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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Restabelecimento de energia por reconfiguração de redes em sistemas de distribuição de grande porte com priorização de chaves, consumidores e definição de sequência de chaveamento / Service restoration by network reconfiguration in large scale distribution systems with switches and consumers priorization and switching sequence definition

Marques, Leandro Tolomeu 29 August 2013 (has links)
Na ocorrência de uma ou de múltiplas faltas permanentes em sistemas de distribuição de energia elétrica é inevitável a ausência de fornecimento à algumas cargas. Contudo, devido à presença de chaves seccionadoras, após a localização e isolação do trecho sob falta, é possível restaurar o abastecimento de energia a estas cargas fora de serviço. Para tal é necessária a obtenção de um plano de restabelecimento adequado, no menor intervalo de tempo possível, capaz de informar as chaves que devem ser operadas a fim de reconectar estas cargas à rede e sem sobrecarregar nenhum equipamento. Neste sentido, têm sido propostas metodologias para auxiliar as atividades dos operadores de sistemas de distribuição por meio do fornecimento de planos de restabelecimento de energia em situações de contingência. Todavia, a aplicação da maioria destas técnicas restringe-se à redes pequenas, quando comparadas às redes reais que possuem milhares de barras e chaves. Em outras metodologias, na tentativa de superar esta limitação, são feitas simplificações na representação da rede, desconsiderando alguns dos seus elementos. Nestes casos, a solução fornecida para a rede simplificada pode não ter o mesmo desempenho na rede em operação, o que compromete a confiabilidade dessas metodologias. Em outros métodos, ainda, a rede é representada com todas as suas barras e chaves, no entanto, deixam de considerar a presença de consumidores especiais, que exigem prioridade de fornecimento, bem como de chaves existentes na rede que podem ser operadas remotamente. Face ao exposto, propõe-se uma metodologia para determinação, em tempo real, de planos de restabelecimento de energia elétrica em sistemas de distribuição de grande porte em situações de uma ou de múltiplas faltas. Para lidar com os múltiplos objetivos deste problema, sendo alguns dele conflitantes entre si, esta será baseada em Algoritmos Evolutivos Multi-Objetivo, enquanto que a representação computacional sem simplificações da rede será proporcionada por uma codificação de dados apoiada na teoria de grafos e denominada Representação Nó-Profundidade. A fim de diminuir o tempo e o custo de implementação dos planos obtidos, será considerada e dado prioridade de manobra às chaves controladas remotamente, que podem ser alteradas do centro de operações. Será dado prioridade também ao fornecimento de energia de consumidores especiais. Por fim, para cada plano de restabelecimento fornecido será definida uma sequência factível de chaves que, quando alteradas, reconectarão as cargas sãs fora de serviço e eliminarão sobrecargas ou perfis de tensão inadequados. Para validar a metodologia proposta serão realizadas simulações computacionais no sistema de distribuição real da cidade de São Carlos-SP, em operação no ano de 1994, e nas suas versões duplicada, quadruplicada e octuplicada. / The occurrence of one or multiple permanent faults in electric power distribution systems is inevitable the privation of the service to some loads. However, due to the presence of switches, after the location and isolation of the faulted section, you can restore the power supply to these out of service loads. To this it is necessary to obtain, as soon as possible, a suitable restoration plan. It must be able to inform the switches that must be operated in order to reconnect these loads without overloading on any network or equipment. In this sense, it has been proposed methods to assist the operators\' activities of the of distribution systems by providing plans to restore the service in contingency situations. However, the application of the most of these techniques is limited to small networks, when they are compared to real networks that have thousands of bars and keys. In other methodologies, in order to overcome this limitation, simplications are made in the representation of the network, ignoring some of its elements. In these cases, the solution provided for a simplied network may not have the same performance on the network in operation, which aects the reliability of these methodologies. In other methods, the network is represented with all of its bars and switches. However, these methodologies do not consider the presence of the special consumers that require service priority neither the switches that can be operated remotely. Given the above, we propose a methodology for determining, in real time, plans for service restoration in large-scale electric distribution systems in situations of one or multiple faults. To deal with the multiple objectives of this problem, some of them con icting, the proposed method will be based on Multi-Objective Evolutionary Algorithms. Moreover, the computational representation without simplications of the network will be provided by a data encoding based in graph theory and called Node-Depth Encoding. In order to reduce the time and cost of the implementation of the plans obtained, it will be considered and given priority to maneuvers in remotely controlled switches, which can be changed from the operation center. Priority will be given also to the power supply of special consumers. Finally, for each restoration plan provided will be gotten a feasible switching sequence that, when implemented, will reconnect the out of service loads and eliminate overloads or inadequate voltage proles. To validate the proposed methodology it will be performed computer simulations in the real distribution system of the São Carlos-SP city, in operation in 1994, and their doubled, quadruplicate and octuplicate versions.
12

Algoritmo para obtenção de planos de restabelecimento para sistemas de distribuição de grande porte / Algorithm for elaboration of plans for service restoration to large-scale distribution systems

