Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-06T21:17:06Z No. of bitstreams: 1 SergioGomesCavalcante_DISSERT.pdf: 2152523 bytes, checksum: 2c09534044f4a7214627c3d49f0aaa8e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-20T23:59:14Z (GMT) No. of bitstreams: 1 SergioGomesCavalcante_DISSERT.pdf: 2152523 bytes, checksum: 2c09534044f4a7214627c3d49f0aaa8e (MD5) / Made available in DSpace on 2017-11-20T23:59:14Z (GMT). No. of bitstreams: 1 SergioGomesCavalcante_DISSERT.pdf: 2152523 bytes, checksum: 2c09534044f4a7214627c3d49f0aaa8e (MD5) Previous issue date: 2017-07-28 / O modelo de sistema el?trico introduzido no Brasil no final da d?cada de 90 produziu um ambiente com alto grau de regula??o. A cria??o da Ag?ncia Nacional de Energia El?trica (ANEEL) e suas regras for?am os agentes envolvidos nesse sistema a sempre procurarem a modicidade tarif?ria com um n?vel elevado de qualidade do servi?o e qualidade do produto. Estas exig?ncias impostas ?s concession?rias de energia no Brasil fazem com que as empresas desenvolvam processos para uma melhoria constante, mas nem sempre essas estrat?gias s?o suficientes para garantir bons indicadores de qualidade. Por vezes o processo n?o mant?m uma sincronia ideal a ponto de evitar falhas em sua execu??o. Outras vezes, as falhas n?o est?o nos processos em si, mas nos pr?prios equipamentos. Como exemplo, podem ser citadas as programa??es de manuten??o preventiva que s?o desenvolvidas em alguns equipamentos de uma subesta??o. Ainda podem ser citadas, as falhas intempestivas que para serem corrigidas ? necess?rio que a informa??o correta, percorra os canais de comunica??o de forma r?pida e precisa chegando at? aos respons?veis pela manuten??o. Nem sempre as informa??es certas chegam aos setores respons?veis com rapidez e precis?o, somado a isso, estas informa??es n?o s?o armazenadas e catalogadas para analises futuras. O presente projeto tem como objetivo fundamental dotar os disjuntores, equipamentos do sistema de prote??o, de intelig?ncia, por meio de um sistema embarcado. Com esta associa??o, os disjuntores ser?o capazes de desempenhar suas funcionalidades com rapidez e assertividade nos dados gerados, podendo antecipar-se ?s falhas tornando o sistema el?trico mais confi?vel e seguro. / The Electric Power System model introduced in Brazil in the late 1990s produced a scenario with a high regulation level. The Ag?ncia Nacional de Energia El?trica (ANEEL) creation and its rules force the agents involved in that system to always seek the low tariffs with a high quality level of service and product quality. The requirements imposed on Brazilian Power Utilities result in the development of processes that allow a continuous improvement. Nevertheless, these strategies are not always sufficient to ensure good quality indicators. Many times, the processes do not hold a perfect synchrony to the point of avoiding execution failures. Other times, the failures are not in the processes, but in the equipment that are objective of the existence of the processes. As an example the preventive maintenance schedules that are developed in certain equipment of a Substation. Another example, unscheduled failures to be corrected is necessary that the correct information, scroll through the channels of communication to quickly and accurately reaching those responsible for maintenance. Correct information does not always reach the department quickly and accurately, but it is stored and cataloged for future analysis. This work aimed to reduce the DEC (Equivalent Duration of Interruption per Consumer Unit) indicator, improvement in maintenance planning and increase in the electrical installations? s safety level in a substation. By building an embedded system designed to monitor the main internal components of a circuit breaker. With the results achieved, it is concluded that the device provided in the project meets the objectives imposed, being able to perform its functions with speed and assertiveness in the data generated. The integration of this equipment into the circuit-breakers will allow anticipating the failures making the electrical system more reliable and safe.

Made available in DSpace on 2015-03-03T15:07:32Z (GMT). No. of bitstreams: 1 LivianeCAM.pdf: 2271497 bytes, checksum: 4d8763a73b7fec60ad7f311e565d45b3 (MD5) Previous issue date: 2008-11-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work presents contributions in the detection and identication of faults in multilevel inverters through the study of the converters behavior under these operation conditions. Basically, the approached fault consists of an open-circuit in any switch of a three-level clamped diode inverter. The converter operation is characterized in the pre and post-fault states. A wave form behavior analysis of the pole voltage, phase current and dc-bus current is also done, which highlights characteristics that allow the detection of failure and, even, under favorable conditions, the identication of the faulty device. A compensation strategy of the approached fault (open-switch) is also investigated with the purpose of maintaining the driving system operational when a failure occurs. The proposed topology uses SCRs in parallel with the internal switches of the inverter, which allows, in some occasions, the full utilization of the dc-bus / Este trabalho apresenta contribui??es para a detec??o e identica??o de faltas em inversores multin?veis, baseado no estudo do comportamento desse conversor sob essas condi??es de opera??o. Basicamente, a falta abordada consiste na abertura n?o comandada de uma das chaves de um inversor de tens?o de tr?s n?veis com diodos de grampeamento. O funcionamento do conversor ? caracterizado nos estados de pr? e p?s-falta. ?, tamb?m, feita uma an?lise dos comportamentos das formas de onda das tens?es de p?lo, corrente de fase e correntes do barramento CC, as quais apontam caracter?sticas que possibilitam detectar falta e, ainda, em condi??es favor?veis, identificar o dispositivo que apresentou defeito. Uma estrat?gia de compensa??o da falta abordada (chave aberta) tamb?m ? investigada, com o prop?sito de manter a continuidade de funcionamento do sistema de acionamento, quando da ocorr?ncia de uma falha. A topologia proposta utiliza SCRs em paralelo com as chaves internas do inversor, a qual permite, em algumas ocasi?es, a total utiliza??o do barramento CC