Impact of the use of vegetable oil on the mechanical failure of the cellulosic insulation of continuously transposed conductors in power transformers

Natural esters have become of interest for the industry in recent years as dielectric liquids for power transformers, and many studies are focused on their dielectric and chemical properties and on their influence in the degradation of the solid insulation due to aging. However, very little is known...

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Detalles Bibliográficos
Autores: Oria Alonso, Carmela|||0000-0003-1014-4414, Méndez Gutiérrez, Cristina|||0000-0002-2845-216X, Carrascal Vaquero, Isidro Alfonso|||0000-0002-7045-1267, Ortiz Fernández, Alfredo, Ferreño Blanco, Diego|||0000-0003-3533-1881
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/24958
Acceso en línea:http://hdl.handle.net/10902/24958
Access Level:acceso abierto
Palabra clave:Accelerated aging
Failure analysis
Insulation
Materials testing
Mechanical behavior
Power transformers
Short circuits
Vegetable oils
Descripción
Sumario:Natural esters have become of interest for the industry in recent years as dielectric liquids for power transformers, and many studies are focused on their dielectric and chemical properties and on their influence in the degradation of the solid insulation due to aging. However, very little is known about their impact on the evolution of the mechanical properties of the paper insulation, which are acknowledged to have a considerable influence in their overall performance and reliability during the operating life of power transformers. This work studies the effects of thermal aging with vegetable oil in some commercial components, which are commonly used in power transformers, such as an insulated continuously transposed conductor (CTC) and samples of thermally upgraded crepe insulation. The changes in the properties of the crepe paper insulation are characterized through the degree of polymerization and tensile testing. Failure initiation and propagation in the insulation of the CTC is analyzed macroscopically. The results are compared with those obtained when using mineral oil, showing that the use of vegetable oil has a protective effect over mechanical properties of the studied types of paper insulation.