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Title: Air cored linear machines for ground transportation
Author: Abel, Edward
ISNI:       0000 0001 3390 8312
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 1981
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The most important areas of interest concerning air cored linear machines (ACLM), their design, development and application to guided ground transportation are presented. A description of the origins of high speed guided ground transportation (HSGGT) is given which covers tracked air cushion vehicle and linear induction motor development, as well as the electromagnetic and electrodynamic systems of levitation. ACLM began as the favoured propulsion option for the electrodynamic system, and the machine characteristics of the linear synchronous motor (LSM) are discussed with optimization techniques given for choice of wavelength. Stress factors for rectangular coils with tight corner radii can be calculated using a circular coil equivalent. The linear commutator motor (LCM) provides a means of achieving high local track power density without degrading overall machine performance. Several forms are examined and the trade off and comparison with LSM made. The system comparison of the electrodynamic and electromagnetic systems (EDS and EMS) of magnetic levitation indicates that specifying Just lift to drag ratio and specific energy Intensity is an insufficient base. Comparison is made of the German EMS and EDS designs, together with a comparison of other groups' EDS vehicles. The German EDS design is found to be heavily penalised by excessive low speed suspension weight. Several variations of a new type of ACLM using on board flux pumping are proposed. The advantages are that a passive track structure is possible, and a cryogenically cooled winding can be used as a cost effective alternative to a superconducting coll. Application of ACLM to propulsion of advanced duorail vehicles is set out together with the possibility of speed extension with reduced track wear and Initial capital coat, as well as reduced manning and maintenance cost. An Advanced Passenger Train with LSM would appear to be a feasible option for future transport needs, and extension to a low speed urban vehicle using for example liquid nitrogen cooled pool boiling coils would similarly present a low cost system. An indexed bibliography containing over 400 HSGGT references is included, with a bias to EDS and ACLM.
Supervisor: Not available Sponsor: Wolfson Foundation
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: TF Railroad engineering and operation