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Desenvolvimento da metodologia de avaliação do estado dos transformadores de potência da rede nacional de transporte
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 5.26 MB | Adobe PDF |
Authors
Abstract(s)
A segurança e a fiabilidade são aspetos críticos para qualquer operador da rede elétrica de
transporte, visto que uma falha no seu sistema elétrico pode afetar e comprometer um vasto
número de consumidores e equipamentos. Nas subestações da rede nacional de transporte,
os transformadores de potência são os equipamentos mais críticos, devido à função que
desempenham, ao seu valor económico e pelo seu carácter potencialmente muito perigoso,
em caso de falha. O envelhecimento da população destes equipamentos é uma das
principais preocupações por parte dos operadores de rede, visto que à medida que estes se
aproximam do seu fim de vida, a sua taxa de falhas tende a aumentar.
Neste trabalho é desenvolvida uma metodologia de avaliação de estado de vida dos
transformadores de potência existentes na rede nacional de transporte, com base nos
relatórios dos ensaios e inspeções realizadas. A metodologia desenvolvida consiste na
determinação de um indicador numérico, que permite classificar o estado dos
equipamentos e hierarquizar as prioridades de manutenção. Este indicador foca-se em
cinco vertentes de análise, de modo a quantificar o grau de degradação dos aspetos mais
críticos do transformador, nomeadamente a parte ativa, o papel e o óleo isolante, os
condutores dos enrolamentos e respetivas travessias.
De modo a suportar e validar o trabalho desenvolvido neste relatório, foi realizado um
levantamento do estado da arte dos processos de diagnóstico e avaliação de estado dos
transformadores, atualmente utilizados, bem como alguns conceitos relevantes à
metodologia aplicada, tais como os principais aspetos construtivos e componentes dos
transformadores de potência. Adicionalmente, foi também realizada uma análise de todas
as indisponibilidades, resultantes de falhas nos transformadores de potência da rede
nacional de transporte, nos últimos 15 anos.
Safety and reliability are critical aspects to any transmission system operator, since a failure in the electrical grid, could affect and compromise a large number of consumers and equipment. In the national transmission system substations, power transformers are the most critical equipment, due to the role they play, their economic value and their potentially very dangerous character, in case of failure. The power transformer’s aging population is a major concern to the system operators, because as they approach their life’s end, their failure rate tends to increase. This paper presents a health status assessment methodology of existing power transformers in the national transmission system, based on reports of performed tests and inspections. This methodology consists in the determination of a numeric indicator that allows to classify the equipment’s condition and rank maintenance priorities. This indicator focuses on five different forms of analysis, in order to quantify the degradation’s degree of the power transformer’s most critical aspects, namely the active part, the paper and oil insulation and the winding’s conductors and respective crossings. In order to support and validate the presented work, a study was conducted, regarding the state of the art diagnostic procedures and health evaluation methods of transformers, currently used, as well some relevant concepts to the presented methodology, such as the power transformer’s main constructive aspects and components. Additionally, it is also presented, an analysis of all the outages resulting from power transformer’s failures in the national transmission system, in the last 15 years.
Safety and reliability are critical aspects to any transmission system operator, since a failure in the electrical grid, could affect and compromise a large number of consumers and equipment. In the national transmission system substations, power transformers are the most critical equipment, due to the role they play, their economic value and their potentially very dangerous character, in case of failure. The power transformer’s aging population is a major concern to the system operators, because as they approach their life’s end, their failure rate tends to increase. This paper presents a health status assessment methodology of existing power transformers in the national transmission system, based on reports of performed tests and inspections. This methodology consists in the determination of a numeric indicator that allows to classify the equipment’s condition and rank maintenance priorities. This indicator focuses on five different forms of analysis, in order to quantify the degradation’s degree of the power transformer’s most critical aspects, namely the active part, the paper and oil insulation and the winding’s conductors and respective crossings. In order to support and validate the presented work, a study was conducted, regarding the state of the art diagnostic procedures and health evaluation methods of transformers, currently used, as well some relevant concepts to the presented methodology, such as the power transformer’s main constructive aspects and components. Additionally, it is also presented, an analysis of all the outages resulting from power transformer’s failures in the national transmission system, in the last 15 years.
Description
Keywords
Transformador de potência Avaliação de estado Índice de estado Gestão de vida útil Ensaios ao óleo Ensaios ao papel Ensaios dielétricos Rede nacional de transporte Power transformer Health status assessment Health status index Life management Oil tests Paper tests Dielectric tests National transmission system