Mansour, Moussa Reda 03 April 2009 (has links)
A elaboração de planos de restabelecimento de energia (PRE) de forma rápida, para re-energização de sistemas de distribuição radiais (SDR), faz-se necessária para lidar com situações que deixam regiões dos SDR sem energia. Tais situações podem ser causadas por faltas permanentes ou pela necessidade de isolar zonas dos SDR para serviços de manutenção. Dentre os objetivos de um PRE, destacam-se: (i) reduzir o número de consumidores interrompidos (ou nenhum), e (ii) minimizar o número de manobras; que devem ser atendidos sem desrespeitar os limites operacionais dos equipamentos. Conseqüentemente, a obtenção de PRE em SDR é um problema com múltiplos objetivos, alguns conflitantes. As principais técnicas desenvolvidas para obtenção de PRE em SDR baseiam-se em algoritmos evolutivos (AE). A limitação da maioria dessas técnicas é a necessidade de simplificações na rede, para lidar com SDR de grande porte, que limitam consideravelmente a possibilidade de obtenção de um PRE adequado. Propõe-se, neste trabalho, o desenvolvimento e implantação computacional de um algoritmo para obtenção de PRE em SDR, que consiga lidar com sistemas de grande porte sem a necessidade de simplificações, isto é, considerando uma grande parte (ou a totalidade) de linhas, barras, cargas e chaves do sistema. O algoritmo proposto baseia-se em um AE multi-objetivo e na estrutura de dados, para armazenamento de grafos, denominada representação nó-profundidade (RNP), bem como em dois operadores genéticos que foram desenvolvidos para manipular de forma eficiente os dados armazenados na RNP. Em razão de se basear em um AE multi-objetivo, o algoritmo proposto possibilita uma investigação mais ampla do espaço de busca. Por outro lado, fazendo uso da RNP, para representar computacionalmente os SDR, e de seus operadores genéticos, o algoritmo proposto aumenta significativamente a eficiência da busca por adequados PRE. Isto porque aqueles operadores geram apenas configurações radiais, nas quais todos os consumidores são atendidos. Para comprovar a eficiência do algoritmo proposto, várias simulações computacionais foram realizadas, utilizando o sistema de distribuição real, de uma companhia brasileira, que possui 3.860 barras, 635 chaves, 3 subestações e 23 alimentadores. / An elaborated and fast energy restoration plan (ERP) is required to deal with steady faults in radial distribution systems (RDS). That is, after a faulted zone has been identified and isolated by the relays, it is desired to elaborate a proper ERP to restore energy on that zone. Moreover, during the normal system operation, it is frequently necessary to elaborate ERP to isolate zones to execute routine tasks of network maintenance. Some of the objectives of an ERP are: (i) very few interrupted customers (or none), and (ii) operating a minimal number of switches, while at the same time respecting security constraints. As a consequence, the service restoration is a multiple objective problem, with some degree of conflict. The main methods developed for elaboration of ERP are based on evolutionary algorithms (EA). The limitation of the majority of these methods is the necessity of network simplifications to work with large-scale RDS. In general, these simplifications restrict the achievement of an adequate ERP. This work proposes the development and implementation of an algorithm for elaboration of ERP, which can deal with large-scale RDS without requiring network simplifications, that is, considering a large number (or all) of lines, buses, loads and switches of the system. The proposed algorithm is based on a multi-objective EA, on a new graph tree encoding called node-depth encoding (NDE), as well as on two genetic operators developed to efficiently manipulate a graph trees stored in NDEs. Using a multi-objective EA, the proposed algorithm enables a better exploration of the search space. On the other hand, using NDE and its operators, the efficiency of the search is increased when the proposed algorithm is used generating proper ERP, because those operators generate only radial configurations where all consumers are attended. The efficiency of the proposed algorithm is shown using a Brazilian distribution system with 3,860 buses, 635 switches, 3 substations and 23 feeders.
13

Algoritmo para obtenção de planos de restabelecimento para sistemas de distribuição de grande porte / Algorithm for elaboration of plans for service restoration to large-scale distribution systems

Moussa Reda Mansour 03 April 2009 (has links)
A elaboração de planos de restabelecimento de energia (PRE) de forma rápida, para re-energização de sistemas de distribuição radiais (SDR), faz-se necessária para lidar com situações que deixam regiões dos SDR sem energia. Tais situações podem ser causadas por faltas permanentes ou pela necessidade de isolar zonas dos SDR para serviços de manutenção. Dentre os objetivos de um PRE, destacam-se: (i) reduzir o número de consumidores interrompidos (ou nenhum), e (ii) minimizar o número de manobras; que devem ser atendidos sem desrespeitar os limites operacionais dos equipamentos. Conseqüentemente, a obtenção de PRE em SDR é um problema com múltiplos objetivos, alguns conflitantes. As principais técnicas desenvolvidas para obtenção de PRE em SDR baseiam-se em algoritmos evolutivos (AE). A limitação da maioria dessas técnicas é a necessidade de simplificações na rede, para lidar com SDR de grande porte, que limitam consideravelmente a possibilidade de obtenção de um PRE adequado. Propõe-se, neste trabalho, o desenvolvimento e implantação computacional de um algoritmo para obtenção de PRE em SDR, que consiga lidar com sistemas de grande porte sem a necessidade de simplificações, isto é, considerando uma grande parte (ou a totalidade) de linhas, barras, cargas e chaves do sistema. O algoritmo proposto baseia-se em um AE multi-objetivo e na estrutura de dados, para armazenamento de grafos, denominada representação nó-profundidade (RNP), bem como em dois operadores genéticos que foram desenvolvidos para manipular de forma eficiente os dados armazenados na RNP. Em razão de se basear em um AE multi-objetivo, o algoritmo proposto possibilita uma investigação mais ampla do espaço de busca. Por outro lado, fazendo uso da RNP, para representar computacionalmente os SDR, e de seus operadores genéticos, o algoritmo proposto aumenta significativamente a eficiência da busca por adequados PRE. Isto porque aqueles operadores geram apenas configurações radiais, nas quais todos os consumidores são atendidos. Para comprovar a eficiência do algoritmo proposto, várias simulações computacionais foram realizadas, utilizando o sistema de distribuição real, de uma companhia brasileira, que possui 3.860 barras, 635 chaves, 3 subestações e 23 alimentadores. / An elaborated and fast energy restoration plan (ERP) is required to deal with steady faults in radial distribution systems (RDS). That is, after a faulted zone has been identified and isolated by the relays, it is desired to elaborate a proper ERP to restore energy on that zone. Moreover, during the normal system operation, it is frequently necessary to elaborate ERP to isolate zones to execute routine tasks of network maintenance. Some of the objectives of an ERP are: (i) very few interrupted customers (or none), and (ii) operating a minimal number of switches, while at the same time respecting security constraints. As a consequence, the service restoration is a multiple objective problem, with some degree of conflict. The main methods developed for elaboration of ERP are based on evolutionary algorithms (EA). The limitation of the majority of these methods is the necessity of network simplifications to work with large-scale RDS. In general, these simplifications restrict the achievement of an adequate ERP. This work proposes the development and implementation of an algorithm for elaboration of ERP, which can deal with large-scale RDS without requiring network simplifications, that is, considering a large number (or all) of lines, buses, loads and switches of the system. The proposed algorithm is based on a multi-objective EA, on a new graph tree encoding called node-depth encoding (NDE), as well as on two genetic operators developed to efficiently manipulate a graph trees stored in NDEs. Using a multi-objective EA, the proposed algorithm enables a better exploration of the search space. On the other hand, using NDE and its operators, the efficiency of the search is increased when the proposed algorithm is used generating proper ERP, because those operators generate only radial configurations where all consumers are attended. The efficiency of the proposed algorithm is shown using a Brazilian distribution system with 3,860 buses, 635 switches, 3 substations and 23 feeders.
14

