Evolution in microprocessor technology poses new challenges for supplying power to these devices. To meet demands for faster and more efficient data processing, modem microprocessors are being designed with lower voltage implementations. More devices will be packed on a single processor chip and the processors will operate at higher frequencies, exceeding 1GHz. New high-performance microprocessors may require from 40 to 80 watts of power for the CPU alone. Load current must be supplied with up to 30A/µs slew rate while keeping the output voltage within tight regulation and response time tolerances. Therefore, special power supplies and Voltage Regulator Modules (VRMs) are needed to provide lower voltage with higher current and fast response. In the part one (chapter 2,3,4) of this dissertation, several low-voltage high-current VRM technologies are proposed for future generation microprocessors and ICs. The developed VRMs with these new technologies have advantages over conventional ones in terms of efficiency, transient response and cost. In most cases, the VRMs draw currents from DC bus for which front-end converters are used as a DC source. As the use of AC/DC frond-end converters continues to increase, more distorted mains current is drawn from the line, resulting in lower power factor and high total harmonic distortion. As a branch of active Power factor correction (PFC) techniques, the single-stage technique receives particular attention because of its low cost implementation. Moreover, with continuously demands for even higher power density, switching mode power supply operating at high-frequency is required because at high switching frequency, the size and weight of circuit components can be remarkably reduced. To boost the switching frequency, the soft-switching technique was introduced to alleviate the switching losses. The part two (chapter 5,6) of the dissertation presents several topologies for this front-end application. The design considerations, simulation results and experimental verification are discussed.

M.S.

The Westinghouse Induction Time Klement Overload Relay, Type CO, a relay operating on the same principle as an alternating current watt-hour meter, is considerably affected in its time of operation when non-sinusoidal waves of potential are applied. If the potential wave applied has a flat top or depressed peak or if the wave has a lagging peak, that is, its maximum instantaneous value occurs more than 90 degrees after the beginning of the cycle, the operation of the relay is accelerated. If the wave of potential applied to the relay reaches its peak more than 90 degrees and less than 180 degrees after the beginning of the cycle, the operation of the relay is retarded from what it would be with a sinusoidal potential applied. The operation of a General Electric Time Current Overload Relay, Type PAC, a plunger type relay with an air bellows time delay, is, in general, retarded in operation by the application of non-sinusoidal potential waves. The operation may be slightly accelerated, however, if the wave distortion is slight, the current setting is low, and the distortion is such that the peak of the wave is flat or lagging. The effect of the wave distortion on other relays requires more study. / Master of Science

Philip M. Lewis II. / "June 7, 1956." "This report is based on a thesis submitted to the Department of Electrical Engineering, M.I.T., May 14, 1956, in partial fulfillment of the requirements for the degree of Doctor of Science." / Bibliography: p. 105. / Army Signal Corps Contract DA36-039-sc-64637 Dept. of the Army Task No. 3-99-06-108 Project No. 3-99-00-100

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains x, 105 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 99-105).

An isolated hybrid system comprised of a dispatchable and a non-dispatchable power generation sources, is proposed to supply the load of a remote village in the west coast region of The Gambia. The thesis presents an artificial neural network (ANN) based approach to tune the parameters of the frequency regulator in hybrid wind/diesel power system for isolated area power supply. The multi-layer feed-forward ANN with the error back-propagation training is employed to tune the frequency regulator in the simulation of hybrid system under different load and wind conditions. Using MATLAB/Simulink, dynamic simulations are performed to investigate the interaction between these two power sources for the load management, and the voltage and frequency behaviors during wind speed and load variations. Simulation results show that the wind turbine and the diesel generator can be operated suitably in parallel. During simulation, the frequency and voltage regulators used in the proposed hybrid system performed fairly well under wind speed variations and load changing conditions. A good frequency regulator interface, which is around 50Hz is observed for nearly the entire period of operation.

M. Tech. Electrical Engineering. / Voltage control is an essential part of the electricity transmission and distribution network system for maintaining voltage within statutory limits at the substation bus and at the consumer's point of supply. The most popular voltage control method on the transmission and distribution network system uses the on-load tap changer (OLTC) transformer. This study proposes the use of Fuzzy Logic Control (FLC) systems on the on-load tap changers when two or more mismatched transformers are connected in parallel in order to control the voltage supply to local customers. The actual voltage recordings and on-load tap change operations for each of the paralleled transformers have been analyzed and modelled on MATLAB/Simulink in order to develop an improved control algorithm using Fuzzy Logic Control. With the two-input, one-output FLC system with seven linguistic values giving 49 control rules, the number of tap change operations are minimized and the bus voltage is maintained within the statutory limits.

No description available.

Thesis (M.Eng.)--University of Wollongong, 2005. / Typescript. Includes bibliographical references: leaf 115-120.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Swaminatham, Madhavan.