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Dissertations / Theses on the topic 'Distance relay'

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Published: 4 June 2021
Last updated: 11 September 2023

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1

Li, Hongwei. "A new adaptive distance relay." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0025/NQ51646.pdf.

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2

Abyaneh, Hossein Askarian. "Assessment of IDMT and distance relay settings." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332331.

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3

Erezzaghi, M. "The effects of FACTS devices on distance relay." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426704.

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4

Smith, David Matthew. "Next-generation, phasor-based distance relay with fault-path resistance immunity." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11012008-063727/.

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5

Wang, Hualei. "The protection of transmission networks containing AC and DC circuits." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655718.

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In 14th August 2003, the Northeast USA suffered its worst power outage event in history. The power disturbance spreading through the system caused mal-trips of the distance relay remote back-up protections, which indeed contributed to the power outage cascading a wide area. The power outage in the Northeast USA was constrained by the presence of HVDC interconnections between the HVAC networks in Ontario and New York. The system collapse did not progress beyond the HVDC interconnection interface with Quebec. The HVDC link can regulate the voltage and current therefore impacts on the performance of the protection and system stability. The distance relay mal-operations were one of the main cause of the Northeast USA blackout as well as the other recent major large area blackouts which were pointed out by the previous papers. This thesis is focus on investigate how HVDC interconnections contribute to maintaining the power system stability. The research work investigated the performance of a distance relay to faults and disturbance on networks containing HVDC interconnection. The research work was carried out by modelling and testing a classic signal processing distance relay in a simple AC network which was based on Kunder’s two areas system using MATLAB/SIMULINK at first. Then the modeled distance relay’s performance was investigated by combining the distance relay and a simple HVDC link based on the Kunder’s two areas system. The research work firstly combined the signal processing distance relay and the HVDC link together to investigate the distance relay’s performance when the protected feeder containing DC link. The distance relay’s performance was investigated when the protected feeders containing HVDC link under fault conditions and power swing conditions. For comparison, a similar power system without HVDC link was also simulated.
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6

Harris, Raymond Trevor. "Replacement of seven 132/66 kv distance protection schemes by means of a generic relay implemented as a strategic spare." Thesis, Port Elizabeth Technikon, 2000. http://hdl.handle.net/10948/34.

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Eskom is experiencing problems in the field of protection maintenance and in-service breakdowns which negatively influence the quality of electrical supply to the consumer, an integral component of the utility business. These facts initiated the research into the further development of a generic relay to be implemented as a strategic spare for the replacement of several schemes operating within Eskom’s southern region. These include the electromechanical, solid state and numerical distance protection relay and scheme failures on the 132 / 66 kV feeder network. Hence, the primary objective of the research is to develop, test and configure the strategic spare in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings for the purpose of the scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three or single pole operation. This is done in conjunction with the internal and external circuit diagrams in order to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime in essence, of all the distance protection schemes that require replacement, is limited to a minimum. This dissertation therefore explores the implementation of the strategic spare.
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7

Bartko, Jan. "Projekt komunikace distančních ochran 7SA 610 pro chránění přenosového vedení." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219032.

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This work describes the structure and function of the distance protection relay Siemens 7SA610 SIPROTEC and presents the basic theoretical knowledge of the communication standard IEC 61850 at the beginning. It focuses on the configuration of the topology of two 7SA610 distance protection relays, PC and secondary relay test set Omicron CMC256 +. These two distance protection relays were programmed by using software implement DIGSI to transmit and receive GOOSE messages. It served to testing this created network by simple function. Computer and tester simulated the control system and commanded auto-reclosure to the first distance protection. Instruction was processed and also sended to the second distance protection. The final objective was to measure the tranfer time of GOOSE message between two distance protection relays. There was used a secondary tester. This measurement was implemented the tester Omicron CMC 256 +, which involves extending the NET-1 and so is compatible with the standard IEC 61850. The results and further actions are summarized in conclusion.
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8

Іванов, Олександр Олександрович, Александр Александрович Иванов, Oleksandr Oleksandrovych Ivanov, О. І. Ігнатова, and С. О. Іванов. "Моделювання дистанційного захисту лінії електропередач в програмному комплексі PSCAD/EMTDC." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41389.

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Стійка робота електричних станцій у великій мірі забезпечується за рахунок надійної роботи релейного захисту їх електрообладнання. В даний час, що характеризуються збільшенням числа аварійних ситуацій, а також зростанням кількості випадків виникнення супутніх ушкоджень, роль релейного захисту постійно зростає. У багатьох випадках через відносну недосконалість релейного захисту не можна запобігти розвитку аварій, які все частіше протікають по найбільш важкому шляху і супроводжуються значними економічними втратами.
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9

Shah, Syed Arif Ullah. "The impacts of series compensated EHV lines on distance protection, and a proposed new mitigation solution." Thesis, KTH, Elektroteknisk teori och konstruktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209916.

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Series compensation is extensively applied to the transmission lines to increase the power transfer capability of transmission lines, reduce transmission losses, improve voltage profiles, and improve power oscillation damping and transient stability of power systems. But it modifies the apparent impedance of the transmission lines during fault conditions and might cause the distance protection of transmission lines to encounter directional discrimination issues and reach problems. The non-linear characteristic of metal oxide varistor in series compensation model creates further complexity to the fault analysis and might affects the performance of conventional distance protection scheme. The distance protection issues in the series compensated lines need to be addressed for the reliable and sustainable operation of power system.The directional discrimination issues related to current inversion and voltage inversion phenomenon, and reach problems related to sub-synchronous oscillation phenomenon are addressed in this thesis report. This report aims to analyse the impacts of series compensation on the performance of conventional distance relays, and proposes a new protection solution to mitigate the shortcomings of distance relays in the series compensated lines. The proposed new protection solution includes: new tripping characteristic of quadrilateral distance relays to cope with the steady-state reach problems due to current or voltage inversion, and a new high-pass filtering technique to handle the transient reach problems due to SSO.The proposed new protection algorithm is developed in MATLAB. The performance of new protection algorithm is evaluated by simulating a 500 kV two-source power system with a 200 km series compensated line in EMTDC/ PSCAD (Manitoba Hydro). The proposed new protection solution is found to be beneficial.
Seriekompensation tillämpas i stor utsträckning på överföringsledningarna för att öka överföringsförmågan hos överföringsledningar, minska överföringsförluster, förbättra spänningsprofiler och förbättra effektdämpning och övergående stabilitet hos elsystem. Men det ändrar transmissionslinjernas uppenbara impedans under felförhållanden och kan orsaka att distansskydd för överföringsledningarna stöter på diskrimineringsproblem och uppnår problem. Den icke-linjära egenskapen hos metalloxidvaristor i seriekompensationsmodell skapar ytterligare komplexitet för felanalysen och kan påverka prestandan hos konventionella distansskyddssystem. Distansskydd problemen i seriekompenserade linjer måste lösas för en pålitlig och hållbar drift av elsystemet. De riktningsdiskrimineringsproblem som är relaterade till det aktuella inversions- och spänningsinversionsfenomenet och uppnår problem relaterade till subsynkron oscillationsfenomen tas upp i denna avhandlingsrapport. Denna rapport syftar till att analysera effekterna av seriekompensation för prestanda hos konventionella distansreläer och föreslår en ny skyddslösning för att mildra bristerna i distansreläerna i seriekompenserade linjer. Den föreslagna nya skyddslösningen innefattar: Ny utlösningskaraktäristik för fyrsidig distansreläer för att klara avståndet med stillastående / räckvidden på grund av ström- eller spänningsinversion och en ny högpassfiltreringsteknik för hantering av övergående över- Nå problem på grund av SSO. Den föreslagna nya skyddsalgoritmen har utvecklats i MATLAB. Utförandet av den nya skyddsalgoritmen utvärderas genom simulering av ett 500 kV två-källa kraftverk med en 200 km serie kompenserad linje i EMTDC / PSCAD (Manitoba Hydro). Den föreslagna nya skyddslösningen har visat sig vara fördelaktig.
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10

Valins, Thiago Ferreira. "Relé digital de distância baseado na teoria de ondas viajantes e transformada Wavelet." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-13032005-113736/.

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Neste trabalho, será abordada a proteção digital fundamentada na teoria de ondas viajantes e da ferramenta Transformada Wavelet. Um algoritmo completo para proteção digital foi implementado, consistindo basicamente nos módulos de detecção, classificação e localização da falta, com a conseqüente determinação das zonas de proteção do relé. Para este esquema completo de releamento, empregou-se como ferramenta de análise a Transformada Wavelet. Sinais transitórios de alta freqüência gerados por uma situação de falta podem ser analisados pela Transformada Wavelet, detectando-se com precisão o instante de chegada das ondas em um ou nos dois terminais da linha. Conhecendo o instante de chegada dessas ondas e sua velocidade de propagação, a zona de proteção na qual a falta está alocada pode ser estimada de maneira fácil e rápida. A capacidade de acusar com precisão os instantes de chegada das ondas torna a Transformada Wavelet adequada ao problema de determinação das zonas de proteção. Nessa implementação, o usuário pode escolher entre as técnicas de aquisição de dados provenientes de um ou de dois terminais. O algoritmo foi implementado através do software Matlabâ e posteriormente testado, quando se utilizaram dados de faltas obtidos através de simulações no software ATP (Alternative Transients Program). Nas simulações aplicadas a este software, considerou-se um sistema de transmissão de 440 kV. As simulações produziram uma base de dados, variando-se os seguintes parâmetros: tipos de faltas, localizações ao longo da linha, ângulos de incidência, resistências de faltas, entre outros. Pelos resultados alcançados, pode-se afirmar que a aplicação é bastante adequada para uso em relés digitais de distância.
The present work deals with digital protection based on the traveling wave theory and Wavelet transform. An complete algorithm for digital protection was implemented. It is composed of modules of fault detection, classification, location, with protection zone determination. For this complete relaying scheme the Wavelet transform was employed as analysis tool. Transient signals of high frequency generated by the fault occurrence was analyzed by the Wavelet transform, and also the instant of the waves arrival was accurately detected in one or two terminals of the line. By knowing the instant of the arrival of the waves and their propagation velocity, the protection zone, in which the fault is located, can be estimated easily and quickly. The Wavelet transform property of accurate detection the instant of waves arrival make it appropriate to the problem of protection zone determination. In this implementation, the user can choose between the location techniques using data from one or two terminals. The algorithm was implemented by Matlab® software and then tested utilizing data of faults obtained by means of simulations of ATP software (Alternative Transients Program). In these simulations, a transmission line of 440 kV was considered. These simulations produced a database composed of various fault types considering different fault locations, fault inception angles and fault resistances. According to the analysis of the test results, it is possible to verify that the application is very adequate for use in digital distance relays.
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11

Souza, Silvio Aparecido de. "Algoritmos genéticos aplicados à proteção e estimação de harmônicos em sistemas elétricos de potência." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-17032009-150821/.

