Reducing dielectric fluid in current transformers via hybrid ester-gel insulation

This letter presents a novel hybrid dielectric system for current transformers (CTs) designed to reduce dielectric fluid volume while maintaining thermal and dielectric performance. The proposed approach incorporates a metallic joint bellow with a hybrid insulation scheme that employs synthetic este...

Descripción completa

Detalles Bibliográficos
Autores: Antolín Maestre, Ismael|||0009-0001-8820-1362, Alonso Martinez, Carlos Hernan, Hu, Zihao, Ortiz Fernández, Alfredo, De León Molina, Francisco
Tipo de recurso: artículo
Fecha de publicación:2026
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:dnet:ucreareposit::53812f01dfdbede5d64e1cdc8dde8a6b
Acceso en línea:https://hdl.handle.net/10902/40308
Access Level:acceso abierto
Palabra clave:Current transformers (CTs)
Dielectric system
Electric field analysis
Silicone gel
Synthetic ester
Thermal analysis
Descripción
Sumario:This letter presents a novel hybrid dielectric system for current transformers (CTs) designed to reduce dielectric fluid volume while maintaining thermal and dielectric performance. The proposed approach incorporates a metallic joint bellow with a hybrid insulation scheme that employs synthetic ester in the upper section and silicone gel in the bushing section of the CT. Numerical Finite Elements (FEM) simulations are conducted to evaluate the dielectric field distribution and thermal behavior under rated operation conditions. Results indicate that the bellow modification alone reduces the dielectric fluid volume by 16.4%, while the hybrid configuration achieves a total reduction of 36.5% when compared to the original design. Electric field simu-lations reveal a decrease of about 10% in maximum field intensi-ty in critical regions, attributed to the dielectric properties of the alternative materials. Thermal simulations confirm that the proposed configuration maintains equivalent heat dissipation to the original design (same hot spot value). The solution is techni-cally viable, allows material volume savings, and improves opera-tional reliability without any loss of performance.