The concentration of this work is in estimating fault locations in power systems. After describing the basic concepts of fault locating methods, this work describes improving the fault location estimates, applying the fault locating methods, and implementing the methods in a software. Every work described in the Chapter will be evaluated whether by actual field data or simulated data based on field parameters. / text

Voltage control in distribution networks is becoming more challenging due to the growing amount of distributed generation that is being connected to the distribution networks in addition to increasing load. The output of the distributed generation can radically change power flows and voltage profiles in distribution networks, creating conditions that adversely affect the performance of automatic voltage control schemes and in addition cause unacceptable voltage rise. On the other hand, inherent limitations and current operational policies of AVC schemes very often restrict the output of DG or even prevent its connection. This thesis investigates and analyses voltage control in terms of the shift from passive to active distribution networks. The thesis also reviews the performance of AVC schemes under varying load and generation output conditions, investigates effective utilisation of distribution network assets and methods to accommodate active voltage control schemes into existing infrastructure. A range of active voltage control and management schemes based on coordinated voltage control is presented and assessed. These schemes can be used to improve the voltage profile in distribution networks and increase their ability to accommodate distributed generation. The functionality of each scheme is assessed based on a number of factors such as the ability of the scheme to increase network capacity, reliability and accuracy. Simulation software to accurately evaluate the performance of an active voltage control scheme in a particular distribution network scenario is essential before the scheme can be deployed. Formal assessment of advanced AVC models and SuperTAPP n+ functionality is performed using simulation software as developed and presented in this thesis. The accuracy of the software results and performance of the SuperTAPP n+ scheme is validated based on network trials carried out in EDF Energy Networks.

Nos dias de hoje, o aumento na demanda de energia no Brasil, associado a fatores econômicos e ambientais, tem dificultado a criação de novas usinas hidrelétricas, necessárias para suprir essa demanda adicional e aumentar a confiabilidade do sistema. Nesse contexto, a geração distribuída se destaca como uma solução adequada, pois economiza investimentos em redes de transmissão e distribuição, reduz perdas e diversifica a matriz energética do sistema elétrico, tornando-o mais robusto e eficiente. Dentre as fontes de energia utilizadas em sistemas de geração distribuída, a microturbina apresenta algumas vantagens em relação a outros modelos de GD, como por exemplo, a possibilidade da utilização de vários tipos de combustíveis. Para verificar as características de operação das microturbinas, foram realizadas simulações baseadas em modelos matemáticos presentes na literatura técnica. Porém, devido às altas velocidades de rotação das turbinas a gás, a energia gerada possui frequências muito altas para ser aproveitada diretamente pelos consumidores, sendo necessária uma interface eletrônica para adequação da energia elétrica. Neste trabalho é abordado o estudo, simulação e implementação da primeira etapa desta interface, um retificador trifásico com correção de fator de potência, para a geração de um barramento de corrente contínua com tensão estável, mantendo as correntes de entrada do retificador com formato senoidal e em fase com a tensão. / Nowadays, the increase in energy demand in Brazil, associated with economic and environmental factors, has hindered the creation of new power plants needed to provide this additional demand and improve system reliability. In this context, distributed generation stands out as an appropriate solution because it saves investments in transmission and distribution, reduces losses and diversify the energy matrix of the electrical system, making it more robust and efficient. Among the energy sources used in distributed generation systems, the microturbine has some advantages over other models of GD, such as the possibility of using various types of fuel. To verify the operating characteristics of microturbines, simulations were performed based on mathematical models present in literature. However, due to high rotation speeds of gas turbines, the energy generated has very high frequencies to be used directly by consumers, which requires an electronic interface to adequate the electricity. This work describe the study, simulation and implementation of the first stage of this interface, a three-phase rectifier with power factor correction, to generate a DC bus voltage stable, keeping the rectifier input current format sinusoidal and in phase with the voltage generated by the microturbine.

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. The case study design is performed on the campus distribution system of California Polytechnic State University, San Luis Obispo, with the design goal of implementing renewable energy sources to make the campus a net zero energy consumer.

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 17, 2007) Includes bibliographical references (p. 77-80).

Thesis (M.S.)--Drexel University, 2007. / Includes abstract. Includes bibliographical references (leaves 81-83).

