Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation proposes two methodologies for the phasor estimation on protective relays in Electrical Power Systems. Firstly, a theoretical introduction of signal processing, the structure of a protective relay and phasor estimation algorithms is presented, including some of the algorithms used on the electrical system, as well as the two proposed methodologies. The first one makes use of the concept of curve-fitting, while the other uses Artificial Neural Networks, both with the goal of performing the real-time estimation of the signal amplitude and phase angle. Secondly, it is made a comparative analysis of the two proposed methods with four well-known and currently used algorithms. This comparison is made through the creation of several test signals with different simulation parameters. From these simulations, six performance indexes are used for the quantitative evaluation of each algorithm, from where the most effective method can be determined through the arithmetic mean of these indexes. Lastly, after all the simulation cases have been presented, a summary of the characteristics of each algorithm is made, based in their numerical results. Then, based on the values obtained on each performance index, the strong and weak points are highlighted, as well as the general classification of each method. / Essa dissertação propõe duas metodologias para a estimação fasorial em relés de proteção em Sistemas Elétricos de Potência. Primeiramente é apresentada uma introdução teórica ao processamento de sinais, à estrutura do relé de proteção, e aos algoritmos de estimação fasorial propriamente ditos, incluindo alguns dos algoritmos utilizados no sistema elétrico, assim como as duas metodologias propostas. A primeira delas faz uso do conceito de ajuste de curvas, enquanto que a segunda utiliza Redes Neurais Artificiais, ambas com o objetivo de realizar a estimação da amplitude e ângulo de fase de um sinal em tempo real. Em um segundo momento, é feita a análise comparativa dos dois métodos propostos com quatro algoritmos bastante conhecidos e utilizados nos relés numéricos. A comparação é feita através da criação de diversos sinais de teste com diferentes parâmetros de simulação. A partir dessas simulações, são usados seis índices de desempenho para a avaliação quantitativa de cada algoritmo, de onde, a partir da média aritmética destes índices, pode-se determinar o método mais eficaz para cada caso. Por fim, após todos os testes terem sido realizados, com base em seus resultados numéricos, é realizada uma condensação das características de cada algoritmo. Com base nos valores obtidos em cada índice de desempenho, são destacados os pontos fortes e fracos, bem como a classificação geral de cada método.

Um relé de distância utilizado na proteção de Linhas de Transmissão é usualmente projetado para atuar sob condições fixas de operação. Portanto, o desempenho destes relés é afetado pela mudança no ponto de operação do sistema. Grandes avanços, relativos à proteção, podem ser alcançados com a implementação de reconhecimento de padrões para o diagnóstico de faltas em sistemas elétricos de potência. Este trabalho demonstra a utilização de Redes Neurais Artificiais operando como um classificador de padrões para a operação de um relé de distância. O projeto utiliza a magnitude dos fasores das três fases de corrente e tensão, de um dos barramentos da Linha de Transmissão, como dados de entrada. O uso de Redes Neurais Artificiais resulta em um melhor desempenho do relé, mantendo seu alcance mesmo diante de diferentes condições de falta ou mudanças no ponto de operação do sistema. / A distance relay for the protection of transmission lines is usually designed on the basis of fixed settings. The performance of such relays is therefore affected by the changing network parameters. The implementation of a pattern recognizer for power system diagnosis can provide great advances in the protection field. This work demonstrates the use of an Artificial Neural Network as a pattern classifier for a distance relay operation. The scheme utilizes the magnitudes of three phase voltage and current phasors, from one busbar of the transmission line, as inputs. An improved performance with the use of an Artificial Neural Networks approach is experienced once the relay can operate correctly, keeping the reach when faced with different fault conditions as well as network parameters change.