Esta pesquisa apresenta o desenvolvimento e a implementação, em uma rotina computacional, de um algoritmo para a localização de faltas em redes primárias de distribuição. Este algoritmo de localização faz parte de um sistema automatizado de localização de faltas, em redes primárias radiais de distribuição, que foi desenvolvido para uma concessionária paulista. O método descrito é capaz de identificar de forma rápida os prováveis pontos de ocorrência do defeito, baseado em medições de tensões e correntes feitas somente na subestação, nos parâmetros elétricos do alimentador de distribuição e na sua topologia. / This research presents the development and implementation in a computational routine of an algorithm for fault location in primary distribution feeders. This algorithm is part of a complete automated fault location system developed to a Brazilian electricity utility. The described method is capable of identifying the most probable fault locations upon its occurrence, based on local measurements of currents and voltages only at the substation, on the electrical parameters of the distribution feeder and its topology.

Esta pesquisa apresenta o desenvolvimento e a implementação, em uma rotina computacional, de um algoritmo para a localização de faltas em redes primárias de distribuição. Este algoritmo de localização faz parte de um sistema automatizado de localização de faltas, em redes primárias radiais de distribuição, que foi desenvolvido para uma concessionária paulista. O método descrito é capaz de identificar de forma rápida os prováveis pontos de ocorrência do defeito, baseado em medições de tensões e correntes feitas somente na subestação, nos parâmetros elétricos do alimentador de distribuição e na sua topologia. / This research presents the development and implementation in a computational routine of an algorithm for fault location in primary distribution feeders. This algorithm is part of a complete automated fault location system developed to a Brazilian electricity utility. The described method is capable of identifying the most probable fault locations upon its occurrence, based on local measurements of currents and voltages only at the substation, on the electrical parameters of the distribution feeder and its topology.

In current distribution automations design, fault flags generated by overcurrent relays are used to detect the feeder fault section. With the integration of distributed generations (DG), fault currents could be contributed from different directions and jeopardize the fault detection function. A large fault current contributed by a DG flows from downstream of a feeder could be detected by the overcurrent relay and lead to the confusion in fault detection function. In this thesis, adjunction current measurements and fault flags are utilized to minimize the possibility of mis-identification of fault section. The structure and data flow of a Java agent development framework (JADE) is adopted for feeder fault detection, identification and service restoration (FDIR). Based on information from local measurements and other agents, the FDIR function can be better conducted by local agents. Test results indicate that multi-agent systems can be used to improve system reliability and reduce service interruption time.

As redes elétricas inteligentes significam um novo paradigma de fornecimento de energia, cuja concepção integra várias áreas de concentração, novas funcionalidades e funções até então não realizáveis, bem como uma pluralidade de tecnologias e a necessidade de infraestrutura de apoio para a sua realização. A transição das redes elétricas atuais para o modelo de rede inteligente constitui-se num processo complexo, que envolve aspectos técnicos, econômicos, regulatórios e sociológicos. Esta pesquisa visa contribuir significativamente para a solução dessa questão pela proposição das bases conceituais para realizar efetivamente um plano de implementação, respeitando condições vigentes e impostas por cenários de outros setores. O modelo proposto, centrado na expansão da automação, lança as bases para a análise dos impactos da rede elétrica inteligente, para a formulação, análise e seleção de alternativas de implementação. É introduzido o conceito e forma de avaliação de uma rede por meio da definição de um índice de inteligência de uma rede elétrica, composto de vários indicadores, de forma a expressar padrões de eficiência energética e operativa, aspectos de gestão de ativos e da qualidade do serviço. A proposta de alternativas para evolução da automação se baseia em um conjunto de funções pré-estabelecidas, que melhoram os indicadores de desempenho e apresentam custos e benefícios quantificáveis. / The smart grids mean a new paragon for energy supply, whose concept integrates several areas of concentration, functionalities and functions non achievable up to now, as well as a plurality of technologies and the need of supporting infrastructure for its accomplishment. The transition of the present electrical networks to the smart grid model constitutes a complex process, which involves technical, economical, regulatory and sociological aspects. This research aims to contribute significantly to the solution of this issue by proposing the conceptual basis for effectively perform an implementation plan taking into account the constraints imposed by scenarios from other sectors. The proposed model, focused in automation expansion, launches the basis for the impact analysis of Smart Grid in order to formulate, analyze and selection alternatives of implementation. The concept and evaluation method of grid through the definition of a grid intelligence index, composed by several indicators is introduced in order to express standards of energy and operational efficiency, asset management and quality of supply. The proposal of alternatives for automation evolution is based on a set of pre established functions, which improve the performance indicators and present valuable costs and benefits.

