Thesis (Ph. D.)--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 29, 2007) Includes bibliographical references.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Robert Ashton. Includes bibliographical references (p. 73-74). Also available online.

Electrical systems have become ubiquitous, and with them come the need to accurately monitor electric current. The aerospace industry is no exception. Modern aircraft may contain more than one hundred current sensors, each one critical to a properly functioning vehicle. While these sensors function acceptably, several areas have been identified for improvement: size, weight, and cost. Each sensor is bulky, taking up valuable space. They are also costly to manufacture. The existing design is based on the Hall effect, and has remained fundamentally unchanged for decades. With the recent progress in manufacturing techniques and materials, it would be beneficial to reexamine these sensors and determine if improvements can be made using the accomplishments of recent years. Of particular interest are microelectromechanical systems, also known as MEMS. Using a sensor based on MEMS technologies in which design, function, and fabrication are closely intertwined would automatically meet two of the three goals: reducing size and weight. MEMS additionally have the potential to allow existing systems to be miniaturized. Also of interest are advanced materials, some of which can behave as transducers, linking different physical phenomenon. The goal of this dissertation is to use advances in manufacturing techniques and materials, specifically those discussed above, to design a better current sensor. As part of this goal, several potential solutions were studied and optimized. Finally, proof-of-concept prototypes were fabricated and tested to validate the feasibility of the designs and offer insight into continued sensor development.

During the past two decades, Quality of Supply has become a serious problem for Variable Speed Drives in the industrial and commercial sectors. Quality of Supply problems can trip Variable Speed Drives, which results in loss of production, which is a significant problem in the paper and pulp industry. Researchers have proposed that Quality of Supply problems can be minimised in-house, using controlled front end rectifiers (boost rectifier), to maintain a regulated DC link voltage in the Variable Speed Drive configuration, as most faults are created by a varying supply voltage. This thesis extends the work performed on boost rectifiers by investigating the feasibility of replacing the classical controllers with a Continual Online Trained Artificial Neural Network current controller. The approach adopted in this thesis was to evaluate and extend the work previously performed on conventional boost rectifier current controllers and Continual Online Trained Artificial Neural Network current controlled inverter, at the University of Natal. During this evaluation, the respective controller shortcomings were identified and addressed. Thereafter the Continual Online Trained Artificial Neural Network current controller was modified, according to the control requirements of the boost rectifier, and used as a replacement for the conventional current controller in the boost rectifier system. Finally, the Continual Online Trained Artificial Neural Network current controller was evaluated to assess its viability as a current controller for a boost rectifier. The concept of implementing the real-time Continual Online Trained Artificial Neural Network current controller using a DSP (Digital Signal Processor) was described, along with the main features and practical limitations of existing commercial DSP's. It is shown that at the time of writing of this thesis, the commercially available DSP' s are not powerful enough to implement the Continual Online Trained Artificial Neural Network current controller. However this thesis also shows that it is feasible to implement the real-time controller on the newly released TMS320C67 DSP card. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.

This thesis presents the operational principles, and analysis, simulation. experimental results of a single-cell full-bridge high frequency (HF) transformer isolated DC-to-DC power converter with an inductive output filter controlled with a new gating scheme. A single-stage multi-cell HF transformer isolated AC-to-DC power converter with the same new gating scheme is designed and tested. The new gating scheme is implemented in a Field-programmable gate-array (FPGA) chip to generate the control gating signals for the DC-to-DC and AC-to-DC converters. The steady-state operation of the DC-to-DC converter controlled with the new gating scheme is analyzed using the equivalent circuits during different intervals of operation. Based on the operational analysis, a set of equations is derived to draw design curves. A design example of 5 kW, 580 V to 620 V input and 420 V output DC-to-DC converter is given to present the design procedure. PSPICE simulation and experimental results obtained from an experimental converter controlled with the FPGA are provided to verify the theoretical analysis, and design procedure. A systematical procedure for finding the parameters of the output RCD snubber circuit is also given. A 3 kW 3-cell 166 V to 260 V input 420 V output single-stage HF transformer isolated AC-to-DC multi-cell converter is designed and tested using a FPGA controller The new gating scheme is implemented on a Xilinx Spartan 11 FPGA chip using two digital pulse-width modulation (DPWM) approaches, the conventional DPWM module and the delay-line DPWM module. The simulation and experimental results are presented.

This thesis deals with hybrid phase modulated converter with inductive output filter as well as capacitive output filter. The operational principles, detailed steady-state analysis for different modes of operation, detailed design procedure with an example. simulation and experimental results are presented for HPMC with inductive output filter. HPMC with inductive output filter has reduced output filter requirements and maintains ZVS for wide line and load variations. This converter suffers from duty cycle loss and output rectifier ringing requiring secondary-side snubbers and higher voltage rated rectifier diodes. To overcome this problem, a hybrid phase modulated DC-DC converter with a capacitive output filter is proposed. Different modes of operation of the proposed converter are identified and a detailed steady-state analysis for these modes of operation is presented. A design example of 200 W, 22 V to 41 V input voltage and 350 V output voltage hybrid phase modulated converter with inductive and capacitive output filter is given to present the design procedure. Simulation and experimental results obtained from the laboratory prototype are provided to verify the performance of the converter. A comparison of performance between the HPMC with inductive and capacitive output filters with standard phase-shifted PWM full bridge converter are also presented.

Thesis (M.S.)--Ohio University, June, 1997. / Title from PDF t.p.

Thesis (MOcE)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 52-54). Also available on the World Wide Web.

Includes bibliographical references (p. 143-153).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.