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / This paper proposes an adaptive protection system (SPA) developed in Matlab, in order to make the smart grid for greater flexibility reliability and security of the electric power system the protection system proposed is able to assist in the study of protection by the choice of settings to be entered in the relay once the mains relays are parameterized adaptive protection is responsible for discerning between a change of setting group or send new settings this decision is taken by the SPA in the control center and sent to the grid relays in real time the SPA was tested in a medium voltage distribution grid and the sending of change protection setting was validated using SEL-751 relay using communication via Telnet based on testing the proposed SPA acted properly ensuring selectivity and coordination of the protection system / Este trabalho propÃe um sistema de proteÃÃo adaptativa (SPA) desenvolvido em Matlab com o intuito de tornar a rede elÃtrica inteligente para maior flexibilidade confiabilidade e seguranÃa do sistema elÃtrico de potÃncia o sistema de proteÃÃo proposto à capaz de auxiliar no estudo de proteÃÃo para a escolha dos ajustes a serem inseridos no relà uma vez que os relÃs da rede elÃtrica estejam parametrizados a proteÃÃo adaptativa à responsÃvel por discernir entre uma mudanÃa de grupo de ajuste ou envio de novos ajustes essa decisÃo à tomada pelo SPA no centro de controle e enviada aos relÃs da rede em tempo real o SPA foi testado em uma rede de distribuiÃÃo de mÃdia tensÃo e o envio de mudanÃa de ajuste da proteÃÃo foi validado em relà SEL-751 usando comunicaÃÃo via Telnet com base nos testes realizados o SPA proposto atuou corretamente garantindo seletividade e coordenaÃÃo do sistema de proteÃÃo

Orientadores: Andre Luiz Morelato França, Walmir de Freitas Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T02:54:55Z (GMT). No. of bitstreams: 1 VieiraJunior_JoseCarlosdeMelo_D.pdf: 1983649 bytes, checksum: 2abfcaa471b650a7138b798950c476a7 (MD5) Previous issue date: 2006 / Resumo: Uma das principais funções dos sistemas de proteção de geradores distribuídos conectados em redes de subtransmissão ou de distribuição de energia elétrica é desconectá-los tão logo uma situação de ilhamento seja detectada. O ilhamento ocorre quando parte da rede elétrica é desconectada do restante do sistema da concessionária, mas continua a ser energizada por um ou mais geradores distribuídos conectados a ela, formando um subsistema isolado da concessionária. Esta ocorrência deve ser evitada porque coloca em risco a segurança de pessoas e equipamentos e pode deteriorar a qualidade da energia suprida aos consumidores locais. Neste contexto, esta tese de doutorado propõe novas metodologias para avaliar de forma sistemática e ajustar alguns dos principais relés de proteção anti-ilhamento de geradores síncronos. As técnicas analisadas compreendem os relés de deslocamento de fase ou ¿salto de vetor¿, relés de taxa de variação de freqüência, relés de sub/sobrefreqüência convencionais e os relés de sub/sobretensão convencionais. A aplicação das metodologias desenvolvidas mostrou que elas são ferramentas eficientes para avaliar e determinar o desempenho desses relés quanto à detecção de ilhamentos, auxiliando na seleção dos esquemas de proteção e ajustes mais adequados / Abstract: One of the main functions of distributed generators¿ protection systems is the capability to disconnect the generators immediately after an islanding occurrence is detected. Islanding occurs when a portion of the distribution system is disconnected from the utility grid, yet remains energized by one or more distributed generators connected to it. This operating condition should be avoided because it poses safety risks to utility personnel and equipments as well as it can cause power quality problems to the local costumers. In this context, this thesis proposes new methodologies to systematically evaluate and adjust some anti-islanding techniques applied to synchronous generators. The techniques analyzed are the under/over frequency relays, the rate of change of frequency (ROCOF) relays, the vector surge or vector jump relays and the under/overvoltage relays. The results have shown that the proposed methodologies can be efficient tools to evaluate and to determine the performance of these anti-islanding relays, consequently, they can help protection engineers to select the most proper protection devices and their settings / Doutorado / Energia Eletrica / Doutor em Engenharia Elétrica

Orientadores: Walmir de Freitas Filho, José Carlos de Melo Vieira Júnior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-19T11:09:25Z (GMT). No. of bitstreams: 1 Delvecchi_EsloanyDaisyCarniatto_M.pdf: 1048681 bytes, checksum: 837e57f3ee3363dd7bb9f49a72408fe1 (MD5) Previous issue date: 2011 / Resumo: Geradores síncronos conectados em redes de distribuição de energia elétrica estão sujeitos a operarem de forma ilhada após a ocorrência de distúrbios na rede elétrica. Ilhamento ocorre quando uma parte da rede de distribuição torna-se eletricamente isolada da fonte de energia principal (subestação), mas continua a ser energizada por geradores distribuídos conectados no subsistema isolado. A prática atualmente utilizada pelas concessionárias e recomendada nos principais guias técnicos é desconectar todos os geradores tão logo ocorra um ilhamento. Tipicamente, é