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The optimal capacitor placement problem is the determination of the optimal location of the shunt capacitors on the sub-transmission networks such that energy losses are minimised, the power factor and the network voltage profile are improved. During this period when Eskom is experiencing an unacceptably low generation reserve margin, it’s quite critical that the electrical Transmission and Distribution network losses be kept to a minimum to optimise on the scarce generation that is available to supply South Africa’s current and future power demand. One of the ways of minimising technical losses is through the optimal placement or installation of capacitor banks on the network. The placement of shunt capacitors on a bulk Transmission network is essentially to improve the voltage profile on the network, increase system security and reduce transmission losses. The optimal placement of shunt capacitors with the above objectives would assist in minimising the cost of the investment whilst maximising the return on investment to the utility. This research subject is treated as an optimization problem and hence optimization solutions were considered to address the “Optimal capacitor placement problem”. This optimisation problem is solved for all loading levels i.e. peak, standard and off peak periods and for different seasons in a given typical year. This thesis investigates the capability of Genetic Algorithms technique in solving this optimisation problem. Genetic algorithms utilize a guided search principle to develop a robust solution to this research problem. Given their capability to traverse the complicated search space with a multivariate objective function, Genetic Algorithm are versatile and robust to locate the global optimum of the objective function. These Genetic Algorithms (GA’s) were implemented on real sub transmission networks modelled on DigSilent/ Powerfactory. The modelled GA’s on DigSilent were then tested on different network types i.e. commercial, mining, residential and industrial load mixes. The solutions determined by the different GA’s are then compared in terms of time taken to locate the solution, reliability and robustness. The most reliable GA is then identified and recommended as the preferred optimisation approach. A methodology of using GA’s to solve the above mentioned problem is therefore proposed / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2009.

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No description available.

With the world’s increasing energy demand and the depletion of fossil fuels, there is a growing demand for the development of alternative and clean energy sources. Batteries and fuel cell technologies have been cited as next generation technologies to provide sustainable energy; however, these technologies are insufficient in supplying high power in short time periods that can be produced by oil as an energy source. In contrast, electrochemical capacitors possess fast charging/discharging capabilities with high power output. As a result, the use of electrochemical capacitors in commercial applications has generated strong interest. Examples of commercial applications include emergency back-up power, consumer electronics, and hybrid vehicles. Commercially available electrochemical capacitors are based on carbonaceous materials with high surface area, excellent electrical conductivity, and wettability which statically store the charges in pores. In contrast, pseudocapacitive materials, namely transition metals, utilize fast reversible faradaic reactions on the surface of the materials which allow for greater energy storage than carbonaceous materials. Currently, many research activities are being focused on pseudocapacitive materials in an effort to enhance their energy storage capabilities. This thesis presents research on a pseudocapacitive material: nickel hydroxide/oxide hybrid. Also, it identifies the hybrid material’s lack of conductivity which can negatively impact its capacitive performance. An addition of carbon supports is recommended to enhance the conductivity. There are two parts to this study. The first study addresses the synthesis of the nickel hybrid structures through solvothermal process and calcination. The materials are thoroughly analyzed through physical and electrochemical characterizations. The issue of using the hybrid material as pseudocapacitor electrodes are identified at this stage. The second part of the study addresses the effect of different carbon additives in the nickel hybrid material. Commonly known carbon additives are incorporated into the nickel hybrid material and analyzed through electrochemical characterization to distinguish the best carbon support for the nickel hydroxide/oxide.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 31, 2008) Includes bibliographical references.

Thesis (M.S.)--Ohio University, November, 1986. / Title from PDF t.p.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vii, 43 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 14).

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (Ph.D.)--Drexel University, 2009. / Includes abstract and vita. Includes bibliographical references (leaves 217-239).