Este trabalho tem por objetivo apresentar metodologia e modelo de simulação para comparação de arranjos de subestações de distribuição através de análise de confiabilidade estática de esquemas de manobra. A comparação entre alternativas de arranjos de subestações, sob o ponto de vista de confiabilidade, será feita de duas formas, a saber: - Comparação direta dos índices de confiabilidade obtidos pela modelagem dos arranjos de subestações, com a utilização de um eficiente algoritmo que se baseia na determinação dos cortes mínimos de uma rede genérica; - Avaliação técnico-econômica dos arranjos de subestações, através de análise com enfoque de múltiplos objetivos, considerando-se os objetivos de minimização dos custos (investimento, operação e manutenção) e de maximização da confiabilidade, através do custo da energia não distribuída. Esta análise é feita para um período de estudo, considerando o crescimento da carga a ser atendida. Os arranjos de subestação podem ser fixos durante todo o período de estudo, ou podem evoluir ao longo do tempo, por exemplo, considerando um primeiro estágio, com uma unidade transformadora, e um segundo estágio, com duas unidades. / This dissertation aims at presenting a methodology and simulation model to compare different distribution substation configurations through a static reliability evaluation model applicable to different switching schemes. The comparison of the substation configuration alternatives, regarding reliability analysis, is carried out by the two following ways: - Straight-forward comparison of reliability indices obtained by modeling the substation configuration alternatives through an efficient algorithm based on the determination of minimum cut sets applied to a generic network; - Technical and economical evaluation of the substation configuration alternatives, through a multiple objective framework, by considering the minimization of costs (investment, operation and maintenance) e maximization of a reliability index, which is the costs due to the non-supplied energy. This analysis is carried out for a study period, considering the corresponding load growth. Substation configurations can be either fixed for the entire study period or can evolve along time. For instance, for the first stage a single transformer unit is used and, for the second stage, the configuration comprises two transformer units.

Este trabalho tem por objetivo apresentar metodologia e modelo de simulação para comparação de arranjos de subestações de distribuição através de análise de confiabilidade estática de esquemas de manobra. A comparação entre alternativas de arranjos de subestações, sob o ponto de vista de confiabilidade, será feita de duas formas, a saber: - Comparação direta dos índices de confiabilidade obtidos pela modelagem dos arranjos de subestações, com a utilização de um eficiente algoritmo que se baseia na determinação dos cortes mínimos de uma rede genérica; - Avaliação técnico-econômica dos arranjos de subestações, através de análise com enfoque de múltiplos objetivos, considerando-se os objetivos de minimização dos custos (investimento, operação e manutenção) e de maximização da confiabilidade, através do custo da energia não distribuída. Esta análise é feita para um período de estudo, considerando o crescimento da carga a ser atendida. Os arranjos de subestação podem ser fixos durante todo o período de estudo, ou podem evoluir ao longo do tempo, por exemplo, considerando um primeiro estágio, com uma unidade transformadora, e um segundo estágio, com duas unidades. / This dissertation aims at presenting a methodology and simulation model to compare different distribution substation configurations through a static reliability evaluation model applicable to different switching schemes. The comparison of the substation configuration alternatives, regarding reliability analysis, is carried out by the two following ways: - Straight-forward comparison of reliability indices obtained by modeling the substation configuration alternatives through an efficient algorithm based on the determination of minimum cut sets applied to a generic network; - Technical and economical evaluation of the substation configuration alternatives, through a multiple objective framework, by considering the minimization of costs (investment, operation and maintenance) e maximization of a reliability index, which is the costs due to the non-supplied energy. This analysis is carried out for a study period, considering the corresponding load growth. Substation configurations can be either fixed for the entire study period or can evolve along time. For instance, for the first stage a single transformer unit is used and, for the second stage, the configuration comprises two transformer units.

<p>At the Division for Electricity at Uppsala University a new marine substation for waveenergy is being built. The marine substation is required to connect the wave energyconverters to the grid. In this thesis a part of the main circuit for the marinesubstation is assembled and tested. Furthermore, a part of the measurement system isdesigned and a prototype is built and evaluated. The test results from the set-up ofthe main circuit agree well with simulations done in MATLAB Simulink. A detailed listof components combined with a finished CAM-model for a measurement card arepresented along with interface cards and shielding solutions.</p>

At the Division for Electricity at Uppsala University a new marine substation for waveenergy is being built. The marine substation is required to connect the wave energyconverters to the grid. In this thesis a part of the main circuit for the marinesubstation is assembled and tested. Furthermore, a part of the measurement system isdesigned and a prototype is built and evaluated. The test results from the set-up ofthe main circuit agree well with simulations done in MATLAB Simulink. A detailed listof components combined with a finished CAM-model for a measurement card arepresented along with interface cards and shielding solutions.