As redes elétricas inteligentes significam um novo paradigma de fornecimento de energia, cuja concepção integra várias áreas de concentração, novas funcionalidades e funções até então não realizáveis, bem como uma pluralidade de tecnologias e a necessidade de infraestrutura de apoio para a sua realização. A transição das redes elétricas atuais para o modelo de rede inteligente constitui-se num processo complexo, que envolve aspectos técnicos, econômicos, regulatórios e sociológicos. Esta pesquisa visa contribuir significativamente para a solução dessa questão pela proposição das bases conceituais para realizar efetivamente um plano de implementação, respeitando condições vigentes e impostas por cenários de outros setores. O modelo proposto, centrado na expansão da automação, lança as bases para a análise dos impactos da rede elétrica inteligente, para a formulação, análise e seleção de alternativas de implementação. É introduzido o conceito e forma de avaliação de uma rede por meio da definição de um índice de inteligência de uma rede elétrica, composto de vários indicadores, de forma a expressar padrões de eficiência energética e operativa, aspectos de gestão de ativos e da qualidade do serviço. A proposta de alternativas para evolução da automação se baseia em um conjunto de funções pré-estabelecidas, que melhoram os indicadores de desempenho e apresentam custos e benefícios quantificáveis. / The smart grids mean a new paragon for energy supply, whose concept integrates several areas of concentration, functionalities and functions non achievable up to now, as well as a plurality of technologies and the need of supporting infrastructure for its accomplishment. The transition of the present electrical networks to the smart grid model constitutes a complex process, which involves technical, economical, regulatory and sociological aspects. This research aims to contribute significantly to the solution of this issue by proposing the conceptual basis for effectively perform an implementation plan taking into account the constraints imposed by scenarios from other sectors. The proposed model, focused in automation expansion, launches the basis for the impact analysis of Smart Grid in order to formulate, analyze and selection alternatives of implementation. The concept and evaluation method of grid through the definition of a grid intelligence index, composed by several indicators is introduced in order to express standards of energy and operational efficiency, asset management and quality of supply. The proposal of alternatives for automation evolution is based on a set of pre established functions, which improve the performance indicators and present valuable costs and benefits.

Favorable price trends and increasing demand for renewable energy sources portend accelerating integration of solar photovoltaic (PV) generation into traditional electric power system networks. Managing the variable output of massive PV resources makes system frequency regulation more complex and expensive. ISOs must procure additional regulation and load following capacity, while power plants must supply more regulation work. In contrast to costly physical storage solutions, this thesis proposes to address the issue by reconfiguring the electricity market pricing structure to translate all power imbalances into real-time market price signals. More accurately determining the instantaneous value of energy, electric power markets could reward participants who can quickly respond to frequency fluctuations. By utilizing short term forward markets to monetize the risk associated with intermittency, the true cost of reliability is determined and could reduce wasteful capacity payments. This market redesign is an ideal open platform for disparate smart grid technologies which could encourage all suppliers, loads and generator, to offer supply or reduce consumption when it is needed most and could vastly improve frequency performance metrics.