Restabelecimento de energia por reconfiguração de redes em sistemas de distribuição de grande porte com priorização de chaves, consumidores e definição de sequência de chaveamento / Service restoration by network reconfiguration in large scale distribution systems with switches and consumers priorization and switching sequence definition

Leandro Tolomeu Marques 29 August 2013 (has links)
Na ocorrência de uma ou de múltiplas faltas permanentes em sistemas de distribuição de energia elétrica é inevitável a ausência de fornecimento à algumas cargas. Contudo, devido à presença de chaves seccionadoras, após a localização e isolação do trecho sob falta, é possível restaurar o abastecimento de energia a estas cargas fora de serviço. Para tal é necessária a obtenção de um plano de restabelecimento adequado, no menor intervalo de tempo possível, capaz de informar as chaves que devem ser operadas a fim de reconectar estas cargas à rede e sem sobrecarregar nenhum equipamento. Neste sentido, têm sido propostas metodologias para auxiliar as atividades dos operadores de sistemas de distribuição por meio do fornecimento de planos de restabelecimento de energia em situações de contingência. Todavia, a aplicação da maioria destas técnicas restringe-se à redes pequenas, quando comparadas às redes reais que possuem milhares de barras e chaves. Em outras metodologias, na tentativa de superar esta limitação, são feitas simplificações na representação da rede, desconsiderando alguns dos seus elementos. Nestes casos, a solução fornecida para a rede simplificada pode não ter o mesmo desempenho na rede em operação, o que compromete a confiabilidade dessas metodologias. Em outros métodos, ainda, a rede é representada com todas as suas barras e chaves, no entanto, deixam de considerar a presença de consumidores especiais, que exigem prioridade de fornecimento, bem como de chaves existentes na rede que podem ser operadas remotamente. Face ao exposto, propõe-se uma metodologia para determinação, em tempo real, de planos de restabelecimento de energia elétrica em sistemas de distribuição de grande porte em situações de uma ou de múltiplas faltas. Para lidar com os múltiplos objetivos deste problema, sendo alguns dele conflitantes entre si, esta será baseada em Algoritmos Evolutivos Multi-Objetivo, enquanto que a representação computacional sem simplificações da rede será proporcionada por uma codificação de dados apoiada na teoria de grafos e denominada Representação Nó-Profundidade. A fim de diminuir o tempo e o custo de implementação dos planos obtidos, será considerada e dado prioridade de manobra às chaves controladas remotamente, que podem ser alteradas do centro de operações. Será dado prioridade também ao fornecimento de energia de consumidores especiais. Por fim, para cada plano de restabelecimento fornecido será definida uma sequência factível de chaves que, quando alteradas, reconectarão as cargas sãs fora de serviço e eliminarão sobrecargas ou perfis de tensão inadequados. Para validar a metodologia proposta serão realizadas simulações computacionais no sistema de distribuição real da cidade de São Carlos-SP, em operação no ano de 1994, e nas suas versões duplicada, quadruplicada e octuplicada. / The occurrence of one or multiple permanent faults in electric power distribution systems is inevitable the privation of the service to some loads. However, due to the presence of switches, after the location and isolation of the faulted section, you can restore the power supply to these out of service loads. To this it is necessary to obtain, as soon as possible, a suitable restoration plan. It must be able to inform the switches that must be operated in order to reconnect these loads without overloading on any network or equipment. In this sense, it has been proposed methods to assist the operators\' activities of the of distribution systems by providing plans to restore the service in contingency situations. However, the application of the most of these techniques is limited to small networks, when they are compared to real networks that have thousands of bars and keys. In other methodologies, in order to overcome this limitation, simplications are made in the representation of the network, ignoring some of its elements. In these cases, the solution provided for a simplied network may not have the same performance on the network in operation, which aects the reliability of these methodologies. In other methods, the network is represented with all of its bars and switches. However, these methodologies do not consider the presence of the special consumers that require service priority neither the switches that can be operated remotely. Given the above, we propose a methodology for determining, in real time, plans for service restoration in large-scale electric distribution systems in situations of one or multiple faults. To deal with the multiple objectives of this problem, some of them con icting, the proposed method will be based on Multi-Objective Evolutionary Algorithms. Moreover, the computational representation without simplications of the network will be provided by a data encoding based in graph theory and called Node-Depth Encoding. In order to reduce the time and cost of the implementation of the plans obtained, it will be considered and given priority to maneuvers in remotely controlled switches, which can be changed from the operation center. Priority will be given also to the power supply of special consumers. Finally, for each restoration plan provided will be gotten a feasible switching sequence that, when implemented, will reconnect the out of service loads and eliminate overloads or inadequate voltage proles. To validate the proposed methodology it will be performed computer simulations in the real distribution system of the São Carlos-SP city, in operation in 1994, and their doubled, quadruplicate and octuplicate versions.
15

Restabelecimento de energia em sistemas de distribuição considerando aspectos práticos / Distribution systems service restoration with the consideration of practical aspects