For a district heating company it is of importance to have an efficient and well performing system. A central part in the work to lower temperature levels in district heating networks is to acknowledge and improve cooling capability in substations. The aim of this thesis is to analyse substations in Polish district heating systems in order to identify reasons of poor cooling and to present suggestions of implementable measures. Furthermore, the economical saving potential from an improved cooling is evaluated. The analysis was carried out for two of the five Polish companies included in this report; Sydkraft EC Slupsk and MEC Koszalin. It was followed by two scenarios created for evaluation of improvement possibilities based on calculated financial savings from reduction of distribution heat losses and distribution pumping. The results show that there are significant improvement possibilities. From the carried out scenarios a saving potential between 15 000 to 20 000 PLN/substation is possible to achieve for selected worst substations, if their individual annual average cooling is set to 30°C. The analysis further shows that causes of poor cooling in substations are highly individual but points out that customer owned substations are represented in the majority of worst substations.

Det här examensarbetet är utfört på uppdrag av Kungälv Energi AB. Syftet med arbetet är att upprätta en nätplan för området M4 Torsby som kan användas som underlag till investeringar. Nätplanen innehåller en geografisk beskrivning som ger en överblick av markförhållanden, en tillståndskontroll av nätet vid normal- samt reservdrift, kontroll av nätets prestanda vid framtida lastökning samt åtgärdsförslag. M4 Torsby är ett landsbygdsnät bestående av fem linjer som matar totalt 1949 kunder. Beräkningar som utförts i Kungälv Energis beräkningsprogram dpPower visar att på linje L403 finns det en Cu 10 friledning som är överbelastad vid normaldrift. I nätet finns även överbelastade transformatorer. Reservdrift i området kan hanteras på alla linjer förutom på linje L401 vid det specifikt valda beräkningsfallet. Undersökning av nätets framtida prestanda har beräknats enligt Kungälv Energis och Kungälv Kommuns planer för området. Även extra last har adderats för att få en högre belastningsökning än de redan planerade. Resultaten visar att nätet klarar denna belastningsökning i normal- och reservdrift förutom då K406 reservmatar stor del av L401. En ACJJ50 kabel i Kärna centrum överbelastas. Arbetet resulterade i åtgärdsförslag för transformatorer samt placering av nya frånskiljare för bättre sektionering av nätet. Även ett åtgärdsförslag på den ACJJ50 kabel som kan bli överbelastad vid framtida reservdrift har framställts. / This thesis is made on behalf of Kungälv Energi AB. The purpose of the thesis is to establish a network plan for the area M4 Torsby that can be used as a foundation for reconstruction and investments in the area. The network plan contains a geographical description that provides an overview of the area including ground conditions and nature reserves. It also procures condition monitoring of the power network to detect its strengths and weaknesses in normal and reserve operation. To detect if the network can handle future loads a simulated scenario has been made. M4 Torsby consists of five lines which supply 1949 customers. Calculations show that a specific part of line L403 and some transformers around the area are overloaded during normal operation. The area can be alternately supplied. Calculations on the simulated future show that the network can handle future loads in both normal and reserve operation if the overloaded part of L403 is upgraded.

A power system protection system consists, at least, of an instrument trans- former, a protective device (relay), and a circuit breaker. Conventional instrument transformers bring currents and voltages from power network levels to much lower scaled-down replicas that serve as input signals to protective relays. The relay's function is to measure input signals (or a relationship among them in some cases) and compare them to defined operating characteristic thresholds (relay settings) to quickly decide whether to operate associated circuit breaker(s). Existing protection systems within a substation are based on a hardwired interface between instrument transformers and protective relays. Recent development of electronic instrument transformers and the spread of digital relays allow the development of an all-digital protection system, in which the traditional analog interface has been replaced with a digital signal connected to digital relays through a digital communication link (process bus). Due to their design, conventional instrument transformers introduce distortions to the current and voltage signal replicas. These distortions may cause protective relays to misoperate. On the other hand, non-conventional instrument transformers promise distortion-free replicas, which, in turn, should translate into better relay performance. Replacing hardwired signals with a communication bus also reduces the significant cost associated with copper wiring. An all-digital system should provide compatibility and interoperability so that different electronic instrument transformers can be connected to different digital relays (under a multi-vendor connection) Since the novel all-digital system has never been implemented and/or tested in practice so far, its superior performance needs to be evaluated. This thesis proposes a methodology for performance and compatibility evaluation of an all-digital protection system through application testing. The approach defines the performance indices and compatibility indices as well as the evaluation methodology.

