D.Ing. / This study describes the technology of the Nonlinear Resonant Pole Converter. The NLRP is a soft switching topology that has different advantages.over other power electronic converters. This study describes the evolution, analysis, application and design of the NLRP. An introduction and background section with operating principles are provided. Detail analysis with operational limits is given ...

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22843号 / 工博第4783号 / 新制||工||1748(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 篠原 真毅, 教授 大村 善治, 准教授 後藤 康仁 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Includes bibliographies. / This study resulted from a perception held by the author that more attention is afforded to complying with the procedural elements of Environmental Impact Assessment (EIA) in South Africa, than to ensuring the validity of its technical content. The routing of high voltage overhead transmission lines provides a relevant field of study in which to address this perception. An initial literature review to contextualise the perceived problem showed that the questionable validity of the technical content of EIA was one of six shortcomings identified. To address the problem, an inductive approach was adopted to focus on the interpretation and prediction activities of EIA and two propositions, stated as research questions for discussion, were developed. These referred to the theoretical question of whether methods are specified for high voltage overhead transmission line EIAs, and to the practical question of whether the environmental impacts that are known to result from transmission line projects are effectively addressed in such EIAs in South Africa. Investigating these questions provides insights into whether the technical content of transmission line EIA is sufficiently rigorous in South Africa. The method of study takes the form of a sequentially more focused examination of the literature on EIA, from the strategic level, to the sectoral level and culminating at the project level. EIA methods specified for linear developments were identified at the sectoral level, while at the project level the known environmental impacts that result from high voltage overhead transmission lines were determined. A theoretical background was compiled in this way, which allowed for comparison with the practice as determined from benchmark and case study Environmental Impact Reports (EIRs).

Nikolai Tesla's revolutionary experiments demonstrated the possible benefits of transmitting power wirelessly as early as 1891. Applications for the military, consumers, emergency personnel, remote sensors, and others use Tesla’s discovery of wireless power. Wireless power transmission (WPT) has the potential to be a common source of consumable energy, but it will only receive serious consideration if the transmit and receive systems are extremely efficient and capable of delivering usable amounts of power. Research has been conducted to improve the efficiency and performance of nearly every aspect of WPT systems, but the relatively new field of metamaterials (MTMs) has yet to play a dominate role in improving system performance. A gradient index (GRIN) MTM lens was designed using Ansoft’s High Frequency Structure Simulator (HFSS) to improve antenna gain and thereby increase WPT system performance. A simple WPT demonstration system using microstrip patch antennas (MPAs) confirmed the benefits of the GRIN MTM lens. The WPT demonstration system, MPAs, and GRIN MTM lens were constructed and experimentally tested near 2.45 GHz. The theoretical and experimental gain improvement of the MPA due to the GRIN MTM lens is 5.91 dB and 7.06 dB, respectively.

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This paper reports the results of a study into V-ribbed belt noise generated as a result of tangential belt slip. The results of experimental studies to identify the belt operating conditions associated with belt noise are presented, together with the results of analytical studies to identify the mechanism of noise generation. It is concluded that tangential slip V-ribbed belt noise generation is controlled only by the amount of slip, and that the mechanism of noise generation is harmonic excitation of the fundamental vibration mode of the belt, with stick¿slip frictional behaviour providing the impetus for the vibration

The work described here has been carried out to obtain a better understanding of the tooth root cracking failure mode of timing belts. Previous work has demonstrated the close dependence of this on the tooth deflections of fully meshed teeth, generated by torque transmission, but has not considered the additional distortions generated in the partially meshed conditions at entry to and exit from a pulley groove. Approximate compatibility and constitutive equations are combined with a rigorous consideration of tooth equilibrium in partial meshing to show how bending moments are generated at both exit from a driven pulley and entry to a driving pulley. Experimentally determined belt lives correlate very well with a combined measure of fully meshed tooth strain and strain due to bending at entry or exit. The analysis also shows that this strain measure reduces with increasing belt tooth stiffness, confirming the importance of a high tooth stiffness for a long belt life. Tooth force variations through the partial meshing cycle have also been predicted and compared with measurements obtained from a special strain gauge instrumented pulley. A greater pulley rotation than is predicted is required for a belt tooth to seat in a pulley groove. There is room for improvement in the modelling

Achieving electrostatic control of quantum phases is at the heart of condensed matter physics allowing us to interface fundamentally different electronic orders and observe their interplay with one another. Recent investigations have revealed emergent superconductivity tuned by the electric field effect in two-dimensional (2D) semimetals and moiré heterostructures. Through electrical transport measurements, we investigate superconductivity in few-layered Td - MoTe2 in this dissertation. Given its sensitivity to the ambient, a process to encapsulate and simultaneously electrically contact the material is developed to preserve the innate properties of MoTe2. At the outset, we observe a dramatic enhancement of superconducting critical temperature (Tc) in few-layered MoTe2. Monolayer’s Tc of ∼ 7.5 K is about 60x higher than the bulk. Reflecting its relatively small Fermi surface, superconductivity is tunable with electrostatic gating andresponse to in-plane magnetic fields reveals a tilted Ising spin texture. Some 2D crystal systems exhibit a polar crystal structure resulting in a robust, nonvolatile and bistable interlayer polarization giving rise to electric-field tunable ferroelectricity. Remarkably, we show that noncentrosymmetric bilayer Td - MoTe2 exhibits such ferroelectric switching while simultaneously being a superconductor, two electronic orders conventionally thought to be incompatible with one another. Further, electrostatic doping unveils a superconductingdome. It is found that the maximum Tc is concomitant with compensated electron and hole carrier densities and vanishes when one of the Fermi pockets disappears with doping pointing towards a pairing mechanism mediated by Fermi surface nesting between electron and hole pockets. Finally, in-plane magnetotransport measurements reveal a two-fold symmetric superconductivity around the crystal axes for bilayer MoTe2. Superconductivity is maximized when magnetic field is parallel to the ?-axis of the crystal and minimized for b-axis. Although unsurprising given the ?2 crystal symmetry, these results lend further credence to the tilted Ising spin texture, as unveiled from Hc2|| measurements on the monolayer.

In this thesis case studies have been made to study the impact ofSMES system on power system transmission with a decoupled Optimal Power Flow program. Linear Programming (LP) and Quadratic Programming (QP) storage scheduling methods including transmission security have been developed, LP method is suitable for single storage system and QP method is capable of solving multiple storage scheduling problem. Results on single storage system is compared with Load Shaving method, which indicate that three methods have approximately the same storage schedule and daily fuel cost. Results on two storage system with QP method suggest that the coordination between storage units can help to transfer more power from base units and reduce total fuel cost in peak hours. / Master of Science

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