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O objetivo de um sistema elétrico de potência é gerar energia elétrica e fornecer continuamente esta energia aos usuários finais dentro de padrões de qualidade aceitáveis. Neste contexto, diferentes aplicações usando algoritmos genéticos (AGs) para resolver problemas relacionados a sistemas elétricos de potência são apresentadas neste trabalho. A estimação de harmônicos, estudos relativos aos relés de freqüência e aplicações da proteção de distância são os assuntos investigados nesta tese. Para análise harmônica foram consideradas freqüências em sistemas de potência de até a vigésima quinta ordem, as quais foram estimadas pelos AGs e comparadas àquelas resultantes da análise quando da aplicação da Transformada Discreta de Fourier (TDF). Com respeito aos relés de freqüência, o objetivo foi estimar a amplitude, freqüência e ângulo de fase para diversas situações de formas de ondas utilizando uma nova estrutura que possa ser implementada dispondo em FPGAs (Field Programmable Gate Array). Finalmente, aplicados à proteção de distância, o principal propósito dos AGs foi identificar os fasores fundamentais da tensão e corrente e, então, calcular a impedância da linha medida pelo relé de distância associado. Cabe ressaltar que estes resultados também foram comparados ao método clássico da TDF. Todas as três abordagens foram formuladas como problemas de otimização, com objetivo de minimizar o erro estimado das variáveis envolvidas. Os resultados dessas aplicações mostram que o desempenho global dos Algoritmos Genéticos foi altamente satisfatório considerando-se as precisões das respostas encontradas.
The aim of electric power systems is to generate electricity and to deliver it continuously to the end-user in an acceptable standard. Therefore, different applications using genetic algorithms (GAs) to solve electric power system problems are presented in this work. Harmonic estimation, frequency relays and distance protection are the subjects investigated in this thesis. Concerning harmonic analysis, the ones up to the 25th order were considered in this work. They were estimated by GAs and compared to results obtained from the Discrete Fourier Transform (DFT) technique. Concerning frequency relays, the main objective was to estimate the amplitude, frequency and phase angle of waveforms using a new structure capable to be implemented in a FPGA (Field Programmable Gate Array). Finally, concerning distance protection, the main purpose was use the GAs to identify the fundamental voltage and current phasors and to calculate the line impedance seen by the distance relay. These results were also compared to those obtained from the classic DFT method. These three problems were formulated as an optimization problem, and the objective was to minimize the estimation error. The results from these applications show that the global performance of the genetic algorithms was highly satisfactory concerning the precision of the responses.
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CAMPOS, Alana Kelly Xavier Santos. "Um novo método de estimação fasorial para uso em relés digitais de proteção." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/582.

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Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-05-04T19:00:50Z No. of bitstreams: 1 ALANA KELLY XAVIER SANTOS CAMPOS – TESE (PPGEE) 2016.pdf: 5517354 bytes, checksum: 24306600f8b9a28a2d230c48b0811a3a (MD5)
Made available in DSpace on 2018-05-04T19:00:50Z (GMT). No. of bitstreams: 1 ALANA KELLY XAVIER SANTOS CAMPOS – TESE (PPGEE) 2016.pdf: 5517354 bytes, checksum: 24306600f8b9a28a2d230c48b0811a3a (MD5) Previous issue date: 2016-10-21
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Um método de estimação fasorial é proposto para ser utilizado em relés digitais de proteção. Este método tem o objetivo de melhorar a característica de rejeição de componentes indesejáveis do sinal, que são introduzidas durante faltas e manobras nos sistemas elétricos de potência e podem comprometer o desempenho dos sistemas de proteção. São realizadas comparações entre o método proposto e outros quatro métodos de estimação fasorial, em relação às respostas no tempo e frequência. Para as comparações de resposta no tempo são utilizados sinais analíticos provenientes do MATrix LABoratory (MATLAB®) e sinais simulados provenientes do Alternative Transients Program (ATP). Um relé de distância foi implementado utilizando a linguagem MODELS do ATP para avaliar o desempenho do relé, utilizando o método proposto e demais métodos avaliados. A partir de alguns parâmetros usados para avaliar quantitativamente os métodos de estimação, observou-se que o método proposto apresenta bons resultados em termos de precisão e velocidade de convergência, com resposta no tempo compatível com os demais métodos comumente utilizados. A resposta em frequência do método proposto se apresenta mais seletiva em relação aos demais, por apresentar menores lóbulos entre as harmônicas e uma banda de passagem mais estreita em torno da frequência fundamental. Outra vantagem do método proposto é que ele é de fácil programação e permite que os usuários alterem parâmetros de projeto de acordo com suas necessidades.
A phasor estimation method is proposed to be used in digital relays for power system protection. It aims to improve the characteristic of filtering out undesirable frequency components of signals, which are introduced during faults and switching events in electric power systems that may compromise the performance of the protection systems. Comparisons are made in relation to time response and frequency response for the proposed method and four phasor estimation methods. In relation to response time are used analytical signals from MATrix LABoratory (MATLAB®) and simulated signals from Alternative Transients Program (ATP). A distance relay was implemented by using the MODELS language in ATP to evaluate the performance of the relay. From some parameters used to evaluate the estimation methods, it was observed that the proposed method shows good results in terms of accuracy and convergence speed, with response time compatible with other methods. The frequency response of the proposed method appears to be more selective than those of the others methods because it presents lower lobes between the harmonics and a narrower pass band around the fundamental frequency. Another advantage of the proposed method is that it can be easily programmed, allowing users to change design parameters according to their needs.
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13

Moro, Vinícius de Cillo. "Metodologia para coordenação otimizada entre relés de distância e direcionais de sobrecorrente em sistemas de transmissão de energia elétrica." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-30102014-093627/.

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A proteção de sistemas de energia elétrica possui papel extremamente importante no aspecto de garantir o fornecimento de energia de maneira segura e confiável. Assim, a ação indevida ou a não atuação deste sistema de proteção pode causar danos materiais ou econômicos tanto para as concessionárias quanto para os consumidores de energia elétrica. Dessa forma, o sistema de proteção deve estar bem ajustado para que possa garantir suas funções, sendo sensível, seletivo, confiável e rápido. Para tanto, uma boa coordenação entre os relés de proteção deve ser estabelecida. No caso de um sistema de transmissão, o qual costuma ser um sistema malhado, a proteção é comumente realizada por relés de distância aliados a relés de sobrecorrente com unidade direcional, sendo que estes funcionam como elemento de retaguarda daqueles. O processo de ajuste desses relés é um trabalho muito difícil e demorado, que pode ainda estar sujeito a erros do engenheiro de proteção responsável pelo estudo. Neste contexto, este trabalho tem como objetivo desenvolver uma metodologia baseada na otimização por enxame de partículas que obtenha automaticamente os ajustes desses relés de forma a garantir a coordenação e seletividade entre eles, tornando assim o processo de ajuste mais rápido e preciso. Dessa forma, essa metodologia pode constituir uma ferramenta de auxílio muito favorável ao engenheiro de proteção. Além disso, como em todo problema de otimização, a função objetivo e as restrições foram definidas de maneira a retratar o problema de coordenação envolvendo tanto os relés de distância quanto os direcionais de sobrecorrente. A metodologia foi aplicada a dois sistemas, um fictício com 16 relés e um sistema de transmissão real com 44 relés, sendo que em ambos os casos ela apresentou resultados bastante satisfatórios proporcionando ajustes bem coordenados.
Electrical power systems protection has a very important role in the aspect of ensuring energy supply with safety and reliability. Thus, improper action or non-actuation of this protection system can cause materials and/or economics damages to electricity utilities as well as ordinary energy consumers. Therefore the protection system must be well adjusted so it can ensure its functions and thus being sensible, selective, reliable and fast. In order to achieve these characteristics, the protective relays must be well coordinated. In the case of meshed transmission systems, the protection is generally performed by distance relays as primary protection associated with directional overcurrent relays as backup protection. The process of adjusting these relays is very tough, slow and it can even be subject to the protection engineer mistakes. In this context, this work aims to develop a particle swarm optimization based methodology that can automatically obtain these relays adjusts so they can ensure relays coordination and selectivity, and then make this setting process faster and more precise. Thus, this methodology may provide a very favorable tool to aid the protection engineer. Moreover, as in any optimization problem, the objective function and the constraints were defined to represent the coordination problem involving both distance and directional overcurrent relays. The methodology was applied to two systems, a fictitious with 16 relays and a real transmission system with 44 relays, and in both cases it showed satisfactory results providing well-coordinated settings.
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Regnier, Wilfried Loïc. "Les écarts interprétatifs sur l'éthique du travail prescrit de surveillance et la compétence de l'assistant d'éducation pour l'esprit du système scolaire." Phd thesis, Université de Haute Alsace - Mulhouse, 2012. http://tel.archives-ouvertes.fr/tel-01058527.

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Être surveillant en 2013, à quel savoir-faire cela correspond-il ? Depuis 2003, nous ne parlons plus de surveillant d'externat, mais d'assistant d'éducation. Comment apprennent-ils leur travail ? Le travail de surveillance ne s'impose plus comme un rite de passage pour devenir enseignant. Les enseignants ont une vocation éducative, mais qu'en est-il des surveillants ? Est-ce que ces derniers interprètent leurs fonctions avec une vocation éducative ? L'assistant d'éducation est un agent employé par l'État pour assurer un service de surveillance au sein d'un établissement scolaire, mais comment construit-il ses compétences ? La compétence est une action, mais aussi une capacité personnelle ou une approche liée à un potentiel d'expériences passées qui risque de perturber le travail. Le surveillant doit mesurer sa pratique entre distanciation critique et implication personnelle comme acteur-relais à l'institution. Nous cherchons à comprendre les mécanismes de l'individu sur son interprétation de sa fonction. Pour comprendre ces dispositions, nous interrogeons les CPE par entretiens semi-directifs, les élèves et assistants d'éducation par questionnaires. Quelles sont les causes qui conduisent l'individu prend le risque d'être à l'écart de sa fonction imposée par la loi ? L'enjeu de ce travail est de comprendre et de décrire la cause d'un écart interprétatif présent dans la pratique d'un professionnel de l'Éducation Nationale. Cet écart se construit entre l'idée que l'acteur a de son métier et la compétence exigée de lui. Nous expliquons que le positionnement de l'individu à être à l'écart de son rôle prescrit est préétabli par la CSP des deux parents intériorisée par les sondés. En effet, l'intercompréhension dans une interaction est anticipée par la CSP maternelle a contrario de l'interdépendance qui est prédestinée par la CSP paternelle. L'être social apprend à se construire une compétence de réflexivité sur son implication personnelle et sur [Ça] façon de faire.
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Liang, Feng. "Performance enhancement of digital relays for transmission line distance protection /." Internet access available to MUN users only, 2003. http://collections.mun.ca/u?/theses,153681.