Electricity construction is required for a country¡¦s fundamental economic development. It provides the needed power and plays an important role in modern society. In order to construct a complete electricity system, Taiwan government will launch the 7th electricity transmission and distribution project in the whole country starting from the year of 2010. The transmission and distribution construction is an interface to transmit high voltage electricity in Taiwan and will take long time to complete. Based on the guidelines of Executive Yuan¡¥s Public Construction Commission, the construction shall focus on material management system; coordinate, monitor and examine the project; review by routine and check on site; integrate technology and experts from the production field to raise the execution effect and process quality. Construction of transmission and distribution consists of substations and circuits. The construction methodology will determine if the construction can be or not completed on time. With reference by managerial and operational scopes of some enterprises, this thesis sets up Architecture-Oriented Transmission and Substation Affairs Management Model, abbreviated as AOTSAMM, to describe the whole picture for the transmission and distribution project and further to achieve the aims on controlling schedule, raising knowledge management, etc. AOTSAMM contains the architecture of transmission and distribution construction. It not only describes the organizational structure and organizational behavior in enterprise value chains, but also integrates with technology application systems. With duplicating and expanding capabilities, AOTSAMM will easily apply to other electricity system and create contemporary enterprise excellences.

Subestações blindadas são utilizadas por empresas de energia há mais de 50 anos. Muitas destas subestações estão em operação até os dias de hoje, sem qualquer modificação em seu projeto original, e ainda assim continuam operando sem apresentar problemas ou indícios de fadiga. Isto pode ser atribuído a sua qualidade construtiva em conjunto com o material isolante utilizado por este tipo de equipamento, o Hexafluoreto de Enxofre (SF6). Este gás possui todas as características desejáveis para manter adequadas as propriedades dielétricas da subestação, além de ser inerte e extremamente estável. O tempo de vida nominal de uma subestação blindada pode ser de 30 a 50 anos, dependendo de suas características ou recomendação do fabricante. A proximidade, ou até a ultrapassagem, do final do tempo de vida gera preocupação às empresas detentoras destes equipamentos antigos no que diz respeito a operação da subestação com segurança. Outro aspecto importante está relacionado a vazamentos de gás na atmosfera, pois o SF6 está entre os elementos mais danosos para o efeito estufa. Por estas razões este trabalho apresenta o desenvolvimento de um sistema para monitoramento de vazamentos e também de parâmetros indicativos do gás SF6 em uma subestação blindada antiga. O objetivo principal foi de desenvolver um sistema com dados históricos para se realizar estudos a respeito do comportamento do gás. A subestação utilizada neste trabalho não possuía nenhum sistema de monitoramento online. Assim, foi desenvolvido um sistema de tempo real para coletar dados de densidade do gás e de ponto de orvalho nos compartimentos da subestação. O sistema de coleta de dados foi instalado em três bays de uma subestação. Foram instalados sensores para medir estas duas grandezas, e também, módulos de aquisição de dados de baixo custo que se comunicam por meio de protocolos padrão e abertos. A partir do sistema instalado, no longo prazo, se espera a redução de vazamentos de gás com a possibilidade de inspeções online. Pode ser atribuído como resultado do trabalho a redução de custos, pois os dados históricos com indicativos favoráveis permitem estender o tempo entre manutenções preventivas. Como resultado complementar deste trabalho, o monitoramento de perdas de gás se torna mais eficiente e rápido, colaborando, assim com as expectativas ambientais atuais. / Gas Insulated Substations (GIS) are used by energy companies for over 50 years. Many early substations have been in operation until the present day, without any modification in its original design, and still are operating without problems or indications of fatigue. This can be attributed to its constructive quality along with the insulating material used for this type of equipment, the gas sulfur hexafluoride (SF6). This gas has all the desirable features for maintaining the dielectric of the substation as well as being inert and extremely stable. The nominal lifetime of a GIS substation can be 30 to 50 years, depending on their characteristics or manufacturer\'s recommendation. The proximity, or even exceeding, the lifetime generates concern to companies holding these old equipment as regards the operation of the substation safely. Another important aspect is related to gas leakages into the atmosphere because SF6 is among the most damaging elements to the greenhouse effect. Therefore, this work presents the development of a system for monitoring leakage and also indicative parameters of SF6 gas at an old GIS. The main objective was to develop a system with historical data to conduct studies about the behavior of the gas. The substation used for this work had no online monitoring system. Thus, it was developed a real-time system for collecting data of gas density and dew point in the compartments of the substation. The data collection system was installed in three bays of the substation. Sensors were installed to measure these two quantities, and also low cost data acquisition modules which communicate via standard and open protocols. In long term, with the system, there should be a reduction of gas leakages with the possibility of online inspections of the gas. May be assigned as a result the reduction of costs, since the historical data with good indicative allows extending the time for preventative maintenance. As additional result of this work, it is expected that the monitoring of leakage become more efficient and faster, thus contributing to the current environmental expectations.

