Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The electromagnetic and mechanical design aspects of an optimally designed double-sided rotor radial flux permanent magnet wind generator with non-overlap iron-cored stator windings are analysed in this thesis. The generator topology proposed in this study aims to reduce the strength demand on the generator structural support, caused by the magnetic attraction forces between the rotor and stator iron components, and in so doing reducing the overall generator mass. The proposed design has very good cooling properties. Compared to a conventional iron-cored permanent magnet generator and an air-cored permanent magnet generator, the double-sided rotor iron-cored topology performs the best with reference to mass and efficiency. / AFRIKAANSE OPSOMMING: Die elektro-magnetiese en meganiese ontwerp-aspekte van ‘n optimal ontwerpte tweesydige rotor radial-vloed permanente magneet windgenerator met nie-oorvleulende ysterkern statorwindings word in hierdie tesis ontleed. Met die generator topologie wat in hierdie studie voorgestel word, word beoog om die strukturele materiaal wat vir die generator benodig is te verminder. Die magnetise aantrekkingskragte tussen die yster komponente van die rotor en stator word dus aangespreek in hierdie studie, om sodoende ook die algehele massa van die permanente magneet generator te verminder. Die voorgestelde tweesydige-rotor ontwerp het baie goeie verkoelings eienskappe en het ‘n kleiner massa en hoër effektiwiteit as beide ‘n konvensionele ysterkern generator met ‘n enkelsydige-rotor en ‘n tweesydige-rotor lugkern permanente magneet generator met dieselfde drywingsvermoë.

Advances in electrical machinery with high efficiencies could significantly reduce the cost of industrial and residential energy systems, thereby reducing fossil fuel needs and emissions. Electrical machine design is a comprehensive process based on several factors, including economic factors, material limitations, specifications and special application-dependent factors. At the same time, machine design is a multi-physics task comprising of electric design, magnetic design, insulation design, thermal design and mechanical design. However, the out-of-date conventional machine design can neither reflect the advances in the past 30 years, nor exploit the trade-offs between design factors from the multi-physics nature of the electrical machine. This work focus on the development a fast and efficient method for the design and optimization of Surface Mount Permanent Magnet (SMPM) machines and induction machines, as influenced by the energy source, mechanical loads, thermal effects, and the up-to-date developments in materials and manufacturing capabilities. A new analytical design method is developed for the electromagnetic design of SMPM machines. Both distributed and concentrated winding types of SMPM machines are considered and compared. Based on the proposed electromagnetic analytical design method and a generic thermo-mechanical machine design model [1], an innovative and computationally efficient electromagnetic-thermo-mechanical integrated design method is developed for SMPM machines. Particle Swarm Optimization (PSO) is applied in a novel way based on this integrated design method for the multi-objective design optimization of SMPM machines. With the proposed method, the thermal and mechanical design is no longer treated separately and heuristically as in the traditional design, but has been systemically integrated with the electromagnetic design; the effect of power source, cooling capability, thermal limits, and up-to-date material capabilities are also reflected in the design and optimization. Superior designs compared to traditional designs can be achieved with PSO based multi-objective optimization. The proposed integrated design approach also has the merit of good computational efficiency and provides a significant time reduction of the design cycle compared to finite element analysis. A novel electromagnetic analytical design method of induction machines has been developed, which needs only six prime design variables but is able to design induction machines in fine details. The advantage over the traditional and other existing design method is that this proposed method does not have the heuristic selection of the design variables and does not need manual design iterations. The computing time is almost negligible and the design cycle is significantly reduced compared to the tradition machine design.

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

Thesis (Ph.D.)--University of Western Sydney, Nepean, 1995. / Includes bibliography.

Thesis (M.Sc (Hons)) -- University of Western Sydney, Nepean, 2000. / "Submitted for the degree of Master of Engineering (Hons), School of Mechatronic, Computer & Electrical Engineering, University of Western Sydney, Nepean" Includes bibliographical references (leaves 107-114).