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16

Rivas, Angel Esteban Labrador. "Coordination of distance and overcurrent relays using a mathematical optimization technique." Universidade Estadual de Londrina. Centro de Tecnologia e Urbanismo. Programa de Pós-Graduação em Engenharia Elétrica, 2018. http://www.bibliotecadigital.uel.br/document/?code=vtls000218372.

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A proteção da rede de transmissão tem um papel importante nos sistemas de energia. Para melhorar a proteção é comum combinar diferentes tipos de relés; a combinação de relés de sobrecorrente e distância é um esquema bem conhecido. A lenta velocidade operacional do relé de sobrecorrente força a aplicação do relé de distância como o dispositivo de proteção principal. Os relés de sobrecorrente são usados como proteção de retaguarda tendo o esquema de distância como principal. Para atingir esse objetivo, a coordenação entre os sistemas de proteção primária e de retaguarda deve ser realizada desenvolvendo uma função objetivo com ambos parâmetros. Velocidade, seletividade e estabilidade são restrições, que devem ser satisfeitas através da coordenação. A coordenação do problema de relés direcionais de sobrecorrente (DOCRs) é um problema de programação não linear (NLP), geralmente resolvido com uma técnica de programação linear (LP) apenas considerando a configuração de tempo de atraso (TDS) como uma variável de decisão, sem lidar com o problema não-linear de configuração da corrente de partida (PS), ou com a resolução do componente PS usando uma técnica heurística. Um método meta-heurístico apresentado para resolver o problema de otimização é o algoritmo de otimização de colônias de formigas (ACO). O ACO empregado é uma extensão do algoritmo ACO para problemas de otimização de domínio contínuo implementados para problemas de otimização de variáveis mistas, condensados em dois tipos de variáveis tanto contínuas como categóricas. Neste trabalho, tanto o TDS como o PS são variáveis de decisão, o TDS é considerado contínuo e o PS categórico. Normalmente, a solução inicial é gerada aleatoriamente, além disso, esses resultados são comparados usando os mesmos valores aleatórios PS para resolver um relaxamento do problema DOCR com LP para obter novos valores TDS. A inclusão de relés de distância na formulação adicionará uma variável de tipo contínuo, mas com características lineares (constantes) que não alteram a formulação de DOCR para este problema de PNL. Para esta metodologia, cinco sistemas de transmissão (3, 6, 8, 9 e 15 Barras) foram avaliados para comparar a coordenação DOCR clássica, a introdução dos relés de distância e a resposta do modelo a soluções iniciais de alta qualidade junto a uma metodologia hibrida utilizando LP.
Protection of power transmission has an important role in power systems. To improve protection is common to combine different types of relays, which combination of overcurrent and distance relays is a well-known protection scheme. A slow operational speed of overcurrent relay forces application of distance relay as the main protection device. Overcurrent relays are used as backup protection to main distance protection system. To achieve this aim, coordination between primary and backup protection systems should be performed developing an objective function with both parameters. Speed, selectivity, and stability are constraints, which must be satisfied by performing coordination. The coordination of directional overcurrent relays (DOCRs) problem is a nonlinear programming problem (NLP), usually solved with a linear programming technique (LP) only considering the time dial setting (TDS) as a decision variable, without dealing with the non-linear problem of plug setting (PS), or solving the PS component using a heuristic technique. A metaheuristic algorithm method presented to solve the optimization problem is an ant colony optimization (ACO) algorithm. The ACO used is an extension of the ACO algorithm for continuous domain optimization problems implemented to mixed variable optimization problems, condensed in two types of variables both continuous and categorical. In this work, both TDS and PS are decision variables, TDS is considered continuous and PS categorical. Normally, the initial solution is random generated, in addition, those results are compared by using the same random PS values for solving a relaxation of the DOCRs problem with LP to obtain new TDS values. Including distance relays in the formulation will add an additional variable continuous type, but with linear (barely constant) characteristics making no changes in DOCRs formulation for this NLP problem. For this methodology, five transmission systems (3, 6, 8, 9, and 15 Bus accordingly) were evaluated to compare classical DOCR coordination, distance relays introduction and model response to high-quality initial solutions within a hybrid method using LP.
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17

Fabián, Espinoza Renzo Grover [UNESP]. "Análise de proteção de linhas de transmissão através de relés numéricos e uso de models externos no ATP (Alternative Transient Program)." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/87138.

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Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA)
Neste trabalho apresenta-se uma metodologia para obter um ambiente interativo de simulação com ferramentas que permitam fazer análises de sistemas de proteção como estudos de coordenação e analises pós falta. As ferramentas estão baseadas no programa de simulação de transitórios eletro- magnéticos EMTP/ATP e na linguagem de programação ANSI C, sobre a plataforma de software livre GNU/Linux. Esta metodologia pode ser implementada, da mesma forma, em qualquer plataforma Windows sobre a qual possa funcionar o EMTP/ATP e o pacote ATP/MingW. Assim, implementou- se um relé de distância numérico através de modelos externos (“foreign models”). Ilustra-se também como usar arquivos no formato COMTRADE na análise com EMTP/ATP. Dessa forma foi possível analisar o comportamento do relé implementado tendo como entradas os sinais de tensões e correntes correspondentes aos eventos reais. Os sinais de disparo, assim como os demais componentes do relé, foram testados usando um sistema teste de referência do Power System Relaying Committee da PES-IEEE e os sinais de faltas reais do Sistema Elétrico Interligado da Colômbia. Por fim, foi feito um estudo de coordenação. Os resultados são apresentados e discutidos. A metodologia proposta pode ser usada para desenvolver qualquer componente ou elemento de controle dentro de um sistema elétrico, onde haja a necessidade de usar o EMTP/ATP para simular condições específicas de operação do sistema elétrico, complementando a simplicidade da linguagem MODELS com a portabilidade e potencialidade da linguagem C
This work presents the methodology to obtain an environment of interactive simulation with tools to perform analysis of protection systems, coordination studies and analysis post fault. These tools are based on the program for electromagnetic transients EMTP/ATP and in ANSI C programming language used in the free GNU/Linux software platform. The same methodology can be followed to be used on any Windows Operating System that can run EMTP/ATP and the package ATP/MingW. Then, for this, a numerical distance relay was implemented by means of foreign models using C programming language. It also shows how to use COMTRADE files in analysis with EMTP / ATP. Thus it was possible to analyze the behavior of the implemented relay with voltage and current signals of real events as inputs. The trip signals, like the other components of the relay, were tested using a testing reference system of Power System Relaying Committee of PES-IEEE and the signals of real faults of Inter- connected Electric System of Colombia. Finally, a coordination study was made. The results are presented and discussed. This methodology could also be used to develop any component or control element within an electrical system that one may need for a particular use; therefore, compensating the simplicity of the language MODELS with the flexibility and portability of C programming language
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18

Fabián, Espinoza Renzo Grover. "Análise de proteção de linhas de transmissão através de relés numéricos e uso de models externos no ATP (Alternative Transient Program) /." Ilha Solteira : [s.n.], 2011. http://hdl.handle.net/11449/87138.

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Orientador: Jose Roberto Sanches Mantovani
Banca: Luiz Fernando Bovolato
Banca: Rodrigo Aparecido Fernandes Pereira
Resumo: Neste trabalho apresenta-se uma metodologia para obter um ambiente interativo de simulação com ferramentas que permitam fazer análises de sistemas de proteção como estudos de coordenação e analises pós falta. As ferramentas estão baseadas no programa de simulação de transitórios eletro- magnéticos EMTP/ATP e na linguagem de programação ANSI C, sobre a plataforma de software livre GNU/Linux. Esta metodologia pode ser implementada, da mesma forma, em qualquer plataforma Windows sobre a qual possa funcionar o EMTP/ATP e o pacote ATP/MingW. Assim, implementou- se um relé de distância numérico através de modelos externos ("foreign models"). Ilustra-se também como usar arquivos no formato COMTRADE na análise com EMTP/ATP. Dessa forma foi possível analisar o comportamento do relé implementado tendo como entradas os sinais de tensões e correntes correspondentes aos eventos reais. Os sinais de disparo, assim como os demais componentes do relé, foram testados usando um sistema teste de referência do Power System Relaying Committee da PES-IEEE e os sinais de faltas reais do Sistema Elétrico Interligado da Colômbia. Por fim, foi feito um estudo de coordenação. Os resultados são apresentados e discutidos. A metodologia proposta pode ser usada para desenvolver qualquer componente ou elemento de controle dentro de um sistema elétrico, onde haja a necessidade de usar o EMTP/ATP para simular condições específicas de operação do sistema elétrico, complementando a simplicidade da linguagem MODELS com a portabilidade e potencialidade da linguagem C
Abstract: This work presents the methodology to obtain an environment of interactive simulation with tools to perform analysis of protection systems, coordination studies and analysis post fault. These tools are based on the program for electromagnetic transients EMTP/ATP and in ANSI C programming language used in the free GNU/Linux software platform. The same methodology can be followed to be used on any Windows Operating System that can run EMTP/ATP and the package ATP/MingW. Then, for this, a numerical distance relay was implemented by means of foreign models using C programming language. It also shows how to use COMTRADE files in analysis with EMTP / ATP. Thus it was possible to analyze the behavior of the implemented relay with voltage and current signals of real events as inputs. The trip signals, like the other components of the relay, were tested using a testing reference system of Power System Relaying Committee of PES-IEEE and the signals of real faults of Inter- connected Electric System of Colombia. Finally, a coordination study was made. The results are presented and discussed. This methodology could also be used to develop any component or control element within an electrical system that one may need for a particular use; therefore, compensating the simplicity of the language MODELS with the flexibility and portability of C programming language
Mestre
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19

Wannous, Kinan Hasan Wafaa. "Distanční ochrana využívající digitální vstupní data." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-414159.

