A research report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree of Master of Science in Engineering, Johannesburg, August 2017 / The objective of this research work is to investigate the use of a high reliability micro grid to supply emergency electrical power to a nuclear facility following loss of offsite power (LOOP) accident. Most of the nuclear facilities around the world utilize diesel generators and battery banks as emergency power to back up the grid power supply. This power supply configuration represents the concept of the micro-grid system. The research work proposes reliability improvement of the emergency power supply by introducing diverse energy sources and energy storage systems. The energy sources and storage systems that were investigated include renewable energy sources, decay heat recovery system and large scale energy storage systems. The investigation results presented include information on the suitable energy sources and energy storage system, establishment of the reliable architectural layout and evaluation of the micro-grid system in terms of capacity adequacy and reliability. / XL2018

Despite a vast research of Russia’s means of power, including its military interventions in Georgia and Ukraine, no comprehensive comparison of Russia’s exercise of power in Georgia and Ukraine has been accomplished, even though they are the most prominent cases of post-Soviet states that have been subjects for Russian military aggression. This study compares the forms of power Russia has been using to implement its foreign policy objectives in Ukraine and Georgia, in order to identify Russia’s power-related behavior and strategies, through an abductive qualitative approach with a comparative method. Russia’s means of power are analyzed through the glasses of the analytical framework of Joseph Nye’s concepts of command power, soft power and smart power. The findings suggest that Russia’s main foreign policy objectives, related to the post-Soviet space, are to prevent the establishment of a pro-Western orientation in the region, make its neighboring countries dependent on Russia, establish closer ties with its neighbors and incorporate them in the Eurasian Customs Union (ECU), but also to achieve military supremacy in the region. It is further apparent that Russia uses similar strategies and means of power in Georgia and Ukraine, both through military actions and economic pressures, that can be categorized under command power, but also through diplomatic means, other economic means, informational tools and co-optation. However, in order to achieve its foreign policy objectives most efficiently, Russia combines command power and soft power. This study can contribute to the research of other dominant countries and unequal relationships; and from the learnings of this study, early warning signs or scenarios with certain foreign policy moves can be detected in other dominant countries’ exercise of power towards less powerful states.

Thesis (PhD (Electrical Engineering))--Cape Peninsula University of Technology, 2018. / Electrical energy can be easily used and converted to other forms of energy for various applications. Technological advancement increases the dependency on electricity to a great extent. Various internal and external factors are responsible for the bad quality of power in power systems. The performance of the system is greatly affected by the presence of harmonics, as well as voltage and frequency variations, which leads to the malfunctioning of the device and decline of power quality and supply at load side. The reactive power compensation is carried out for better power quality. The literature survey is done to find the best and efficient scheme for reactive power compensation and mitigation of various power quality problems. The devices which are used to measure various power quality factors are discussed. Various mitigating schemes are surveyed in order to compensate reactive power and to improve the power quality at the distribution end. The integration of the most widely used renewable energy, wind energy in the distribution system creates technical issues like stability of the grid, harmonic distortion, voltage regulation, active and reactive power compensation etc. which are restricted to IEC and IEEE standards. One of the topics this thesis addresses is regulation in the reactive power generated along with voltage regulation by using an effective power electronics device known as a STATCOM. The main power quality factors like overvoltage and voltage flickers are mitigated by establishing STATCOMs in small wind farms. The wind farms are equipped with three wind turbines. These three wind turbines found in the wind farm can be operated together or one after another with an introduced delay. A glitch in even a little piece of a power grid can result in loss of efficiency, income and at times even life. In this manner, it is basic to outline a system which can distinguish the faults of the power system and take a faster response to recover it back to required reactive power. Two devices STATCOM and D-STATCOM are used for this purpose in this thesis. The D-STATCOM circuit and operating principle are also discussed in thesis. Different topologies of D-STATCOM discussed with their benefits and shortcomings. The voltage, current and hybrid technologies of D-STATCOM are also discussed.

Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018. / A smart grid is an intelligent power delivery system integrating traditional and advanced control, monitoring, and protection systems for enhanced reliability, improved efficiency, and quality of supply. To achieve a smart grid, technical challenges such as voltage instability; power loss; and unscheduled power interruptions should be mitigated. Therefore, future smart grids will require intelligent solutions at transmission and distribution levels, and optimal placement & sizing of grid components for optimal steady state and dynamic operation of the power systems. At distribution levels, feeder reconfiguration and Distributed Generation (DG) can be used to improve the distribution network performance. Feeder reconfiguration consists of readjusting the topology of the primary distribution network by remote control of the tie and sectionalizing switches under normal and abnormal conditions. Its main applications include service restoration after a power outage, load balancing by relieving overloads from some feeders to adjacent feeders, and power loss minimisation for better efficiency. On the other hand, the DG placement problem entails finding the optimal location and size of the DG for integration in a distribution network to boost the network performance. This research aims to develop Particle Swarm Optimization (PSO) algorithms to solve the distribution network feeder reconfiguration and DG placement & sizing problems. Initially, the feeder reconfiguration problem is treated as a single-objective optimisation problem (real power loss minimisation) and then converted into a multi-objective optimisation problem (real power loss minimisation and load balancing). Similarly, the DG placement problem is treated as a single-objective problem (real power loss minimisation) and then converted into a multi-objective optimisation problem (real power loss minimisation, voltage deviation minimisation, Voltage stability Index maximisation). The developed PSO algorithms are implemented and tested for the 16-bus, the 33-bus, and the 69-bus IEEE distribution systems. Additionally, a parallel computing method is developed to study the operation of a distribution network with a feeder reconfiguration scheme under dynamic loading conditions.

