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Investigation, analysis and design of the linear brushless doubly-fed machineSeifkhani, Farroh 08 February 1991 (has links)
This thesis covers the efforts of the design, analysis,
characteristics, and construction of a Linear Brush less Doubly-Fed
Machine (LBDFM), as well as the results of the investigations and
comparison with its actual prototype.
In recent years, attempts to develop new means of high-speed,
efficient transportation have led to considerable world-wide interest
in high-speed trains. This concern has generated interests in the
linear induction motor which has been considered as one of the more
appropriate propulsion systems for Super-High-Speed Trains (SHST).
Research and experiments on linear induction motors are being
actively pursued in a number of countries. Linear induction motors are
generally applicable for the production of motion in a straight line,
eliminating the need for gears and other mechanisms for conversion
of rotational motion to linear motion.
The idea of investigation and construction of the linear brushless
doubly-fed motor was first propounded at Oregon State University,
because of potential applications as Variable-Speed Transportation
(VST) system. The perceived advantages of a LBDFM over other LIM's
are significant reduction of cost and maintenance requirements.
The cost of this machine itself is expected to be similar to that
of a conventional LIM. However, it is believed that the rating of the
power converter required for control of the traveling magnetic wave
in the air gap is a fraction of the machine rating. The constructional
design of the machine is such that the primary contains two 3-phase
windings. One of these 3-phase systems is connected directly to the
utility grid; the second 3-phase system, with a different number of
poles, is connected to a power electronic converter which has the
capability of providing adjustable frequency and amplitude of voltage
or current. The speed of the traveling magnetic field can be varied
simply by controlling the output frequency of the power electronic
converter. The design of the actual machine is such that the two
3-phase systems laid in the primary of the machine are magnetically
decoupled from each other because of the difference in pole number
of the two systems, (e.g. 6-pole and 2-pole for the test prototype
machine in our research lab). The other degree of freedom that this
machine provides, is the operation of the machine under two distinct
speeds by implementing the pole change technique. This mode of
operation can give only discrete changes in speed, however, it
provides efficient running at those speeds with a minimum of control
mechanism. On the other hand, it is anticipated that the LBDFM with
two actively fed windings will produce a continuously adjustable speed
over a wide range. Hence, LBDFM will be superior if it can be designed
to function effectively. / Graduation date: 1991
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Development of a high power density motor for aircraft propulsionDibua, Imoukhuede Tim Odion 25 April 2007 (has links)
Electric propulsion has been studied for a long time. Most of the electrically
propelled vehicles that have been developed however have been ground vehicles.
Recent research by NASA has promoted the development of electric aircraft. Most
aircraft are currently powered by heavy gas turbine engines that require fueling. The
development of electric motors to replace gas turbines would be a big step towards
accomplishing more efficient aircraft propulsion.
The primary objective of this research extends previous work by developing a
high power density motor for aircraft propulsion. This design is novel because it does
not require a dynamometer to provide the torque to drive the vehicle. Equally important
for successful testing of the motor was the design and development of a spin pit interface
that was used as a containment vessel during testing.
The research led to a designed, fabricated, assembled, modeled, and tested motor.
Voltages, currents and power outputs of the motor were measured and used to determine
the motorâÂÂs efficiency. The gaps between the motorâÂÂs magnets were related to the
current and power it produced, and modifications were made based on this relation. The vibrations of the motor were also studied and MATLAB codes were written and used to
reduce these vibrations.
Significant among the objectives was monitoring the temperatures of the motorâÂÂs
stators due to their close association with the rotating parts. The windage and friction
losses between the stators and the magnets provided a challenging hurdle in the research.
These windage and friction losses were predicted, analyzed and measured, and
modifications were made to reduce them.
Finally, results were compiled, tabulated, and analyzed. Results obtained before
and after the modifications were compared, and these comparisons were used to assess
the necessity and effectiveness of the modifications. The efficiency of the motor was
found to be 82.9% and the power density was evaluated as 33.1 W/lb based on a rotor
weight of 497 lb. It was concluded that the litz wire used in the motor has high,
frequency related impedances that could be reduced but not eliminated.
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Geometric design optimization of brushless permanent magnet motors /Martin, Benjamin C. January 2009 (has links)
Thesis (M.S.) in Electrical Engineering--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaf 49).
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Load tests on a wound rotor polyphase induction motor with unbalanced voltages on the statorMoshy, Albert Meir 05 1900 (has links)
No description available.
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Noise in induction motors.Attas, Isaac. January 1949 (has links)
Psychologists have found that noise reduces human efficiency. This effect may be considerable even for the most phlegmatic individuals. Moreover, almost everyone objects to unnecessary noises. In recent years there has arisen a very insistent demand for quieter electrical apparatus. This applies particularly to household apparatus such as refrigerator motors, vacuum sweepers and the like. Practically noiseless motors are also required for various drives ( refrigerating plants, circulation pumps of hot water systems, big ventilating systems for rooms, organ bellows etc. ) in non industrial plants such as storerooms, business houses, hotels, hospitals, churches, theatres etc> where all noise should be suppressed. It must also be noted that the stage has been reached where it is taken for granted that the products of the better known manufacturers will give entirely satisfactory performance, and often, the deciding factor between various makes is only the quietness with which the equipment operates. However,noise and vibration are not merely annoyances which may affect the sale of a product or lower the efficiency of a worker. They are often evidences of defects in design and manufacture which seriously affect the life of the equipment and, in many cases, the safety of the user.[...]
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Design, analysis, control and application of permanent-magnet hybrid brushless machinesLiu, Chunhua, January 2009 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 240-266). Also available in print.
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Design, control and application of double-stator permanent magnet brushless machinesNiu, Shuangxia. January 2009 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 151-164). Also available in print.
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Über die Entwicklungsmöglichkeiten des Induktionsmotors für Einphasen-WechselstromKoch, R. von. January 1905 (has links)
Thesis (doctoral)--Königliche Technische zu Berlin, 1905. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. [103]-104).
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A new phase decoupling permanent magnet brushless DC motor and its control /Xia, Wei. January 1996 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1996. / Includes bibliographical references.
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Design of an alternating current squirrel-cage induction motorThompson, Thomas Moffett. January 1925 (has links) (PDF)
Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1925. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed September 16, 2009) Includes bibliographical references (p. 30) and index (p. 31-32).
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