Marques, Leandro Tolomeu 13 June 2018 (has links)
No contexto da operação de sistemas de distribuição, um dos problemas com os quais os operadores lidam frequentemente é o de restabelecimento de energia. Este problema surge na ocorrência de uma falta permanente e pode ser tratado por meio de manobras em chaves presentes na rede primária. Uma vez que tais redes operam com topologia radial, a ocorrência de uma falta pode resultar no desligamento de consumidores saudáveis. Desta maneira, o problema consiste em definir, num curto intervalo de tempo, um número mínimo de chaves que devem ser operadas a fim de isolar a falta e restaurar o máximo de consumidores saudáveis desligados. Os esforços para a obtenção de ferramentas computacionais para fornecimento de soluções para o problema de restabelecimento têm sido intensificados nos últimos anos. Isto ocorre, em especial, devido aos enormes prejuízos causados pela falta de energia às companhias de eletricidade e a toda a sociedade. Neste sentido, o objetivo deste trabalho é a obtenção de um método para auxiliar o trabalho dos operadores através do fornecimento de planos adequados de restabelecimento em curtos intervalos de tempo. Os diferenciais deste método proposto são a sua capacidade de: lidar, em especial, com redes reais de grande porte com reduzido esforço computacional; considerar a existência de vários níveis de prioridade de atendimento entre os consumidores (note, por exemplo, que um hospital ou um centro de segurança pública devem ter maior prioridade de atendimento que um grande supermercado ou unidades residenciais) e priorizar o atendimento deles de acordo a sua prioridade; fornecer uma sequência por meio da qual as chaves possam ser operadas a fim de isolar os setores em falta e reconectar o maior número de consumidores saudáveis desligados executando-se o mínimo de manobras em chaves e priorizando os consumidores com maior prioridade; ser capaz de selecionar cargas menos prioritárias para permaneceram desligadas nas situações em que não é possível obter uma solução que restaure todas as cargas saudáveis fora de serviço; e, adicionalmente, priorizar a operação de chaves controladas remotamente, que, diferentemente das chaves controladas manualmente, podem ser operadas com menores custos e de maneira mais rápida. O método proposto consiste, de maneira sintética, na união de uma busca exaustiva aplicada localmente a um novo algoritmo evolutivo multi-objetivo em tabelas de subpopulação que faz uso de uma estrutura de dados eficiente denominada Representação Nó-Profundidade. Para avaliar a performance relativa do método proposto, simulações foram realizadas num sistema de distribuição de pequeno porte e os resultados foram comparados com os obtidos por um método de Programação Matemática. Na sequência, novos experimentos foram realizadas em diversos casos de falta na rede de distribuição da cidade de Londrina-PR e cidades adjacentes. As soluções fornecidas mostraram-se adequadas ao tratamento dos casos de falta, assim como as sequências de chaveamento associadas a elas, as quais foram capazes de priorizar o restabelecimento dos consumidores prioritários seguindo seus níveis de prioridade. Adicionalmente, estudos avaliaram a variação do tempo de processamento computacional do método proposto com a dimensão das redes de distribuições e também com o número de gerações realizadas pelo algoritmo evolutivo multi-objetivo proposto e os resultados mostraram-se satisfatórios às necessidades do problema Portanto, pode-se comprovar que o método proposto atingiu os objetivos especificados, em especial, o tratamento de aspectos práticos do problema. Além do próprio método proposto, algumas contribuições desta pesquisa são a proposição um novo algoritmo evolutivo multiobjetivo em tabelas de subpopulação e de um novo operador para manipulação de florestas de grafo armazenadas pela Representação Nó-Profundidade e voltado ao problema de restabelecimento. / In the context of distribution systems operation, service restoration is one of the problems with which operators constantly deal. It arises when a permanent fault occurs and is treated trough operations in switches at primary grid. Since distribution systems are usually radial, fault occurrence turns-off healthy customers. Thereby, the service restoration problem consists in defining, in a short processing time, the minimum amount of switches that must be operated for the isolation of the fault and reconnection of the maximum amount of healthy out-of-service customers. The efforts of developing computational tools for getting solution to this problems has increased in the last years. It is, in special, due to enormous losses caused to the utilities and to the whole society. In this sense, the main objective of this research is getting a method able to help the distribution system operator\'s work through providing service restoration plans quickly. The differentials of this research are its ability to: deal, in special, with large scale grids whit a reduced computational effort; consider costumers of several priority levels (note, for instance, a hospital has a higher supply priority in relation to a big supermarket) and prioritize the higher priority customers; provide a switching sequence able to isolate and reconnect the maximum amount of healthy out-of-service customer by the minimum amount of switching actions; select lower priority customers to keep out-of-service in order to reconnect higher priority customers when a it is not possible to restore all customers; and, additionally, prioritize switching operation in remotely controlled switches, whose operation is faster and cheapest than the operation of manually controlled switches. The proposed method mixes a local exhaustive search and a new multi-objective evolutionary algorithm in subpopulation tables that uses a data structure named Node-Depth Encoding. For evaluating the relative performance of proposed method, simulations were performed in small distribution systems and the performance was compared with the performance a Mathematical Programing method from literature. New experiments were performed a Mathematical Programing method from literature. New experiments were performed in several fault situations in the real and large-scale distribution system of Londrina-PR and adjacent cities. The solutions provided were appropriated to the treatment of such contingency situations. The same occurs with the switching sequences provided, which were able to prioritize the restoration of higher priority customers. Additional studies evaluated the variation of the running time with the size of grids and with the values adopted for the maximum number of generations of the evolutionary algorithm (which is an input parameter). The results expressed the running time of the proposed method is suitable to the problem needs. Therefore, it could be proved the proposed method achieved the specified objectives, in special, the treatment of practical aspects of the problem. Besides the proposed method, some contributions of this research are proposition of a new multi-objective evolutionary algorithm in subpopulation tables and a new reproduction operator to manipulate graph forests computationally represented by Node-Depth Encoding.
16

Restabelecimento de energia em sistemas de distribuição considerando aspectos práticos / Distribution systems service restoration with the consideration of practical aspects

