Thesis (M.Com. (Development Theory and Policy))--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Economic and Business Sciences, 2016. / The paper identifies that due to the historic evolution of the South African economy, particularly the emphasis placed on energy provision as a catalyst for successful mineral extraction; the seeds were sown for South Africa to be an industrial hub in transformer manufacturing. However, this opportunity has not been realised. Domestic transformer manufacturers have continued to lose market share both domestically and globally. The research identifies a lack of demand, locally, for domestically manufactured transformers as an inherent cause of the challenges faced by the local transformer industry. This lack of demand is also recognized as the reason constraining the potential growth of the industry. The paper identifies a virtuous cycle between capacity utilization and expansion, wherein; higher capacity utilization favourably influences price competitiveness, which increases market share and induces investment into additional capacity. As greater market share is 2 | P a g e attained due to price competitiveness, even higher capacity utilization is achieved; therefore further inducing investment on the expanded capacity and the cycle continues with further expansion. The paper investigates sectoral designation as an industrial policy instrument to achieve this model, that is; increase demand, capacity utilization and ultimately broaden the industrial base of transformer manufacturing. The paper advocates that, while growing in the export market is the ideal end point, the industry would grow its current production capacity threefold if it were provided the opportunity to fully satisfy domestic demand1. As a result, this should be the first market to conquer. It is also identified in the research that sectoral designation as a policy instrument is not without shortfalls, particularly given the unique characteristics inherent in the transformer industry. The paper concludes with policy recommendations to overcome the identified shortfalls and proposes a model for consideration. This dissertation is submitted for the completion of a Master of Commerce in Development Theory and Policy degree. I would like to express utmost gratitude to Dr Paul Jourdan for his supervision, guidance and valuable contribution in the preparation of this research report. / MT2017

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Lors de la réalimentation des auxiliaires d’une tranche nucléaire, l’étape la plus à risque est la remise sous tension brusque du transformateur à cause des surtensions. Dans un soucis perpétuel d’amélioration de la modélisation de ces transitoires, les modèles et techniques doivent évoluer. Le but de ces travaux de thèse est de proposer de nouvelles méthodologies permettant d’évaluer les paramètres mal connus de la modélisation. Lors des mises sous tension des lignes électriques, une méthodologie s’appuyant sur l’identification (optimisation ou techniques issues du traitement du signal) permet de déterminer les paramètres variables de la modélisation. Cependant, un des paramètres influents pour les surtensions est le flux rémanent. Face aux problèmes actuels rencontrés pour l’estimer (méthode non directe, dérive, …), une nouvelle méthode basée sur la mesure des flux de fuites du circuit magnétique est proposée. Des mesures réelles utilisant des capteurs de technologie « fluxgate » sont réalisées et permettent d’estimer le flux rémanent. / During the re-energization of the auxiliaries of a nuclear power plant, the more dangerous step is the re-energization of the power transformer, because of the temporary overvoltages. In order to improve the transient modeling, models and techniques may be improved. The purpose of this thesis is to suggest new methodologies to identify the uncertain parameters of the model. When the line re-energization occurs, an identification methodology (optimization or methods using signal processing) allows determining the model variable parameters. However, one of the most important parameters in the overvoltages is the residual flux. Given the actual problems found on estimation strategies (no direct method, derivation,…), a new method established for the leakage flux measurement of the magnetic circuit is proposed. Real measurements using « fluxgate » technology sensors were realized, permitting to estimate the residual flux.