Multifactor Aging Characteristics of GIS Solid Insulation: Effect of Electrical, Thermal, and Vibration Stresses

Solid insulation in gas-insulated switchgear (GIS), like the basin insulator, is vital for supporting high-voltage conductors, isolating GIS compartments, and providing ground insulation. Multifactor accelerated aging tests play a crucial role in evaluating GIS solid insulation conditions and predicting its lifetime. Yet, there is less research on mechanical stress-induced aging compared with electrical and thermal stresses, and even fewer studies on their combined effects. Intending to achieve a more precise assessment of the aging status and lifetime prediction of GIS solid insulation, a series of cylinder insulator specimens are specially designed, as well as a three-factor aging test platform established involving electrical, thermal, and vibration components in this study. And, the aging effects and mechanisms of these three factors on GIS solid insulation are subsequently analyzed. The results indicate that electrical, thermal, and mechanical factors all have significant impacts on the deterioration of the solid insulation materials. The application of thermal-mechanical stress exacerbates the potential degradation risks of the polymer internal structure under high-electrical field conditions, leading to a significant reduction in the lifetime of GIS equipment.