Leandro Tolomeu Marques 13 June 2018 (has links)
No contexto da operação de sistemas de distribuição, um dos problemas com os quais os operadores lidam frequentemente é o de restabelecimento de energia. Este problema surge na ocorrência de uma falta permanente e pode ser tratado por meio de manobras em chaves presentes na rede primária. Uma vez que tais redes operam com topologia radial, a ocorrência de uma falta pode resultar no desligamento de consumidores saudáveis. Desta maneira, o problema consiste em definir, num curto intervalo de tempo, um número mínimo de chaves que devem ser operadas a fim de isolar a falta e restaurar o máximo de consumidores saudáveis desligados. Os esforços para a obtenção de ferramentas computacionais para fornecimento de soluções para o problema de restabelecimento têm sido intensificados nos últimos anos. Isto ocorre, em especial, devido aos enormes prejuízos causados pela falta de energia às companhias de eletricidade e a toda a sociedade. Neste sentido, o objetivo deste trabalho é a obtenção de um método para auxiliar o trabalho dos operadores através do fornecimento de planos adequados de restabelecimento em curtos intervalos de tempo. Os diferenciais deste método proposto são a sua capacidade de: lidar, em especial, com redes reais de grande porte com reduzido esforço computacional; considerar a existência de vários níveis de prioridade de atendimento entre os consumidores (note, por exemplo, que um hospital ou um centro de segurança pública devem ter maior prioridade de atendimento que um grande supermercado ou unidades residenciais) e priorizar o atendimento deles de acordo a sua prioridade; fornecer uma sequência por meio da qual as chaves possam ser operadas a fim de isolar os setores em falta e reconectar o maior número de consumidores saudáveis desligados executando-se o mínimo de manobras em chaves e priorizando os consumidores com maior prioridade; ser capaz de selecionar cargas menos prioritárias para permaneceram desligadas nas situações em que não é possível obter uma solução que restaure todas as cargas saudáveis fora de serviço; e, adicionalmente, priorizar a operação de chaves controladas remotamente, que, diferentemente das chaves controladas manualmente, podem ser operadas com menores custos e de maneira mais rápida. O método proposto consiste, de maneira sintética, na união de uma busca exaustiva aplicada localmente a um novo algoritmo evolutivo multi-objetivo em tabelas de subpopulação que faz uso de uma estrutura de dados eficiente denominada Representação Nó-Profundidade. Para avaliar a performance relativa do método proposto, simulações foram realizadas num sistema de distribuição de pequeno porte e os resultados foram comparados com os obtidos por um método de Programação Matemática. Na sequência, novos experimentos foram realizadas em diversos casos de falta na rede de distribuição da cidade de Londrina-PR e cidades adjacentes. As soluções fornecidas mostraram-se adequadas ao tratamento dos casos de falta, assim como as sequências de chaveamento associadas a elas, as quais foram capazes de priorizar o restabelecimento dos consumidores prioritários seguindo seus níveis de prioridade. Adicionalmente, estudos avaliaram a variação do tempo de processamento computacional do método proposto com a dimensão das redes de distribuições e também com o número de gerações realizadas pelo algoritmo evolutivo multi-objetivo proposto e os resultados mostraram-se satisfatórios às necessidades do problema Portanto, pode-se comprovar que o método proposto atingiu os objetivos especificados, em especial, o tratamento de aspectos práticos do problema. Além do próprio método proposto, algumas contribuições desta pesquisa são a proposição um novo algoritmo evolutivo multiobjetivo em tabelas de subpopulação e de um novo operador para manipulação de florestas de grafo armazenadas pela Representação Nó-Profundidade e voltado ao problema de restabelecimento. / In the context of distribution systems operation, service restoration is one of the problems with which operators constantly deal. It arises when a permanent fault occurs and is treated trough operations in switches at primary grid. Since distribution systems are usually radial, fault occurrence turns-off healthy customers. Thereby, the service restoration problem consists in defining, in a short processing time, the minimum amount of switches that must be operated for the isolation of the fault and reconnection of the maximum amount of healthy out-of-service customers. The efforts of developing computational tools for getting solution to this problems has increased in the last years. It is, in special, due to enormous losses caused to the utilities and to the whole society. In this sense, the main objective of this research is getting a method able to help the distribution system operator\'s work through providing service restoration plans quickly. The differentials of this research are its ability to: deal, in special, with large scale grids whit a reduced computational effort; consider costumers of several priority levels (note, for instance, a hospital has a higher supply priority in relation to a big supermarket) and prioritize the higher priority customers; provide a switching sequence able to isolate and reconnect the maximum amount of healthy out-of-service customer by the minimum amount of switching actions; select lower priority customers to keep out-of-service in order to reconnect higher priority customers when a it is not possible to restore all customers; and, additionally, prioritize switching operation in remotely controlled switches, whose operation is faster and cheapest than the operation of manually controlled switches. The proposed method mixes a local exhaustive search and a new multi-objective evolutionary algorithm in subpopulation tables that uses a data structure named Node-Depth Encoding. For evaluating the relative performance of proposed method, simulations were performed in small distribution systems and the performance was compared with the performance a Mathematical Programing method from literature. New experiments were performed a Mathematical Programing method from literature. New experiments were performed in several fault situations in the real and large-scale distribution system of Londrina-PR and adjacent cities. The solutions provided were appropriated to the treatment of such contingency situations. The same occurs with the switching sequences provided, which were able to prioritize the restoration of higher priority customers. Additional studies evaluated the variation of the running time with the size of grids and with the values adopted for the maximum number of generations of the evolutionary algorithm (which is an input parameter). The results expressed the running time of the proposed method is suitable to the problem needs. Therefore, it could be proved the proposed method achieved the specified objectives, in special, the treatment of practical aspects of the problem. Besides the proposed method, some contributions of this research are proposition of a new multi-objective evolutionary algorithm in subpopulation tables and a new reproduction operator to manipulate graph forests computationally represented by Node-Depth Encoding.
17

Controlling Factors Of Life Cycle And Distribution Of Chironomid Key Species In The Mesotrophic Saidenbach Reservoir