necessário detectar uma situação de ilhamento em menos de dois segundos, dependendo, principalmente, do tempo de operação dos religadores automáticos. Os métodos mais comuns e baratos para detectar ilhamento compreendem relés baseados em medidas de freqüência (sub/sobrefrequência, taxa de variação de frequência e "salto de vetor") e o relé de tensão. No entanto, esses relés podem falhar se os níveis de desbalanço de potência ativa e reativa no subsistema ilhado forem pequenos. Portanto, o objetivo dessa dissertação é investigar a potencialidade de novos sinais para detectar ilhamento de geradores síncronos distribuídos, como forma de substituição ou complementação aos dispositivos de proteção anti-ilhamento convencionais. Os sinais analisados neste trabalho são taxa de variação da potência ativa (dP/dt), a relação Volts por Hertz (V/Hz), a variação da impedância (Z) medida no ponto de acoplamento comum (PAC), e a diferença angular ('delta' 'teta') entre as tensões medidas no PAC e na subestação. A investigação é baseada no levantamento de um conjunto de curvas relacionando tempo de detecção e desbalanço de potência ativa/reativa e nas zonas de não detecção, as quais fornecem os pontos de operação para os quais o relé em estudo falha na detecção do ilhamento. As curvas e as zonas são obtidas através de simulações de transitórios eletromagnéticos trifásicas considerando diferentes perfis de carga-geração na rede ilhada. Os resultados obtidos mostram que os sinais analisados têm um grande potencial para esse tipo de aplicação, porém são sujeitos à atuação indevida no caso da ocorrência de eventos que não sejam ilhamentos na rede de distribuição. Assim, uma análise de falsa operação também é conduzida e são propostas melhorias para minimizar e/ou eliminar a atuação indevida desses relés aqui investigados / Abstract: Synchronous generators connected to distribution power networks are likely to operate islanded following faults clearance in the system. Islanding occurs when a portion of the distribution system becomes electrically isolated from the substation, yet it continues energized by distributed generators connected to the islanded system. Utilities and standards recommend the disconnection of distributed generators immediately after islanding occurrences, otherwise it can lead to a number of problems to the generator and the connected loads. Typically, it is required to detect an islanding situation faster than two seconds after the island formation, depending, mainly, on the operation time of automatic reclosers. The most common and economical methods to detect islanding include the relays based on measures of frequency (under/over frequency, rate of change of frequency and vector surge) and voltage. However, these relays can fail if the active and reactive power imbalance levels in the islanded system are small. Therefore, the objective of this thesis is to investigate the potentiality of new signals to detect islanding of distributed synchronous generators, as replacement or complement to conventional protection anti-islanding devices. The signals analyzed in this research are the rate of change of generator active power (dP/dt), the ratio Volts per Hertz (V/Hz), impedance variation (Z) measured at the point of common coupling (PCC), and the angular difference ('delta' 'teta') between the voltage angle measured at the PCC and at the utility substation. The investigation is based on a set of curves, which relate time of islanding detection and active/reactive power imbalance and on the nondetection zones, which provide the operating points for which the relay fails to detect the islanding. These are obtained through electromagnetic transient three-phase simulations considering different profiles of generation-load in the islanded network. The results show that the signals analyzed have a huge potential for this type of application, however, their performance can decrease in case of occurrence of non-islanding events in the distribution system. Thereby, an analysis of false operation is conducted in order to propose improvements to minimize and/or to eliminate improper behavior of these relays / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Les systèmes de communication FSO sont des candidats potentiels pour de solutions de transmission spatiale à large bande. C’est pourquoi la présente thèse s’inscrit dans une contribution d’une nouvelle architecture de réseau FSO dans le cas d’une liaison de communication entre un satellite géostationnaire et une station terrienne. Elle traite aussi de l’influence de l’angle zénithal sur la qualité de la liaison optique en raison de la variation de la scintillation due à la complexité de l’atmosphère. Nous avons établi un nouveau canal de communication tenant compte de la subdivision de l’atmosphère en deux grandes zones de turbulence. Pour améliorer la performance de la liaison, nous avons d’abord placé un relais AF optiques ente le