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Standard IEC 61850-9-2 definuje přenos vzorkovaných měřených hodnot (sampled measured values, SMV) prostřednictvím sítě Ethernet a využití SMV získaných ze slučovacích jednotek nebo přístrojových transformátorů. Implementace IEC 61850-9-2 závisí na vlastnostech datového souboru, jakými jsou časová synchronizace, počet vzorků a časový interval. Dizertační práce je zaměřena na algoritmy chránění a analýzu vlivu standardu IEC61850-9-2LE na fyzická zařízení ochran s analogově/digitálními vstupními daty o proudu a napětí. S ohledem na narůstající míru interakce mezi fyzickými zařízeními a komunikačními prvky byl navržen test pro analýzu komunikace pro rozvodnu využívající konvenční metody (analogové vstupy) a metody digitální založené na standardu IEC 61850-9-2. Práce dále popisuje funkci slučovací jednotky využívající standard IEC61850-9-2LE. Navržená metoda definuje zdroj SMV a analyzuje přenos dat. V rámci práce byl za využití softwaru Matlab naprogramován algoritmus ochrany. Vytvořený model je schopen vyhodnotit vliv harmonického zkreslení na funkci digitálních ochran a vliv přesycení proudového transformátoru na distanční ochranu. V práci jsou zhodnoceny i možnosti zrychlení testování systémů chránění s využitím neuronové sítě. Závěrečná kapitola se zabývá aplikacemi v reálném čase, využívajícími data z rozvodny v blízkosti Vysokého učení technického v Brně. K přenosu dat z rozvodny do univerzitní laboratoře je zde využíváno SMV přenášených optickým kabelem o délce 16 km. Aplikace je vytvořena v programu Matlab a je schopna číst data z ethernetového portu, dekódovat je, převést z formátu ASCII do desítkové soustavy a poté vykreslit průběhy proudu a napětí. Mezi vlastnosti aplikace se řadí jednoduchost použití, schopnost implementace funkcí distanční ochrany, výpočet RMS hodnot proudu a napětí a harmonického zkreslení, harmonická analýza prostřednictvím rychlé Fourierovy transformace a výpočet impedance poruchové smyčky. Všechny výpočty běží v reálném čase a provedena je i citlivostní analýza modelu.
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20

Morais, Adriano Peres de. "Algoritmo de alto desempenho para proteção numérica de linhas de transmissão imune a oscilações de potência." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/3672.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
This Doctoral Thesis proposes a new methodology for transmission line protection tolerant to power swings. The algorithm developed has the ability to detect, classify and locate all fault types with and without power swings, including those that produce high values of fault resistance. In a first step, it is proposed a fault distance estimator based on the leastsquare curve fitting. The fault locator, for protection proposes, was modeled by a series R-L circuit and differential equations. In a second step, the main causes and consequences of power swings in transmission lines distance relays are introduced. Also in this context, techniques to minimize these effects are presented. Besides, computer simulations of power swings, with different fault scenarios, were carried out to realize comparative analyses between the methods. The results show that none of the methods is efficient in all scenarios. Hence, there is still some concern about the performance of the protection methods against power swings. In a third step, it was developed an algorithm for numerical protection in transmission lines immune to power swings. The detection and classification steps are based on Mathematical Morphology. In order to obtain a safer operation of the relay, especially in the boundaries of threshold set, a counting strategy was developed. The main innovation of the work is based on difference of behavior of the exponentially decaying component (dc component) during a fault and during a power swing. The dc component, obtained by means of morphological filter, is used as a tripping criterion. Finally, in order to evaluate the algorithm performance, tests with different fault and power swings scenarios were performed. The results show that the technique has the speed and safety required even during power swings due to the simplicity of the algorithm used in mathematical operations.
Neste trabalho propõe-se uma nova metodologia de proteção de linhas de transmissão, tolerante as oscilações de potência. O algoritmo desenvolvido tem a capacidade de detectar, classificar e localizar todos os tipos de faltas, com e sem a presença de oscilações de potência, inclusive aquelas que produzem altos valores de resistência de falta. Em uma primeira etapa com o emprego do método de ajuste de curvas por mínimos quadrados desenvolve-se um estimador para localizar a posição das faltas. Para fins de proteção, este é modelado por meio de um circuito R-L série representado por suas equações diferenciais. Em uma segunda etapa são apresentadas as principais causas das oscilações de potência, bem como suas consequências para os relés de distância de linhas de transmissão. Ainda neste contexto, são apresentadas, analisadas e comparadas algumas técnicas destinadas a minimizar estes efeitos. Essas técnicas foram testadas por meio de simulações computacionais, sob condições de oscilação de potência com e sem a presença de curtos-circuitos, considerando-se diversos valores de carregamento e frequências de oscilação. Os resultados mostraram que nenhum método é totalmente eficiente para todos os cenários. Desse modo, ainda há algumas incertezas sobre o desempenho das técnicas de proteção contra as oscilações de potência existentes. Em uma terceira etapa, foi desenvolvido um algoritmo para proteção numérica de linhas de transmissão imune as oscilações de potência. A metodologia faz uso da Morfologia Matemática nas etapas de detecção e classificação das faltas. De modo a se obter uma maior segurança na operação do relé, especialmente na região próxima ao limiar de operação, incorporou-se uma estratégia de contagem diferente das tradicionais. A principal contribuição do trabalho relaciona-se com a análise da diferença comportamental da componente exponencial decrescente (componente dc) para uma situação de falta e de oscilação de potência. Ou seja, a componente dc, obtida por meio de um filtro morfológico, é utilizada como critério de disparo do relé de distância. Para avaliar o desempenho do algoritmo desenvolvido, uma série de testes com diferentes cenários de faltas com e sem a presença de oscilações de potência foram realizadas. Devido à simplicidade das operações matemáticas utilizadas no algoritmo, a técnica apresenta segurança e velocidade na sua operação, mesmo durante oscilações de potência.
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21

Benfarah, Ahmed. "Sécurisation d'un lien radio UWB-IR." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961228.

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Du fait de la nature ouverte et partagée du canal radio, les communications sans fil souffrent de vulnérabilités sérieuses en terme de sécurité. Dans ces travaux de thèse, je me suis intéressé particulièrement à deux classes d'attaques à savoir l'attaque par relais et l'attaque par déni de service (brouillage). La technologie de couche physique UWB-IR a connu un grand essor au cours de cette dernière décennie et elle est une candidate intéressante pour les réseaux sans fil à courte portée. Mon objectif principal était d'exploiter les caractéristiques de la couche physique UWB-IR afin de renforcer la sécurité des communications sans fil. L'attaque par relais peut mettre à défaut les protocoles cryptographiques d'authentification. Pour remédier à cette menace, les protocoles de distance bounding ont été proposés. Dans ce cadre, je propose deux nouveaux protocoles (STHCP : Secret Time-Hopping Code Protocol et SMCP : Secret Mapping Code Protocol) qui améliorent considérablement la sécurité des protocoles de distance bounding au moyen des paramètres de la radio UWB-IR. Le brouillage consiste en l'émission intentionnelle d'un signal sur le canal lors du déroulement d'une communication. Mes contributions concernant le problème de brouillage sont triples. D'abord, j'ai déterminé les paramètres d'un brouilleur gaussien pire cas contre un récepteur UWB-IR non-cohérent. En second lieu, je propose un nouveau modèle de brouillage par analogie avec les attaques contre le système de chiffrement. Troisièmement, je propose une modification rendant la radio UWB-IR plus robuste au brouillage. Enfin, dans une dernière partie de mes travaux, je me suis intéressé au problème d'intégrer la sécurité à un réseau UWB-IR en suivant l'approche d'embedding. Le principe de cette approche consiste à superposer et à transmettre les informations de sécurité simultanément avec les données et avec une contrainte de compatibilité. Ainsi, je propose deux nouvelles techniques d'embedding pour la couche physique UWB-IR afin d'intégrer un service d'authentification.
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22

Logan, Kit. "Observational studies of the learning behaviour of distance education students using an asynchronous, remote, recording and replay tool." Thesis, Open University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418514.

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23

Alanzi, Sultan. "Analysis of a Major Electric Grid – Stability and Adaptive Protection." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365969976.

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24

Leopoldino, Kleison Jos? Medeiros. "As rela??es afetivas na pr?tica tutorial e sua rela??es com a aprendizagem no curso a dist?ncia de licenciatura plena em Qu?mica." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17665.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In distance learning degree in Chemistry in full of the Secret?ria de Educa??o a dist?ncia da Universidade Federal do Rio Grande do Norte (SEDIS / UFRN). The teacher-tutor to establish the experimental subjects closer relationships with students, mediating the pedagogical actions that develop in the distance learning course, with a view to achieving the principles of autonomy and learning, contributing to the creation of learning environments collaborative, guided by affection.The article presents the results of an empirical research on affectivity in practice this tutorial experimental classes in higher distance education in the full degree course in Chemistry Polo Currais Novos/ RN, held between 2009 and 2010. The study is based on qualitative methodology, whose data were collected through questionnaires and semi-structured interviews with 48 (forty eight) students involved in distance learning courses and selected in order to compose a group of subjects who showed variability, as guidelines that guide the sampling procedures in qualitative research. The results, based on category theory and empirical analysis of data from the interviews were supplemented by information obtained from participant observation which also served to guide the data collection of the corpus of this work. With the results we understand that there is clarity about what characterizes a loving relationship between those involved in the process of teaching and learning in experimental classes in high school chemistry Distance Education. Furthermore, it was also clear that the communication process in dialogic teaching and learning in higher distance education in chemistry at the trial need to mark out in balanced affective attitudes, the experimental error that value and respect the many possible construction of knowledge by movements social interaction of individual and collective
No ensino ? dist?ncia de licenciatura plena em Qu?mica da Secret?ria de Educa??o ? dist?ncia da Universidade Federal do Rio Grande do Norte (SEDIS/UFRN) o professor-tutor de disciplinas experimentais estabelece as rela??es mais pr?ximas com os alunos, mediando as a??es pedag?gicas que se desenvolvem, tendo em vista, a concretiza??o dos princ?pios da autonomia e da aprendizagem, contribuindo para a cria??o de ambientes de aprendizagem colaborativos pautados pela afetividade. O trabalho exp?e o resultado de uma pesquisa emp?rica sobre esta afetividade na pr?tica tutorial em aulas experimentais na modalidade de ensino ? dist?ncia no curso de licenciatura plena em Qu?mica do polo de Currais Novos/RN, realizado entre os anos de 2009 e 2010. O estudo est? fundamentado na metodologia semiquantitativa, onde os dados foram coletados por meio de question?rios e entrevistas semi-estruturadas, com 48 (quarenta e oito) discentes envolvidos no curso ? dist?ncia e selecionados visando compor um grupo que apresentasse variabilidade, conforme as diretrizes que guiam os processos de amostragem nas pesquisas semiquantitativas. Os resultados, baseados em categorias te?ricas e emp?ricas provenientes da an?lise dos dados das entrevistas, foram complementados pelas informa??es obtidas com a observa??o participativa que serviu tamb?m para orientar a coleta de dados do corpus deste trabalho. Com os resultados obtidos foi poss?vel entender que h? clareza, sobre o que caracteriza uma rela??o afetiva entre os envolvidos no processo de ensino e aprendizagem em aulas experimentais do ensino em Qu?mica da Educa??o ? dist?ncia (EaD). Al?m disso, ficou evidente, tamb?m, que o processo dial?gico no ensino-aprendizagem, e na experimenta??o de Qu?mica da educa??o superior ? dist?ncia precisa se balizar em atitudes afetivas equilibradas, que valorizem o erro experimental e o respeito ?s m?ltiplas possibilidades de constru??o do conhecimento por movimentos de intera??o social, seja individuais e/ou coletivos
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25

Leoppoldino, Kleison Jos? Medeiros. "As rela??es afetivas na pr?tica tutorial e sua rela??o com a aprendizagem no curso a dist?ncia de licenciatura plena em qu?mica." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17670.

