This thesis develops a hardware circuit implementation of an active filter for reducing a SRM drives input current ripple or equivalently to improve the SRM drives input power quality. Its an alternative to the simple inductor and capacitor in a conventional passive filter. For the same filtering capability the size of the two physical capacitors in the active filter will be much less than the size of the capacitor in a conventional filter. Also the size of the two inductors in the active filter will be much less than the size of the inductor in a conventional filter. Some of this size reduction will be consumed by the power semiconductors but their size is much smaller than the filter components being replaced. This thesis describes the design of the active filter circuit which can replace the conventional passive filter. In this thesis, feedback control is also used with the active filter to force the filter voltage to be the desired value to minimize the effects of the circuits resonances. The active filter circuit is tested experimentally with a test circuit that mimics the current ripple generated by an SRM drive system. The experimentally generated output is verified by comparing it with simulation results from a detailed SIMULINK model and a B2 spice model of the experimental system.

The increase in the occurrence of non-linear loads in power systems has caused considerable concern to power utilities and manufacturers of power electronics equipment. To alleviate the problems caused by generation of current harmonics, there has been considerable interest in the use of active filters. This thesis presents a unified approach to the design of active filter configurations. It is shown that this approach offers a systematic method of classifying existing structures and it can be used for developing new circuits.

There is a great deal of interest in monitoring atmospheric greenhouse gases such as methane. Although distributed feedback edge-emitting lasers are often used for atmospheric detection, the development of the vertical cavity surface-emitting laser (VCSEL) has allowed for an alternative source. The VCSEL exhibits several advantages over distributed feedback (DFB), edge-emitting lasers, especially in terms of power requirements and tuning capabilities. A second harmonic spectroscopy system based on a VCSEL laser is presented. Battery operation of the driver, temperature control and receiver is achieved. The system is used to detect methane gas in open path situations, as well as in gas cylinders. Temperature and current scanning are compared as methods for laser wavelength modulation. Mathematical methods for characterizing and filtering absorption signals are investigated. The receiver system is also used with a DFB laser to compare performance with the VCSEL. A software receiver using LabVIEW is implemented, and its performance is compared with the hardware designs. A minimum detectable limit of 1.4 ppmm of methane for the hardware receiver is reported. / Photonics and Plasmas

Thesis (PhD)--University of South Australia, 1997

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 74-76). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph.D.)--University of Delaware, 2009. / Principal faculty advisor: Wenbo Li, Dept. of Mathematical Sciences. Includes bibliographical references.

Inaug.-Diss.--Uppsala. / Extra t.p., with thesis note, inserted. Includes bibliographical references (p. [61]-64).

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.