Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 1995. / "December 1995." Thesis advisor(s): John G. Ciezki. Bibliography: p. 107-108. Also available online.

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 85 p. : ill. Includes abstract. Includes bibliographical references (p. 70-71).

Thesis (M.Eng.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 165-176.

Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 71-79). Also available on the World Wide Web.

The objective of this dissertation is to analyse the performance of a linear induction motor suitable to drive a circular saw blade. A selection of analytical methods available from the field of electrical machine theory was used to investigate the particular type of motor. The theoretical analysis is supported by an extensive experimental investigation. Although LIMs have been designed, analyzed and applied in other applications, significant differences exist between those LIMs and the one used for the new application. These include: the annular shaped motor, the smaller air gap, and the rotor which is thin and made of steel. Because of these differences, the methods used by previous investigators were not sufficient to design the LIM required. The theoretical analysis used a selection of methods described in the literature to quantify the effect of the rotor material, the end effect and the edge effect. New methods are described to analyse the effect of the annular shape, the normal forces on the rotor and the coil connection. In addition, a new consideration in the optimisation of these type of motors is described. An extensive experimental program was undertaken. Six different linear motors were constructed with output powers ranging from one to fifty kWatts. In addition, inverters, dynamometers, flux measurement apparatus, speed measurement, thrust measurement and friction measurement apparatus were designed and constructed. The effects on performance of slot harmonics, winding connections, the end effect and the edge effect were measured. Several contributions to the field of electrical machine theory are presented. The first is a new annular disc motor resistivity correction factor. Second, is the analysis of the effects of poles in parallel versus in series in linear induction motors. Third, is the experimental comparison between odd and even pole designs. The fourth is a second optimum goodness consideration for LIMs, which had not previously been considered. The fifth is the analysis of the rotor/stator attractive force for magnetic rotor double sided motors and a description of the flux (crenelated flux) which causes the force. Finally, a criterion for when the re-entry effect may occur is presented. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

No description available.

Thesis (PhD (Electric and Electronic Engineering))--University of Stellenbosch, 2006. / This study focuses on the drive control system of a novel direct field and torque current control applied to a six-phase induction motor. Special phase current waveforms that make it possible to have separate field and torque windings and currents in the motor are proposed. In this thesis the control of these field and torque windings to control directly the flux and torque of the motor is investigated. With the special phase current waveforms the performance of the six-phase induction motor is evaluated through theoretical and finite element analysis. In the analysis the air gap resultant field intensity and flux density produced by the stator field, stator torque and rotor currents are investigated. It is shown that with the special current waveforms a quasi-square shaped, smooth rotating air gap flux density is generated. This smooth rotating flux is important for proper induction motor operation. An equation for the electromagnetic torque is derived and used in the theoretical calculations. The ease of the torque performance calculations is conspicuous. An approximate magnetic circuit calculation method is developed to calculate the air gap flux density versus field current relationship taking magnetic saturation into account. The air gap MMF harmonics and the per phase self and mutual inductances are analysed and calculated using, amongst other things, winding functions. In the finite element analysis specific attention is given to the MMF balanced condition (zero quadrature flux condition) in the motor and the development of a per phase equivalent model. The drive system’s performance with the proposed direct control technique is verified by a developed Matlab simulation model and measurements on a small (2 kW) two-pole, six-phase induction motor drive under digital hysteresis current control. It is shown in the thesis that the calculated results from theoretical derived equations are in good agreement with finite element and measured results. This is particularly the case for the formulas of the MMF balanced constant (zero quadrature flux linkage constant) used in the control software. The results of the simulated and measured linear relationship between the torque and torque current show that MMF balance is maintained in the motor by the drive controller independent of the load condition. The direct control of the torque also explains the good measured dynamic performance found for the proposed drive.

No description available.

In this thesis, the analysis of the dynamic response of a Linear Induction Motor as an electromechanical system is done, accounting for all the governing equations implied in the process which are used to develop the corresponding simulation models. Once this model is presented, a feedback control system is implemented in order to analyze the controlled response of the motor, considering the applications and conditions analogue to aircraft launcher systems. Also a comparison between the Linear and Rotary induction motors describing the differences, similarities and equivalences will be developed. / by Armando Josâe Sinisterra. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Adjustable Speed Drive (ASD) systems are widely used in industry to effectively improve process efficiency and control. Typically, an ASD system consists of a motor with its speed controlled by a power electronics converter via varying the amplitude and frequency of the input voltage. However, several abnormal insulation failures of random wound motors in ASD applications have been reported. These failures were related to voltage transients caused by inverters employing fast insulated Gate Bipolar Transistors (IGBTs) combined with long cables that connect motors to inverters. This thesis further analyzes the distribution of voltage waveforms generated by a pulse-width modulated (PWM) inverter at the motor terminals and windings. Experimental work was performed at the Motor Systems and Resource Facility (MSRF) at Oregon State University on a specially made 5hp induction motor with taps from the first and second coil and from the first four and last two turns in every phase. Tests were performed with long and short cables and results are compared. A simple simulation model was created in PSpice and used to predict maximum voltage transients across coils and turns. The validation of the model is demonstrated by its capability to predict most of the experimental results. / Graduation date: 2000