satellite et la station terrienne, ensuite nous avons introduit un paramètre construit `a partir de valeurs : p et 1-p. Le paramètre p correspond au ratio de la distance entre la station terrienne et le relais sur la distance de 36 000 Km correspondant a` l’orbite GEO. Dans notre cas, le relais est placé a 1000 Km a l’exosphère, le paramètre p = 1/36 et enfin la technique de diversité spatiale est appliquée en réception. Les résultats de simulation ont confirmé que les architectures des systèmes proposés sont meilleures que les performances de liaisons optiques directes. / Free space optical systems are potential candidates of large band spatial transmission solutions. In this thesis, FSO network architecture in the case of geo- stationary satellite to earth communication link is investigated and the influence of zenith angle on the quality of the link has been evaluated. Because of the variation of scintillation due to the complexity of the atmosphere, the optical space to earth communication link channel model has been developped. In order to overcome the main limitations of the prop- agation, optical relays with low earth orbit satellites and spatial diversity on earth could improve the link performance. To improve the link performance, an aggregated simulation model turbulence has been built based on parameters ”p” and ”1-p” introduced in the combined model a↵ecting the considered channels. The parameter ” p ” corresponds to the ratio of the distance from the earth to the relay over the total distance of 36 000Km. In the case of 1000 Km for a relay in the exosphere, p = 1/36. Simulation results show that the proposed network system architecture has outperformed the direct link performance

Orientador: Maria Cristina Dias Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T00:34:34Z (GMT). No. of bitstreams: 1 Dias_OzenirFarahdaRocha_M.pdf: 5023742 bytes, checksum: b0fe9b9418551d927583a884fbec6e92 (MD5) Previous issue date: 2015 / Resumo: Este trabalho apresenta a implementação de um esquema de religamento monopolar adaptativo rápido baseado na medição do conteúdo harmônico da tensão da fase aberta nas extremidades da linha de transmissão. O objetivo principal deste esquema é controlar e reduzir o tempo compreendido entre a abertura e o religamento da fase em falta, como também bloquear a manobra em caso de faltas permanentes. O esquema proposto foi implementado em um relé de distância e um medidor de conteúdo harmônico. O método está baseado na identificação do instante de extinção da corrente de arco secundário para casos de faltas transitórias. Já para faltas permanentes é implementado o bloqueio da manobra automática e a abertura tripolar do disjuntor da linha protegida. A medição do conteúdo harmônico foi feita primeiramente utilizando um medidor de qualidade de energia comercial, que realiza a medição do conteúdo harmônico de acordo com a norma IEC 61000-4-3. Em seguida, foi utilizado outro método de medição do conteúdo harmônico, chamado de filtro de medição do conteúdo harmônico rápido, elaborado dentro do Simulador Digital em Tempo Real (RTDS). O sistema de transmissão utilizado foi modelado no RTDS e seus dados são dados reais do sistema interligado nacional (SIN). As faltas monofásicas transitórias foram simuladas utilizando o modelo de arco do próprio RTDS. Já para falta permanente utilizou-se uma resistência de 1 'ômega'. O esquema foi avaliado através de testes variando o ponto de aplicação do defeito e o valor da corrente de arco secundário / Abstract: This work presents the implementation of a scheme of fast adaptive single-phase reclosing based on measuring the voltage harmonic content at the opened faulty phase terminals. The main objective of this scheme is to control and to reduce the time between opening and reclosing of the phase in fault, and also to block the maneuver in case of permanent faults. The proposed scheme is implemented in a distance relay and a harmonic content meter. The method is based in the identification of the secondary arc current extinction moment for transient faults cases. For permanent faults an automatic blocking followed by circuit-breaker three-phase opening is implemented. The measurement of harmonic content was made initially using a commercial power quality meter, which performs the harmonic content measurement according to IEC 61000-4-3 standard. Another harmonic content measurement method was tested, the fast harmonic content filter measurement, elaborated within the real-time digital simulator (RTDS). The transmission system used was modeled on RTDS and the data corresponds to an actual Brazilian 500 kV system. To represent the transient single-phase fault it was used RTDS arc model. The permanent fault was modeled with an 1'ômega' resistance. The scheme was evaluated by varying the fault application point and the secondary arc current value / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

No description available.