Hempel, Esther 24 August 2011 (has links) (PDF)
In den Jahren 2005 bis 2010 erfolgte im Rahmen der Erarbeitung der vorliegenden Dissertationsschrift eine ökologische Untersuchung der Chironomidenfauna in der Talsperre Saidenbach (Sachsen, Erzgebirge). Drei Arten mit hoher Abundanz konnten bei der umfassenden Artenanalyse im Jahr 2005 ermittelt werden: Procladius crassinervis, P. choreus und Chironomus anthracinus. Zusätzlich wurde die Art C. plumosus aufgrund ihrer engen Verwandtschaft zu C. anthracinus in die Untersuchung einbezogen. Die Arbeit ist auf vier Schwerpunkte fokussiert, wobei die Larven und Puppen der vier Arten analysiert wurden. (1) Die Erarbeitung einer zuverlässigen Methode zur Unterscheidung der Larven der beiden eng verwandten Procladius-Arten basierend auf morphologischen Kriterien (Imaginalscheiden-entwicklung, Kopfkapselgröße und Körperlänge) sowie die Tiefenverteilung der Puppen waren eine Vorbedingung für weiterführende Analysen des Lebenszyklus (LZ) dieser beiden Arten. (2) Die Untersuchung des LZ war der zweite Schwerpunkt. Der LZ wurde stark von abiotischen Faktoren wie Temperatur, Sauerstoff und Biovolumen des Phytoplanktons kontrolliert. (3) Die raum-zeitlichen Verteilungsmuster der vier Arten wurden zunächst bezüglich großräumiger Unterschiede über einen Tiefengradienten innerhalb eines Transektes analysiert. Hierbei zeigte sich bei allen vier Arten eine zeitliche Änderung im jeweiligen Hauptverbreitungsgebiet. Die jungen Larven von C. anthracinus, C. plumosus und P. choreus wanderten im Verlauf ihrer Entwicklung bis zur Verpuppung in flachere Bereiche, P. crassinervis wanderte in tiefere Bereiche. Die Analyse der Verteilungsunterschiede der Larven zwischen zwei verschieden stark eutrophierten Buchten ergab höhere Dichten der beiden Chironomus-Arten in der Bucht mit dem größeren Zulauf und der höheren Phytoplanktonkonzentration im Vergleich mit den anderen Arten. Eine Analyse des kleinräumigen Verteilungsmusters fokussierte auf der Frage, ob die Larven gleichmäßig verteilt oder aggregiert auftraten. Die Untersuchung des vertikalen Verteilungsmusters erforschte das Schwimmverhalten der Larven. (4) Der letzte Aspekt war eine experimentelle Untersuchung, die am Beispiel von C. anthracinus durchgeführt wurde mit dem Ziel, den Proximatfaktor für die beobachtete Wanderung der Larven zu ermitteln, der letztendlich die Temperatur war. Puppen bevorzugten im Experiment wärmere Temperaturen und junge Larven kühlere Temperaturen. Die fünfjährige Untersuchung der Chironomiden in der Talsperre Saidenbach beschreibt insgesamt die komplexe Verhaltensreaktion der Chironomiden, die einen wesentlichen Teil der benthischen Lebensgemeinschaft darstellen, bezüglich der Lebenszyklusmuster (Voltinismus, Verpuppung), der Abundanzänderungen (inner- und zwischenjährlich) sowie der groß- und kleinräumigen Verteilung unter der Einwirkung der wichtigsten Umweltfaktoren. / In the context of the present dissertation an ecological study was performed about chironomids in Saidenbach Reservoir in the Saxony Ore Mountains, Germany during the five years from 2005 to 2010. A preliminary overall species analysis in 2005 showed that three species were most abundant: Procladius crassinervis, P. choreus and Chironomus anthracinus. Additionally, the species C. plumosus was examined because of its close relationship to C. anthracinus. The study is focussed on four subjects, whereby larvae and pupae of the four species were analysed. (1) The elaboration of a reliable method to distinguish the larvae of the two closely related species P. crassinervis and P. choreus on the basis of morphological criteria (imaginal disc development, larval head capsule size and body length) as well as the depth distribution of their pupae was a precondition to the profound analysis of their life cycles. (2) The investigation of the life cycle pattern of the four species was the second focus. The life cycle of the four species was found to be strongly influenced by abiotic conditions such as temperature, oxygen and biovolume of the phytoplankton. (3) The spatial and temporal distribution pattern of the four species was analysed in view of large scale differences over a depth gradient in one transect. Here, in all four species a shift in the mainly settled lake bottom area occurred. The young larvae of C. anthracinus, C. plumosus and P. choreus migrated during maturing and pupation towards shallower areas; P. crassinervis migrated to deeper areas. The distribution differences between two different bays showed that the two Chironomus species had higher densities in the bay with the higher inflow which resulted in a higher phytoplankton standing stock compared to the other species. A small scale distribution pattern analysis focussed on finding out whether the larvae were aggregated or randomly distributed. The vertical distribution analysis examined the swimming behaviour of the larvae. (4) The last aspect was an experimental setup exemplarily driven with C. anthracinus which showed that the migration was stimulated by the proximate factor temperature as pupae preferred warmer temperatures and young larvae colder temperatures. Altogether, the five year study about chironomids in Saidenbach Reservoir pointed out the complex reaction in the behaviour of an important part of the benthic community concerning the life cycle pattern (voltinism, pupation pattern), the changing in abundances (inter-annual and intra-annual) and the large scale and small scale distribution pattern under the rule of the most important environmental factors.
18

Controlling Factors Of Life Cycle And Distribution Of Chironomid Key Species In The Mesotrophic Saidenbach Reservoir

