2026-09-19T21:56:46Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/338542022-01-13T07:54:29Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023
James L. Kirtley, Jr.
Reddy, Sivananda Kumjula
Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
2006-08-25T18:51:12Z
2006-08-25T18:51:12Z
2005
2005
http://hdl.handle.net/1721.1/33854
66272282
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.
Includes bibliographical references (leaves 117-118).
Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation is implemented. Since wind speed varies, the shaft speed should too. But electrical output frequency should be synchronous and Induction machines on their own do not allow for variable ratio of shaft speed to electrical frequency. Permanent Magnet (PM) machines have major advantages: Efficiency and power density are both high: they are also inherently synchronous. A prototype ([approx]20 kW) of a novel hybrid machine that encompasses the desired features of Permanent Magnet Generators and Doubly-Fed Induction Generators (DFIGs) is being built. This novel geometry machine has to be tested for stability on a test-bed and controlled using an appropriate power electronics and controller circuit. A MATLAB 5th order model of the machine is built, linearized. simulated and examined for stability. The dynamics of the PM rotor is studied. The electrical equivalent behavior of this component of the machine is vital because the frequency of the output power is a direct function of its mechanical speed. As a culmination of this research work, possible paths for the scope of future work on this technology is presented.
(cont.) Keywords: wind turbines, modified torus geometry, permanent magnet, doubly-fed induction. dynamic state-space model, electromechanical stability analysis.
by Sivananda Kumjula Reddy.
S.M.
118 leaves
5260673 bytes
5266173 bytes
application/pdf
application/pdf
eng
Massachusetts Institute of Technology
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.
http://dspace.mit.edu/handle/1721.1/7582
Electrical Engineering and Computer Science.
Operational behavior of a double-fed permanent magnet generator for wind turbines
Thesis
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<Abstract>Greater efficiency in wind turbine systems is achieved by allowing the rotor to change its rate of rotation as the wind speed changes. The wind turbine system is decoupled from the utility grid and a variable speed operation is implemented. Since wind speed varies, the shaft speed should too. But electrical output frequency should be synchronous and Induction machines on their own do not allow for variable ratio of shaft speed to electrical frequency. Permanent Magnet (PM) machines have major advantages: Efficiency and power density are both high: they are also inherently synchronous. A prototype ([approx]20 kW) of a novel hybrid machine that encompasses the desired features of Permanent Magnet Generators and Doubly-Fed Induction Generators (DFIGs) is being built. This novel geometry machine has to be tested for stability on a test-bed and controlled using an appropriate power electronics and controller circuit. A MATLAB 5th order model of the machine is built, linearized. simulated and examined for stability. The dynamics of the PM rotor is studied. The electrical equivalent behavior of this component of the machine is vital because the frequency of the output power is a direct function of its mechanical speed. As a culmination of this research work, possible paths for the scope of future work on this technology is presented.</Abstract>
<Abstract>(cont.) Keywords: wind turbines, modified torus geometry, permanent magnet, doubly-fed induction. dynamic state-space model, electromechanical stability analysis.</Abstract>
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