En tranmissionsledning är delen av elsystemet som överför ström från kraftverk till slutanvändare. Därför är det av vikt att en transmissionslinje alltid ska vara skyddad. Syftet med detta examensarbete var att utveckla och prova en konfiguration av teleskyddsschema med kommunikation mellan två reläskydd med distans- och jordfelsskydd över längsdifferentialskyddets kommunikationskanaler. Detta för att skydda elnätet och koordinera utlösningstiden.  Konfigurationen av reläskydden har utvecklats med mjukvaran ABB PCM600, och funktionerna som valdes är adekvata funktioner för distansskydd, jordfelsskydd och teleskyddsschema.  Provningen delades till två delar. Först verifierades funktionaliteten av distansskyddet och jordfelsskyddet på var och en av reläskydden som självständig skydd, detta för att säkerställa självständiga funktionaliteten av var och en av reläskydden med distans- och jordfelsskydd i fall teleskyddschemat inte var fungerande. Därefter har teleskyddsschemats sändnings- och mottagningsfunktionalitet mellan reläskydden för både distansskyddet och jordfelsskyddet kontrollerats att möjligtvis fungera genom att endast använda en fiberoptisk kabel. Ett fungerande och pålitligt teleskyddsschema med kommunikation mellan två reläskydd kunde säkerställas fungerande genom användning av längsdifferentialskyddets kommunikationskanaler för distans- och jordfelsskydd. Teleskyddsschemat förstärkte distansskyddet och jordfelsskyddet genom accelerering av utlösningssignal, och som en konsekvens samordna utlösningstiden mellan reläskydden vid felavkänning, vilket förbättrade skyddet ännu mer. Direkt kommunikation mellan reläskydden har visat sig vara användbar och tillämpbar, och en användning av sådan implementation är möjlig för isolerade linjer och anläggningar samt mikronät som inte kräver en kontinuerlig övervakning och kontroll. / A transmission line is the part of the electrical system that transfers current from power stations to the end-user. Therefore, it is of importance that a transmission line stays always protected. The purpose of this bachelor thesis is to develop and test a configuration for teleprotection scheme communication between two protective relays with distance and earth fault protection using line differential protection communication channels, that is to protect the electrical grid and coordinate tripping time. The configuration has been developed with the software ABB PCM600, and the chosen functions are adequate functions for distance and earth fault protection and the Teleprotection scheme. The testing has been divided into two parts. Primarily, the functionality of distance and earth fault protection has been tested and verified on each one of the protective relays, that is to ensure the independent functionality of each one of the protective relays with distance and earth fault protection in case there is no Teleprotection scheme functioning. next, the sending and receiving functionality of the teleprotection scheme between the protective relays with distance protection and earth fault protection has been controlled to be possibly functioning through using only a fiber-optic cable. A functioning and reliable Teleprotection scheme with communication between two protective relays could be verified functioning through using line differential protection communication channels for distance and earth fault protection. The Teleprotection scheme strengthened the distance protection and earth fault protection through acceleration of trip signal, and as a consequent coordinating the trip time in case of fault detection. Direct communication between protective relay using fiber-optic cable has proven to be useful and applicable, and a using of such implementation is possible for isolated electrical line and facilities and also micro grids that does not require continuous monitoring and control.

