Research on Cross-Linked Polyethylene Insulated Core Degassing and By-Product Diffusion

High-voltage cable insulation commonly employs peroxide-crosslinked polyethylene. During cross-linking process, by-products such as methane and acetophenone are generated, which can easily lead to insulation breakdown and partial discharge, and thus must be removed through a degassing process. However, degassing process is constrained by long cycle times and high energy consumption. To overcome these limitations, detection methods for by-products are systematically reviewed and influence of temperature, time, cable structure, material parameters, and multi-component diffusion on degassing process is clarified in the paper, providing a theoretical basis for subsequent experimental and simulation studies. Analysis indicates that measurement technologies are advancing toward non-destructive in-situ detection methods; simulation models have evolved from simplified one-dimensional models to coupled thermal and mass transport two-dimensional finite element models, with significantly enhanced analytical capabilities, though the description of multi-component competitive diffusion mechanisms remains incomplete. It is confirmed that temperature, time, and material properties such as insulation thickness and crystallinity are key factors determining degassing efficiency, while multi-component competitive diffusion behavior critically influences electrical performance of the insulation. Future efforts should focus on establishing multi-component mass transfer models based on non-equilibrium thermodynamics, building a validation system driven by both experiments and simulations, developing intelligent degassing processes that integrate mechanistic understanding with data-driven approaches, and combining models with hybrid heating technologies to achieve precise control, thereby advancing cable manufacturing toward intelligent and green upgrading.