Subestações blindadas são utilizadas por empresas de energia há mais de 50 anos. Muitas destas subestações estão em operação até os dias de hoje, sem qualquer modificação em seu projeto original, e ainda assim continuam operando sem apresentar problemas ou indícios de fadiga. Isto pode ser atribuído a sua qualidade construtiva em conjunto com o material isolante utilizado por este tipo de equipamento, o Hexafluoreto de Enxofre (SF6). Este gás possui todas as características desejáveis para manter adequadas as propriedades dielétricas da subestação, além de ser inerte e extremamente estável. O tempo de vida nominal de uma subestação blindada pode ser de 30 a 50 anos, dependendo de suas características ou recomendação do fabricante. A proximidade, ou até a ultrapassagem, do final do tempo de vida gera preocupação às empresas detentoras destes equipamentos antigos no que diz respeito a operação da subestação com segurança. Outro aspecto importante está relacionado a vazamentos de gás na atmosfera, pois o SF6 está entre os elementos mais danosos para o efeito estufa. Por estas razões este trabalho apresenta o desenvolvimento de um sistema para monitoramento de vazamentos e também de parâmetros indicativos do gás SF6 em uma subestação blindada antiga. O objetivo principal foi de desenvolver um sistema com dados históricos para se realizar estudos a respeito do comportamento do gás. A subestação utilizada neste trabalho não possuía nenhum sistema de monitoramento online. Assim, foi desenvolvido um sistema de tempo real para coletar dados de densidade do gás e de ponto de orvalho nos compartimentos da subestação. O sistema de coleta de dados foi instalado em três bays de uma subestação. Foram instalados sensores para medir estas duas grandezas, e também, módulos de aquisição de dados de baixo custo que se comunicam por meio de protocolos padrão e abertos. A partir do sistema instalado, no longo prazo, se espera a redução de vazamentos de gás com a possibilidade de inspeções online. Pode ser atribuído como resultado do trabalho a redução de custos, pois os dados históricos com indicativos favoráveis permitem estender o tempo entre manutenções preventivas. Como resultado complementar deste trabalho, o monitoramento de perdas de gás se torna mais eficiente e rápido, colaborando, assim com as expectativas ambientais atuais. / Gas Insulated Substations (GIS) are used by energy companies for over 50 years. Many early substations have been in operation until the present day, without any modification in its original design, and still are operating without problems or indications of fatigue. This can be attributed to its constructive quality along with the insulating material used for this type of equipment, the gas sulfur hexafluoride (SF6). This gas has all the desirable features for maintaining the dielectric of the substation as well as being inert and extremely stable. The nominal lifetime of a GIS substation can be 30 to 50 years, depending on their characteristics or manufacturer\'s recommendation. The proximity, or even exceeding, the lifetime generates concern to companies holding these old equipment as regards the operation of the substation safely. Another important aspect is related to gas leakages into the atmosphere because SF6 is among the most damaging elements to the greenhouse effect. Therefore, this work presents the development of a system for monitoring leakage and also indicative parameters of SF6 gas at an old GIS. The main objective was to develop a system with historical data to conduct studies about the behavior of the gas. The substation used for this work had no online monitoring system. Thus, it was developed a real-time system for collecting data of gas density and dew point in the compartments of the substation. The data collection system was installed in three bays of the substation. Sensors were installed to measure these two quantities, and also low cost data acquisition modules which communicate via standard and open protocols. In long term, with the system, there should be a reduction of gas leakages with the possibility of online inspections of the gas. May be assigned as a result the reduction of costs, since the historical data with good indicative allows extending the time for preventative maintenance. As additional result of this work, it is expected that the monitoring of leakage become more efficient and faster, thus contributing to the current environmental expectations.