Hempel, Esther 30 June 2011 (has links)
In den Jahren 2005 bis 2010 erfolgte im Rahmen der Erarbeitung der vorliegenden Dissertationsschrift eine ökologische Untersuchung der Chironomidenfauna in der Talsperre Saidenbach (Sachsen, Erzgebirge). Drei Arten mit hoher Abundanz konnten bei der umfassenden Artenanalyse im Jahr 2005 ermittelt werden: Procladius crassinervis, P. choreus und Chironomus anthracinus. Zusätzlich wurde die Art C. plumosus aufgrund ihrer engen Verwandtschaft zu C. anthracinus in die Untersuchung einbezogen. Die Arbeit ist auf vier Schwerpunkte fokussiert, wobei die Larven und Puppen der vier Arten analysiert wurden. (1) Die Erarbeitung einer zuverlässigen Methode zur Unterscheidung der Larven der beiden eng verwandten Procladius-Arten basierend auf morphologischen Kriterien (Imaginalscheiden-entwicklung, Kopfkapselgröße und Körperlänge) sowie die Tiefenverteilung der Puppen waren eine Vorbedingung für weiterführende Analysen des Lebenszyklus (LZ) dieser beiden Arten. (2) Die Untersuchung des LZ war der zweite Schwerpunkt. Der LZ wurde stark von abiotischen Faktoren wie Temperatur, Sauerstoff und Biovolumen des Phytoplanktons kontrolliert. (3) Die raum-zeitlichen Verteilungsmuster der vier Arten wurden zunächst bezüglich großräumiger Unterschiede über einen Tiefengradienten innerhalb eines Transektes analysiert. Hierbei zeigte sich bei allen vier Arten eine zeitliche Änderung im jeweiligen Hauptverbreitungsgebiet. Die jungen Larven von C. anthracinus, C. plumosus und P. choreus wanderten im Verlauf ihrer Entwicklung bis zur Verpuppung in flachere Bereiche, P. crassinervis wanderte in tiefere Bereiche. Die Analyse der Verteilungsunterschiede der Larven zwischen zwei verschieden stark eutrophierten Buchten ergab höhere Dichten der beiden Chironomus-Arten in der Bucht mit dem größeren Zulauf und der höheren Phytoplanktonkonzentration im Vergleich mit den anderen Arten. Eine Analyse des kleinräumigen Verteilungsmusters fokussierte auf der Frage, ob die Larven gleichmäßig verteilt oder aggregiert auftraten. Die Untersuchung des vertikalen Verteilungsmusters erforschte das Schwimmverhalten der Larven. (4) Der letzte Aspekt war eine experimentelle Untersuchung, die am Beispiel von C. anthracinus durchgeführt wurde mit dem Ziel, den Proximatfaktor für die beobachtete Wanderung der Larven zu ermitteln, der letztendlich die Temperatur war. Puppen bevorzugten im Experiment wärmere Temperaturen und junge Larven kühlere Temperaturen. Die fünfjährige Untersuchung der Chironomiden in der Talsperre Saidenbach beschreibt insgesamt die komplexe Verhaltensreaktion der Chironomiden, die einen wesentlichen Teil der benthischen Lebensgemeinschaft darstellen, bezüglich der Lebenszyklusmuster (Voltinismus, Verpuppung), der Abundanzänderungen (inner- und zwischenjährlich) sowie der groß- und kleinräumigen Verteilung unter der Einwirkung der wichtigsten Umweltfaktoren.:1. GENERAL INTRODUCTION 2. MORPHOLOGICAL DIFFERENTIATION OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 2.1 Introduction 2.2 Material and methods 2.2.1 Sampling of larvae 2.2.2 Species identification 2.2.3 Differentiation of the Procladius species by means of head capsule size and depth distribution 2.2.4 Other morphological criteria 2.2.5 Development of imaginal discs 2.3. Results 2.3.1 Procladius crassinervis and P. choreus 2.3.2 Chironomus anthracinus and C. plumosus 2.4. Discussion 2.4.1 Method discussion 2.4.2 Head capsule width 2.4.3 Larval growth 3. FIVE - YEAR LIFE CYCLE PATTERN OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 3.1 Introduction 3.2 Material and methods 3.2.1 Study area 3.2.2 Sampling of chironomid larvae 3.2.3 Sampling of chironomid pupae 3.2.4 Mortality 3.2.5 Abiotic conditions and phytoplankton 3.3 Results 3.3.1 Abiotic conditions and phytoplankton 3.3.1.1 Temperature 3.3.1.2 Oxygen 3.3.1.3 Phytoplankton 3.3.2 Life cycle analysis 3.3.2.1 Composition of instars 3.3.2.2 Procladius crassinervis 3.3.2.3 Procladius choreus 3.3.2.4 Chironomus anthracinus 3.3.2.5 Chironomus plumosus 3.3.2.6 Tanytarsini 3.3.2.7 Other species 3.3.3 Influence of abiotic conditions on pupation and life cycle 3.3.3.1 Procladius crassinervis 3.3.3.2 Procladius choreus 3.3.3.3 Chironomus anthracinus 3.3.3.4 Chironomus plumosus 3.3.3.5 Tanytarsini 3.3.4 Mortality of larvae during pupation 3.4 Discussion 3.4.1 Method discussion 3.4.2 Life cycle 3.4.3 Influence of controlling factors 3.4.4 Larval mortality and chironomid pupae as prey 4. SMALL AND LARGE SCALE DISTRIBUTION ASPECTS AND MIGRATION OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 4.1 Introduction 4.2 Study area 4.3 Material and methods 4.3.1 Sampling of chironomid pupae 4.3.2 Sampling of chironomid larvae 4.3.3 Large scale distribution 4.3.3.1 Depth gradient of the larval abundance 4.3.3.2 Distribution between different lake areas 4.3.4 Small scale distribution - patchiness 4.3.5 Vertical distribution 4.3.5.1 Residence depth in the sediment 4.3.5.2 Larvae in the water column 4.4 Results 4.4.1 Large scale distribution 4.4.1.1 Depth gradient of the larval abundance 4.4.1.2 Distribution between different lake areas 4.4.2 Small scale distribution - patchiness 4.4.3 Vertical distribution 4.4.3.1 Residence depth in the sediment 4.4.3.2 Larvae in the water column 4.5 Discussion 4.5.1 Large scale distribution 4.5.1.1 Depth gradient of the larval abundance 4.5.1.2 Distribution between different lake areas 4.5.2 Small scale distribution - patchiness 4.5.3 Vertical distribution 4.5.3.1 Residence depth in the sediment 4.5.3.2 Larvae in the water column 5. INVESTIGATIONS ON THE PREFERENCE TEMPERATURE OF C. ANTHRACINUS FROM THE MESOTROPHIC SAIDENBACH RESERVOIR 5.1 Introduction 5.2 Material and methods 5.2.1 Influence of temperature on the timing of pupation 5.2.2 Preference temperature 5.2.3 Locomotory activity of larvae 5.3 Results 5.3.1 Migratory activity of C. anthracinus in the field 5.3.2 Influence of temperature on the timing of pupation 5.3.3 Preference temperature 5.3.4 Locomotory activity of larvae 5.4 Discussion 5.4.1 Influence of temperature on the timing of pupation 5.4.2 Preference temperature 5.4.3 Agitation activity of larvae 6. OVERALL