use of Analogue to Digital converters together with analogue circuitry. The modulator described in this thesis is based on an iterative numerical algorithm, and is thus fundamentally different from all previous techniques. The algorithm is limited only by the speed and precision of the associated digital circuitry and can achieve higher modulating frequencies with greater accuracy than can be realised using any of the methods that have previously been investigated. The use of high switching frequencies simplifies the design of filters to reduce both unwanted harmonics and acoustic noise. In this thesis, an equation of a multiphase digital oscillator is derived which is simple to implement and will operate over a wide range of frequencies. The conditions for stable oscillation are derived, and two classes of oscillator are developed. It is shown how the frequency and amplitude of oscillations can be independently and continuously varied. The errors in computing the amplitude and frequency are analysed, and are shown to be cyclic. Upper bounds for the amplitude errors are derived. Single and three phase PWM modulators are described and the implementation procedures for their practical realisation are developed. Two specific implementations of the algorithm are investigated and experimental results confirm theoretical analyses. The algorithm can be incorporated in the Space Vector Modulation (SVM) method of PWM, to improve the resolution at low speeds and to enable the SVM technique to be applied at high gear ratios. A 3-phase 16-bit PWM modulator was built and operated satisfactorily with a pulse switching frequency of 20 kHz and an output frequency range of 1000:1. / Thesis (Ph.D.)-University of Natal, Durban, 1989.

Thesis (M Eng (Research)) -- University of South Australia, 1992

Thesis (M Eng (Research)) -- University of South Australia, 1992