Multiscale Analysis of the Aging Process of Cable Insulation

Cables, transmitting both power and signal, are essential in electric power systems. Due to the combined effect of electromagnetic and thermal fields, cable insulation aging starts from the destruction of polymer molecular structure and deteriorates in the form of insulation defects, resulting in the degradation of cables eventually. In this article, multiscale simulation is implemented to comprehensively analyze the insulation aging mechanism and reveal the variation law of aging characteristics. Regarding multiscales, by molecular dynamics (MD) simulation and finite-element method (FEM), the material and electrical parameters are calculated and quantitatively analyzed. According to the findings, tiny molecular products resulting from thermal and electrical aging are the main causes of dielectric constant and electrical conductivity variations. Field distribution inside the cable is distorted due to the degradation of material parameters, thus changing power loss and electrical parameters. The multiscale analysis method in this article can make the cable insulation aging analysis more time- and resource-efficient, providing the theoretical basis and data support for cable fault diagnosis and remaining useful life prediction.