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Made available in DSpace on 2014-12-17T15:41:59Z (GMT). No. of bitstreams: 1 KleisonJML_DISSERT.pdf: 2363827 bytes, checksum: 4aa59ad298de0da3cbcb7da4fac8623c (MD5) Previous issue date: 2012-02-16
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In distance learning degree in Chemistry in full of the Secret?ria de Educa??o a dist?ncia da Universidade Federal do Rio Grande do Norte (SEDIS / UFRN). The teacher-tutor to establish the experimental subjects closer relationships with students, mediating the pedagogical actions that develop in the distance learning course, with a view to achieving the principles of autonomy and learning, contributing to the creation of learning environments collaborative, guided by affection.The article presents the results of an empirical research on affectivity in practice this tutorial experimental classes in higher distance education in the full degree course in Chemistry Polo Currais Novos/ RN, held between 2009 and 2010. The study is based on qualitative methodology, whose data were collected through questionnaires and semi-structured interviews with 48 (forty eight) students involved in distance learning courses and selected in order to compose a group of subjects who showed variability, as guidelines that guide the sampling procedures in qualitative research. The results, based on category theory and empirical analysis of data from the interviews were supplemented by information obtained from participant observation which also served to guide the data collection of the corpus of this work. With the results we understand that there is clarity about what characterizes a loving relationship between those involved in the process of teaching and learning in experimental classes in high school chemistry Distance Education. Furthermore, it was also clear that the communication process in dialogic teaching and learning in higher distance education in chemistry at the trial need to mark out in balanced affective attitudes, the experimental error that value and respect the many possible construction of knowledge by movements social interaction of individual and collective
No ensino a dist?ncia de licenciatura plena em Qu?mica da Secretaria de Educa??o a dist?ncia da Universidade Federal do Rio Grande do Norte (SEDIS/UFRN), o professor-tutor de disciplinas experimentais estabelece as rela??es mais pr?ximas com os alunos, mediando as a??es pedag?gicas que se desenvolvem, tendo em vista a concretiza??o dos princ?pios da autonomia e da aprendizagem, contribuindo para a cria??o de ambientes de aprendizagem colaborativos pautados pela afetividade. O trabalho exp?e o resultado de uma pesquisa emp?rica sobre esta afetividade na pr?tica tutorial em aulas experimentais na modalidade de ensino a dist?ncia no Curso de Licenciatura Plena em Qu?mica do Polo de Currais Novos/RN, realizado entre os anos de 2009 e 2010. O estudo est? fundamentado na metodologia semiquantitativa, cujos dados foram coletados por meio de question?rios e entrevistas semiestruturadas, com 48 (quarenta e oito) discentes envolvidos no curso a dist?ncia e selecionados visando compor um grupo que apresentasse variabilidade, conforme as diretrizes que guiam os processos de amostragem nas pesquisas semiquantitativas. Os resultados, baseados em categorias te?ricas e emp?ricas provenientes da an?lise dos dados das entrevistas, foram complementados pelas informa??es obtidas com a observa??o participativa que serviu tamb?m para orientar a coleta de dados do corpus deste trabalho. Com os resultados obtidos, foi poss?vel entender que h? clareza sobre o que caracteriza uma rela??o afetiva entre os envolvidos no processo de ensino e aprendizagem em aulas experimentais do ensino em Qu?mica da Educa??o a dist?ncia (EaD). Al?m disso, ficou evidente, tamb?m, que o processo dial?gico no ensino-aprendizagem e na experimenta??o de Qu?mica da educa??o superior a dist?ncia precisa se balizar em atitudes afetivas equilibradas, que valorizem o erro experimental e o respeito ?s m?ltiplas possibilidades de constru??o do conhecimento por movimentos de intera??o social, seja individuais e/ou coletivos
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26

Garlapati, Shravan Kumar Reddy. "Enabling Communication and Networking Technologies for Smart Grid." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/56629.

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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.
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27

Jorge, David Calhau. "Redes neurais artificiais aplicadas a proteção de sistemas elétricos de potência." Universidade de São Paulo, 1997. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-19012018-161622/.

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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.
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28

Husen, Khalid, and Mousa Fadi Imad. "Implementation Av Reläskyddssamverkan : En studie om en effektiv reläskyddssamverkan med hjälp av längsdifferentialskyddets kommunikationskanaler." Thesis, KTH, Hälsoinformatik och logistik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296485.

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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.
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29

Shih-chieh, Liao, and 廖世傑. "Design of a computer based distance relay." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/11268929604649396437.

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30

Chen-YuLu and 呂宸有. "A Study on Distance Relay Protection Setting for theLong-Distance Submarine Cable." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/4k66s3.

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碩士
國立成功大學
電機工程學系
103
The thesis aims to study the distance relay protection setting for the long-distance submarine cable. A case study based on the double-curcuit submarine cable linking Taiwan grid and Penghu renewable energy system is demonstrated. The power system simulation package PSS/E is utilized for system modeling and simulation analysis. The protection zones for the distance relay installed on the submarine cable is defined, also, the relay operating characteristic and associated system responses as a three phase ground fault occusr on the submarine cable in different protection zones are simulated. The feasibility of distance relay is also investigated. The research results reveal that the typical mho type distance relay can not offer a complete protection effect for the sake of ignoring the line-to-ground capacitance effect of long-distance submarine cale. Accordingly, a modified mho type distance relay taking the effect of cable capacitance into account is proposed, and it can be verified from the PSS/E simulation that the planning can provide a more complete protection in comparison with the typical one as fault occurs on the cable. The research can provide a reference for the planning of protection for long-distance submarine cable in the future.
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31

Lin, Jia-Renn, and 林家任. "The Effect of Load Models on the Setting of Distance Relay and Overcurrent Relay." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/06755666821207393956.

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碩士
國立臺北科技大學
電機工程系碩士班
89
The purpose of this thesis is to study the effect of load models on the setting of distance relay and overcurrent relay in the transmission system of Taipower. Five suitable load models for the Taipower system are adopted here in order to discuss the effect of the load characteristics on the setting of the relay during the incident, as a basis for setting the standard for the protective relay: (1) Static ZIP model; (2) Dynamic Motor model; (3) Composite model; (4) PTI IEEE model; (5) Exponential model. In distance protection, the main concerns are on the setting of the impedance value for the three protective zone of the distance relay and the protection against out-of-step in the outermost periphery; whether the load models will cause a malfunction in the distance relay when the system swings due to a sudden change in the power system; an analysis on the swing of the power system in coordination with the blocking time of out-of-step; and a simulation of the effect of the blocking time of out-of-step using actual values of conditions for setting the blocking time from experiences. In overcurrent protection, the main concerns are using the fault current to set relay’s tap value and the plotting of characteristic curve to probe into the overcurrent relay’s effect of load models. It is expected that the overcurrent relay can be rapidly separate or clear the fault current during the time of the accident happen, in order to lower the damage caused by the accident and maintain the stability of the power supply of the power system.
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32

KUMAR, RAKESH. "ZONE PROTECTION SYSTEM OF TRANSMISSION LINE BY DISTANCE RELAY." Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16977.

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In this thesis design and modeling of Distance Relay has been done using MATLAB-SIMULINK. When microprocessor technology was implemented in the relay designing technique it gave birth to a new type of protection methodology known as Numerical relay. Numerical relays can interact with the peripheral devices and other numerical relays also, resulting in overall economy of the protection system equipments. A power system network and the distance relay model has been developed and the response of the distance relay has been verified by plotting the data generated by the relay on R-X diagram. The input voltage and current signal from the power system network contains dc offset values and higher order harmonics these are the unwanted quantities of the signal which need to be filtered out for proper functioning of the relay, Discrete Fourier Transform (DFT) can easily isolate these unwanted quantities from the signals. DFT has been used for the designing of the proposed distance relay. This report tells about the necessities of this relays in a power system and why these are so important for generator only and why not for others. This model in Simulink is treated with different types of faults such as line and ground fault. This report also tells about the brief discussion about the excitation system relating to the generator protection and coordinating with other devices.
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33

(12214559), Sonal Chawda. "Determination of distance relay characteristics using an inductive learning system." Thesis, 1993. https://figshare.com/articles/thesis/Determination_of_distance_relay_characteristics_using_an_inductive_learning_system/19326599.

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In this research an attempt has been made to design distance relays as per protection system requirements. This is achieved by using an Inductive learning technique. The inductive learning algorithm which belongs to the family of machine learning by examples is used to convert a set of impedance values into a decision tree. The impedance values are obtained by conducting fault study on the system to be protected. A number of tests have been carried out on various transmission line configurations. The required software for generating the
decision tree has been developed.
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34

SINGH, AJIT KUMAR. "MODELING AND SIMULATION OF DISTANCE RELAY FOR POWER SYSTEM PROTECTION." Thesis, 2016. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15303.

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In the present thesis work design and modeling of Distance Relay has been done using MATLAB-SIMULINK. When microprocessor technology was implemented in the relay designing technique it gave birth to a new type of protection methodology known as Numerical relay. Numerical relays can interact with the peripheral devices and other numerical relays also, resulting in overall economy of the protection system equipments. A power system network and the distance relay model has been developed and the response of the distance relay has been verified by plotting the data generated by the relay on R-X diagram. The input voltage and current signal from the power system network contains dc offset values and higher order harmonics these are the unwanted quantities of the signal which need to be filtered out for proper functioning of the relay Discrete Fourier Transform (DFT) can easily isolate these unwanted quantities from the signals. DFT has been used for the designing of the proposed distance relay.
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35

Lin, Tzu-Chiao, and 林子喬. "The Design and Analysis of Digital Distance Relay Based on FPGA." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/17649057744776649411.