An optimally designed thermosiphon for power electronics cooling is developed. There exists a need for augmented grid assets to facilitate power routing and decrease line losses. Power converter augmented transformers (PCATs) are critically limited thermally. Conventional active cooling system pumps and fans will not meet the 30 year life and 99.9% reliability required for grid scale implementation. This approach seeks to develop a single-phase closed-loop thermosiphon to remove heat from power electronics at fluxes on the order of 10 - 15 W/cm2. The passive thermosiphon is inherently a coupled thermal-fluid system. A parametric model and multi-physics design optimization code will be constructed to simulate thermosiphon steady state performance. The model will utilize heat transfer and fluid dynamic correlations from literature. A particle swarm optimization technique will be implemented for its performance with discrete domain problems. Several thermosiphons will be constructed, instrumented, and tested to verify the model and reach an optimal design.

This thesis proposes an algorithm and develops a program for fault detection and system restoration in medium voltage distribution systems. In Turkey, TUBITAK-UZAY developed distribution automation system including fault detection and service restoration functions for Bogazici Electricity Distribution Company. By the time, expanding of distribution system with nonstandardized infrastructure (for example more than one circuit breaker in the feeder, mesh and closed loop feeder structure), developed automation system have not properly worked under these unplanned situations. Taking into consideration of previously utilized TUBITAK Distribution Automation System (TUDOSIS), fault isolation algorithm is improved to cope with practical problems as non-standardized infrastructure and selectivity issue in protection system, and the proposed isolation algorithm is simulated. Further system restoration solution for mesh distribution systems is analyzed for distribution system in Turkey and expert system based algorithm is proposed.

The objective of the research is to develop a cost-effective, dynamic grid controller called the controllable network transformer (CNT) that can be implemented by augmenting existing load tap changing (LTC) transformers with an AC-AC converter. The concept is based on using a fractionally rated direct AC-AC converter to control the power through an existing passive LTC. By using a modulation strategy based on virtual quadrature sources (VQS), it is possible to control both the magnitude and the phase angle of the output voltage of the CNT without having any inter-phase connections. The CNT architecture has many advantages over existing power flow controllers, like absence of low frequency storage, fractional converter rating, retro-fitting existing assets and independent per-phase operation making it potentially attractive for utility applications. The independent control of the magnitude and the phase angle of the output voltage allow independent real and reactive power flow control through the CNT-controlled line. In a meshed network with asymmetric network stresses this functionality can be used to redirect power from critically loaded assets to other relatively under-utilized parallel paths. The power flow controllability of CNT can thus be used to lower the overall cost of generation of power. The solid state switches in the CNT with fast response capability enable incorporation of various additional critical functionalities like grid fault ride through, bypassing internal faults and dynamic damping. This bouquet of features makes the CNT useful under both steady state and transient conditions without compromising the grid reliability.

This dissertation presents a comprehensive and integrated design methodology to optimize both the electrical and the economic performance of a utility power distribution system. The proposal is structured to facilitate its adoption and incorporation into the existing utility infrastructure by allowing the various portions of the new design to be implemented gradually into the existing infrastructure without the need to abandon the portions of the existing system that are performing satisfactorily. The topology of the substation plays a vital role in determining both the reliability and the economy of the distribution system. The ring bus topology is offered as the best topology design, and its characteristics as seen at the distribution level are examined. A key concept presented in this dissertation is that the distribution system must be optimized as a whole, not subsystem by subsystem. Optimizing the substation and the primary feeder system separately does not assure an optimal system; in fact, independent design of the two subsystems is likely to produce a non-optimal system laden with operational problems. An integrated approach is essential to assure optimum performance, and the integration process requires an iterative approach. This iterative approach is presented using an example. Innovative changes to the protection strategy of the feeder system can greatly enhance the reliability of the distribution system. The use of communication-based overcurrent detection is presented. This transmission-like scheme, when applied at the distribution level, improves both the reliability and the economy of the system substantially over traditional time-coordinated overcurrent protection philosophies. An application of these proposed innovations leads to the design of a hypothetical system, which is in turn analyzed from both electrical and economic perspectives.