Orientador: Dionízio Paschoareli Júnior / Banca: Luis Carlos Origa de Oliveira / Banca: Walmir de Freitas Filho / Resumo: O setor de distribuição de energia elétrica vem apresentando constantes mudanças para se adaptar à necessidade de atendimento das crescentes demandas com recursos financeiros e energéticos cada vez mais escassos. Concessionárias têm buscado eficiência operacional em seus processos através de tecnologias que visam atender a um consumidor cada vez mais exigente por qualidade na utilização da energia elétrica. Neste cenário, a utilização de equipamentos que flexibilizem a operação das redes de distribuição apresentam-se como alternativas menos onerosas quando comparadas com a realização de grandes investimentos na expansão. O uso de equipamentos de flexibilização nas redes de distribuição possui peculiaridade específicas que prevê adaptações de natureza elétrica e física no sistema. O compensador série controlado a tiristores apresenta-se como uma alternativa a ser considerada para aplicação em redes de até 36kV. Aspectos de robustez face a necessidade de flexibilização são discutidos de modo a analisar sua postergação de investimentos visando mitigar ou diminuir o impacto de grandes alterações em redes de distribuição. Tais adaptações são comparadas com a sua viabilidade econômica, a partir da adequação da relação custo-benefício. Os resultados das análises apontam para uma tendência favorável à utilização do compensador série controlado a tiristores na rede de distribuição (D-TCSC), quando considerados os valores de implantação, tempo de execução física, instituição de condições mais favoráveis para realização de manobras e retorno mais rápido na imobilização de cálculos de tarifas e retorno do capital investido / Abstract: The electrical distribution system has presented constant changes to adapt to the growth in power demand with reducing financial and energetic resources availability. Utilities are looking for improvement in operating conditions using new technologies to attend to high power quality by the most demanding consumer. The use of equipment to improve the flexibility of distribution systems is an alternative which postpone large investments in system expansion. The thyristor-controlled series compensator is an attractive option for networks up to 36 kV. In this work, flexible solutions are discussed to postpone investments. Economical viability of a series controlled compensator in a distribution system is presented. The results take in account the initial cost, time of implementation, return on invested capital, among others / Mestre

The Internet of Things (IoT) is now permeating our daily lives, providing critical data for every decision. IoT architecture consists of multiple layers with unique functions and independent components. Each layer of IoT architecture requires different power sources and power delivery schemes. Therefore, different types of power management architectures are required for individual IoT components. Fortunately, advances in metal oxide semiconductor (MOS) technology have made it possible to implement a variety of high-performance power management architectures. These power management architectures should not only create the power rails required for IoT components but also serve additional functions depending on the application. The power management architecture of IoT devices needs to support sub-mW- or mW-scale power consumption. In addition, the power management architecture should be either fully integrated on a chip or miniaturized with few passive components to minimize the size of IoT devices. Building-scale data centers, on the other hand, need various power conversion stages. In this scenario, power conversion from an intermediate DC bus to many point of loads (PoL) requires a high conversion ratio DC-DC converter. Because each PoL draws enormous amounts of power, the power management architecture should withstand high currents and include protection circuitry to prevent damage. This thesis presents research on the design of power management architectures required by IoT devices and data centers. Chapter 2 presents the design and circuit techniques of power management architectures for IoT devices. Chapter 2 outlines a new methodology for co-designing an integrated switched-capacitor (SC) DC-DC converter and a load circuit in ultra-low-power IoT devices. This methodology enables the implementation of an area-efficient fully integrated IoT system-on-chip (SoC) while maintaining high power conversion efficiency (PCE). Chapter 3 presents a 10-output ultra-low-power single-inductor-multiple-output (SIMO) DC-DC buck converter with integrated output capacitors for sub-mW IoT SoCs. Featuring a continuous comparator-based output switch controller and a digital pulse-width modulation (PWM) controller for ultra-low feedback latency, this SIMO converter produces ten independent output voltages with high PCE. Lastly, in Chapter 4, an integrated programmable gate timing control and gate driver chip for an active-clamp forward converter (ACFC) Power Block for data center applications is developed. While the ACFC Power Block converts 12-48 V intermediate DC bus voltage to a digital PoL voltage, the gate timing control and driver chip can optimize PCE and reduce the system form factor.

Research report submitted to the faculty of Commerce, Law and Management, University of Witwatersrand, in 50% fulfilment of the requirements for the degree of Master of Management in the field of Public and Development Management. March 2018 / The outputs in this report are based on the experiences, beliefs and perceptions of a crosssection of Solar Photovoltaic industry stakeholders on whether Local Content Requirements is an appropriate policy instrument for building a local industry and the extent to which the Local Content Requirements of the Renewable Energy Independent Power Producer Procurement Programme have led to an increase in the South African solar component manufacturing capacity since the programme’s inception in November 2011. Protectionist policies, including Local Content Requirements, were used by now industrialised countries to develop their respective countries, and continue to be used to this day despite World Trade Organisation prohibitions. Four models on building local industries are discussed and their relationship to the two research questions explored. Interview participants agreed that the Renewable Energy Independent Power Producer Procurement Programme was instrumental in building a large-scale local renewable energy industry in the country, created jobs and excitement around manufacturing capacity potential. However, many believe that programme design and implementation interventions are required to improve the programme’s localisation impacts. The latest draft Integrated Resource Plan’s sizeable allocation for Solar Photovoltaic until 2030 presents an opportunity to drastically improve localisation benefits for the country. / GR2019

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It is the purpose of this study to show how successfully electric power systems were operated by smaller units of government. One of the most notable power plants is operated in Denton, Texas. In this study, the history of this system will be presented, followed by an analysis of its social and economic significance.