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碩士
國立高雄應用科技大學
電機工程系碩士班
92
This thesis proposes an approximated method to simulate and design the functions of distance relay (impendence relay) to efficiently detect the three-phase balanced fault on the transmission line, as well as to analyze the reach of digital distance relay in three types of power system models. Based on the proposed methodology, the FPGA technique is applied to design and implement the digital distance relay. Finally, a sensitivity analysis is applied to discuss the effect of grounding impedance, voltage source ratio to the value of relay terminal impedance and then the modified error is introduced to improve the ability of fault location detection. There are two purposes in this thesis. The first purpose of this thesis is to utilize the MATLAB package to run the power flow and fault calculation to obtain the parameters of voltage, current and then impedance at relay location with respect to different faulted located along the transmission line. Based on the simulation results, the relationship between relay measured impedance and faulted location (impedance) can easily be established. Several extreme cases in different faulted location are simulated to establish the exact protection area. In the case of occurring faults on transmission line, the proposed approach can efficiently detect the fault situation and can estimate the faulted location. The second purpose of this thesis is to apply FPGA XC2s200 chip and their peripheral produced by Xilinx corp. and local Zeppe corp. respectively to finish the design procedures of synthesis, justification, simulation, pin assignment, generating program, and program download for FPGA. Finally the verification for the FPGA design shows that the better performance and the effectiveness of the proposed methodology can be achieved.
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36

Srivastava, Sachin. "Behavior of Distance Relay Characteristics on Interconnecting Lines Fed From Wind Farms." Thesis, 2015. https://etd.iisc.ac.in/handle/2005/3539.

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Distance relays due to their selectivity and operating speed are used in HV/EHV line protection. The dynamic nature of Mho characteristic, which happens to be most primitive technique in line protection implemented with distance relaying, is built by using the measurement of local voltage and current signals. These signals have been influenced substantially by fault resistance and the source impedance feeding the line. In case of different generation sources, the source impedance and fault characteristic also change accordingly. Environmental benefit of wind turbine technology is making it a potential source of energy. These wind turbine-generating units (WTGU) use rugged induction/synchronous machines along with power electronics converters as controlling equipment. This gives a new challenge to distance relays, as the fault current contribution of these sources depends on the converter operational principle. In this thesis a typical wind farm of Indian systems are modeled in an IN-HOUSE tool developed as part of fault analysis on wind farm system. Directly connected and front-end converter based wind turbines with their interconnections are modeled in this simulation tool. Fault voltage and current waveforms are obtained for all types of wind turbine-generating units with both radial and LILO (Loop in Loop out) connection. PSCAD based modeling has been done for DFIG type of wind turbines. The fault waveforms are generated to evaluate relay performance. Five case studies having both Radial and Loop in Loop out (LILO) connection of wind farms are simulated. These case studies generate approximately 20000 cases, which are analyzed for distance relay performance studies. In addition, the analysis is further verified on relay hardware having three characteristics, namely Self Polarized Mho (SPM), Quadrature Polarized Mho (QPM) and Quadrilateral (QUAD) characteristics. The detailed studies are carried out in this thesis to ensure and suggest the system operators with appropriate relay characteristics to be used for transmission line protection in the case of wind farms interconnected to Grid. Based on the studies carried out in the thesis, LILO connection has no impact on distance relay characteristic. In radially connected wind farms, grid side relay will operate reliably for all types of faults. It has been recommended in the thesis that wind farm side distance relay characteristics should be adjusted based on the types of wind turbines (Type-1, Type-2, Type-3 and Type-4). Based on the investigations carried out in the thesis, voltage based phase selector has been recommended for Type-4 WTGU based wind farms.
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37

Srivastava, Sachin. "Behavior of Distance Relay Characteristics on Interconnecting Lines Fed From Wind Farms." Thesis, 2015. http://etd.iisc.ernet.in/2005/3539.

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Distance relays due to their selectivity and operating speed are used in HV/EHV line protection. The dynamic nature of Mho characteristic, which happens to be most primitive technique in line protection implemented with distance relaying, is built by using the measurement of local voltage and current signals. These signals have been influenced substantially by fault resistance and the source impedance feeding the line. In case of different generation sources, the source impedance and fault characteristic also change accordingly. Environmental benefit of wind turbine technology is making it a potential source of energy. These wind turbine-generating units (WTGU) use rugged induction/synchronous machines along with power electronics converters as controlling equipment. This gives a new challenge to distance relays, as the fault current contribution of these sources depends on the converter operational principle. In this thesis a typical wind farm of Indian systems are modeled in an IN-HOUSE tool developed as part of fault analysis on wind farm system. Directly connected and front-end converter based wind turbines with their interconnections are modeled in this simulation tool. Fault voltage and current waveforms are obtained for all types of wind turbine-generating units with both radial and LILO (Loop in Loop out) connection. PSCAD based modeling has been done for DFIG type of wind turbines. The fault waveforms are generated to evaluate relay performance. Five case studies having both Radial and Loop in Loop out (LILO) connection of wind farms are simulated. These case studies generate approximately 20000 cases, which are analyzed for distance relay performance studies. In addition, the analysis is further verified on relay hardware having three characteristics, namely Self Polarized Mho (SPM), Quadrature Polarized Mho (QPM) and Quadrilateral (QUAD) characteristics. The detailed studies are carried out in this thesis to ensure and suggest the system operators with appropriate relay characteristics to be used for transmission line protection in the case of wind farms interconnected to Grid. Based on the studies carried out in the thesis, LILO connection has no impact on distance relay characteristic. In radially connected wind farms, grid side relay will operate reliably for all types of faults. It has been recommended in the thesis that wind farm side distance relay characteristics should be adjusted based on the types of wind turbines (Type-1, Type-2, Type-3 and Type-4). Based on the investigations carried out in the thesis, voltage based phase selector has been recommended for Type-4 WTGU based wind farms.
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38

Bheemraj, T. S. "Prediction and Prevention of Load Encroachment for Reliable Operation of Distance Relay." Thesis, 2017. http://ethesis.nitrkl.ac.in/8939/1/2017_MT_TSBheemraj.pdf.

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Electric power systems are complex and commonly run near their operational limits. In power systems, total or partial blackouts are unavoidable. A distance relay can provide remote backup protection by zones 2 and 3, but may mal-operate under heavy loading conditions and cause cascading trips in the network, which could further lead to a widespread blackout. Usually, load blinders or load encroachment elements block the distance relay when there is a heavy load in the system. The improved protection technique for zone 3 prevents mal-operation and, thus, power systems become more reliable. The most of the improved techniques prevents the load encroachment by blocking the performance of distance relay. Also those techniques don’t provide solution to reduce the loading limits. In the research project, the increment of load is predicted from the load curve. If the load approaches the relay characteristics, the load on that particular line is reduced by optimal scheduling of generators or loads or both. The load encroachment phenomenon is not allowed to occur, before the load encroaches the action is taken preventing distance relay from tripping.
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39

Lee, Chen-Hui, and 李振輝. "Researches on Maximum Transmission Distance and Relay Grouping Algorithm over Cooperative Communication Systems." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/84074391017793009707.

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碩士
國立暨南國際大學
電機工程學系
102
With a higher system performance, the cooperative communication has been wildly discussed among the recent researches. Concerning within the relay location and the power allocation in the cooperative communications, the major purpose of this work is to evaluate the system performance under the related limitation. According to the theoretical derivation and simulation results, one can find that the diversity gain in the communication could be obtained with the relay station in decode and forward mode. While the path loss from the source station to destination station is large, the relay station could benefit to the transmission performance. Besides, concerning of propagation distance from the source station to destination station, this work adopts the outage probability as the threshold and analyzes the maximum transmission length. The relay deploy scheme could be applied with this significant consequence. Moreover, applied the cooperative communication to the satellite system, this work evaluates the three relay-destination matching schemes. The probability of successful matching depends on the number of destination stations. This work contributes the cooperative communication with the tradeoff between the relay location and the power allocation. Also, the research on maximum transmission length in the cooperative communication system could provide an important reference to the relay deploy schemes.
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40

Lin, Yu-liang, and 林裕梁. "Computer-Aided Calculation and Setting for Zone-2 Distance Relay Protection of Transmission Line." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/vzuz4e.

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碩士
國立臺灣科技大學
電機工程系
95
In Taiwan, the main protection scheme of transmission lines include current differential relay, distance relay and pilot wire relay. The backup protection scheme of transmission lines include three zone distance relay and directional overcurrent relay. Among them, the settings of the backup protective relays need to be coordinated. According to the principle of the distance relay settings at present, this paper plans to use the relay settings coordination theory, the network admittance matrix abbreviation and the fault current distribution calculation trying to develop the windowlizing calculating program of distance relay settings. Then using ASPEN software to simulate directional overcurrent relay settings to achieve the coordination between distance relays and directional overcurrent relays of the transmission line. This paper hopes to evaluate the coordination situation of the domestic transmission lines by computer procedure immediately and pinpoint the problems. Then studying the way to improve and providing more suitable approach of the Zone-2 setting of the distance relay. The results of the systematic simulation have been observed, up till now, that the influences of the apparent impedance caused by the infeed and outfeed effects can't be ignored, because the distributed generations are increasing. Or it will cause distance relays to make misjudgment whether the fault point is within the protection zone. this paper further considers the situation in case of one transmission line outage (N-1). The new Zone-2 setting can be used in more extensive power system structure and needn’t change the settings when one transmission line outage temporary. From the results of this paper, the promotion of the Zone-2 protection zone also be observed. So that the approach can be the reference when revising the principle of the distance relay settings at present.
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41

Yang, Chih-Chiao, and 楊智喬. "Relay Selection Schemes Based on Channel Gain and Distance Information for Cooperative Wireless Networks." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/56625675987416100801.

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Abstract:
碩士
國立清華大學
通訊工程研究所
97
In wireless networks, cooperative relaying is an emerging technique that provides spatial diversity in an alternative way. With the help of relays, the source has more opportunities to transmit its data to the destination; in other words, the increased degrees of freedom due to relays can be utilized to combat channel impairments effectively. Therefore, how to choose the optimal relay among a set of available relays for meeting some requirements naturally becomes a critical issue. Recently, various relay selection schemes being proposed aim at choosing one and the best relay in cooperative wireless networks. Some of them require a lot of channel estimations to achieve full diversity order; some of them, on the other hand, avoid high computational complexity as well as frequent channel estimations, but the diversity order is reduced to 2 only. It is the trade-off between the system performance and complexity. In this thesis, we propose two relay selection schemes which need the partial channel state information (CSI), including instantaneous channel power and distance information, to improve the system performance and reduce the system complexity, compared to the existing work. Simulation results demonstrate that the proposed relay selection schemes can achieve better SER performance than the geographic-based scheme and worse SER performance than the instantaneous channel-gain-based scheme.
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42

Dubey, Rahul Kumar. "Adaptive distance relay setting for transmission lines in presence Of UPFC and wind farms." Thesis, 2012. http://ethesis.nitrkl.ac.in/4073/1/My-M.Tech-Thesis2.pdf.