With an increasing interest for renewable power, photovoltaics (PV) have becomemore and more common in the distribution network. If a customer wants to install aPV system, or another type of distributed generation (DG), the distribution systemoperators (DSO) needs a good way to determine if it the grid can handle it or not. InSweden, a guideline to aid the DSO was published in 2011. However, this guidelineonly considers one connection without considering other DG units. This project isabout developing new guidelines for DG connections in grids with a large number ofDG units. Based on a literature study it has been concluded that one of the mostcritical issue is over-voltage, which is the main focus of this project. Two new methods have been developed; the first proposed method is based onneglecting reactance and losses in the grid, a simple linear relationship between thevoltage level, the resistance in the lines, and the installed power is obtained. Thisrelationship is then used to calculate the voltage level at critical points in the grid. Thesecond method is to find the weakest bus, with a connected DG unit. By assumingthat all power is installed at that point we get a very simple guideline; it is veryconservative but can be used before the first method. A simulation tool has been developed in order to analyze the voltage level in grids forvarious cases with connected DG units. The simulated results have proven that theproposed guidelines are, when considering voltage issues, very reliable and can beuseful. However, further work needs to be done to ensure that other problems donot occur.

Renewable distributed generation such as wind power and photovoltaics are gaining popularity all over the world. The overall aim of this Master thesis was to gather experience and knowledge regarding small wind power and photovoltaic with both a market based evaluation and technical description. Methods used have been literature review, interviews with market participants, evaluation of a wind mill and a photovoltaic system simulation with PVsyst 5.41. It was found that the main common incentive today for the development and spread of small wind power and photovoltaics for market participants is the symbolic value. It was also discovered that the market situation is complicated for the producing consumer. The spread of small wind power and PV today are a few per mille of a future potential, where politics largely control development and spread of small-scale solutions. The market is unclear and solutions around net charge is still an ongoing debate. Majority of the interviewed persons believes more in PV than in small wind power due to facts such as wind power is size-dependent and not optimal to build in urban areas. Results show that power quality issues are dependent on the network system as a whole and are often a matter of cost and can be prevented with different technical solutions. One conclusion was that bidirectional power flow increase complexity of problems around protection. Major energy companies are involved in projects to gather knowledge how to deal with DG both in technical aspects and how to deal with customers practically.

This thesis addresses the future of sustainable energy distribution and transportation in the United States. Predictions of future energy and transportation demands promote localized energy as the most likely situation. Existing proposals outlining the benefits of decentralized energy production fail to engage architecture. Cities will require new architectural typologies that can integrate new energy infrastructure in the city. Los Angeles, the archetype of the decentralized American city, is introduced as a case study. The city is examined at multiple scales for the integration of a decentralized electricity network and an efficient transportation infrastructure. Siting the proposed facilities capitalizes on new and existing transportation infrastructures and local energy resources. The new electricity-transportation infrastructure is adapted to a decentralized network functioning on principles of ecosystems and energy economics at an urban scale. Energy storage is paired with multi-modal transportation to develop new architectural and urban typologies. This enables the decentralized urban proposal to function as a network exhibiting mutually beneficial characteristics.

Distribution system design and planning is facing a major change in paradigm because of deregulation of the power industry and with rapid penetration of distributed generation (DG) sources. Distribution system design and planning are key features for determining the best expansion strategies to provide reliable and economic services to the customer. In classical planning, the load growth is typically met by adding a new substation or upgrading the existing substation capacity along with their feeders. Today, rapid advances in DG technology and their numerous benefits have made them an attractive option to the distribution companies, power system planners and operators, energy policy makers and regulators, as well as developers. This thesis first presents a comprehensive planning framework for the distribution system from the distribution company perspective. It incorporates DG units as an option for local distribution companies (LDCs) and determines the sizing, placement and upgrade plans for feeders and substations. Thereafter, a new heuristic approach to multi-year distribution system planning is proposed which is based on a back-propagation algorithm starting from the terminal year and arriving at the first year. It is based on cost-benefit analysis, which incorporates various energy supply options for LDCs such as DG, substations and feeders and determines the size, placement and upgrade plan. The proposed heuristic approach combines a bi-level procedure in which Level-1 selects the optimal size and location of distribution system component upgrades and Level-2 determines the optimal period of commissioning for the selected upgrades in Level-1. The proposed heuristic is applied to a 32-bus radial distribution system. The first level of the distribution system planning framework is formulated as a mixed integer linear programming (MILP) problem while the second level is a linear programming (LP) model. The results demonstrate that the proposed approach can achieve better performance than a full optimization for the same distribution system.