Transforming the aging electric grid to a smart grid is an active area of research in industry and the government. One of the main objectives of the smart grid is to improve the efficiency of power generation, transmission and distribution and also to improve the stability and the reliability of the grid. In order to achieve this, various processes involved in power generation, transmission, and distribution should be armed with advanced sensor technologies, computing, communication and networking capabilities to an unprecedented level. These high speed data transfer and computational abilities aid power system engineers to obtain wide area measurements, achieve better control of power system operations and improve the reliability of power supply and the efficiency of different power grid operations. In the process of making the grid smarter, problems existing in traditional grid applications can be identified and solutions have to be developed to fix the identified issues. In this dissertation, two problems that aid power system engineers to meet the above mentioned smart grid's objective are researched. One problem is related to the distribution-side smart grid and the other one is a part of the transmission-side smart grid. Advanced Metering Infrastructure (AMI) is one of the important distribution-side smart grid applications. AMI is a technology where smart meters are installed at customer site which gives the utilities the ability to monitor and collect information related to the amount of electricity, water, and gas consumed by the user. Many recent research studies suggested the use of 3G cellular CDMA2000 for AMI network as it provides an advanced and cost effective solution for smart grid communications. Taking into account both technical and non-technical factors such as extended lifetime, security, availability and control of the solution, Alliander, an electric utility in Netherlands deployed a private 3G CDMA2000 network for smart metering. Although 3G CDMA2000 satisfies the requirements of smart grid applications, an analysis on the use of the current state of the art 3G CDMA2000 for smart grid applications indicates that its usage results in high percentage of control overhead, high latency and high power consumption for data transfer. As a part of this dissertation, we proposed FLEX-MAC - a new Medium Access Control (MAC) protocol that reduces the latency and overhead in smart meter data collection when compared to 3G CDMA2000 MAC. As mentioned above the second problem studied in this dissertation is related to the transmission-side grid. Power grid transmission and sub-transmission lines are generally protected by distance relays. After a thorough analysis of U.S. historical blackouts, North American Electric Reliability Council (NERC) has concluded that the hidden failure induced tripping of distance relays is responsible for 70% of the U.S. blackouts. As a part of this dissertation, agent based distance relaying protection scheme is proposed to improve the robustness of distance relays to hidden failures and thus reduce the probability of blackouts. This dissertation has two major contributions. First, a hierarchically distributed non-intrusive Agent Aided Distance Relaying Protection Scheme (AADRPS) is proposed to improve the robustness of distance relays to hidden failures. The problem of adapting the proposed AADRPS to a larger power system network consisting of thousands of buses is modeled as an integer linear programming multiple facility location optimization problem. Distance relaying protection scheme is a real time system and has stringent timing requirements. Therefore, in order to verify if the proposed AADRPS meets the timing requirements or not and also to check for deadlocks, verification models based on UPPAAL real time model checker are provided in this dissertation. So, the entire framework consisting of AADRPS that aids in increasing the robustness of distance relays and reducing the possibility of blackouts, the multiple facility location optimization models and the UPPAAL real time model checker verification models form one of the major contributions of this dissertation. The second contribution is related to the MAC layer of AMI networks. In this dissertation, FLEX-MAC - a novel and flexible MAC protocol is proposed to reduce the overhead and latency in smart meter data collection. The novelty of the FLEX-MAC lies in its ability to change the mode of operation based on the type of the data being collected in a smart meter network. FLEX-MAC employs Frame and Channel Reserved (FCR) MAC or Frame Reserved and Random Channel (FRRC) MAC for scheduled data collection. Power outage data in an AMI network is considered as a random data . In a densely populated area, during an outage, a large number of smart meters attempt to report the outage, which significantly increases the Random Access CHannel (RACH) load. In order to reduce the RACH traffic during an outage, this dissertation proposes a Time Hierarchical Scheme (THS). Also, in order to minimize the total time to collect the power outage data, a Backward Recursive Dynamic Programming (BRDP) approach is proposed to adapt the transmission rate of smart meters reporting an outage. Both the Optimal Transmission Rate Adaption and Time Hierarchical Scheme form the basis of OTRA-THS MAC which is employed by FLEX-MAC for random data collection. Additionally, in this work, Markov chain models are presented for evaluating the performance of FCR and FRRC MACs in terms of average throughput and delay. Also, another Markov model is presented to find the mean time to absorption or mean time to collect power outage data of OTRA-TH MAC during an outage. / Ph. D.