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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Bulk system reliability evaluation in a deregulated power industry

Li, Yifeng 08 December 2003
The basic function of an electric power system is to supply its customers with electric energy as economically as possible and with a reasonable degree of continuity and quality. Power system reliability evaluation techniques are now highly developed through the work of many researchers and engineers. It is expected that the application of power system reliability evaluation in bulk power systems will continue to increase in the future especially in the newly deregulated power industry. This thesis presents research conducted on the three areas of incorporating multi-state generating unit models, evaluating system performance indices and identifying transmission deficiencies in composite system adequacy assessment. The research was done using a previously developed software package designated as MECORE. Many generating companies in both the traditionally regulated and newly deregulated electrical power industry have large generating units that can operate in one or more derated states. In this research work, load point and system reliability indices are evaluated using two-state and multi-state generating unit models to examine the impact of incorporating multi-state generating unit models in composite system adequacy assessment. The intention behind deregulation in the power industry is to increase competition in order to obtain better service quality and lower production costs. This research illustrates how Canadian power systems have performed in the past using data compiled by the Canadian Electricity Association. A procedure to predict similar indices is presented and used to estimate future performance and the effects of system modifications. The incentives for market participants to invest in new generation and transmission facilities are highly influenced by the market risk in a deregulation environment. An adequate transmission system is a key element in a dynamic competitive market. This thesis presents a procedure to identify transmission deficiencies in composite generation and transmission system. The research work illustrated in this thesis is focused on the application of probabilistic techniques in composite system adequacy assessment and particularly in the newly deregulated electric power industry. The conclusions and the techniques presented should prove valuable to those responsible for power system planning.
2

Bulk system reliability evaluation in a deregulated power industry

Li, Yifeng 08 December 2003 (has links)
The basic function of an electric power system is to supply its customers with electric energy as economically as possible and with a reasonable degree of continuity and quality. Power system reliability evaluation techniques are now highly developed through the work of many researchers and engineers. It is expected that the application of power system reliability evaluation in bulk power systems will continue to increase in the future especially in the newly deregulated power industry. This thesis presents research conducted on the three areas of incorporating multi-state generating unit models, evaluating system performance indices and identifying transmission deficiencies in composite system adequacy assessment. The research was done using a previously developed software package designated as MECORE. Many generating companies in both the traditionally regulated and newly deregulated electrical power industry have large generating units that can operate in one or more derated states. In this research work, load point and system reliability indices are evaluated using two-state and multi-state generating unit models to examine the impact of incorporating multi-state generating unit models in composite system adequacy assessment. The intention behind deregulation in the power industry is to increase competition in order to obtain better service quality and lower production costs. This research illustrates how Canadian power systems have performed in the past using data compiled by the Canadian Electricity Association. A procedure to predict similar indices is presented and used to estimate future performance and the effects of system modifications. The incentives for market participants to invest in new generation and transmission facilities are highly influenced by the market risk in a deregulation environment. An adequate transmission system is a key element in a dynamic competitive market. This thesis presents a procedure to identify transmission deficiencies in composite generation and transmission system. The research work illustrated in this thesis is focused on the application of probabilistic techniques in composite system adequacy assessment and particularly in the newly deregulated electric power industry. The conclusions and the techniques presented should prove valuable to those responsible for power system planning.
3

Oxidation Kinetics of Methyl Linoleate and α-Linolenate in Bulk and Oil-in-water Emulsion Systems / バルク系およびO/Wエマルション系におけるリノール酸メチルとα-リノレン酸メチルの酸化動力学

Ma, Tiezheng 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18313号 / 農博第2038号 / 新制||農||1020(附属図書館) / 学位論文||H26||N4820(農学部図書室) / 31171 / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 安達 修二, 教授 河田 照雄, 教授 保川 清 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
4

BULK SYSTEM ADEQUACY ASSESSMENT INCORPORATING WIND AND SOLAR ENERGY

2016 March 1900 (has links)
Renewable energy sources have received increasing attention in electric power systems around the world due to growing environmental concerns. Wind and solar are among the most promising alternatives to conventional energy generation. There has been a rapid growth of wind and solar energy integration in power systems in the last decade, and is expected to grow further in the years to come. The main concern with wind and solar energy sources is the uncertainty and the intermittency of power generation, which leads to problems in maintaining the overall system reliability. The impacts of these sources on bulk system reliability depend on a large number of factors. The strength of the wind or solar resource at the installation site, the existing renewable power penetration level in the system, the points of connection of these sources to the power grid, the correlation in resource availability between multiple installation sites, and the correlation between the load and the renewable power are key factors that are analyzed in this thesis. These factors are considered in evaluating the bulk system reliability and reliability benefits of wind and solar power sources, and the reliability worth to the electricity customers from the addition of these energy sources. The IEEE-RTS test system is utilized throughout the thesis to evaluate the effects of these factors on bulk system adequacy. Swift Current and Saskatoon wind resources are modeled and utilized in this thesis. The Swift Current area has a strong wind resource and provides better reliability benefit and reliability worth than the Saskatoon wind resource. The benefits from wind and solar power integration, however, also depend significantly on the location where it is connected to the grid network. Wind farms that are diversified in multiple regions with independent wind speed profiles provide superior reliability benefits and worth than wind farms located in one region. The incremental benefits of adding wind or solar power decreases as the renewable power penetration is increased in the power system. Wind power at practical locations provides higher reliability benefits than photovoltaics. However, the daytime contribution of photovoltaics to system reliability is relatively high. The reliability benefits and reliability worth of solar power are significantly different for different seasons. A comparison study on reliability benefit and worth between a wind integrated bulk system and a solar integrated bulk system is also done in this thesis in order to identify the best option for bulk system reliability.
5

Stochastic models of steady state and dynamic operation of systems of congestion

Erasmus, Gert Botha 18 October 2006 (has links)
(i) The thesis sets out to address the problematic phenomenon of Systems of Congestion via Basic Queueing Theory. The theory, and its application in practice, appears to be a field of study which is the common domain of “theorists” and “practitioners”. (ii) This professional dichotomy has come about due to diverging interests in that one group is mainly interested in the purity of mathematical modelling, and the other group is motivated to use modelling, which conveniently employs applications oriented solutions. (iii) The schism between the groups has been accentuated by the “practitioners” who in addition to having an interest in steady state system behaviour make use of methods of modelling of the transient operation of complex Systems of Congestion. (iv) At the outset the thesis demonstrates how closed form solutions are obtained for steady state and transient state operation of a selection of Systems of Congestion. The attendant mathematical derivations are elegant and intricate. (v) Having revealed the limited utility of closed-form solutions the thesis proceeds to investigate the feasibility of using dynamical systems theory to study the transient behaviour of complex Systems of Congestion. (vi) The creation of Chaos Theory in recent decades suggests that it may be employed as a useful tool in analysing Systems of Congestion. Iterative Chaos Theory methods of orbit generation for complete Systems of Congestion are therefore examined. The use of such orbit generation methods is found to be satisfactory for simple Systems of Congestion. More than a perfunctory knowledge of chaos mapping is however required. The simplicity of modelling is emphasized. (vii) Based on the results of benchmarking the creation of dynamic system orbits against an existing simulation method, the research advances to modelling of the transient operation of complex systems. Once again the iterative method of orbit generation displays the ease of modelling while simultaneously unfolding system dynamics graphically. (viii) One may hopefully contend that a tool of eminent utility has been developed to aid practitioners in studying and optimizing Systems of Congestion. / Thesis (PhD (Industrial Engineering))--University of Pretoria, 2006. / Industrial and Systems Engineering / Unrestricted

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