Show simple item record

dc.contributor.advisorToliyat, Hamiden_US
dc.creatorAhmed, Shehaben_US
dc.date.accessioned2010-01-15T00:01:34Zen_US
dc.date.accessioned2010-01-16T01:35:11Z
dc.date.available2010-01-15T00:01:34Zen_US
dc.date.available2010-01-16T01:35:11Z
dc.date.created2007-05en_US
dc.date.issued2009-05-15en_US
dc.identifier.urihttp://hdl.handle.net/1969.1/ETD-TAMU-1289
dc.description.abstractThe quest for energy is leading the industry into drilling deeper wells. Typically, a temperature gradient of 1°C/150 ft can be expected, with bottom hole temperatures reaching beyond 200°C in many areas of the world. Moreover, the increased recovery benefits and cost reductions possible with the use of horizontal and multilateral wells has triggered a need for higher power energy conversion systems in bottom hole assemblies, such as rotary steerable tools and downhole tractors. The concepts developed throughout this work address some of these new needs. This research investigated improvements, novel solutions and considerations that will lead to significant advantages in terms of reliability, extended temperature operation, increased power capability and reduced size and cost of compact harsh environment energy conversion systems. Improvements to both the electromechanical subsystem and the power electronic subsystem are introduced. Air gap viscous losses were shown to a have a significant effect on the optimal design of submersible PM (permanent magnet) machines, and a design procedure to account for this loss component in the design was developed. The application of a dual winding exterior rotor PM machine in a downhole environment enabled a significant increase in the application’s torque capability, provided protection against generator winding over voltage, and reduced parts count. Comprehensive switching device qualification, testing, and simulation lead to a simple failure mitigation technique for the operation of the most suitable devices at elevated temperature. A flying capacitor multilevel inverter was then successfully constructed and temperature tested. A novel motor drive concept suited for elevated temperature oil filled environment applications concluded the research.en_US
dc.format.mediumelectronicen_US
dc.format.mimetypeapplication/pdfen_US
dc.language.isoen_USen_US
dc.subjectmotor designen_US
dc.subjectpower conversionen_US
dc.titleCompact harsh environment energy conversion systemsen_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentElectrical and Computer Engineeringen_US
thesis.degree.disciplineElectrical Engineeringen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameDoctor of Philosophyen_US
thesis.degree.levelDoctoralen_US
dc.contributor.committeeMemberBhattacharyya, Shankaren_US
dc.contributor.committeeMemberEnjeti, Prasaden_US
dc.contributor.committeeMemberPalazzolo, Alanen_US
dc.type.genreElectronic Dissertationen_US
dc.type.materialtexten_US
dc.format.digitalOriginborn digitalen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record