Thesis (M.S.)--Cleveland State University, 2010. / Abstract. Title from PDF t.p. (viewed on June 3, 2010). Includes bibliographical references (p. 118-120). Available online via the OhioLINK ETD Center and also available in print.

Thesis (M.Eng.)--Memorial University of Newfoundland, 2003. / Bibliography: leaves 121-132. Also available online.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 140-147).

Electric vehicles present an opportunity to reduce the substantial global footprint of road transportation. Cost and range anxiety issues, however, remain major roadblocks to their widespread adoption. One of the simplest ways to reduce cost is to remove components from the vehicle via novel topologies, estimation and control; to reduce range anxiety, charging infrastructure needs to be simplified and the power electronics in the vehicle made more efficient. This thesis proposes a bidirectional non-isolated fast charger integrated in the traction drivetrain of an electric vehicle that is enabled by a modular power electronic converter topology called the autoconverter module. The autoconverter module is an evolution of previous modular power electronic concepts with the goal of a highly integrated, high performance converter capable of being used in a number of applications through simple parallelization. By simplifying system design through the use of one base power conversion block, overall system cost can be reduced. Key to the realization of the power module is state estimation. To enable high performance operation of the system, low noise state information must be provided to the controller. State estimation is capable of filtering measurement noise to achieve this goal. However, conventional estimation techniques typically have low bandwidth and a convergence time associated with them, limiting the overall control system's performance. Higher performance techniques, such as receding horizon estimation, offer near-instantaneous estimation with noise rejection capabilities, which makes it an attractive solution. State estimators can also realize a cost reduction through the removal of sensors with little to no performance degradation. Using high performance state estimation and three autoconverter modules in parallel, a novel three-phase inverter/rectifier topology is conceived. Using this topology, a bidirectional non-isolated integrated fast charger capable of universal, i.e. single- and three-phase AC and DC, electric vehicle charging is realized. To interface with the AC power grid and AC traction motor, a novel three-phase common mode voltage controller is developed. By controlling the common mode voltage, leakage currents, which are generated by the fluctuation of the common mode voltage across a parasitic capacitance, can be attenuated and the transformer safely removed from the system. The removal of the transformer presents a significant cost and efficiency gain for both on-board chargers and dedicated charging units. With no transformer, the need for a dedicated on-board charger is obviated; instead, the existing high power traction inverter can be used as the primary charging interface, significantly reducing the cost, size and weight of on-board charging. High efficiency in charging mode is demonstrated, with a peak efficiency of 99.4% and an efficiency at rated power of 11kW of 98.4% shown. Traction mode efficiency with the proposed integrated charger is increased by 0.6% relative to a standard drive at the motor's rated power of 5kW. Damaging leakage currents and shaft voltages are reduced by over 90% because of the common mode voltage control, which will increase drive reliability and lifetime. The topology can be applied to motor drive applications outside automotive to increase efficiency and reliability. State estimation theory for permanent magnet synchronous machine drives is expanded upon and guarantees for estimatability and stability of the estimators are provided. Two estimation schemes, a Luenberger observer and a receding horizon estimator, are studied for sensor removal and the development of a failsafe operating mode involving one phase current sensor. Both estimators function equivalently in the steady state with the receding horizon estimator having slightly better transient performance. The Luenberger observer has conditions on estimatability, whereas the receding horizon estimator has none. Both estimators permit the removal of one current sensor for cost reduction. In regular operation, there is no performance degradation.

Permanent magnet brushless dc (PMBDC) and synchronous machines (PMSM) drives are favored in variable speed applications for their high efficiency operation. Energy efficiency improvement in such motor drives is of interest in recent times because of rising cost of energy. Accordingly, two current control options for improving efficiency of these drives are taken for study and they are; (i) injecting sinusoidal and non-sinusoidal currents in PMBDC machines and (ii) lowering switching frequency of inverter driving the PMSM but without having significant low ordered sidebands of currents. Both these methods are applicable to existing types of permanent magnet motors and hence do not upset their existing optimized designs. / Ph. D.