published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

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Many high performance drive applications require wide Constant Power Speed Range (CPSR) for efficient use of energy. The examples of such applications are the starter alternator system of automobiles proposed for the 42V PowerNet, traction in the hybrid/electric vehicle, wind power generator etc. The Permanent Magnet (PM) machine is the natural choice of such niche applications because of their higher efficiency and compact size. However, the Surface Permanent Magnet (SPM) machine with sine distributed winding and radially-laminated Interior Permanent Magnet (IPM) machine with conventional structure has very limited or zero flux-weakening capability. The flux-weakening capability of the SPM machine can be improved by using concentrated, fractional-slot stator but here well-known advantages of the sine distributed winding are needed to be compromised. In the IPM machine, fluxweakening was improved using axial lamination and more than two magnet layers per pole. However, the construction of such IPM machine is complicated and expensive. This thesis presents design and analysis of a new type of the Interior Permanent Magnet (IPM) machine that have a very wide Constant Power Speed Range (CPSR) without compromising simplicity of construction and advantages of the distribution winding. In the new IPM machine, the magnet poles were segmented in the radially direction and the iron bridges between magnet segments provide for additional paths of flux-canalization to give the rotor an inherent capability of fluxweakening. Consequently, a very wide constant power speed range can be achieved in such machines. The proposed IPM machine of this work was referred as the Segmented IPM machine. The thesis focuses on the optimization of the Segmented IPM machine in a 42V environment of the automobile. First, for the conceptual evaluation a 4 pole, 550W Segmented Magnet IPM machine was optimized using finite element analysis. The parameters were calculated for prediction of the steady-state and transient performances. The torque- and power-speed capability were estimated using time-step, circuit-coupled finite element analysis. The cogging torque and variation of iron loss with frequency were also investigated during the design process. A prototype machine was constructed on the basis of the optimized design. The steady-state and transient performances of the prototype machine were measured and compared with the predicted results for experimental verification. The measured performance analysis was found to match very well with the predicted results. The measured torque- and power-speed capability of the Segmented IPM machine was also compared to those of a conventional, non-segmented IPM machine of similar rating and size. The thesis also presents the optimized design of a 6kW, 12 pole Segmented Magnet IPM machine for application in the Integrated Starter Alternator (ISA) of the electric/hybrid vehicle. It can be concluded from the predicted steady-state analysis of the 6 kW, 12 pole Segmented Magnet IPM machine that it should be able to satisfy most of the required criteria of an ISA with appropriate design optimization.

Thesis (M. Phil.)--University of Hong Kong, 1991.

Thesis (M.Eng.)--Memorial University of Newfoundland, 1999. / Bibliography: leaves 97-101.

Thesis (M.S.)--Florida State University, 2006. / Advisor Juan C. Ordonez, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains x, 267 pages. Includes bibliographical references.

A microprocessor control scheme for variable speed switched reluctance motor(SRM) drives is discussed. A particular implementation derived from first principles of the SRM is presented. The Intel 8088 microprocessor is used for the design implementation. It is shown that given the control requirements of the SRM like firing different phases according to rotor position and phase currents, a microprocessor controller is a good choice. The controller is economical since it uses standard TTL chips. The slow response at low speeds is also discussed. Experimental results performed on a static inductive load using a simulated position feedback are presented, showing how the current control available at lower speeds is lost at higher speeds, due to limited dc bus voltage. A listing of the controller software with adequate comments and the circuit diagrams are appended. / Master of Science

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Vita. / Includes bibliographical references. / Ph.D.

A project funded by the Southern California Edison (SCE) Company, Research Center of Irwindale, California, has supported the development of a performance and parameter prediction software program for use during the refurbishment of large synchronous machines, turbine generators, and synchronous condensers. The computer program was developed for SCE to allow user friendly input of a machine's physical parameters such as pole/field/winding/stator dimensions, type of steel, and other related information in order to calculate the machine's reactances, time constants, and performance curves. The program also allows some degree of design calculation to be performed in order to meet certain design criteria where appropriate. The theory behind the calculations upon which the electrical calculations are built is obtained primarily from literature published in the early 1950's. Since that time, however, machine design has progressed into ever larger generators, most often in the hundreds of Megawatt range with some units exceeding one thousand Megawatts. This size increase has established the practice of winding the stator coils into parallel circuits to maintain acceptable flux and generated voltage levels. These design practices justify a re-examination of the traditional methods used to calculate a machine's reactances and time constants. Accordingly, the use of parallel circuits in the stator winding and their effect on machine parameters has not, to this author's knowledge, been addressed in public literature. These issues are exam fled and modifications to the traditional formulas have been derived for the reactances along with the process of carrying out the calculations on a per pole basis. In addition, the calculation of the parameter and performance equations of a machine are suitable for implementation on a computer due to the length and often iterative calculation procedures. The procedures used to calculate the capability and saturation curves directly from the machine's physical dimensions are developed. During development of the program a forty megawatt generator was measured in order to test and debug the program. Results of this test case are presented and compared to test values obtained at the time of the generator's installation. / Graduation date: 1994

Thesis (Ph.D.)--Memorial University of Newfoundland, 2000. / Bibliography: leaves 179-191.