It has been proven that the burgeoning power of the EU is not negligible. However, it is still debatable whether the EU acts as a smart power in its external human rights policy. Through Joseph Nye's theory of hard, soft, and smart power, this thesis will offer a critical understanding of a wide range of factors which merits the EU's role as a smart power. The contemporary history of Belarus also illustrates that the political, economic, and cultural endeavours of the EU reveal the institution's role as a smart power. Within the theoretical framework predicated on Nye's theory on the aforementioned powers, the EU-Belarus relations will be be analysed in order to lay bare the power of the EU and to shed light on the significance of human rights in the EU policies.

Orientador: Luiz Carlos Pereira da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-22T01:49:18Z (GMT). No. of bitstreams: 1 Geraldi_Douglas_M.pdf: 3918130 bytes, checksum: a6b640b4707af6b9173674deab29eece (MD5) Previous issue date: 2013 / Resumo: Existe atualmente um consenso de que as Redes Inteligentes favoreçam a solução de diversos problemas presentes no dia a dia das concessionárias distribuidoras de energia elétrica, tais como a gestão inteligente do carregamento e o gerenciamento automático na recuperação do fornecimento de energia (self-healing). Por outro lado, a implantação de tecnologias de redes inteligentes também pode criar novas dificuldades para as distribuidoras. Especial atenção deve ser dada à facilidade do acesso ao sistema elétrico por parte da microgeração - quer seja solar, eólica, micro turbinas a gás, etc. - possibilitada pela substituição dos medidores atuais por medidores inteligentes e por legislação específica recentemente publicada pela ANEEL. Neste trabalho busca-se apontar e quantificar alguns impactos técnicos relacionados à injeção de potência em um circuito secundário de distribuição. Através do estudo de cenários com crescente nível de penetração de microgeradores fotovoltaicos residenciais (tetos solares) são analisados os impactos na curva de carga do prossumidor, no perfil de tensão da rede, nas perdas elétricas e no desequilíbrio de tensão. As simulações dos cenários supracitados são realizadas através do software livre Gridlab-D, desenvolvido pela Pacific Northwest National Laboratory (PNNL) para estudos de aspectos de redes inteligentes via simulação computacional. Uma das vantagens desse pacote é a integração com base de dados meteorológicos, permitindo, por exemplo, a estimativa da geração fotovoltaica mês a mês para um determinado ano constante na base de dados / Abstract: Nowadays, there is a consensus that the Smart Grid can promote the solution of various problems present in distribution utilities, such as intelligent load management and self-healing. How-ever, the deployment of smart grid technologies can also create new difficulties. Special attention should be given to the open access to the electrical grid from the micro-generation plants, such as solar photovoltaic, wind turbines and gas micro-turbines, which will be possible with the re-placement of the current meters for smart meters and by specific regulation recently published by ANEEL. This work intends to identify and quantify some technical impacts related to power injection from micro-generators in a secondary distribution circuit. Through the study of scenarios with increasing penetration of residential photovoltaic micro-generators (solar roofs) some impacts are analyzed: impacts on the load profile of the prosumer; impacts on the voltage profile of the network; impacts on the electrical losses and voltage imbalance. The simulations of the above scenarios are performed by using Gridlab-D, free software developed by Pacific Northwest National Laboratory (PNNL) to study aspects of smart grids via computer simulation. One ad-vantage of this package is the integration with meteorological database, enabling, for example, the estimation of photovoltaic generation every month for a given year contained in the database / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Zielstellung dieser Arbeit ist es, Methodik und Verfahren zur Modellierung von Leistungshalbleitern zu erarbeiten, um die Verfügbarkeit und Handhabbarkeit dieser Modelle für die Schaltungsanalyse zu erhöhen. Ausgangspunkt ist eine Analyse der Anforderung und ein Vergleich mit den gegebenen ökonomischen und fachlichen Möglichkeiten. Im Ergebnis wird ein hierarchischer Aufbau von Verhaltensmodellen befürwortet. Die zur Modellrealisierung benötigten Techniken werden vorgestellt. Das erarbeitete Verfahren zur verhaltensbeschreibenden Modellierung erfordert eine am Modellumfang orientierte Wahl der Beschreibungssprache und zeichnet sich durch Verwendung von Datenblattangaben zur Parametrisierung und geringem Simulationszeitbedarf der Modelle aus. Für diskrete Einzelhalbleiter werden physikalisch interpretierbare Ersatzschaltungen auf Grund ihrer hoher Anschaulichkeit und der erreichbaren Portabilität der Modelle bevorzugt, komplexere Modelle mit Steuer- und Schutzeinrichtungen sind mit Zustandsbeschreibungen zu kombinieren. Der allgemeingültige Ansatz ist auf beliebige Leistungshalbleiter anwendbar und wird ausführlich anhand des IGBT, von Smart-Power-Elementen und anderer Bauelemente dargelegt.

