Browsing by Author "Gaunt, Charles"

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    An analytic framework to advance understanding of power sector reforms in Sub-Saharan Africa
    (2023) Hampton, Brent; Gaunt, Charles
    This thesis seeks to advance knowledge of electricity sector reform by providing a framework of critical elements of sector reform for analyzing the context of proposed reform and to provide a basis for preparing sustainable reform policy. Modern market-based electricity sector reforms were first implemented in Chile in 1979 followed by the UK in 1990. This model of reform continued to be used globally as the basis for reform over a period of more than 30 years. While the approach has proved moderately successful in some developed countries, the outcomes in developing countries, and particularly in Sub-Saharan Africa, have been generally unsatisfactory. The expected improvements in utility efficiency, access and private sector financing have mostly not materialized. The direction regarding reform policy going forward is currently unclear and a return to the drawing board appears to be imminent. The research involves a deep review of the origins and spread of market-based reforms and outcomes, with a focus on developing countries, and Sub-Saharan African countries in particular. A set of critical elements impacting sector reform outcomes was identified from analysis of the literature and field research and developed into a proposed framework of analysis with three tiers and a set of cross cutting elements. Verification of the plausibility of the analytic framework was carried out using a two-pronged approach. First, a set of three in depth Sub-Saharan Africa country case studies was undertaken, covering each element in the framework. Secondly a set of interviews was conducted with a spectrum of senior stakeholders from the sector to establish views on the importance and scope of each element of the framework. Both methods confirmed that the proposed framework was a valid, adequate and robust tool for analyzing the sector and likely reform outcomes, and that the proposed working hypothesis did not adequately cover the requirements for effective reform policy. The research has implications for international development funding and the attainment of Sustainable Development Goal 7 (access to clean energy) and may be extended to other sectors.
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    Investigations into the Effect of Temperature on Power-line Corona using Bridge Measuring Techniques
    (2024) Pieterse, Petrus; Gaunt, Charles
    The need for more power and the limitations on building new power lines have made compact power lines a necessity. To design these lines, it is essential to understand the behavior of corona, which is a form of unwanted plasma discharge that causes electrical interference, power loss, and audible noise. Compact power lines require tighter conductor spacings and special high-temperature, low-sag conductors, which makes the accurate prediction of corona behavior even more crucial. This paper examines the impact of conductor temperature on corona performance, as it is an important factor that is often overlooked. Despite earlier research showing that elevated conductor temperature has a direct effect on power line corona discharge magnitude, the effect of conductor temperature on corona performance is generally not considered since the line is not expected to remain at high temperatures for extended periods and since foul weather corona is considered worse. However, since high temperature low sag conductors may operate at much higher temperatures, the effect of temperature on the corona performance has to be considered. Earlier work has shown that simple correction factors based on the assumed local reduction of air density can be applied to predict the inception value for higher conductor temperatures. Likewise, the work of Chartier and Stearns showed a dependency of the corona noise measurement on the conductor temperature, albeit only up to a temperature of 50˚C. To date no relationship between conductor temperature and corona power losses has been published. This dissertation demonstrates that losses for conductors exceeding 60˚C can be significant and follow a simple relationship with temperature. A new bridge detection method is introduced to evaluate corona loss performance by assessing positive and negative corona loss separately through postprocessing of acquired data. The experiments were performed in a laboratory using a small coaxial conductor system or corona cage with a smooth aluminium heated centre conductor ranging in temperature from 14˚C to 140˚C. The visible corona inception point is found to be lower than the point of rapid charge increase (as can be easily detected by the bridge circuit) which also follows approximately the Peek criteria with substitution of the ambient temperature for the conductor temperature, proving the bridge method to be more reliable than earlier visual observation methods. This dissertation highlights the importance of considering the effect of conductor temperature on corona performance when designing compact power lines. By doing so, the detrimental impact of corona on practical systems can be minimized.