Studies in Electrical Machines & Wind Turbines associated with developing Reliable Power Generation

The publications listed in date order in this document are offered for the Degree of Doctor of Science in Durham University and have been selected from the author’s full publication list. The papers in this thesis constitute a continuum of original work in fundamental and applied electrical science, spanning 30 years, deployed on real industrial problems, making a significant contribution to conventional and renewable energy power generation. This is the basis of a claim of high distinction, constituting an original and substantial contribution to engineering science

Application of EL CID to salient-pole electrical machines

Sutton introduced EL CID in the 1970's. This thesis records the development of EL CID theory, with particular reference to its application to large, salient-pole, water-turbine driven, electrical machines, known as hydrogenerators. Factors are identified and clarified which otherwise may cause misunderstanding of hydrogenerator stator core interlamination insulation condition. Features discussed, with reference to their impact upon the detected EL CID signal, are alternative forms of excitation winding of the stator core, its constructional features, including core build bars (or key bars), core segmentation, proximity of ferrous components, plus ancillary matters such as the location of brake/jack units, the degree of machine assembly, whether in or out of the operational situation, the extent of the machine enclosure, and the presence of the stator winding and rotor-mounted salient poles. Although satisfactory application of EL CID to turbogenerators was achieved in the 1970's, anomalies arose when applied to salient-pole machines, due to shorter stator winding end-overhang, its multi-parallel circuits, and also the disincentive of realignment of the rotor if removed, making access to the stator bore and accurate location of the excitation cable more difficult. When present, joints in very large hydrogenerator stator frames and cores, for transportation, made analysis of EL CID results particularly difficult. The problem presented by core joints arose in the initial factory demonstration of application of EL CID to hydrogenerators. The solution recognises the interdependence of the two orthogonal EL CID signal components, which indicate EL CID as analogous to a transformer, with two short-circuited secondary windings; one for interlamination fault current (designated "delta"), the other being the stator winding, when present. In order to draw the phasor diagram with reference to the secondary side of the analogous transformer, the direction of the excitation phasor is reversed, since the fault current is detected in a secondary circuit. Application of standard transformer theory produces an appropriate EL CID phasor diagram, in various forms, depending upon the particular test circumstance. In this context, the significant concept of a line for which interlamination fault current (delta) is zero (i.e. a zero delta line) was introduced. The two orthogonal EL CID signals, designated PHASE and QUAD, are plotted on equal scales; unless related appropriately by a technique described, which takes the difference into account, to ensure the highest accuracy. Evaluation of delta indicates the effectiveness of core repairs, which supports the usefulness of the EL CID technique when applied to hydrogenerators, as well as turbogenerators. At core joints, the detected maximum fault current (deltamax) is usually appreciably greater than the traditional acceptance criterion of 100 mA. This is discussed, and the conclusion drawn that the distribution of delta along the core length provides an adequate indication of any weak region of interlamination insulation. The practise of routinely resetting the Phase Reference for an EL CID test is examined, and found to be not acceptable, unless the results are subsequently referred back to the basic reference. As a final demonstration of the EL CID technique usefulness, the analysis of results from a core joint, where there was an imposed artificial fault, identifies the location concerned

Selected Papers Compiled from Presentations - Leningrad Task Force Meeting, May 24-29, 1982, Leningrad, USSR

In line with the selected methodology, the Management and Technology area at IIASA decided to have the Innovation Management Task concentrate on sectors in an attempt to analyze the situation at this level of the economy before making any aggregations or conclusions relevant to management. In order to properly cover industry, it was suggested that branches that are at differing stages or that display different kinds of development be chosen for the study. Electrotechnology or power electrical engineering was one of the branches selected being an example of mature industry. The task force meeting held in Leningrad from May 24-29, 1982, was the first attempt LO scan problems in this branch and gain some kind of understanding as to the research that has been performed. The event was a multiobjective undertaking intended to identify the interest in this field. potential collaborators, and relevant issues. Due to the unique opportunity of becoming acquainted with the work of Soviet scientists, the papers presented were not only by researchers and scholars in this field, but also by decision makers on the different levels of management. For the first time, several issues are exposed for the English speaker, thus, rendering a service to the English speaking community of researchers, and enhancing the contacts with collaborators in socialist countries. The papers are arranged into four sections, each devoted to issues that can be viewed as interesting topics for further research. The discussion, found in the back of the proceedings as Appendix A, reflects the character of the productive and creative environment at the meeting. The reader must bear in mind that this is only an attempt to reflect the "milieu" as accurately as possible. It almost seems impossible to express the true working atmosphere created by the participants. The task force meeting was also the first attempt to see if IIASA could prepare a program of interest to representatives of industrial enterprises. Many questions were raised and discused. The reactions expressed by the participants at the meeting and later on significantly prove that the answer is generally positive