Le recours fréquent à l'expression anglo-saxonne soft power traduit le « moment gramscien » des relations internationales dans lequel l'hégémonie symbolique compterait autant dans la balance des pouvoirs que les déterminants matériels classiques (démographie, armée, économie), (Chaubet, 2013). Dans ce cadre la culture comme mode d'influence deviendrait un enjeu stratégique par l'intervention des politiques de diplomaties d'influence devenu un nouveau champ d'affrontement des états. Dans un contexte où la question de ce qui fait puissance sur la scène internationale est posée et débattue, les politiques internationales de prestige s'envisagent en lien avec l'essor du numérique et l'émergence d'une opinion publique internationale. Ces nouveaux paramètres conduiraient à la mise en place d'une « nouvelle diplomatie culturelle de la France » (Fabius, Filippeti, 2013). Parallèlement l'hypothèse du glissement du « centre de gravité du monde » vers l'Asie, ainsi que l'histoire commune entre la France et le Vietnam, a conduit l'auteur à analyser l'évolution de la diplomatie culturelle/publique de la France dans un processus de redéfinition d'une dynamique d'internationalisation. L'auteur examine le passage d'une logique diplomatique de présence à une logique diplomatique d'influence impliquant la communication. La méthode intègre une analyse de corpus et une enquête sur le terrain (deux ans de présence au Vietnam). / ....

Energy consumption in the form of fuel or electricity is ubiquitous globally. Among energy types, electricity is crucial to human life in terms of cooking, warming and cooling of shelters, powering of electronic devices as well as commercial and industrial operations. Therefore, effective prediction of future electricity consumption cannot be underestimated. Notably, repeated imbalance is noticed between the demand and supply of electricity, and this is affected by different weather profiles such as temperature, wind speed, dew point, humidity and pressure of the electricity consumption locations. Effective planning is therefore needed to aid electricity distribution among consumers. Such effective planning is activated by the need to predict future electricity consumption within a short period and the effect of weather variables on the predictions. Although state-of-the-art techniques have been used for such predictions, they still require improvement for the purpose of reducing significant predictive errors when used for short-term load forecasting. This research develops and deploys a near-zero cooperative probabilistic scenario analysis and decision tree (PSA-DT) model to address the lacuna of significant predictive error faced by the state-of-the-art models and to analyse the effect of each weather profile on the cooperative model. The PSA-DT is a machine learning model based on a probabilistic technique in view of the uncertain nature of electricity consumption, complemented by a DT to reinforce the collaboration of the two techniques. Based on detailed experimental analytics on residential, commercial and industrial data loads, the PSA-DT model with weather profiles outperforms the state-of-the-art models in terms of accuracy to a minimal error rate. This implies that its deployment for electricity demand planning will be of great benefit to various smart-grid operators and homes. / School of Computing / M. Sc. (Computer Science)

Les travaux de recherche présentés dans ce mémoire s'inscrivent dans le cadre du développement des techniques d'intégration de puissance SMART POWER, technologies où cohabitent sur le même substrat des composants de puissance haute tension (dans la gamme de 80V) et des composants de commande base tension de type CMOS. Nous étudions les modes de fonctionnement anormaux pendant lesquels l'isolation entre les différents blocs du circuit n'est plus assurée. Les diodes d'isolation, normalement maintenues à l'état bloqué, se retrouvent polarisées en direct ce qui se traduit par l'injection d'un important courant d'électrons dans le substrat du circuit intégré (Ie>1A). Nous détaillons d'abord les caractéristiques et les conséquences de ces courants parasites et donnons un inventaire des techniques de protection employées. Sur la base d'une compréhension physique des mécanismes mis en jeu, appuyés par des simulations numriques 2D, nous présentons deux familles de solutions permettant de protéger le circuit intégré contre ces courants de substrat. La première, dite passive, exploite au mieux la collection et la recombinaison de ces électrons, soit par des anneaux de garde, soit par des MOS de puissance isolés. La seconde dite active, agi sur la polarisation du substrat lui-même et permet, soit de détourner efficacement le courant parasite des zones sensibles, soit de maintenir la diode d'isolation à l'état bloqué. Nous avons ensuite validé ces propositions par des composants de tests spécifiques, puis caractérisé leur efficacité au sein de circuits intégrés complets, réalisés dans des technologies SmartMosTM. Nous avons ainsi obtenu des circuits intégrés dont les courants de substrat sont inférieurs à 50µA.