SUMMARY AND FUTURE PROSPECTS 7. REFERENCES EIDESSTATTLICHE ERKLÄRUNG DANKSAGUNG / In the context of the present dissertation an ecological study was performed about chironomids in Saidenbach Reservoir in the Saxony Ore Mountains, Germany during the five years from 2005 to 2010. A preliminary overall species analysis in 2005 showed that three species were most abundant: Procladius crassinervis, P. choreus and Chironomus anthracinus. Additionally, the species C. plumosus was examined because of its close relationship to C. anthracinus. The study is focussed on four subjects, whereby larvae and pupae of the four species were analysed. (1) The elaboration of a reliable method to distinguish the larvae of the two closely related species P. crassinervis and P. choreus on the basis of morphological criteria (imaginal disc development, larval head capsule size and body length) as well as the depth distribution of their pupae was a precondition to the profound analysis of their life cycles. (2) The investigation of the life cycle pattern of the four species was the second focus. The life cycle of the four species was found to be strongly influenced by abiotic conditions such as temperature, oxygen and biovolume of the phytoplankton. (3) The spatial and temporal distribution pattern of the four species was analysed in view of large scale differences over a depth gradient in one transect. Here, in all four species a shift in the mainly settled lake bottom area occurred. The young larvae of C. anthracinus, C. plumosus and P. choreus migrated during maturing and pupation towards shallower areas; P. crassinervis migrated to deeper areas. The distribution differences between two different bays showed that the two Chironomus species had higher densities in the bay with the higher inflow which resulted in a higher phytoplankton standing stock compared to the other species. A small scale distribution pattern analysis focussed on finding out whether the larvae were aggregated or randomly distributed. The vertical distribution analysis examined the swimming behaviour of the larvae. (4) The last aspect was an experimental setup exemplarily driven with C. anthracinus which showed that the migration was stimulated by the proximate factor temperature as pupae preferred warmer temperatures and young larvae colder temperatures. Altogether, the five year study about chironomids in Saidenbach Reservoir pointed out the complex reaction in the behaviour of an important part of the benthic community concerning the life cycle pattern (voltinism, pupation pattern), the changing in abundances (inter-annual and intra-annual) and the large scale and small scale distribution pattern under the rule of the most important environmental factors.:1. GENERAL INTRODUCTION 2. MORPHOLOGICAL DIFFERENTIATION OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 2.1 Introduction 2.2 Material and methods 2.2.1 Sampling of larvae 2.2.2 Species identification 2.2.3 Differentiation of the Procladius species by means of head capsule size and depth distribution 2.2.4 Other morphological criteria 2.2.5 Development of imaginal discs 2.3. Results 2.3.1 Procladius crassinervis and P. choreus 2.3.2 Chironomus anthracinus and C. plumosus 2.4. Discussion 2.4.1 Method discussion 2.4.2 Head capsule width 2.4.3 Larval growth 3. FIVE - YEAR LIFE CYCLE PATTERN OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 3.1 Introduction 3.2 Material and methods 3.2.1 Study area 3.2.2 Sampling of chironomid larvae 3.2.3 Sampling of chironomid pupae 3.2.4 Mortality 3.2.5 Abiotic conditions and phytoplankton 3.3 Results 3.3.1 Abiotic conditions and phytoplankton 3.3.1.1 Temperature 3.3.1.2 Oxygen 3.3.1.3 Phytoplankton 3.3.2 Life cycle analysis 3.3.2.1 Composition of instars 3.3.2.2 Procladius crassinervis 3.3.2.3 Procladius choreus 3.3.2.4 Chironomus anthracinus 3.3.2.5 Chironomus plumosus 3.3.2.6 Tanytarsini 3.3.2.7 Other species 3.3.3 Influence of abiotic conditions on pupation and life cycle 3.3.3.1 Procladius crassinervis 3.3.3.2 Procladius choreus 3.3.3.3 Chironomus anthracinus 3.3.3.4 Chironomus plumosus 3.3.3.5 Tanytarsini 3.3.4 Mortality of larvae during pupation 3.4 Discussion 3.4.1 Method discussion 3.4.2 Life cycle 3.4.3 Influence of controlling factors 3.4.4 Larval mortality and chironomid pupae as prey 4. SMALL AND LARGE SCALE DISTRIBUTION ASPECTS AND MIGRATION OF TWO PROCLADIUS AND TWO CHIRONOMUS SPECIES IN THE MESOTROPHIC SAIDENBACH RESERVOIR 4.1 Introduction 4.2 Study area 4.3 Material and methods 4.3.1 Sampling of chironomid pupae 4.3.2 Sampling of chironomid larvae 4.3.3 Large scale distribution 4.3.3.1 Depth gradient of the larval abundance 4.3.3.2 Distribution between different lake areas 4.3.4 Small scale distribution - patchiness 4.3.5 Vertical distribution 4.3.5.1 Residence depth in the sediment 4.3.5.2 Larvae in the water column 4.4 Results 4.4.1 Large scale distribution 4.4.1.1 Depth gradient of the larval abundance 4.4.1.2 Distribution between different lake areas 4.4.2 Small scale distribution - patchiness 4.4.3 Vertical distribution 4.4.3.1 Residence depth in the sediment 4.4.3.2 Larvae in the water column 4.5 Discussion 4.5.1 Large scale distribution 4.5.1.1 Depth gradient of the larval abundance 4.5.1.2 Distribution between different lake areas 4.5.2 Small scale distribution - patchiness 4.5.3 Vertical distribution 4.5.3.1 Residence depth in the sediment 4.5.3.2 Larvae in the water column 5. INVESTIGATIONS ON THE PREFERENCE TEMPERATURE OF C. ANTHRACINUS FROM THE MESOTROPHIC SAIDENBACH RESERVOIR 5.1 Introduction 5.2 Material and methods 5.2.1 Influence of temperature on the timing of pupation 5.2.2 Preference temperature 5.2.3 Locomotory activity of larvae 5.3 Results 5.3.1 Migratory activity of C. anthracinus in the field 5.3.2 Influence of temperature on the timing of pupation 5.3.3 Preference temperature 5.3.4 Locomotory activity of larvae 5.4 Discussion 5.4.1 Influence of temperature on the timing of pupation 5.4.2 Preference temperature 5.4.3 Agitation activity of larvae 6. OVERALL SUMMARY AND FUTURE PROSPECTS 7. REFERENCES EIDESSTATTLICHE ERKLÄRUNG DANKSAGUNG

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