How middle managers draw on cultural resources to shape their behaviors during the orchestration of ambidexterity

This study is motivated by the growing influence in organisational research on the perspective of culture as a toolkit of resources from which individuals can draw on to develop strategies of action. Research has established that ambidextrous organisations succeed both in incremental and discontinuous innovation. However, there remains a scarcity of study on how managers orchestrate ambidexterity. This thesis extends the ambidexterity research by investigating how managers orchestrate ambidextrous strategies and how these strategies are shaped by elements of the organisational culture in high technology firms. An interpretive case study approach was used to achieve the aims of the study. Focusing on two engineering projects, 55 interviews were conducted alongside documentary reviews and participant observation for 6 months at Brush Electrical Machines Ltd, UK. Analysis of the findings is conducted using thematic analysis to identify common themes and NVivo was used to draw out patterns until relationships among the emerging themes became clearer. The thesis makes important contributions to the organisational ambidexterity literature by providing useful empirically-driven insights and deconstructing the roles of middle managers in facilitating ambidexterity. The findings of the research indicate that most of the middle managers demonstrated ambidextrous behaviours. These middle level managers enabled their behaviours through diverse cultural resources selected from the organisation s cultural toolkit. Thus, important contributions are made to the literature on organisational culture, specifically on the toolkit perspectives. The thesis takes the perspective that organisational culture should be viewed as heterogeneous and not homogeneous. The study concludes by suggesting that middle management ambidextrous behaviours shaped by cultural resources may be vital for the realisation of improved or sustained competitiveness in organisations

Aeronautical engineering: A continuing bibliography with indexes (supplement 277)

This bibliography lists 467 reports, articles, and other documents introduced into the NASA scientific and technical information system in Mar. 1992. Subject coverage includes: the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines); and associated aircraft components, equipment, and systems. It also includes research and development in ground support systems, theoretical and applied aspects of aerodynamics, and general fluid dynamics

Systematic development of equivalent circuits for synchronous machines.

Imperial Users onl

An Economic Study of the University of Tennessee Power Plant

A history of the University of Tennessee Power Plant is helpful in that it serves to emphasize the importance of having a planned program for future operation based on sound economic and engineering principles. The present power plant is the result of the expansion over a period of years of the facilities and services offered by the University and is one of the finest University Power Plants in the South

Research on spacecraft and powerplant integration problems Spacecraft analysis topical report

Nuclear-electric power generating requirements for unmanned scientific solar system probe

The Electrification of Russia, 1880-1926

≤p≥The Electrification of Russia, 1880–1926 is the first full account of the widespread adoption of electricity in Russia, from the beginning in the 1880s to its early years as a state technology under Soviet rule. Jonathan Coopersmith has mined the archives for both the tsarist and the Soviet periods to examine a crucial element in the modernization of Russia. Coopersmith shows how the Communist Party forged an alliance with engineers to harness the socially transformative power of this science-based enterprise. A centralized plan of electrification triumphed, to the benefit of the Communist Party and the detriment of local governments and the electrical engineers. Coopersmith's narrative of how this came to be elucidates the deep-seated and chronic conflict between the utopianism of Soviet ideology and the reality of Soviet politics and economics.<p

Renewable energy sources from oceans

Obnovitelné zdroje jsou v dnešní době velmi diskutované téma především kvůli vyvstávajícím problémům v rámci ekologie a úspory energií. I přes nejvíce zastoupenou část v této oblasti vodními, větrnými a solárními elektrárnami, se tato práce zabývá méně vyvinutou formou čerpání energie pomocí obnovitelných zdrojů, a tím jsou energie z oceánů. Příbojové a přílivové technologie jsou dvěma základními možnostmi, jak efektivně získat určité množství energie. V úvodu jsou popsány jednotlivé možnosti obnovitelných zdrojů a jejich zastoupení v rámci produkce elektřiny. Především jsem se však zabývala jednotlivými typy elektráren a na jakých principech fungují. Výsledkem je shromáždění informací o využívaných metodách v oblasti oceánské energie, spolu s nejvýznamnějšími elektrárnami světa.Renewable resources are nowadays a serious topic in terms of ecology and energy savings. Renewable resources, wave technologies, wave converters, tidal technologies, tidal power plantsThe dominant producers of clean energy are hydro, wind and solar power plants, however, this paper deals with a less covered type and that is the ocean energy. The efficient harness of energy using ocean power can be distinguished into a wave and tidal technologies. However, this paper covers the background of renewable resources and their worldwide production of electricity, as well as the function of wave and tidal power plants. The result is a summarization of information about wave and tidal converters in order to increase the awareness of this form of utilization of ocean energy.