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Abstract:
This thesis presents an adaptive distance relay setting for transmission lines with Unified Power Flow Controller (UPFC) and wind farms together. The ideal trip characteristics of distance relay is greatly affected in presence of UPFC in transmission lines as the apparent impedance is significantly affected. Similarly, the reach setting of the relay for the lines connecting wind farms is significantly affected as the relay end voltage fluctuates continuously. Thus, the proposed study focus on developing adaptive relay setting for transmission lines including both UPFC and wind farms considering variations in operating conditions of UPFC as well as wind farms together.
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43

Lin, Heng-An, and 林恆安. "Protection Zone Planning of Distance Relay for the Long Submarine Cables of Large Offshore Wind Farm." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/mwv45j.

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Abstract:
碩士
國立臺北科技大學
電機工程系所
102
This thesis is to study the protection zone planning of distance relays for long submarine cables of large offshore wind farm. A case study based on Tai-Peng submarine cables of Peng-Hu offshore wind farm with type-C double-fed induction wind generators is presented. A software package namely PSS/E is used for the modeling and simulation. Three protection zones are defined for submarine cable distance relays and the three phase short circuit (3ΦSC) fault characteristics of different protection zones are simulated under different wind farm operation situations. The availabilities of distance relays are surveyed including to find the defects of conventional planning and to proposed improved planning of protection zones. The study results show that the conventional quadrilateral distance relay can not provide sufficient protection for long submarine cables because of neglecting the effects of cable capacitances and the variations of wind farm operation. Therefore, a novel quadrilateral protection zone for distance relay is panned considering the effects of cable capacitances and the variations of wind farm operation. The availabilities of proposed planning had been certified by PSS/E simulation, which is also a good reference for the planning of long cable protection coordination.
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44

Maturu, Suresh. "Performance Evaluation Of Distance Relays For FACTS Compensated Transmission Lines." Thesis, 2011. https://etd.iisc.ac.in/handle/2005/2084.

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Abstract:
With limited enhancement or expansion of the transmission infrastructure, the contemporary power systems are operating under more stressed conditions. It becomes important to fully utilize the existing transmission system to supply load demand as much as possible, thus eliminating or reducing the need for new transmission investment. Flexible AC Transmission System (FACTS) technology provides an alternative to fully utilize the existing transmission lines as well as new and upgraded lines, by controlling power and also enhancing the power transfer capability of transmission lines. However, the implementation of FACTS controllers in the transmission system has introduced new power system dynamics that must be addressed in the area of power system protection, such as rapid changes in line impedance, power angle, line currents, transients introduced by the occurrence of fault and associated control action of the FACTS controller. Therefore, the performance of the protection system must be carefully analyzed in the presence of FACTS controllers. The thesis aims at evaluating the performance of distance relays when different types of FACTS controllers, in particular Voltage Source Converter (VSC) based FACTS controllers, are incorporated at the midpoint of the transmission system to achieve voltage profile improvement and power transfer capability. The detailed models of these controllers and their control strategies are described. The presence of FACTS controllers in the loop affects both steady state and transient components of voltage and current signals. The rapid response of FACTS controllers to different power system configurations significantly affects the apparent impedance seen by distance relays. The apparent impedance seen by distance relays would be different from that of the system without FACTS controller. Due to this, the distance relay may malfunction, resulting in unreliable operation of the power system during faults. Furthermore, the effect of FACTS controllers on distance relay operation depends on the type of FACTS controller used, the application for which it has been installed and its location in the power system. The distance relay is evaluated for different loading conditions and for various fault conditions. Simulation studies are carried out using PSCAD/EMTDC based transient simulation package.
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45

Maturu, Suresh. "Performance Evaluation Of Distance Relays For FACTS Compensated Transmission Lines." Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/2084.

Full text
Abstract:
With limited enhancement or expansion of the transmission infrastructure, the contemporary power systems are operating under more stressed conditions. It becomes important to fully utilize the existing transmission system to supply load demand as much as possible, thus eliminating or reducing the need for new transmission investment. Flexible AC Transmission System (FACTS) technology provides an alternative to fully utilize the existing transmission lines as well as new and upgraded lines, by controlling power and also enhancing the power transfer capability of transmission lines. However, the implementation of FACTS controllers in the transmission system has introduced new power system dynamics that must be addressed in the area of power system protection, such as rapid changes in line impedance, power angle, line currents, transients introduced by the occurrence of fault and associated control action of the FACTS controller. Therefore, the performance of the protection system must be carefully analyzed in the presence of FACTS controllers. The thesis aims at evaluating the performance of distance relays when different types of FACTS controllers, in particular Voltage Source Converter (VSC) based FACTS controllers, are incorporated at the midpoint of the transmission system to achieve voltage profile improvement and power transfer capability. The detailed models of these controllers and their control strategies are described. The presence of FACTS controllers in the loop affects both steady state and transient components of voltage and current signals. The rapid response of FACTS controllers to different power system configurations significantly affects the apparent impedance seen by distance relays. The apparent impedance seen by distance relays would be different from that of the system without FACTS controller. Due to this, the distance relay may malfunction, resulting in unreliable operation of the power system during faults. Furthermore, the effect of FACTS controllers on distance relay operation depends on the type of FACTS controller used, the application for which it has been installed and its location in the power system. The distance relay is evaluated for different loading conditions and for various fault conditions. Simulation studies are carried out using PSCAD/EMTDC based transient simulation package.
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46

Lin, Chao-Ting, and 林昭廷. "Research on Adaptive Setting and Simulation of Distance Protection Relay in a Long Transmission System Connected to an Offshore Wind Farm." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/81592839289930777037.

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Abstract:
碩士
國立中正大學
電機工程研究所
103
Offshore wind power has become the focus of the world’s renewable energy development. In Taiwan, several demonstration offshore wind turbines will be scheduled to be established by 2015, and more than 300MW capacity of offshore wind farm to be installed by 2020. As the penetration level of wind energy increases, more reliable protection systems for offshore wind farms are required. The wind farm protection system is usually divided into different protection zones including the wind farm area, wind farm collection system, wind farm interconnection system and the utility area. Different protective zones have different protection schemes and relay settings. This project has proposed an adaptive distance relay that protects submarine cables between an offshore wind farm and an AC grid. The double-circuit submarine cables that connect offshore wind farm in Penghu and Taiwan grid will be utilized as an example. First, the apparent impedance of the relay is mathematically derived using a detailed equivalent circuit model, and the characteristic trip boundaries of the relay in various scenarios are obtained. The nonlinear characteristics of the trip boundaries that are used in a typical distance relay with four protection zones will be discussed. Furthermore, the effects of the uncontrollable factors on the performance of a distance relay have been considered into the simulations. These system disturbances include wind speed variation, system short circuit faults, or system component failures. These case studies have been presented using the simulation package to evaluate the feasibility of the distance relay setting that is developed in this project.
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47

Liao, Jyun-Da, and 廖俊達. "Implementation and Testing of Digital Distance Relays." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/52179789648923841566.

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Abstract:
碩士
國立臺灣大學
電機工程學研究所
93
This paper capitalizes the commercialized production of DSP (digital signal process)chip， and make use of digital distance algorithm to realize digital distance relays. When a fault occurs on line during operation， the signals of voltage and current would be severely distorted. These signals may contain decaying dc components. It could seriously influence the judgment and accuracy of relays. For the purpose of achieving the goal of fast response， relays have to quickly obtain the fundamental signals of voltage and current from the input signal containing noise. This paper accomplishes COSFilter by TMS320VC33 DSP，simulation and verify to realize the digital distance relays.
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48

Bhimasingu, Ravikumar. "Intelligent Systems Applications For Improving Power Systems Security." Thesis, 2009. https://etd.iisc.ac.in/handle/2005/1031.

Full text
Abstract:
Electric power systems are among the most complex man made systems on the world. Most of the time, they operate under quasi-steady state. With the ever increasing load demand and the advent of the deregulated power market recently, the power systems are pushed more often to operate close to their design limits and with more uncertainty of the system operating mode. With the increasing complexity and more interconnected systems, power systems are operating closer to their performance limits. As a result, maintaining system security and facilitating efficient system operation have been challenging tasks. Transmission systems are considered the most vital components in power systems connecting both generating/substation and consumer areas with several interconnected networks. In the past, they were owned by regulated, vertically integrated utility companies. They have been designed and operated so that conditions in close proximity to security boundaries are not frequently encountered. However, in the new open access environment, operating conditions tend to be much closer to security boundaries, as transmission use is increasing in sudden and unpredictable directions. Transmission unbundling, coupled with other regulatory requirements, has made new transmission facility construction more difficult. Unfortunately these transmission lines are frequently subjected to a wide variety of faults. Thus, providing proper protective functions for them is essential. Generally the protection of Extra High Voltage (EHV) and Ultra High Voltage (UHV) transmission lines are carried out by the use of distance relays in view of the fact that they provide fast fault clearance and system coordination. Transmission line relaying involves detection, classification and location of transmission line faults. Fast detections of faults enable quick isolation of the faulty line from service and hence, protecting it from the harmful effects of fault. Classification of faults means identification of the type of fault and faulted line section, and this information is required for finding the fault location and assessing the extent of repair work to be carried out. Accurate fault location is necessary for facilitating quick repair and restoration of the line, to improve the reliability and availability of the power supply. Generally, the protection system using conventional distance relaying algorithm involves three zones. The first zone (Z1) of the relay is set to detect faults on 80%90% of the protected line without any intentional time delay. The second zone (Z2) is set to protect the remainder of the line plus an adequate margin. Second zone relays are time delayed for 1530 cycles to coordinate with relays at remote bus. The settings of the third zone (Z3) ideally will cover the protected line, plus all of the longest line leaving the remote station. Z3 of a distance relay is used to provide the remote backup protection in case of the failure of the primary protection. Since Z3 covers an adjacent line, a large infeed (outfeed) from the remote terminal causes the relay to underreach (overreach). Thus, a very large load at the remote terminal may cause distance relays to mal-operate. Settings for conventional distance relays are selected to avoid overreach/underreach operation under the worst case scenarios. Studies of significant power system disturbances reported by North American Electric Reliability Council (NERC) indicate that protective relays are involved, one way or another, in 75% of the major disturbances and the most troublesome ones are backup protection relays. With their limited view of the interconnected network based on their locally measured inputs, conventional backup protection relays generally take actions to protect a localized region of the network without considering the impact on the whole network. Relay mal-operations or unintended operations due to overload, power swing, and relay hidden failure are the main factors contributing to the blackouts. Most of the problems are associated with relays tripping too many healthy lines. Since a relay makes the decision automatically to remove a component from the system according to its internal mechanism, the relay mal-operation or unintended operation can make an effective influence on the system stability. Approaches to reduce the relay misbehavior need to be identified. Real time monitoring tools to assess the relay misbehavior are needed, providing the system operator, the accurate information about unfolding events. Existing transmission line protection scheme still has drawbacks. Advanced fault analysis mechanism to enhance the system dependability and security simultaneously is desirable. Relay settings play a significant role in major blackouts. So correct settings should be calculated and coordinated by suitable studies. Attempts are to be made to employ highly accurate AI techniques in protective system implementation. The research work focussed on developing knowledge based intelligent tools for the improving the transmission system security. A process to obtain knowledgebase using SVMs for ready post-fault diagnosis purpose is developed. SVMs are used as Intelligent tool for identifying the faulted line that is emanating from a substation and finding the distance from the substation. The approach uses phasor values of the line voltages and currents after the fault has been detected. The approach is particularly important for post-fault diagnosis of any mal-operation of relays following a disturbance in the neighboring line connected to the same substation. This may help in improving the fault monitoring/diagnosis process and coordination of the protective relays, thus assuring secure operation of the power systems. The approach based on SVMs, exploits the first part of this goal. For comparison, a classifier and regression tools based on the RBFNNs was also investigated. The RBFNNs and SVM networks are introduced and considered as an appropriate tool for pattern recognition problems. Results on a practical 24Bus equivalent EHV transmission system of Indian Southern region and on IEEE39 bus New England system are presented to illustrate the proposed method. In a large connected power network, the number of generators are more in number and their set patterns number will be large. As the line flows are sensitive to generator set patterns, it is difficult to consider all the combinations of generators while simulating the training and testing patterns as input to SVMs. To simulate the training and testing patterns corresponding to possible changes in line flows to meet the load in the present deregulated environment, line flow sensitive generators set to be identified/merit-listed. In this regard, to identify the most sensitive generators for a particular line of interest, a method from the literature is adopted and developed a software program based on the graph theory concepts. Case studies on generator contributions towards loads and transmission lines are illustrated on an equivalent 33bus system, a part of Indian Northern grid with major part of Uttar Pradesh and also with an equivalent 246bus system of practical Indian Southern grid. A distance relay coordination approach is proposed using detailed simulation studies, taking into account various operating conditions and fault resistances. Support Vector Machines as a pattern classifier is used for obtaining distance relay coordination. The scheme uses the apparent impedance values observed during fault as inputs. SVMs are used to build the underlying concept between reach of different zones and the impedance trajectory during fault. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as line flow changes are illustrated with an equivalent 246bus system of practical Indian Southern grid and also with an equivalent 265bus system of practical Indian Western grid. A strategy of Supportive System is described to aid the conventional protection philosophy in combating situations where protection systems are mal-operated and/or information is missing and provide selective and secure coordination. Highly accurate identification/discrimination of zones plays a key role in effective implementation of the region-wide supportive system. This typically requires a multiclass SVM classifier to effectively analyze/build the underlying concept between reach of different zones and the apparent impedance trajectory during fault. Different multiclass methods are compared for their performance with respect to accuracy, number of iterations, number of support vectors, training and testing time. The performance analysis of these methods is presented on three data sets belonging to the training and testing patterns of three supportive systems for a region, part of a network, which is an equivalent 265bus system of practical Indian Western grid.
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49

Bhimasingu, Ravikumar. "Intelligent Systems Applications For Improving Power Systems Security." Thesis, 2009. http://hdl.handle.net/2005/1031.

Full text
Abstract:
Electric power systems are among the most complex man made systems on the world. Most of the time, they operate under quasi-steady state. With the ever increasing load demand and the advent of the deregulated power market recently, the power systems are pushed more often to operate close to their design limits and with more uncertainty of the system operating mode. With the increasing complexity and more interconnected systems, power systems are operating closer to their performance limits. As a result, maintaining system security and facilitating efficient system operation have been challenging tasks. Transmission systems are considered the most vital components in power systems connecting both generating/substation and consumer areas with several interconnected networks. In the past, they were owned by regulated, vertically integrated utility companies. They have been designed and operated so that conditions in close proximity to security boundaries are not frequently encountered. However, in the new open access environment, operating conditions tend to be much closer to security boundaries, as transmission use is increasing in sudden and unpredictable directions. Transmission unbundling, coupled with other regulatory requirements, has made new transmission facility construction more difficult. Unfortunately these transmission lines are frequently subjected to a wide variety of faults. Thus, providing proper protective functions for them is essential. Generally the protection of Extra High Voltage (EHV) and Ultra High Voltage (UHV) transmission lines are carried out by the use of distance relays in view of the fact that they provide fast fault clearance and system coordination. Transmission line relaying involves detection, classification and location of transmission line faults. Fast detections of faults enable quick isolation of the faulty line from service and hence, protecting it from the harmful effects of fault. Classification of faults means identification of the type of fault and faulted line section, and this information is required for finding the fault location and assessing the extent of repair work to be carried out. Accurate fault location is necessary for facilitating quick repair and restoration of the line, to improve the reliability and availability of the power supply. Generally, the protection system using conventional distance relaying algorithm involves three zones. The first zone (Z1) of the relay is set to detect faults on 80%90% of the protected line without any intentional time delay. The second zone (Z2) is set to protect the remainder of the line plus an adequate margin. Second zone relays are time delayed for 1530 cycles to coordinate with relays at remote bus. The settings of the third zone (Z3) ideally will cover the protected line, plus all of the longest line leaving the remote station. Z3 of a distance relay is used to provide the remote backup protection in case of the failure of the primary protection. Since Z3 covers an adjacent line, a large infeed (outfeed) from the remote terminal causes the relay to underreach (overreach). Thus, a very large load at the remote terminal may cause distance relays to mal-operate. Settings for conventional distance relays are selected to avoid overreach/underreach operation under the worst case scenarios. Studies of significant power system disturbances reported by North American Electric Reliability Council (NERC) indicate that protective relays are involved, one way or another, in 75% of the major disturbances and the most troublesome ones are backup protection relays. With their limited view of the interconnected network based on their locally measured inputs, conventional backup protection relays generally take actions to protect a localized region of the network without considering the impact on the whole network. Relay mal-operations or unintended operations due to overload, power swing, and relay hidden failure are the main factors contributing to the blackouts. Most of the problems are associated with relays tripping too many healthy lines. Since a relay makes the decision automatically to remove a component from the system according to its internal mechanism, the relay mal-operation or unintended operation can make an effective influence on the system stability. Approaches to reduce the relay misbehavior need to be identified. Real time monitoring tools to assess the relay misbehavior are needed, providing the system operator, the accurate information about unfolding events. Existing transmission line protection scheme still has drawbacks. Advanced fault analysis mechanism to enhance the system dependability and security simultaneously is desirable. Relay settings play a significant role in major blackouts. So correct settings should be calculated and coordinated by suitable studies. Attempts are to be made to employ highly accurate AI techniques in protective system implementation. The research work focussed on developing knowledge based intelligent tools for the improving the transmission system security. A process to obtain knowledgebase using SVMs for ready post-fault diagnosis purpose is developed. SVMs are used as Intelligent tool for identifying the faulted line that is emanating from a substation and finding the distance from the substation. The approach uses phasor values of the line voltages and currents after the fault has been detected. The approach is particularly important for post-fault diagnosis of any mal-operation of relays following a disturbance in the neighboring line connected to the same substation. This may help in improving the fault monitoring/diagnosis process and coordination of the protective relays, thus assuring secure operation of the power systems. The approach based on SVMs, exploits the first part of this goal. For comparison, a classifier and regression tools based on the RBFNNs was also investigated. The RBFNNs and SVM networks are introduced and considered as an appropriate tool for pattern recognition problems. Results on a practical 24Bus equivalent EHV transmission system of Indian Southern region and on IEEE39 bus New England system are presented to illustrate the proposed method. In a large connected power network, the number of generators are more in number and their set patterns number will be large. As the line flows are sensitive to generator set patterns, it is difficult to consider all the combinations of generators while simulating the training and testing patterns as input to SVMs. To simulate the training and testing patterns corresponding to possible changes in line flows to meet the load in the present deregulated environment, line flow sensitive generators set to be identified/merit-listed. In this regard, to identify the most sensitive generators for a particular line of interest, a method from the literature is adopted and developed a software program based on the graph theory concepts. Case studies on generator contributions towards loads and transmission lines are illustrated on an equivalent 33bus system, a part of Indian Northern grid with major part of Uttar Pradesh and also with an equivalent 246bus system of practical Indian Southern grid. A distance relay coordination approach is proposed using detailed simulation studies, taking into account various operating conditions and fault resistances. Support Vector Machines as a pattern classifier is used for obtaining distance relay coordination. The scheme uses the apparent impedance values observed during fault as inputs. SVMs are used to build the underlying concept between reach of different zones and the impedance trajectory during fault. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as line flow changes are illustrated with an equivalent 246bus system of practical Indian Southern grid and also with an equivalent 265bus system of practical Indian Western grid. A strategy of Supportive System is described to aid the conventional protection philosophy in combating situations where protection systems are mal-operated and/or information is missing and provide selective and secure coordination. Highly accurate identification/discrimination of zones plays a key role in effective implementation of the region-wide supportive system. This typically requires a multiclass SVM classifier to effectively analyze/build the underlying concept between reach of different zones and the apparent impedance trajectory during fault. Different multiclass methods are compared for their performance with respect to accuracy, number of iterations, number of support vectors, training and testing time. The performance analysis of these methods is presented on three data sets belonging to the training and testing patterns of three supportive systems for a region, part of a network, which is an equivalent 265bus system of practical Indian Western grid.
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50

Chung, Jarm-Long, and 鍾彰榮. "Exploring the Protective Coordination Problems of Overcurrent Relays and Distance Relays in Transmission Networks." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/xjce89.

Full text
Abstract:
博士
國立臺北科技大學
電機工程系所
98
The protective coordination provided by protective relays in the transmission systems is important for power safety and quality. Overcurrent relays are mainly used in protecting the subtransmission and distribution systems. In practice, the coordination curve intersection of a downstream and upstream relay pair will cause unexpected augmentation of the blackout area as a fault occurs in the downstream relay side. In addition, in a single ring or a complex low voltage power transmission network with many buses cascaded, expensive power equipments would be damaged due to long operating times of relays when a fault occurs in a transmission line. EHV and HV transmission networks usually employ distance relays as protective devices. In practice, miscalculation of the apparent impedance and the short length of a transmission line are two major problems encountered in the distance relay protective coordination. In this thesis, these problems are investigated and the preceding protective coordination the novel approache mothod are proposed to effectively solve the improper coordination.
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